hey guys,
just wondering if anyone knows how much difference a hi flow cat, pacemaker extractors and a straight through muffler will make.
thanx guys
mike

they are getting installed on saturday, does it make much of a difference????

Yes it does make a difference, how much difference you might ask?
Hard to say, i'd say maybe 20-30kw at the engine if you're lucky.
Might drop about a second off your 1/4 mile.

ohhh sweet bigger than i thought, im so very happy now, thanx for that

Yes it does make a difference, how much difference you might ask?
Hard to say, i'd say maybe 20-30kw at the engine if you're lucky.
Might drop about a second off your 1/4 mile.

one second? since wen did exhausts on a magna do that??? even superchargers only take round 1-1.5secs off the quarter

or am i sensing sarcasm? :bowrofl:

so theres a variety of results hmm, can people tell me how much of a dfference it made for them, ill let you know when i get them on saturday

Only true way you will tell is a dyno run before and after and a 1/4 mile run before and after.

i was gonna go tonite, but kwinana raceway was shut because of the rain, ahhhhh

will make more like .5 of a second on ur quarter

ok thanx mate

Yes it does make a difference, how much difference you might ask?
Hard to say, i'd say maybe 20-30kw at the engine if you're lucky.
Might drop about a second off your 1/4 mile.

Sorry but that's quite unrealistic.

straight-through muffler: 5-8kw if you have a crappy restricive triflow muffler like the execs and Veradas. Is your TH sports muffler the same as the TJs? If so I think you will gain a few kw tops, as the stock ones aren't too bad. Revvability will be improved slightly, and some nice noise depending on which muffler you choose (read: don't get a tin can, magnaflow is the way to go IMO)

Hi-flow cat: Unsure about this one..I'm guessing a few kw, and some more if you do enough mods so that the stock one becomes a resriction, or if your stock cat is on the way out. By the way, some of the cheaper aftermarket cats are no better or even worse than stockers..get a quality metal-cored cat if you are going to get one. Might improve revvability slightly.

Pacies: Probably only 3-5kw peak power. However, correctly installed headers can very noticeable gains in midrange power, meaning on average you are making more power than the 3-5kw peak power gain suggests. Problem is, most people install headers but leave the stock flexpipe in place, which is restrictive. If you're gonna install headers, do it properly and upgrade the flex pipe IMO, or don't bother at all.

Honestly, value-wise your best bet is saving your money for an intake manifold upgrade, I.e the one EZboy is working on. This will probably cost $700-900 from EZboy, or $1100 from RPW and makes a huge difference from what I've been told. Once again, like the headers, most of the gains are in the mid-range, but you'll feel it up top as well. This mod alone probably would take 0.5 or so off your 1/4 mile time..those other mods mentioned combined won't even do that I believe.

IMO if you are on a budget, get the manifold first, then think about the rest of your exhaust, when more info becomes available on what mods make a difference with it and what doesn't. I suspect once you get a new manifold, upgrading to 2.5" piping with headers and a high-flow cat and muffler might make more of a difference.

ok now i have a range of opinions, which on should i believe lol. i think what the general impression is, makes a small difference, but not much, depending on what else u do to the car.

ok now i have a range of opinions, which on should i believe lol. i think what the general impression is, makes a small difference, but not much, depending on what else u do to the car.

That's correct, with n/a cars those kind of mods only do a little bit by themselves (except the manifold which is great even on its own it seems), its when you combine a bunch of them and get your car breathing well the difference becomes quite noticeable. Remember, it's not just about peak power. E.g a car with, headers and upgraded manifold might say only make 10-15kw more peak power (actually maybe more, testing pending), but it'll make STACKS more power in the mid-range, and therefore be signifcantly quicker. A peak power reading on a dyno doesn't really tell you how fast the car accelerates, you have to look at how much power its making over say 3-6k rpm.

And oh yeah, make yourself a DIY CAI (pm me if you wish, I've already written it up for a few guys here and can forward it), it's the cheapest 5-6 kw at the wheels you'll ever gain($30-$60 depending on how you do it).

Basically, to get your engine breathing as well as possible you want:

-upgraded intake manifold
-headers/extractors/exhaust manfold (same thing) with upgraded flex pipe
-DIY CAI
-Free flowing muffler (probably don't necessary for sports/vrx models)
-High flowing metal cat
-K&n panel
-2.5" exhaust piping - remove the centre muffler and hot dogm apparently they are only 2.25".

thanks alot for your help, you must know alot about engines, because i as sure as hell dont

one second? since wen did exhausts on a magna do that??? even superchargers only take round 1-1.5secs off the quarter

or am i sensing sarcasm? :bowrofl:
My car went from a 16.3 to a 15.7 with just a muffler change and on the 2nd outing the track temp was actually warmer! So with extractors, muffler and high flow cat i couldn't see why a second was out of the question.

