Anyone ditched 2 of their cat convertors and put extractors on? I gather Magna 6G74 extractors will fit the 380s (same heads and all).

What are your impressions. I bet it freed up a few healthy ponies!

It kills the euro 3 compliance or something, makes it a pain to get registered... read it in these forums a while ago somewhere.

It kills the euro 3 compliance or something, makes it a pain to get registered... read it in these forums a while ago somewhere.

I know all that, just wondering if someone has done it thou. Probably in a 3.8 to Magna transplant. Anyone tried it?

Would it be much hassle to just use the 3.8 block in a Magna? It would be nice to have the extra capacity and 10:1 CR. I'm sure that even with ralliart cams, full exhaust and proper tuning 190-200 fly wheel kW isn't out of the question. And most likely closer to 350Nm.

In a light TE-TF Magna, thats a possible high 13 second run. :P

I'd be really keen doing this down the track a bit. It's very frustrating knowing all the power is there, just waiting for a better intake and removing exhaust restrictions. The engine is a real sleeper.

Hell, can't even get any info about aftermarket SC the 3.8 either.

Mitsiman, can you keep us up to date re the auto installation; I'm sure a few of us would be interested once the sensors are sorted?

nice to have the extra capacity and 10:1 CR. I'm sure that even with ralliart cams

i thought the 3.8L already had ralliart cams..??

i thought the 3.8L already had ralliart cams..??
Yep, The 380 motor uses all the development of the ralliart engine.

Now, don't think its possible to chuck the 380 engine in a magna because the 380 uses
multi-plexed data cables instead of a wiring loom.

i thought the 3.8L already had ralliart cams..??

Yes the 3.8's use the same cams as the ralliart. But I was referring to just using the new block in a Magna, meaning Magna heads and intake manifold etc... (for emissions reasons)


Now, don't think its possible to chuck the 380 engine in a magna because the 380 uses multi-plexed data cables instead of a wiring loom.

I'm sure it won't be hard to adapt a Magna wiring loom onto the 6G75 block. You can swap over all the necessary sensors over from the Magna block. And with the help of an aftermarket ECU make use of the knock sensors (I think the 380 has them) and to tune it.

Yep, The 380 motor uses all the development of the ralliart engine.

Now, don't think its possible to chuck the 380 engine in a magna because the 380 uses
multi-plexed data cables instead of a wiring loom.
Anything can be done with enug time and money.


Mitsiman: You're making the extractors onsite now or are they Hurricanes? I'd say they're a lot of pricked ears at this atm, hoping to get some more poke from their 380s.

RPW manafactures extractors for the 380.

Worked perfect in a manuel car no problems.
But the one auto customer is having issues with check engine lights and fouling of O2 sensors.

Of the five sets now sold, three have been fine, 1 no word back and 1 customer with the auto having heaps of problems with check engine lights.

The magna units won't bolt up due to the completely different cross member setup on the 380 and the taller engine block as well as the need for extra O2 sensors etc.

But the manuel cars picked up impressive gains - around 20hp at the wheels from feedback from one customer which is reasonale considering it has gone from 3 cat converters down to 1 cat converter like a normal magna.

Interesting.
How does it affect the 5/10 warranty with MMAL?

Interesting.
How does it affect the 5/10 warranty with MMAL?

Would viod the warranty on the engine if they want to be bastards

because the 380 uses multi-plexed data cables instead of a wiring loom.

What a multi-plexed data cable?It that the same as a computer uses(pc):eh:

What a multi-plexed data cable?It that the same as a computer uses(pc):eh:

Yes, similar. The auto industry has finally moved into the 20th century. It uses data cables
where multiple signals are multiplexed much like network traffic and then demultiplexed at
certain points so that a particular component can read data intended for it.

This also means electrical problems are much easier to diagnose.

See http://www.autospeed.com.au/cms/A_1797/article.html

I take it no 380 owners here have gone with extractors yet? Although I'm sure we are all interested.
Has anybody at least done a sports exhaust? (ie changed exhaust from catalytic convertor back with smaller resonators, etc).
Would like to know what it sounds like; even with stock exhaust, my 380 has a bit of a rumbly note to it (which others owners have also confirmed in a previous thread).

I take it no 380 owners here have gone with extractors yet? Although I'm sure we are all interested.
Has anybody at least done a sports exhaust? (ie changed exhaust from catalytic convertor back with smaller resonators, etc).
Would like to know what it sounds like; even with stock exhaust, my 380 has a bit of a rumbly note to it (which others owners have also confirmed in a previous thread).

I've been trying to get extractors from RPW for ages now with no success. I have a cat back dual exhaust with 2 resonators in the main pipe & a muffler on each outlet. Sounds nice & goes harder with better ecomomy.

Hey mate, welcome to a growing list AMC 380 owners!:D

Ride looks pimpin, got any picks of your exhaust setup you could post???

Hi Foozrcool,

Are you in Brissy? Who did the work for you?


Welcome!

those 19s look great with Adrenalin.

admin edit

Low demand is probably due to the slow take up of the model.

However, no auto owner is going to fit the extractors if the problems aren't solved as you've posted above. This needs sorting because voiding warranty is enough of a risk for the owner let alone the car not running properly as well. Extractors have traditionally been a no fuss performance enhancement

I've been trying to get extractors from RPW for ages now with no success. I have a cat back dual exhaust with 2 resonators in the main pipe & a muffler on each outlet. Sounds nice & goes harder with better ecomomy.
Hi, very nice car there!
How much extra work was needed to install the exhaust on the other side? (brackets, & spoiler cut, etc).
Much power gain from that setup? If better, don't worry about the extractors. From what I've heard they are too difficult for 380.
Also how much have you lowered it? The ride height looks good in the pic!

