I noticed a massive amount of people all have cat-back exhausts and some have extractors etc. Just looking to learn so how is a cat-back exhaust different from like a full system and how much are they etc? I know it means from the catalytic converter back but that's all I know. Also extractors for a magna: easy to find? expensive?

Cheers all any info appreciated

You would only do a 'full system' if you replaced the extractors, I think some come with the piping to fit into the cat

See diagram:

http://www.boltonautorepair.com/images/diagram_exhaust.jpg

Extractors are easy to find lots of brands (Pacemakers, HM)

Look on eBay or check out RPW

CAT-back means a system from after the CAT convertor, and is probably the most common way of "doing the exhaust". Generally you won't get big gains here, although in some cars the rear muffler is quite restrictive (e.g the execs and veradas with magnas), so you will pick up a bit of power going to better flowing item.

A full system also includes extractors, flex/dump pipe (the bit between the extractors and CAT), and a high-flow CAT.

If you are happy to shell out for a well-designed full system, you will make some gains (but nothing to write home about on its own). Otherwise if you are just after a bit of noise, IMO replace the rear muffler with something less muffled. Straight-through mufflers flow the best and sound good when you hit it, but are too droney down low for some people (especially if you have an auto).

If you are doing extractors, make sure to do the flex/dump pipe section as well, as the factory unit is only 2.25", and IMO largely negates the point of having exractors. There are plenty on the market, but some are rubbish. Look for equal-length primaries and mandrel bends.

pacemaker are well-desgined and cheap, but i suggest you also get a larger flex/dump pipe section made at the same time.

If you want to go a full system, IMO 2.5" is good for a stock or mildly modded 3-3.5L magna. Btw the centre resonator is 2.25", so make sure you get rid of it as well.

CAT-back means a system from after the CAT convertor, and is probably the most common way of "doing the exhaust". Generally you won't get big gains here, although in some cars the rear muffler is quite restrictive (e.g the execs and veradas with magnas), so you will pick up a bit of power going to better flowing item.

A full system also includes extractors, flex/dump pipe (the bit between the extractors and CAT), and a high-flow CAT.

If you are happy to shell out for a well-designed full system, you will make some gains (but nothing to write home about on its own). Otherwise if you are just after a bit of noise, IMO replace the rear muffler with something better-flowing. Straight-through mufflers flow the best and sound good when you hit it, but are too droney down low for some people (especially if you have an auto).

If you are doing extractors, make sure to do the flex/dump pipe section as well, as the factory unit is only 2.25", and IMO largely negates the point of having exractors. There are plenty on the market, but some are rubbish. Look for equal-length primaries and mandrel bends.

pacemaker are well-desgined and cheap, but i suggest you also get a larger flex/dump pipe section made at the same time.

If you want to go a full system, IMO 2.5" is good for a stock or mildly modded 3-3.5L magna. Btw the centre resonator is 2.25", so make sure you get rid of it as well.

Yep this man is correct, if you want to keep the noise down and want something that looks a little cooler, you can split it just before the rear axle and run 2x2inch pipes with a box at each end for "dualies" will be a bit quieter but no performance gained.

For a good cheap option a AL4-5597 is 208 delievered from any supercheap in aus, which is from the rear flange onward, makes a good note once burned in, hardly any droning and on any pov pack magna/verada should pick up around 7-10kw give or take.

just a quick question while the subjects up, for the 3.5l v6, how would it react to having a 3 inch cat back exhaust? along with getting extractors, flex pipe (not sure about the size, 3 inch as well?) and a hi flow cat (maby 3 inch too?) im looking at chassing power more the noise so what do you guys think? would going 3 inch have a negative effect on a stock engin? what about a engin with ralliart heads and cams and a piggy back ecu?

The impression I'm under is that 2.5" is more than enough unless you're doing some serious engine mods later on (N/A rebuild or forced induction).

3" isn't suitable no.

not for a fairly, stock engine, 3" would only be for a FI engine, putting some good power

cool,thanks for that, thought i would ask the question. another one though, if i kept the cat back 2.5 inch, what should i do about the flex pipe and cat converter?? go 2.5 inch as well? or would they benifit from going to 3 inch?

cool,thanks for that, thought i would ask the question. another one though, if i kept the cat back 2.5 inch, what should i do about the flex pipe and cat converter?? go 2.5 inch as well? or would they benifit from going to 3 inch?
No you wont benefit from 3" anywhere on the car on a stock magna.
Only people i think 250kw's are putting 3" on

haha, dont think im going to even try for 250kw, thanks for the help everyone

if u own an awd magna/verada the stock system is 2.5in

if u own an awd magna/verada the stock system is 2.5in

All TL/KLs on had 2.5, I'm sure. Maybe the late TJs too. I'll go out n measure later if I get off the chair :D

From the Magna FAQ (http://www.wermspowke.net/wiki/index.php/Main_Page):

The stock exhaust (cat back) for 3rd gens (3.5L) is quite good for a standard exhaust system. The standard exhaust piping measures 58mm (2.3") at its smallest diameter on a bend, and 60mm (2.4") along its straight sections.

