what ever happened to this subject? i read up about about it and it sounds awesome. but no one seems to be talking about it. this is pritty dissapointing cause i was filled with hopes and dreams when i first read the frigen 16 page forum on it, has there been a loos of intrest? cause 24.2% increase of torque and power ant high and low rpm sound pritty dam benificial.

What are you talking about?

RPW has finished their new intake plenums. They're available to buy now.

Did we ever get a clearer dyno of what it does alone? Anyone else experiences? Also they are on special this month.

On the dyno figures you gave there was a minimum increase in hp of 12.2% and a maximum of 24.2% !!

Here, I've worked them out.....

HP Before/After Tq Before/After ---HP increase ----Tq increase
2500 66hp/82hp 185nm/225nm ----24.2% ---------21.6%
3000 82hp/92hp 188nm/220nm ----12.2% ---------17%
4000 120hp/145hp 212nm/253nm - 20.8% ---------19.3%
4200 135hp/155hp 215nm/260nm - 14.8% ---------20.9%
5000 158hp/180hp 205nm/250nm - 13.9% ---------21.95%
5400 158hp/186hp 195nm/243nm - 17.7% ---------24.6%


Now I know it doesn't work quite like this, but based on these percentages that would conservatively make a Ralliart around 211Kw and a VRX/Sport around 194Kw !! (based on a 17.7% increase at 5400rpm)


thats a direct quote by the way.

thats why im suprised it didnt take off
the prices from rpw was around the 1k mark
but with trumpets 1.1k but u needed a piggy back
i think the dino figures was from a 3.5L auto with extractors and not to much else.
haha since im a fitter/ boiler maker, i think i might make my own, looks simple enough

thats why im suprised it didnt take off
What do you mean by that? Off the top of my head I can think of three people on AMC alone who have one of these on their car..

I'd have one too, but I had Street Torque make me something else instead.

We only make them in batches of 5 at a time and the first batch of 5 + 1 demo model were sold out around 4 weeks ago.

The next batch of 5 are already got 3 pre sold so they are moving quite nicely - these are one of those more serious mods.

ANd good news is we are trialling in the next two weeks our new throttle body options - lets just say if it works which we beleive it will, 80 and 90mm throttle bodies are going to become an option now with these manifold with piggy back ecu systems

mitsiman im wondering,

if u could have one or the other, would it be ur stage 2 cams or the inlet manifold? just curious cos i think im only going to go one or the other realisticly

also these TB's .. i know they r still in the works but r u saying ull need the inlet manifold to be able to use ur new TB's?

thnx :)

i hope u dont think im ripping u off in any way mitsiman, its just im a first year aprentice on like $6 an hour and cant aford one, but have the equipment and know how to make me one.

You are welcome to try and make one - but its a lot more work than it looks. Especially the internal ram tubes which we have to custom make to fit inside the tubing, and then fit everything around. We made special jigs so that the support bolts, accelerator cable bracketing etc all fitted up around so that it made it a direct bolt up. Doing a one off custom will mean a couple of fittings to get all the little things right.

I would go manifold before camshafts if you have a piggy back ecu because it provides the maximun air flow advantage to the engine. Camshafts acheive similiar results but of course air flow into the motor is always an issue as well.

YEs because of the diameter we are able to go to one the new throttle bodies - 80mm min sizing, you woudl not be able to machine enough out of the stock manifold to allow an 80mm opening. WIth our manifolds we can go up to a 100mm internal diamater butterfly and still bolt things up.

well having both inlet manifold and the cams... the cams were definately worth it. the inlet manifold well... i gained about 5% torque midrange and 3-4 kw so i cant say it was a worth it mod for me. i believe though that it had a lot to do with my throttle body being limiting (still trying to find a solution to that *cough*rpw hurry up*cough*).. till then.. the cams were definately more worth while.

since im a fitter/ boiler maker, i think i might make my own, looks simple enough

Ive made my own inlet manifold for my car, its similar to the RPW unit but it has cost me a bucket load less cash.
I first designed what i needed/wanted on 3D CAD and then machined up the 6 inlet trumpets on our CNC lathes, fitted them and then welded on the new much larger plenum (this is all im prepared to discuss about my manifold). It wasnt hard to do IF you have the knowledge and skills, its like everything if you do your R&D then there will be no issues.

It is currently away being flow tested (along with a standard unit) so it can be compared against the standard manifold, early tests have shown a huge increase in airflow.

Iam very proud of my inlet manifold/throttle body as i beleive in doing as much on my car as i can myself, hence why i havnt spent lots of $$$ on my car to get it to where it is.

tommorrow morning i bet ur inbox will be full of AMC enquiries of how u did it haha .... its funny cos its true :P

tommorrow morning i bet ur inbox will be full of AMC enquiries of how u did it haha .... its funny cos its true :P

Na mate, my inbox will stay empty :badgrin:
Most people would rather pay good hardearned money for someone else to make and do things on there cars then whinge at how expensive everything is, even doing basic things can save people money.
Its good to know there is a few people out there making and doing things on there cars themselves though (ya know who you are) :)

If you are prepared to discuss it did you use the stock runners?