Hi, very nice car there!
How much extra work was needed to install the exhaust on the other side? (brackets, & spoiler cut, etc).
Much power gain from that setup? If better, don't worry about the extractors. From what I've heard they are too difficult for 380.
Also how much have you lowered it? The ride height looks good in the pic!

Nice questions.
Am wanting to know the exact same thing !

Hmmm, still no reply. :confused:
I guess he must be busy hooning around in his loud 380. :cool:

Have included pic of rear of car, I actually had the exhaust fitted from new by the dealer. All seems to fit under no probs, the back infill panel was sliced to match the original opening on the otherside & repainted. (All part of the deal, not sure on cost coz wheels & lowering were all bundled) I think it has king springs with about a 30mm drop.

hey Foozrcool nice car. Would you be able to get a good recording of your exhaust? I would love to know what it sounds like as i would like to do something like that to my car, but i dont want the droning sound you hear coming from many p plater commos at cruising speed

Can't really do the recording but I can assure you it's nothing like a commodore. Sounds as sweet as especially accelerating through the gears.

Can't really do the recording but I can assure you it's nothing like a commodore. Sounds as sweet as especially accelerating through the gears.

I've found before that recording your sports exhaust never gives it full justice, and always comes out sounding tinny and/or crappy.
On another note, I'm impressing with all the 380 owners here getting so much "dealer-installed" work bundled into the purchase price (eg bigger rims, lowering, and now a custom exhaust setup) of their car. Very impressive stuff from the MMAL dealers!

Just talked to my local dealer where I bought the car.

They are saying that they have never done a twin exhaust for the 380 and that they can't offer it. Weird.

They suggest I take it directly to an aftermarket exhaust specialist.

Thats a bummer...I wasn't expecting that. I've been thinking about it hard for the past month and had finally made up my mind. If the quote was reasonable from Mitsubishi I was going to go ahead and get it done !

What a waste of brain power :confused: :D

Unless you really had your heart set on the twin system, why not settle for a rebuilt single line? The twin pipes really look awesome, but it requires more custom work (which means more $$$) - and I'm not sure if the power difference (ie twin over single) would be noticable. For less work and money, a single system (cat back) would be just as powerful I reckon. But I'm not trying to change your mind.

The coolness factor was the majority of the reason I was doing it :D

For those interested just had word back from the Automatic owner and the problem with the vehicle has been solved.

The issue he had was not with the extractors, but by a botched piggy back ecu install which damaged the factory ECU.

He has reported a check engine light, which is bringing up a warning that the rear o2 sensor (After the single replacement cat) is not getting hot enough, but this is an emmission check light now, not a tuning issue and does not affect the power or performance of the vehicle, and more importantly no more dreaded shutting down or fail safe mode activations.

We are looking at probably supplying an O2 simulator kit with the extractors for the rear O2 sensors to stop the light from coming on.

But otherwise, the cars made good power and no more problems. Just the same issues of CEL lights the USA has had for the past 15 years on emmisions.

Hey that's great news Mitsiman.

Do we PM you for prices and availability (state outlets/suppliers) ?

Cheers.

For those interested just had word back from the Automatic owner and the problem with the vehicle has been solved.

The issue he had was not with the extractors, but by a botched piggy back ecu install which damaged the factory ECU.

He has reported a check engine light, which is bringing up a warning that the rear o2 sensor (After the single replacement cat) is not getting hot enough, but this is an emmission check light now, not a tuning issue and does not affect the power or performance of the vehicle, and more importantly no more dreaded shutting down or fail safe mode activations.

We are looking at probably supplying an O2 simulator kit with the extractors for the rear O2 sensors to stop the light from coming on.

But otherwise, the cars made good power and no more problems. Just the same issues of CEL lights the USA has had for the past 15 years on emmisions.

Nice
Make sure to keep us updated !

can you make an estimate on the power increase ?

I am going to be getting a batch made now - now that I know there good for resale.

They come as a complete bolt on system as alwasy headers - flex pipe - high flow cat converter.

It will be approx 6 weeks before we have them in stock.

HP Gains we were advised 25hp at the wheels by some manuel owners in the first test fitment with much better throttle response. Due to the restrictive triple cat covnerter setup, this is a credible result.

You can PM me for pricing informaiton but detals wll be up on the website in the next 4 weks time with pricing.

We also now have K&N panel filters in stock for the 380 now as well as starting to stock some suspension gear so its all starting to happen.

Mitsiman -

What is the situation with the extractors and emission laws?
I ask because my car is still on lease and I'm restricted to what is fully compliant with ADRs until the car is fully owned.
I know the exhaust is Euro 3 compliant and that was done in advance before the new rules were in place.
The extractors will feed into one cat; will we need to get an engineers cert. to verify it complies with current emission laws?

Also, based on some Gen 3 owners experience (the AWDs in particular) will this make a big increase in noise/droning?

Any thoughts or comment would be helpful.

Well this is a very good question. Technically fitting extractors to any vehicle or exhaust changes - change the emmissions on any vehicle. Doing an air intake or a throttle body change all effect emmisions.

The answer is none of us really know at this stage. Whilst there is no doubt that the reverting of a triple cat converter back to a single cat converter will more than likely result in increased emmissions, it does in that regard make the system illegal.