I'm doin my exhaust system soon,gettin pacemaker headers with HPC coating and changing the muffler to a sports lukey one like the ralliart magna's.
Will post up how it all works out when it all gets done but my mechanic said its a good combo because of how good the stock exhaust is.

if u own an awd magna/verada the stock system is 2.5in


Are you sure about this? Even if it's 2.5" in some places, it's probably smaller in other places (e.g flex pipe, cat flange, centre resonator inlet/oulet, press-bent bends).

I've never looked closely at a stock awd so I'm not disagreeing with you, just pointing the above out.

I have a FWD model so there is a difference between them and the AWD models.
I will find out how it all goes when its done then i'll post the outcome when i get the car back which is due to go in within a week or so,just wantin for the HPC coating to get done on the extractors.
My mechanic is fitting them and he does alot of performance stuff so there will be good bang for buck without a doubt.

Got the car back from the mechanics with the extractors and exhaust done.
Pacemaker headers HPC coated into the factory cat with a ralliart magna exhaust.
Makes a great difference,not cheap but would scream on a manual version or 5 speed tippy model.
There will be a big gain if i do somethin with the intake and mod chip to shorten the lower gears and have it dyno tuned.
Overall,i like the combination i have gone but if you feel the need to have everyhting replaced,shouldnt make any massive difference if you got a high flowed cat but like my mechanic said,if the whole system is running too big,back pressure is lost and you may loose power instead if the car is practicually stock but if you have alot of work done like cam,chip,intake and other upgrades,then the big setup will help.
Hope this info helps but definately worth getting pacemakers HPC coated aswell,they look sweet and do justice aswell.

There will be a big gain if i do somethin with the intake and mod chip to shorten the lower gears and have it dyno tuned.


shorten the lower gears????? yeah good luck with that :nuts:

shorten the lower gears????? yeah good luck with that :nuts:

Parker's right being that the auto box 's ratios are mechanical (aka set in the gearbox) it would be impossible to do electronically unless you have it short shift through the earlier gears. Thats under the assumption you can crack the TCU.

I guess it comes down to when it gets done then.
He's done it with a few other cars and put it this way,i think he knows what he's talking about especially building cars that produce more than 1000Hp.
Most mechanics are good but there arent alot that specialise in performance and know what they are talking about and even executing it!
I have a performance shop next to me and they have no idea at all so maybe you have to get to know the quality before you question what someone can do unless your a performance guy or engineer yourself!

I guess it comes down to when it gets done then.
He's done it with a few other cars and put it this way,i think he knows what he's talking about especially building cars that produce more than 1000Hp.
Most mechanics are good but there arent alot that specialise in performance and know what they are talking about and even executing it!
I have a performance shop next to me and they have no idea at all so maybe you have to get to know the quality before you question what someone can do unless your a performance guy or engineer yourself!

Again, the magna is vastly, i repeat VASTLY different to any streamline cars. 1000hp isnt too hard with motors like 2jz, rb26, etc. The forumla is simple, punch as much air as possible into the chamber at as highest pressure the heads can handle, a good spray of motion lotion, and ignite with the strongest fattest spark as possible.

Thats a very very basic way of how power is made. Look i dont deny that they are in the know with certain cars, but when it comes to magnas only a handful of people really know what is what.

I agree but i spoke to my mechanic today and like it is true,the tip tronic is controlled by a computer(i.e,electronics) so therefore if you can change the pattern of the ecu section that controls this,then the gear change can become shortrer or shift harder.
To hard to say really when i get it done but until then,i can post an outcome when it gets done.

how must were the extractors inc. install?

I agree but i spoke to my mechanic today and like it is true,the tip tronic is controlled by a computer(i.e,electronics) so therefore if you can change the pattern of the ecu section that controls this,then the gear change can become shortrer or shift harder.
To hard to say really when i get it done but until then,i can post an outcome when it gets done.

Yes, the TCU controls the basics of the auto, however the pressure of the clutch packs is mechanical, and you cannot change this short of rebuilding the box, also the TCU is a locked unit you cannot flash it, edit it, or run a piggyback on it or in place of it.

but like my mechanic said,if the whole system is running too big,back pressure is lost and you may loose power instead

Ahahaha, loosing back pressure will hurt your performance?

No....Backpressure is bad for performance, Delta P pressure is good, as is the speed of the exhaust gass flow....

The reason why an overly large exhaust may harm performance is due to the exhaust gasses not being able to flow fast enough out of the cylinder, and consequently either not all the gasses are extracted from the cylinder, or are partially sucked back in.

