hey all,

I'm just in search of some peoples opinions, While I will be getting extractors at some point (hopefully at the end of the year) I'm not sure if I need to get a 2.5" cat back as well. I'm unsure about the cat back mainly due to the fact that most people think that the cat back doesn't really do anything worthwhile and the normal system is good enough (I have a 3L TE).

Saying this though I'm assuming if I put extractors in with just the standard system I won't get as much power increase from them due to the restrictive piping.

So what I'm asking is when I get my extractors would it be worthwhile to pay the extra and get a cat back installed at the same time or just leave the old piping in?

Ok well, to get the extractors alone you will get a gain because the OE is cost effective, and not prformance aimed. Yes you will get the full benefit from installing a 2.5 cat back sytem.
Up to you on if you got the Moolah! Simple

a set of tuned length headers will remove your exhaust gasses better than the manifold you have now which will help in the top end

you are far better off going extractors and a stock system from the cat back than getting a cat back system with standard manifolds

yes the note will change but you won't get any real gains

a good set of extractors "typically" will net a 10-15% power increase

except mitsu engineers have claimed that the ralliart extractors were only worth approx 1kw as the factory cast manifolds on the magna flow really well

i went from totally stock to extractors and full custom exh, before i got sc'd and apart from the noise and 1L/100km better on the fuel there was no difference at all...

extractors are better though as the cool down quicker, and it helps with the under bonnet temps... the cast manifold retains the heat for hours lol

lol this is my first magna so everything i say on here is not model specific but generic experience

as i've said my last 4 cars have been V8's and petrol prices have forced me to get a 2nd car so if i screw up any info then by all means put me back in my box :cool:

but i think on "most" points i'm on the money :D

I think the piping is already 2inch or more from the cat back anyway. But in terms of exhaust velocity and all that, the gains from manifold designs relies also alot on the design of the piping it connects to. Man, I'd go full setup since the piping is around $200 inc. labour which isn't much of a price to pay when it comes to building performance. Maybe you could sweet talk a deal since your asking for a complete exhaust rebuild, excluding catalytic converter. Either way, the piping will help in the future if your going full rebuild so why not make the most of it now?

except mitsu engineers have claimed that the ralliart extractors were only worth approx 1kw as the factory cast manifolds on the magna flow really well

i went from totally stock to extractors and full custom exh, before i got sc'd and apart from the noise and 1L/100km better on the fuel there was no difference at all...

extractors are better though as the cool down quicker, and it helps with the under bonnet temps... the cast manifold retains the heat for hours lol

Have you seen a factory designed TE Magna manifold for a 3L? Seriously, I wouldn't describe its flow design as "really well".

just get the extractors, low restriction cat and a straight through rear muffler, i asked a exhaust specialist and he said the piping is adequate for the moment unless i get it forced inducted.

you won't really net much gains in any exhaust modifications. Really i think it comes down to the fact that these engines aren't pushing out much in the way of the exhaust gases. Where flow efficiency is is more important on turbo cars or large displacement you would see the good gains.

Full 2.5" system with stock cams and internals would cost well over 1k$ for netting only a handful of kw... depends what you wanna do further with your car.

If you just want it to sound better just change the muffler.

Have you seen a factory designed TE Magna manifold for a 3L? Seriously, I wouldn't describe its flow design as "really well".

I agree with what you are saying... to look at them they don't look like miracles of modern engineering, but I think most members on here who have had extractors fitted to their cars will agree that they make bugger all difference in peak power (maybe 2-3 kW at most). They do however "seem" to make a mild improvement in mid range torque.

i put extractors on my 3.5L and didn't really notice a thing. i changed the cat back and noticed a gain. i changed the air filter to a k&n panel and also notice a gain. with the full motor back exhaust i picked up 11hp on my last magna, and i think most of it was just in the cat back. i was really dissapointed with the extractors. i put some on my old SSS pulsar and it made a HUGE difference, but on the magna i didn't really notice a thing.