Basically you are at the same point as any vehicle modifier - in any pursuit of power / economy emmissions are usually the first thing that gets put aside.

An engineer may still pass the car because you are still running a cat converter, but it would meet the older emmissions, not the newer uero 3 emmissions

Basically you are at the same point as any vehicle modifier - in any pursuit of power / economy emmissions are usually the first thing that gets put aside.

An engineer may still pass the car because you are still running a cat converter, but it would meet the older emmissions, not the newer uero 3 emmissions

Fair enough and thanks for being honest.

I don't have a problem with that as an owner; I might have to be little careful until that time.

Fair enough and thanks for being honest.

I don't have a problem with that as an owner; I might have to be little careful until that time.

As long as the upgraded system isn't overly loud, I can't see the deletion of the two pre-cats causing any legal trouble. I mean, who's going to check anyway? :)

As long as the upgraded system isn't overly loud, I can't see the deletion of the two pre-cats causing any legal trouble. I mean, who's going to check anyway? :)

Yes ur quite right. It's a matter of doing it on the quiet, just that insurance is involved and the lease company who technically own the car (at the moment).

Yes ur quite right. It's a matter of doing it on the quiet, just that insurance is involved and the lease company who technically own the car (at the moment).

I see, maybe you could make some factory looking heat shields to cover the extractors, make it look all factory like. :D

So...ah...how much for a double exhaust with extractors ?
:badgrin: :cool:

So...ah...how much for a double exhaust with extractors ?
:badgrin: :cool:

I had an interesting conversation with the dealer I bought from. When I got mine there was a black lowered dual exhaust VRX in the yard. Turns out the exhaust was installed by Mitsu as a trial. The car was sold but the exhaust was removed (!) and the dealer replaced it with a locally sourced set.
The dealer claims there was quite a power difference with the Mitsu tuned exhaust. Of course, when I asked; no, I can't get one.
Grrrr... I hate these "searching for the Holy Grail" type situations....

Anyway, when RPW releases their extractors, I will be getting a set and then matching with dualies from a good exhaust shop here in Brisbane :badgrin:

I had an interesting conversation with the dealer I bought from. When I got mine there was a black lowered dual exhaust VRX in the yard. Turns out the exhaust was installed by Mitsu as a trial. The car was sold but the exhaust was removed (!) and the dealer replaced it with a locally sourced set.
The dealer claims there was quite a power difference with the Mitsu tuned exhaust. Of course, when I asked; no, I can't get one.
Grrrr... I hate these "searching for the Holy Grail" type situations....

Anyway, when RPW releases their extractors, I will be getting a set and then matching with dualies from a good exhaust shop here in Brisbane :badgrin:

Did you get your car from Nundah? I drove an auto 380 VRX with dual exhausts, it went bloody hard, a few months later i drove a manual VRX with a single exhaust and it didnt feel like it had the pull of the auto!!!! Yeah the auto had noise to it to, still quiet but a nice noise not overly loud.

So the 380 has 3 cats. How many big resonators?
Go from 3 cats to 1 is going to increase the noise levels - as we know. But to keep within "stealth mode", couldn't the big resonators be retained and/or replaced with something to keep the noise level down.
I think the header pipes in the engine bay wouldn't be a problem. Being front wheel drive, you'll only see 1 side anyway, and the heatshield suggestion is a good one.
If the exhaust is quiet(ish) the vehicle should not present any rego problems I assume (hope!).
Anway, the thought of these powers gains is very impressive!

Did you get your car from Nundah? I drove an auto 380 VRX with dual exhausts, it went bloody hard, a few months later i drove a manual VRX with a single exhaust and it didnt feel like it had the pull of the auto!!!! Yeah the auto had noise to it to, still quiet but a nice noise not overly loud.

Yep, Nundah. It was June last year.
It's hard to take the dealer's word at face value but if you've driven it as well that adds to the veracity of his claim.

Yes, Grubco, if dual exhaust (correctly designed - that is crucial) can make such a difference and then adding "catless" extractors -

should see some really worthwhile power gains :dancin:

All that without touching the intake and I'd like to try RPW's 76mm throttle body at some point in the future.

Noise control will be a bit of an issue with the extractors but nothing that can't be solved.

Oh yes, I forgot the 380 headers have cats built in. Bugger. That really will free up some power. And I am very certain the noise can be kept quiet if that is what you want (but who does?)
When you say dual exhaust, do you mean twin pipes out the back? Or 2 pipes joining to 1 at the back?

When you say dual exhaust, do you mean twin pipes out the back? Or 2 pipes joining to 1 at the back?

Very good question. I have been thinking about this o/night (as you do ;)).

All the installations I know of so far have been from the single cat back.

With the mystery Mitsu set, maybe it was from each pipe off the headers? That might explain the big performance gain and why they decided to take it off when it was sold?

If so, that configuration needs investigating i.e. dual pipes off the headers to a reasonator then hi flo muffler each, no third cat .

I recall reading that a dual system forming 1 at rear has a greater back pressure than a dual system from front to rear, meaning you could have more power with a 2-to-1 system over a 2-to-2 system.
Could be wrong though.

I recall reading that a dual system forming 1 at rear has a greater back pressure than a dual system from front to rear, meaning you could have more power with a 2-to-1 system over a 2-to-2 system.
Could be wrong though.
AFAIK, its the other way around. More back pressure creates more torque (its like its got
something to push against) where as less back pressure creates more power. And, its
always a trade off for everyday cars. In racing, depends on the circuit, cars may be tuned
for more torque (more twisty tracks) or more power (less twisty tracks).