I must have made a typo but sounds like you know heaps!

Sometimes I do.

Just things like backpressure are myths. Possibly your mechanic didnt feel like explaining lots of terms to you so just used the word 'backpressure'....

Maybe!
He is pretty technical when explaining things but he also busy aswell so dont get alot of time to chat into detail unless he's not too busy which is hardly ever.

i just though id bring this back for a bit because of somthing my old car was doing. i was told that a TE TF magna, 4 speed auto V6 3l will shift from 1st to 2nd gear, foot flat to the ground at around 80ks a hour at 5800 rpm, is this what there supose to do? because my car was shifting foot flat to the ground (just in drive) at 60ks a hour, at 6200 rpm, can any one explain why this may have been? i had two gear boxs in the car, the origonal one, and a rebuilt one from a TH magna (off the 3l v6) and both of them did this so im assuming that it had to do with the TCU maby? any one got any ideas?
my old car was a TE

i just though id bring this back for a bit because of somthing my old car was doing. i was told that a TE TF magna, 4 speed auto V6 3l will shift from 1st to 2nd gear, foot flat to the ground at around 80ks a hour at 5800 rpm, is this what there supose to do? because my car was shifting foot flat to the ground (just in drive) at 60ks a hour, at 6200 rpm, can any one explain why this may have been? i had two gear boxs in the car, the origonal one, and a rebuilt one from a TH magna (off the 3l v6) and both of them did this so im assuming that it had to do with the TCU maby? any one got any ideas?
my old car was a TE

Wrong. A 3L will shift at about 60-65km/6000ish rpm if you were flooring it. The 3.5L however is up around the 75 mark at the same revs.

ok then, thought i would ask about that because some one had told me that there 3L shifts at around 80ks, thanks for that

I took my car for a long drive a day ago to the middle of new south wales,since i've put the extractors and muffler,i now get an extra 40km's to a full tank driving on highways.
Pretty good bang and economy for buck i say!
Bit of info for anyone interested in getting them!

Ahahaha, loosing back pressure will hurt your performance?

No....Backpressure is bad for performance, Delta P pressure is good, as is the speed of the exhaust gass flow....

The reason why an overly large exhaust may harm performance is due to the exhaust gasses not being able to flow fast enough out of the cylinder, and consequently either not all the gasses are extracted from the cylinder, or are partially sucked back in.

Hah! I was about to dig in to this, but u beat me to it (bit long ago really).
One thing to point out tho - backpressure is a real mechanical term! In 2-stroke non valved grasscutter motors....
Pehaps this Mechanic friend doesn't know Magna is 4-stroke and has cams, 2 actually, and plenty of valves? :)

Also, why do ppl talk about 2.5" being insufficient and 3" good and then talk about lack of backpressure if the piping is too large..... contradictory..... confusing.... :redface:
Deliberate misleading of lack of verbal skills?

Hah! I was about to dig in to this, but u beat me to it (bit long ago really).
One thing to point out tho - backpressure is a real mechanical term! In 2-stroke non valved grasscutter motors....
Pehaps this Mechanic friend doesn't know Magna is 4-stroke and has cams, 2 actually, and plenty of valves? :)

Also, why do ppl talk about 2.5" being insufficient and 3" good and then talk about lack of backpressure if the piping is too large..... contradictory..... confusing.... :redface:
Deliberate misleading of lack of verbal skills?

2.5inch is fine for a NA magna 3.0 and 3.5

Imho you only go 3inch for FI magnas

2.5inch is fine for a NA magna 3.0 and 3.5

Imho you only go 3inch for FI magnas

I love seeing 4" drainpipe exhausts on SR20DET's.....

4" is enough to flow a turbo V8.....lol

I love seeing 4" drainpipe exhausts on SR20DET's.....

4" is enough to flow a turbo V8.....lol

4inch is getting close to intake's on CAT 625's used in the Kenworth trucks we have at work

4 inch! would this size pipe bugger up back pressure needed at lower revs

4 inch! would this size pipe bugger up back pressure needed at lower revs

Not on turbo cars, the general rule there is the bigger the pipe the better the power, as the turbine, collectors and dump do all the work on them.

*** back pressure needed at lower revs
Having us on?
Trying to stirr the pot?
Ok, tell us what you mean. :cool: Cos it sure makes no technical sense......

BTW, even in FI systems, correctly designed exhaust is required, not just massive pipes opening up after headers. Really. Check some header (?) designs on top power dragsters for a hint.

If your so good and know what your talking about,gives us the best guide then!
The combination i have on my car is great,my car doesnt have a turbo and doesnt need a massive exhaust cause its not a high performance car,it does the job very well so it must be a good setup done by a good mechanic because i just paid the funds and he did the rest.