As above... i think most cars can benifit from a good set of extractors, but unless they are properly designed they may make no difference at all apart from asthetics.... And yes they do need to be fitted to the correct cat and exhaust to keep flow speeds high and to maintain little or no backpressure. Then it gets complicated, N/A cars do require a little backpressure to get good power, so its all going to be give and take as to where you want the power. Dont go high flow cats as they are not needed in NA applications. Tubos do on the other hand, Zero backpressure is whats needed here...

a set of tuned length headers will remove your exhaust gasses better than the manifold you have now which will help in the top end

you are far better off going extractors and a stock system from the cat back than getting a cat back system with standard manifolds

yes the note will change but you won't get any real gains

a good set of extractors "typically" will net a 10-15% power increase

typically you mean you have seen the "ads" for extractors. Extractors will do good for 3-4kw differance. You need further mods to see an increase like 10-15%. i would love to say my car went from 163kw to 176-180 with extractors...it just doesn't happen.

Get extractors and a rear muffler. The rest is a waste of $$$$$ until more mods are done

Well I understand many people have said that extractors and full exhaust don't exactly give you the most significant gain performance wise, but we are all forgetting the design of the "extractors" in the first place. In extractor design, it all depends on where you want the most torque in the RPM range. As blackbeard was saying, it doesn't make much difference in "peak" power output, yet it does make a difference in the torque curve within the mid range (with a certain extractor design).

Ok, my opinion to justify most extractor designs and how effective they can be, when we compare a cars kw output from a dyno of a car before and after extractor installation, we can usually note a higher and more broader mid range torque curve which flattens out at a certain RPM after extractors have been installed.

"But this torque curve does nothing for my peak kw!"

Its not about peak kw's, its about how fast and hard a car can reach its peak RPM. The difference is in acceleration. RPW Race Design/Pacemakers are designed for more torquey mid ranges, therefore providing more power at those RPMs, therefore providing more acceleration. So even though your "peak kws" won't be affected -much-, your mid range will gain the most benefits. And since there is now more torque in your mid range, you'll find there is less trouble reaching that lovely top end RPM while cruising flat foot.

So don't expect extractors to pull out nice numbers on a dyno, they are simply used for moving the torque band up or down which in turn provides more acceleration in those regions.

Yep thats it... nothing more to say, well now theres not.:D

Good answer KingTipz.

If I can put it simply, by design the modified exhaust system improves the power range.

yeah but thats what we're saying the gains aren't worth the money spent for 90% of these cases.

Ok so the general conclusion is that I shouldn't get the cat back, so I don't think I will.

In terms of the extractors, since I only have a 3L I suffer from lack of torque in the lower rev range. Anyone know which extractors would be best designed for getting that lower torque boost?

You have the 3L motor, so I'm not sure how my experience relates to yours.

Peak power gain is neglible, as the limiting factor for top-end breathing is the camshaft profile. However, I did feel a quite a noticeable increase in midrange punch (I did extractors by themselves first, the rest of the exhaust later). This is something you can feel in everyday driving, especially if you are on the heavy side with the throttle.

Really, doing your exhaust is just support for further mods, like FI or a cam swap. IMO if you are gonna stop at the exhaust, don't bother with it, the gains for the mone aren't great.

If the 3Ls are anything like the 3.5L non-sport/vrx/ralliart models, most of the gain from the exhaust for a stocker is in the rear muffler.

So get a quality free-flowing rear muffler, this will give you a decent note, and liberate some kw, if the 3Ls have restrictive mufflers like the 3.5s.


Ok so the general conclusion is that I shouldn't get the cat back, so I don't think I will.

In terms of the extractors, since I only have a 3L I suffer from lack of torque in the lower rev range. Anyone know which extractors would be best designed for getting that lower torque boost?

You want equal length headers with long primaries. This means Pacemakers, or RPW race-spec. If you go pacemakers you may need to get a new 2.25-2.5" flex pipe section, depending on restrictive the factory one is. The RPW ones include a 2.5" flex/dump pipe section (well for 3.5L they do anyway).

All i know is that when i got my extractors, hi-flow cat and 2 1/2 pipe done. i felt it accelerate alot smoothley.. not quicker just easier.. but once i hit 3500rpm and you can feel it just keep pulling you... i think its fantastic.

and i get better fuel economy i dont know how thats happened but i have..

i also use a k&n panal filter.