All the installations I know of so far have been from the single cat back.
With the mystery Mitsu set, maybe it was from each pipe off the headers? That might explain the big performance gain and why they decided to take it off when it was sold?
If so, that configuration needs investigating i.e. dual pipes off the headers to a reasonator then hi flo muffler each, no third cat .



AFAIK, its the other way around. More back pressure creates more torque (its like its got
something to push against) where as less back pressure creates more power. And, its
always a trade off for everyday cars. In racing, depends on the circuit, cars may be tuned
for more torque (more twisty tracks) or more power (less twisty tracks).

Ok, my mistake. Then according to laws of back pressure, a twin exhaust system from the 2 headers, all the way to the rear withOUT merging, would have the best power output (though at sake of torque), yes?
It would have to be a very well designed system without bends, kinks, or cheap mild steel for the exhaust, etc - and good headers that allow equal use of all 6 pipes, etc (ie like good turbo set ups).
But each 'line', if separate, would need its own catalytic converter, resulting in losing only 1 of the original 3, right? How much power does a cat soak up?
Knotched: I wonder what reason dealers/exhaust shops are using for not being interested in making one of these full-dual exhausts (as you mentioned the rarity of such a set up) when they appear to free up a lot more power than a standard 2-into-1 system.

Ok, my mistake. Then according to laws of back pressure, a twin exhaust system from the 2 headers, all the way to the rear withOUT merging, would have the best power output (though at sake of torque), yes?
It would have to be a very well designed system without bends, kinks, or cheap mild steel for the exhaust, etc - and good headers that allow equal use of all 6 pipes, etc (ie like good turbo set ups).
But each 'line', if separate, would need its own catalytic converter, resulting in losing only 1 of the original 3, right? How much power does a cat soak up?
Knotched: I wonder what reason dealers/exhaust shops are using for not being interested in making one of these full-dual exhausts (as you mentioned the rarity of such a set up) when they appear to free up a lot more power than a standard 2-into-1 system.

D&T Performance here in Adelaide had a dual system for the magnas. Check out their
website. Exhaust companies don't see the magna/380 as performance cars (just like the
camrys and aurions) so they couldn't be bothered with investing money into developing
system for them when they think that they won't sell that many compared to systems for
falcodores.

D&T Performance here in Adelaide had a dual system for the magnas. Check out their
website. Exhaust companies don't see the magna/380 as performance cars (just like the
camrys and aurions) so they couldn't be bothered with investing money into developing
system for them when they think that they won't sell that many compared to systems for
falcodores.
Yeah, you're right. Pity. I went to that D&T site and couldn't find anything on Magna or 380. Then went to RPW site; while they had a big range of Magna stuff, still nothing for 380. :cry:

http://www.rpw.com.au/shop/index.php?option=com_virtuemart&page=shop.browse&category_id=76&Itemid=31

I think we have a few things for the 380

Extractors will be added to the website within two weeks time.

http://www.rpw.com.au/shop/index.php?option=com_virtuemart&page=shop.browse&category_id=76&Itemid=31

I think we have a few things for the 380

Extractors will be added to the website within two weeks time.

mitsiman,

in that link for the 380 it lists the rpw plenum for magnas as a 380 mod ? does this mean my rpw plenum will fit on the 380?

No the plenum won't fit up, but we can make a 380 plenum the same way was we make the magna plenums, just takes a little longer and is currently only special order until demand picks up for them.

Well I had a good look under my car at an exhaust specialist today. The standard header pipes are pretty interesting. Two and a 1/4 inch, maybe even a bit smaller and the rear headers turn almost 180 degrees before joining the front then into the 3rd cat.

There could be some big gains with performance extractors just in this area alone, particularly if you consider the cats on the headers will be gone as well.

I won't be going dual exhaust. I have a towbar which already is bent for the single and it'll complicate a second tip.
Two separate exhaust runners off each cylinder bank will be far too noisy and create a lot of drone, so I'll remain with the single system but remove the 3rd cat and go to a hi flo muffler and 2.5 inch system, using the standard tip (don't want to advertise and I think the VRX tip is good).
Down the track will replace the standard headers and then re-insert a sports cat.

The cost for what I propose is $320 from the headers back so will get this done in the next two weeks.

Sounds good. Keep us informed!
When I did the exhaust on my Magna, I did a 'sports exhaust' system first up, too (2.5" from cat back, removing the big resonator, etc). Most of the noise (engine note) came from this. Putting the headers on later, made a slightly throatier note but mainly achieved the big power gain. But anyway, I'm interested to hear (even if only via typed word-of-mouth) how the sports system goes - especially for that good price!

OK. Got 2.5" system from headers fitted today.

This includes new reasonator and sports muffler only, so std reasonator, third cat and muffler have gone.

Results;

Sound; great, not loud and silent off the throttle. Nice coming into 2500-3000 rpm range.

Performance;


As far as I can detect, nil - infact I think I've lost a little bit right down low. maybe it's moved up the rev range a bit but unable to detect anything significant.

So, overall, disappointing result.

If done with performance extractors I'd say it would be worth it, otherwise don't bother. See update 1st Sept.

It may realise more gains when we can obtain the 90mm intake snorkel.
In fact the guy at teh exhaust shop remarked he could hear the intake noise really loud when I was blipping the throttle; maybe another indication the engine is starved of O2.