I just finished test driving my car after fitting the RPW plennum w/ internal ram tubes and I've got two words to say about it:

F*CK!!!! WOW!!!!

awesome, awesome mod. If you can afford it - get one. If you can make your own - do it.

And the difference it made to the sound of the car - well lets just say, thats one of the nicest surprises I've had in a while.

can i ask how much it all costed u in the end including buying the inlet manifold, getting it fitted and tuned?

lol - glad to see it made an impression on you. Yes the change in sound is something we noticed as well.

Did you tune it as well or just put it on with the stock computer - cause if its not tuned yet - there are more gains to be had.

Glad your enjoying it - keep us up to date.

How did the fitting go by the way? Nice and easy?

can i ask how much it all costed u in the end including buying the inlet manifold, getting it fitted and tuned?

Inlet manifold was about $1,100. Fitted it myself today (1st day of 3 weeks holiday - yay!), but if you get it fitted by a workshop and they charge you for more than 3 hours labour - they're ripping you off.

Presently I don't have a piggyback installed (pretty sure it's not compulsory for this mod), but I do have a G-Reddy sitting in my garage - and hopefully will be getting it fitted and tuned this week, for which I expect to pay somewhere between $600 - $900 (hard to say when you can't find a workshop that's tuned a magna before).

oh so this mod can be done without a piggy back? ( obviously it wouyld hinder the new mod without a tune though) .... how much more would u get out of it from stock ecu--> piggy back and tuned? im just curious , cos id rather pay for one dyno tune than multiple ones everythiem i have a new mod

geez blackbeard i'd like to see your car at the end of the hols...cant wait to see it on the next cruise?? hows it sound??

oh so this mod can be done without a piggy back? ( obviously it wouyld hinder the new mod without a tune though) ....
Can be.. but to get the most out of it, as you say, you'd want a tune. I'd be concerned that the car would run lean unless you get a tune done. At the very least I'd want to take the car to a dyno shop and get them to monitor the Air/Fuel ratios.

Mitsiman has probably had a chance to check this behaviour out and might have more info.


how much more would u get out of it from stock ecu--> piggy back and tuned? im just curious , cos id rather pay for one dyno tune than multiple ones everythiem i have a new mod
How long is a piece of string? ;) It'll largely depend on whether you've done enough other mods to get the full potential out of this one. Conservatively, I'd say.. lots.

geez blackbeard i'd like to see your car at the end of the hols...cant wait to see it on the next cruise?? hows it sound??

It seems to have made the exhaust note a bit deeper in general. You can also hear a very noticable 'sucking' sound comming directly from the plennum chamber - off the top of my head, I'd say it's from air getting drawn in by the trumpet opening of the internal 'ram tubes'. At first I thought I had a vacuum leak - cause it was heaps louder, and more prounouced than just the pod filter / CAI.

I've had a ride in a vehicle equipped with this mod and **** was it pulling hard. This car hadn't been tuned and had a header leak. I've driven 351 Clevelands, super6's and turbo 4's and this Magna was pulling like a turbo.

Bang for you buck? I'd say skip the exhaust and do the manifold first. Quote me if you want. I'll stand by it.

You can always chip away at other components when $ presents itself, but the manifold improvement is sweet-as. Remember in the not to distant past, extra power meant bolting on more carbis and a better manifold - feeding the powerplant. Most Magna owners chase gains thru their exhausts - after the powerplant. Weird huh?

i'd get one, just worried about running lean because i wont b chipping for some time...

although a $300 apexi safc2 would fix this problem.

The vehicle doesn't run lean with the kit- it actually ends up running rich for some reason.

The extra noise you hear in the engine bay is becauise of the thinner material used in the plenum chamber being so big which amplifies the noises of the engine. Heck on my car you think you had a diesel in there cause of the amplification of all the rocker gear due to the larger camshafts and the heavy duty valves and injectors whch are also noisy cause they are so big.

Bang for buck this manifold has turned out to surpass our expectations and wait another month till the new throttle body options are released (Which will definitly require ecu tuning).

wait another month till the new throttle body options are released (Which will definitly require ecu tuning).

Dave - what are the options for owners of the current design when the new "larger T/B" designs come out. I assume bolting a bigger T/B onto the current design plennums isn't an option.

Assuming the new design will be based on the plennum chamber dimensions of the current design - will an 'exchange' deal be offered to those with current design plennums??

we are still in the research phase so I don't have any exact answers yet. But we may set up an exchange manifold with the new throttle body plate for those wanting an aftermarket billet throttle body option instead.

Once we have done the testing then we will finalise options and pricing.

Hmmmm I designed and made my own, saving over $600 thats what i call bang for bucks. :D

Id have to say its been one of the better mods that i have done and made.

does anyone know how much of the torque inc was due to increasing the size of the throttle body, versus inc the size of the plenum .. . . .

rgds

simon

great job! :D