Ok so the general conclusion is that I shouldn't get the cat back, so I don't think I will.

In terms of the extractors, since I only have a 3L I suffer from lack of torque in the lower rev range. Anyone know which extractors would be best designed for getting that lower torque boost?

Short answer - get Pacemakers, don't touh the cat, do get a full system at some point.

Long answer. I am running 3L TF tiptronic Sports with 170,000km on it. First thing I did was fit complete Redback system from behind the cat to the exhaust tip. Didn't expect power gains, didn't get any. But the exhaust note - lordy!!! Then I did ceramic coated Pacemaker extractors. As others have said, don't expect peak power gains. What you will get is a very noticeable difference in mid range torque. This manifests itself in a newfound eagerness for the motor to get to the redline and a much more solid wack in the back on kickdown anywhere between 2,500 and 4,500 rpm. No obvious change in fuel consumption. Oh, and adding the extractors changes the exhaust note again - depper, more burbly at low revs plus classic V6 wail at high rpm.

Cats. I've said this somewhere else on this forum (can't remember where), but the guy who did my system also hand fabricates tuned length extactrors for some of the nations top street machines. When I asked him about replacing the factory cat he said that it had more than adequate flow even after all the other mods. His experience said that the only reason you would ever bin a factory Magna cat is if you go turbo or supercharged (when you need greater flow through the cat) or if the ceramic catylisers break up. Only then would he recommend going to a new metal catyliser cat.

Oh, and if you go extractors, you should also figure in the cost of new flex bellows as the factory one is not big enough to mate with the extractor exit flange.

Bottom line - do the extractors for the torque gain, do the exhaust for sound.

Short answer - get Pacemakers, don't touh the cat, do get a full system at some point.

Long answer. I am running 3L TF tiptronic Sports with 170,000km on it. First thing I did was fit complete Redback system from behind the cat to the exhaust tip. Didn't expect power gains, didn't get any. But the exhaust note - lordy!!! Then I did ceramic coated Pacemaker extractors. As others have said, don't expect peak power gains. What you will get is a very noticeable difference in mid range torque. This manifests itself in a newfound eagerness for the motor to get to the redline and a much more solid wack in the back on kickdown anywhere between 2,500 and 4,500 rpm. No obvious change in fuel consumption. Oh, and adding the extractors changes the exhaust note again - depper, more burbly at low revs plus classic V6 wail at high rpm.

Cats. I've said this somewhere else on this forum (can't remember where), but the guy who did my system also hand fabricates tuned length extactrors for some of the nations top street machines. When I asked him about replacing the factory cat he said that it had more than adequate flow even after all the other mods. His experience said that the only reason you would ever bin a factory Magna cat is if you go turbo or supercharged (when you need greater flow through the cat) or if the ceramic catylisers break up. Only then would he recommend going to a new metal catyliser cat.

Oh, and if you go extractors, you should also figure in the cost of new flex bellows as the factory one is not big enough to mate with the extractor exit flange.

Bottom line - do the extractors for the torque gain, do the exhaust for sound.

Hey Schnell

One thing I remembered about pacemakers is that they have a clearance issue with 3L engines since the 3L exhaust ports sit lower than the 3.5L. Is this true? Are you having an issues with clearance? And if you are, how lowered is your car?

Mine is lowered 30mm. I haven't so far had any probs with clearance of the extactors. I actually find that being lowered the real clearance issue is with the front lower edge of the bumper - if that clears driveways, speedbumps etc then I know the extractors will be OK. But just to make sure I had my exhaust guru hand fabricate a 5mm bash guard which is about 200mm wide and 500mm long. Its has welded on brackets which use the existing extractor flange bolts under the car to mount the plate at two points. So if anything scrapes, it will be the bash guard and not my beautiful silver ceramic coated extacrtors :) I can post pics if u r interested to copy

I recently sold a TH Sports which I had replaced the standard rear muffler with a straight thru (the exhaust guy reckons the brand I got was designed/dyno tested specifically for Magna's) and I definetely noticed a difference (I just did the same to my new 380 with the same results). The car is much more responsive & revs out better. 2 different exhaust shops told me the piping is good on Magnas/380, just the rear muffler is restrictive and after having them replaced, I couldnt agree more. For less then $200 fitted, I would recommend it to anyone.