Pics - the first shows in orange how the rear header flows back into the front. Second is the std with 3rd cat then reasonator. Didn't bother with the new system as there is not much to show.

yeah from what i can gather thats about on the money, the restriction is mainy the extractors and intake, not so much the header back piping,

tis good some info on experience with modding is coming to head now

Hey, sorry to hear that. An actual loss of power from a mod is not nice to hear, but at least you got some more engine noise. I was also hoping that would be a tidy little power+noise gain, as the price you mentioned was very doable. It looks like the headers are the only way to release more power, afterall.

Yeah, probably haven't lost overall. it's probably moved the power further up the rev range. This might be an effect of lower back pressure.

That header design is a joke man. Get some decent extractors on there bro and I wouldn't be suprised if you see a 15-20kW gain.

Well, I was Wrong Wrong Wrong

Verily, I say unto you –
The sleeping dragon of the top end of the engine has awoken (albeit one eye opened!), and
Yay, it is good! :pray:

Sorry to be melodramatic but…

I’ve been on night shifts and pulled the car over on the quiet motorway and done some 0-100kph tests on the way to work. My previous conclusions were from a 30 min drive from the exhaust shop back home in medium traffic.
The car now has a real urgency in the mid and upper rev ranges that was completely lacking in my view before. It really feels like it has higher compression and good cams, although still not substantially liberated yet. The drop off in torque at 4000rpm seems to have gone and torque is available much further up.
Yes it’s true the lower end of the range has lost it’s crispness but that’s really all. From a standing start it still fights the traction control, spinning the wheels, and once going accelerates much better and revs cleanly into the upper band.
The upper rev band is alive and well and feels smooth and strong.
If this is an indication of potential then we are on the right track and I’m a little bit excited (as you can tell).
The 90 mm inlet should redress the drop in lower end torque and only enhance the gains from the exhaust but that will be tested in a few weeks when my snorkel arrives.

Verdict;
Has freed the top end proving there is a seam of real power to be mined with more substantial future mods.

My suggestions from this point are;

Manual- DO IT!
Manual gearbox can utilise this better mid and upper range at any time bypassing any slight shortfall low down. Type40, hope you are listening!

Tiptronic – Choice
1. If you are concerned re loss of torque lower down (the car is less comfortable when taking hills in fifth and less responsive at 60-70kmh up until 80) and drive mostly in D mode, then wait and see the result of the 90mm intake.
2. If you are happy to use the tippy more and drop a gear or two and explore the mid range then I’d go for it. Again the 90mm intake will probably fatten the torque available even more.

I’ve got no doubt now that my car would beat a standard manual from standstill.
EDIT: Another drive and... it seems like a different engine. I've been on and off the throttle 4000-5000rpm in second and it revs so smoothly right up to 6000 and beyond. Hard to believe what it was like before. It now revs like a 2 litre twin cam.

Thats awesome news knotched, glad to see you have noticed the difference and should give all the other 380 owners something to look forward to, especially type40!!!

:thumbsup:

Manual- DO IT!
Manual gearbox can utilise this better mid and upper range at any time bypassing any slight shortfall low down. Type40, hope you are listening!
Ha! Type40 always listens to good advice! I am definitely interested in this mod but im currently having some issues suspension wise so when thats all sorted i will be looking into this.

Good to hear that you are happy with the result! :D

Ha! Type40 always listens to good advice! I am definitely interested in this mod but im currently having some issues suspension wise so when thats all sorted i will be looking into this.

Good to hear that you are happy with the result! :D

Bah now you start listening to someone saying to do stuff to your exhaust:upyours: lol :) :cool: hehehehe

Good stuff Richard, nice to see someone taking the risks of doing "uncharted" mods, and paving the way for other 380 owners.

As I've stated in another thread, I feel the extra capacity and higher CR of the 6G75 should mean there are nice gains to be had the usual basic n/a mods. The higher CR is also gonna be a big help for being able to run a relatively large cam without needing to up the CR.

For us 3.5L boys the limiting factor is definantely the low 9:1 CR, which obviously requires costly new pistons, since the heads can't be shaved much, without running into clearance issues.

My feeling is with a cam swap you'll be able to get fairly spectacular gains without needing to change pistons, my only concern is how well the heads flow without getting work done.

I'll be watching with great interest any further mods you do :)


Yeah, probably haven't lost overall. it's probably moved the power further up the rev range. This might be an effect of lower back pressure.

Hate to be pedantic, but I feel the old back-pressure myth needs to be stamped out.

The ideal exhaust system has 0 backpressure at all rpms, loads and throttle position. Of course this isn't possible, there's always a compromise regarding how wide a spread of rpm/load you can get maximum efficiency from. This is because as revs/throttle position rise, so does the volume of exhaust gas that needs to be evacuated from the cylinders.

Now, when you go to an absurdly large system (e.g 3" on an excel), what happens is backpressure is CREATED at low rpm/load. Because there isn't enough gas to fill the exhaust fast enough, gas velocity drops. When velocity drops too far, backpressure is created. This is because when the exhaust gas moves too slowly, it is able to cool while still inside the exhaust, which further exacebates the problem. Slow gas velocity also ruins the scavenging effect of properly designed extractors. Basically instead of the exhaust gas pulses forming a vacuum and helping to draw the one behind it out, the pulses of gas get "backed" up after the collecter.

So an overly large exhaust sux because it actually CREATES excessive backpressure when volume/velocity of gas flow is too small. I believe the common backpressure mythstems from the fact that people tend to get the concepts of backpressure and velocity confused.

Now 2.5" isn't excessively large at all for our motors, so I'm surprised you are reporting a loss of low-down grunt. I'm interested to find out why this is.

Perhaps it's upset engine management? I know newer cars have much tighter emission controls, I've heard with certain new cars where if you toy with the exhaust the ECU gets unhappy and goes into some kind of power-reduction mode. Due to the stringent emission requirements built in, I think in some new cars the ECU is very sensetive to any changes to the exhaust, e.g you get a warning light come up on the dash.

Or perhaps the low-rpm range feels a little sluggish, because in comparison the midrange is now stronger? Or maybe it's just "bad placebo effect" due to you worrying it would happen? What do you think? How noticeable is the reducing in bottom-end power?

Cheers,
Andy

Or perhaps the low-rpm range feels a little sluggish, because in comparison the midrange is now stronger? Or maybe it's just "bad placebo effect" due to you worrying it would happen? What do you think? How noticeable is the reducing in bottom-end power?
If there seems to be a drop in low rpm torque/power, i reckon this would be why. Can't say for certain, but would be my best guess.

If there seems to be a drop in low rpm torque/power, i reckon this would be why. Can't say for certain, but would be my best guess.

Also when you start making significant changes to exhaust, the AFRs can change (i.e too rich), straying from optimum range. A retune fixes this.

That header design is a joke man. Get some decent extractors on there bro and I wouldn't be suprised if you see a 15-20kW gain.

I agree, due to the larger bore on the 75 over the 74 I would expect even larger gains to be found in the top end than previous engines.


With exhaust systems, you're always sacrificing some power somewhere to gain power somwhere else.

Get a freer flow exhaust = backpressure low down due to less restriction = less torque low down, but more power up higher in the rev range

The only way to know for sure was to put it on a dyno before you had the work done to it, and then again afterwards. But it's too late for that now. :(

Also when you start making significant changes to exhaust, the AFRs can change (i.e too rich), straying from optimum range. A retune fixes this.
That's probably right too. If there's more flow now in the lower RPM band it may be running a little too lean or rich (I'm thinking too rich as the ECU is seeing all this extra air and is freaking out so it's dumping in heaps more fuel) Be interesting to see the AFR's if it gets put on a dyno.

My feeling is with a cam swap you'll be able to get fairly spectacular gains without needing to change pistons, my only concern is how well the heads flow without getting work done.
Yes, but this won’t be me as I still don’t technically own the car yet! (don’t worry, I can always make that happen if it becomes a problem). W hat we need in the 380 division is a Sports, Ego, Chultulu to do a hardcore upgrade and really bring out the 380’s potential. Then that extra 200kg won’t be much of a factor and the stiffer chassis, better braking etc will make other AMCers think it might be a serious alternative to an aging Magna.


I'll be watching with great interest any further mods you do :) Thanks mate, we’ll appreciate very much any guidance you or other modders can give us.


Hate to be pedantic, but I feel the old back-pressure myth needs to be stamped out.
Don’t worry, my knowledge is hardly comprehensive and if, in my ramblings, I bring out some old wives tales, and you and others debunk them then we’ve all gained and will march on the golden road to a serious 380. And I won’t be offended if any tells me I’m talking a crock of s****. My experience comes from a couple of turbo cars in the past (Mazda 626 and Nissan S13), and a couple of early model Celicas which I converted to twin cam and that’s it, so I have zilch experience with large capacity tinkering.


Now 2.5" isn't excessively large at all for our motors, so I'm surprised you are reporting a loss of low-down grunt. I'm interested to find out why this is.
I’ve been thinking about this. The problem is, that everyone knows, subjective assessment is a rotten way of comparison; why we have dynos and ¼ mile times, eh?
I reported loss of “crispness” and this was due to when I applied a sudden and significant increase in throttle at low speeds and then released the throttle, I didn’t experience the push and then instant decelerate as of before. Now that decelerate part maybe what gave me a mistaken impression. It may have been due to the stock exhaust’s resistance. Now when I do it, it doesn’t decelerate as quickly. Therefore maybe there is no change at all to acceleration.
Also, this morning there is a reasonable slope of a hill that I always drive home on. The car will pull up the hill in fifth at 1000rpm or even less, at constant 60-65 kmh and has done this since new. After the exhaust change I felt it was less “comfortable” i.e. labouring doing this but I maybe mistaken because the integrated auto/engine management will not allow the engine to strain and the impression maybe just from the exhaust sound very deep due the low revs.


Perhaps it's upset engine management? I know newer cars have much tighter emission controls, I've heard with certain new cars where if you toy with the exhaust the ECU gets unhappy and goes into some kind of power-reduction mode. Due to the stringent emission requirements built in, I think in some new cars the ECU is very sensetive to any changes to the exhaust, e.g you get a warning light come up on the dash.

The exhaust shop, who has a close association with the local Mitsu dealer here, discussed this with me. The exhaust mod didn’t affect or remove any sensors as they are all located in the headers with the pre-cats. They have already installed a few dual systems on these cars and had no problems as opposed to other models (VE in particular).
What may occur is that the ECU will readjust timings etc over a week or so as it responds to the modifications.
I also have been talking to Stafford Tune, a shop that does Mo-Tech and might do a tune for the phantom supercharger owner that I am yet to track down. The guy there assured me that the latest cars, including the 380, can easily and efficiently cope with exhaust and intake changes.