I recently sold a TH Sports which I had replaced the standard rear muffler with a straight thru (the exhaust guy reckons the brand I got was designed/dyno tested specifically for Magna's) and I definetely noticed a difference (I just did the same to my new 380 with the same results). The car is much more responsive & revs out better. 2 different exhaust shops told me the piping is good on Magnas/380, just the rear muffler is restrictive and after having them replaced, I couldnt agree more. For less then $200 fitted, I would recommend it to anyone.


What brand of muffler??

Mine is lowered 30mm. I haven't so far had any probs with clearance of the extactors. I actually find that being lowered the real clearance issue is with the front lower edge of the bumper - if that clears driveways, speedbumps etc then I know the extractors will be OK. But just to make sure I had my exhaust guru hand fabricate a 5mm bash guard which is about 200mm wide and 500mm long. Its has welded on brackets which use the existing extractor flange bolts under the car to mount the plate at two points. So if anything scrapes, it will be the bash guard and not my beautiful silver ceramic coated extacrtors :) I can post pics if u r interested to copy

Pics please. :)

Pics as requested. As you can see, what it's designed to do is stop the left hand pair of flanges from grounding out or getting hooked on anything. The right foldback pipe flange sits high enough and is tight enough behind the sump that the sump would get wiped out first before the the pipe or flange does.

http://img453.imageshack.us/img453/6454/skidplateundersh9.th.jpg (http://img453.imageshack.us/my.php?image=skidplateundersh9.jpg)

http://img453.imageshack.us/img453/7594/skidplaterhfn9.th.jpg (http://img453.imageshack.us/my.php?image=skidplaterhfn9.jpg)

Very niiiiiice.......:D

My 3L engine gained nice mid and high RPM power from replacing std can with XForce. RPW HPC headers added even more grunt to the mid to very high RPMs. But I'd questimate replacing the can was more beneficial in eliminating power loss (aka power increase).
If one had to choose either or, I'd choose can instead of headers for BFB.

Back pressure? Who mentioned back pressure when chatting about 4-stroke donks? That term applies to 2-strokes - where it is necessary.

Pics as requested. As you can see, what it's designed to do is stop the left hand pair of flanges from grounding out or getting hooked on anything. The right foldback pipe flange sits high enough and is tight enough behind the sump that the sump would get wiped out first before the the pipe or flange does.

http://img453.imageshack.us/img453/6454/skidplateundersh9.th.jpg (http://img453.imageshack.us/my.php?image=skidplateundersh9.jpg)

http://img453.imageshack.us/img453/7594/skidplaterhfn9.th.jpg (http://img453.imageshack.us/my.php?image=skidplaterhfn9.jpg)

okay, it's great looks and all, but that scuff plate doesn't protect where the extractors are more likely to be impacted from.

I have a 3L, had pacemakers on them for 5 years now, I don't have a single bump where you've got your scuff plate, all the bumps and scratches are from the first 3 primaries, just before the front bank 3-1 collector. That's where you should have placed the scuff plate.

other than that. it looks very nice your silver extractors.

okay, it's great looks and all, but that scuff plate doesn't protect where the extractors are more likely to be impacted from.

I have a 3L, had pacemakers on them for 5 years now, I don't have a single bump where you've got your scuff plate, all the bumps and scratches are from the first 3 primaries, just before the front bank 3-1 collector. That's where you should have placed the scuff plate.

other than that. it looks very nice your silver extractors.

Hey WhiteDevil,

So what your saying is that you did have an issue with clearance? If so, how lowered is your car?

And referring to Schnell's scuff plate, well I guess you could say protection is protection.

yes I did have clearance issues, When I bought my car, it was already lowered by 50mm and it was on 225/50/16.

But ever since I changed the tyres to 225/55/16, no more problems with clearance. for a non-lowered 3L, you would not have any clearance issues.