Or perhaps the low-rpm range feels a little sluggish, because in comparison the midrange is now stronger? Or maybe it's just "bad placebo effect" due to you worrying it would happen? What do you think? How noticeable is the reducing in bottom-end power?

Yes, that definitely could be a factor. The top end has been transformed so markedly that the low rev range feels a bit lifeless.

Two things needed I think;
1. Dyno readings to see exactly what is happening,
2. Another owner to do the same and get some other feedback.

I agree, due to the larger bore on the 75 over the 74 I would expect even larger gains to be found in the top end than previous engines.


With exhaust systems, you're always sacrificing some power somewhere to gain power somwhere else.

Get a freer flow exhaust = backpressure low down due to less restriction = less torque low down, but more power up higher in the rev range

The only way to know for sure was to put it on a dyno before you had the work done to it, and then again afterwards. But it's too late for that now. :(

not really, if the car was stock originally you could put it on a dyno and get a rough guide
as to what has changed. compare your figures with those from the factory.

Can i just chip in and say you guys are doing a great job with modifying the 380! This thread is a great read, and should you guys see results a heavily depreciated 380 is looking tempting :p

The best way to find out if you lost down low torque would have been to do a drag run with and without the exhaust and look at the 60ft times. But if someone with a stock auto could go out with you one night to willowbank you'll see the strengths and weakness to each if you get my meaning.

Also have you taken the snorkel off he car and taken it for a spin, that'll tell you that the original is a restriction and the gains you'll have soon enough, but consintant with cold air, not hot air inducion lol

Dynoed my car today.

Fuel 98RON

http://i189.photobucket.com/albums/z179/Krossbolt/Car%20Pics/My%20Car/HPSportsExrdi.jpg

http://i189.photobucket.com/albums/z179/Krossbolt/Car%20Pics/My%20Car/AFRSportsExrdi.jpg

The AFR is shyte, basically. The readings drop off the scale very early; it is running so rich. The guy who is doing it is going to try and suck out the maps from the ECU on Wednesday and then send the maps to the States for modification. Has been successfully done with the EVOs.

Sorry about the size of the files, have to be mindful of that next time.

The HP equates fairly accurately to KW at the flywheel, so we have gained 7+ KW already just by replacing the system from the headers back. Not bad, folks lol

Also the torque, the red dotted line in the second graph, doesn't fall away as pronounced as the graph for the stock system. In driving reality, you can really feel this (sorry, I'm starting to sound like a broken record :) )

Sorry about the size of the files, have to be mindful of that next time.

The HP equates fairly accurately to KW at the flywheel, so we have gained 7+ KW already just by replacing the system from the headers back. Not bad, folks lol

Also the torque, the red dotted line in the second graph, doesn't fall away as pronounced as the graph for the stock system. In driving reality, you can really feel this (sorry, I'm starting to sound like a broken record :) )

Nah nah, it's good to see someone's done a mod and actually got it dynoed. I say throw a huge pod on there or a CAI setup and you'll find some more power up higher due to restricted intake, then dyno it after that. GOGOGO!!

Dude that is running rich as. Your AFR is sitting on 10. You could lean it out to like 11.5 - good gains there. My Ralliart post tune dyno'd 195hpatw on Bob Romanos dyno.

Dude that is running rich as. Your AFR is sitting on 10. You could lean it out to like 11.5 - good gains there. My Ralliart post tune dyno'd 195hpatw on Bob Romanos dyno.

Yeah that way too conservative even for a factory tune. Torque looks nice and flat though.

looks like mitsu has put an ultra safe tune. 10AFR is way to much

As has been said 11.5 to maybe 12 (pushing it) would give better gains.

Good Luck

so mitsu could have tuned it properley and had MORE POWER and BETTER ECONOMY

surley that would have gotten more sales!?! what do these goons think!

good work there, and good luck with the mods!

if you cant make 200hpatw with nothing other than bolt ons intake exh etc... we need to change makes!

so mitsu could have tuned it properley and had MORE POWER and BETTER ECONOMY

surley that would have gotten more sales!?! what do these goons think!

good work there, and good luck with the mods!

if you cant make 200hpatw with nothing other than bolt ons intake exh etc... we need to change makes!
Like most car manufacturers, they tune it really rich to suit the "worst case scenario"

Example: if you are towing a caravan, with 4 x 120kg passengers on a 40 degree day with the A/C on.

Dude that is running rich as. Your AFR is sitting on 10. You could lean it out to like 11.5 - good gains there. My Ralliart post tune dyno'd 195hpatw on Bob Romanos dyno.

Actually, it's even worse. Chris Romano said it basically went off the scale below 10 so god knows how bad it is.
But... all nice future gains to be had. Looks like even more KW at the top end just with resetting the maps.

But first I need to wait for the new intake in a few weeks.

Chris is going to try and download the maps off the ECU on Wednesday. If that doesn't work I'll have to go to piggy back.

Cost is about 700 for remapping (maps go to the US) or 1400 for piggyback so looks like it's going to get a bit serious from here in. Since I'm going to stop with the intake (sorry boys :D ) I'll be happy just with the remapping.

Hey Disciple, as an aside, got on really well with the Romanos. Nothing was too much trouble, Chris was quite interested in what we could get in the future, and it's an advantage they do EVOs for the software.

Actually, it's even worse. Chris Romano said it basically went off the scale below 10 so god knows how bad it is.


Gross... good for you though... big easy gains. Wonder how retarded the timing is too, especially since it's 10:1 comp.

Like most car manufacturers, they tune it really rich to suit the "worst case scenario"

Example: if you are towing a caravan, with 4 x 120kg passengers on a 40 degree day with the A/C on.
Yep spot on. I suppose its better to be safe than sorry but wouldn't you think with the computing power new ECU's have they would be a lot more adaptable to variables? They shouldn't need to to have such a conservative map.

Yep spot on. I suppose its better to be safe than sorry but wouldn't you think with the computing power new ECU's have they would be a lot more adaptable to variables? They shouldn't need to to have such a conservative map.
You'd think that would be the case in this day and age. Even my XR8 from standard drinks alot of juice as standard to cope for all conditions.

When I had th Verada Supercharged and I had it tuned for the second time, they made it so it runs an AFR around 11-12 and retarded the timing quite a bit. But when the temperature went above 28-30 degrees the ECU would make it run richer.
And it only took the mechanic 10 minutes to figure out how to make it work.

Actually, it's even worse. Chris Romano said it basically went off the scale below 10 so god knows how bad it is.
But... all nice future gains to be had. Looks like even more KW at the top end just with resetting the maps.

But first I need to wait for the new intake in a few weeks.

Chris is going to try and download the maps off the ECU on Wednesday. If that doesn't work I'll have to go to piggy back.

Cost is about 700 for remapping (maps go to the US) or 1400 for piggyback so looks like it's going to get a bit serious from here in. Since I'm going to stop with the intake (sorry boys :D ) I'll be happy just with the remapping.

Hey Disciple, as an aside, got on really well with the Romanos. Nothing was too much trouble, Chris was quite interested in what we could get in the future, and it's an advantage they do EVOs for the software.
Lower than 10? :shock: Man you will get awesome gains there tuning it to 98 ron and adjusting those AFR's. Chris is a nice bloke, so is Bob - they run a very good business. He will try to flog you the Haltech gear because they get bonuses for selling them. They do EVO's yes, but I'll be taking mine to APC I think.

Hey Richard very interesting to see :)

~136+ fwkw is great from an auto, seems you must have got a pretty decent gain from the exhaust.

Even if we play the devil's advocate and assume the dyno reading is a little optmistic, that's still a great result considering it's auto and is running horribly rich at the top end.

As we discussed earlier, I wonder if your exhaust has actually made it run richer than stock, I find it hard to believe that even a conservative/rich factory tune would be that bad.

Regarding a retune, IMO definantely go the piggback. A custom tune is always gonna be better than a generic map, as they have to be a one-size-fits-all type of thing, so it wont be optimum. Also if you end up doing more mods and need another retune, it's gonna be much cheaper/better to do be able to custom tune your car, rather than getting another generic map from overseas.

Although I guess if you're sure you won't be needing another tune, and that generic tune is relatively good, maybe the saving over a piggback is worthwhile.

Good results :).

Thought about looking for a 2nd hand piggyback? A while back a mate picked up a Unichip on the Ford Forums for $150!!! Installation and tuning is another $4-450.

Keep up the good work, reading with interest. :P

:)


Regarding a retune, IMO definantely go the piggback. A custom tune is always gonna be better than a generic map, as they have to be a one-size-fits-all type of thing, so it wont be optimum. Also if you end up doing more mods and need another retune, it's gonna be much cheaper/better to do be able to custom tune your car, rather than getting another generic map from overseas.

Although I guess if you're sure you won't be needing another tune, and that generic tune is relatively good, maybe the saving over a piggback is worthwhile.


Mmmmm... how am I going to justify this to the financial controller? :cry: lol I'm not allowed new wheels til next year

Yes, I'm tending towards piggy back for the flexibility, but there are going to be warranty issues and tears when they see a funny box with wires sticking out :shock: :belt: . If it's a remap it's less likely to be picked up.
Not sure what to do yet.

:)
Yes, I'm tending towards piggy back for the flexibility, but there are going to be warranty issues and tears when they see a funny box with wires sticking out :shock: :belt: . If it's a remap it's less likely to be picked up.
Not sure what to do yet.

I guess it'll be harder to hide as the 380 ECU is in the engine bay, I never had a problem with servicing with my Magna, but it was out of site.

But the possitive of a piggy back is that you can unplug it and the car will run on the standard ECU, then just plug it back in after you're done with the dealer...:D

But the possitive of a piggy back is that you can unplug it and the car will run on the standard ECU, then just plug it back in after you're done with the dealer...:D

That's not a bad idea, as long as it doesn't lose it's settings. I'll discuss the options with the tuner tomorrow.

In the meantime I gotta get myself one of dem intakes.

Mitsiman,
Has RPW been able to access the ECU for the 380 yet?

I've just been to my tuner here in Brisbane who does Haltech as well but they've been unable to detect or access the ECU. It seems there is no longer a MUX input for the 380 only an AV interface unlike the Magna?

I know you may be giving away trade secrets but can you give any indications?

My car is running very rich and is basically untunable ATM.

BTW, mate, your PM mailbox is full otherwise I would've just PM'ed you.

An engineer may still pass the car because you are still running a cat converter, but it would meet the older emmissions, not the newer uero 3 emmissions

Or come and live in perth where ypu dont go over the pits yearly.
Ive had cars for nearly 20 years and never been to the pits to certify car.
Cops over here may yellow sticker u then you have to get it passed
over pits..