As for the power figures i quoted, ok maybe not 30 kw, but would have to be close to 20kw in an ideal world.
You've got a rear muffler which is anywhere between 5-10kw.
Extractors i've been told roughly 5kw, and i figured a high flow cat might be around the 5kw mark as well? Would be close to 20kw at the engine.

thank you very much. im quite happy bout this upgrade now

im also looking at getting a CAI system, will this make much of a difference?

im also looking at getting a CAI system, will this make much of a difference?
On a 3rd gen the standard intake is very good, the only thing i would change is remove the dust plate on top of the grille, this will allow air to flow into your grille and into your intake. Just keep in mind your air filter will get dirtier quicker if you drive on dusty roads.

What about just getting some nice growls out of the rear end? I'd like mine to sound like it's angry when I put the foot down.

i only no one person who has the RPW manifold (with ram tubes).. did absolutly nothing on the dyno or drag strip...same power, same 1/4 times... ppl seem to thing they're excellent, anyone got one and had great results????

so getting a CAI wouldnt make any difference being a third Gen?

i was told there not very good considering there location

so getting a CAI wouldnt make any difference being a third Gen?

i was told there not very good considering there location
What's wrong with their location? The snorkels intake is right on one of the pressure points of air flow, maybe make the opening to the snorkel abit better by doing what i said and can't remember if 3rd gens have rubber bonnet seals, but if they do cutting some of that away will definitely help.

yeh mine has a rubber seal going along in front of it, so wouldnt this reduce the airflow? correct me if im wrong

yeh mine has a rubber seal going along in front of it, so wouldnt this reduce the airflow? correct me if im wrong
I would say yes, by how much i couldn't say without running 100's of atmospheric tests at different speeds etc.
If i were you i'd:

Cut out the section of this rubber in front of the snorkel and
Remove the dust plate on top of the grille OR just cut out some of the dust plate where the intake for the snorkel is.

ok kool thanx mate

My car went from a 16.3 to a 15.7 with just a muffler change

Well 5-10kw at the engine simply aint gonna drop your 1/4 by that much..and a 10kw gain from a muffler change is unrealistic IMO. Consider that with the TJIIS the Sports and VRX only had 8kw extra...and not all of that is from the muffler, e.g they have slightly higher base timing. I would suggest the muffler is worth about 5kw, but does aid in top-end breathing, so the power drops off a bit less after peaking.


Laws of physics dictate 5kw aint gonna drop your quatermile time by 0.6 seconds...that is the sort of gain you might expect from doing doing the whole exhaust, plus manifold and piggback. if your time improved that much, I would suggest there was some other factor..different tyres, your driving, grip levels of the track on that particular day etc. Honestly I think you'd gain 2 tenths at best down the quarter mile from a muffler...


What's wrong with their location? The snorkels intake is right on one of the pressure points of air flow, maybe make the opening to the snorkel abit better by doing what i said and can't remember if 3rd gens have rubber bonnet seals, but if they do cutting some of that away will definitely help.

The Snorkel is ****house no matter how you look at it..measure the cross-section and you'll see just how restrictive it is..all those little things you can do to it don't correct a fundamentally flawed design (believe me, I've tired all of them)

Don't waste your time mucking about with it..any improvements you can make on the snorkel are marginal, and it's still way too restrictive. Ditch it for a DIY CAI and enjoy the cheapest 5-6 kw at the wheels you'll ever get, as well as dropping a bit less power after it peaks.

OP: I know what I'm telling you isn't what you wanto hear, but really you have to realistic or you're gonna be wasting your money and time on the wrong things and be dissapointed when you don't get as good gains as you are expecting..Also when do you mods you've gotta take care to do it the right way, or you are wasting money/time. E.g if you get headers, make sure to get a new flex pipe done at the same time. Similarly with a high-flow cat, don't get a cheapy, i may flow even worse than a stocker..go for a 3" metal-cat. And beware, there's alot of dodgy/unknowledgable salesmen who will give you wrong expectations/info about mods..tread with caution, if something sounds too good to be true, it probably is.

Well 5-10kw at the engine simply aint gonna drop your 1/4 by that much..and a 10kw gain from a muffler change is unrealistic IMO. Consider that with the TJIIS the Sports and VRX only had 8kw extra...and not all of that is from the muffler, e.g they have slightly higher base timing. I would suggest the muffler is worth about 5kw, but does aid in top-end breathing, so the power drops off a bit less after peaking.


Laws of physics dictate 5kw aint gonna drop your quatermile time by 0.6 seconds...that is the sort of gain you might expect from doing doing the whole exhaust, plus manifold and piggback. if your time improved that much, I would suggest there was some other factor..different tyres, your driving, grip levels of the track on that particular day etc. Honestly I think you'd gain 2 tenths at best down the quarter mile from a muffler...



I pretty much agree with this. I have a SPORTS so obviously has the standard sports muffler. I upgraded to a 2.5" hi flow cat and cat back system and it made only a different note. I ran a 1/4 mile 15.3 before and after the exhaust change (both with extractors) It was recommended to me (by the cat manufacturer)not to change the cat as they flow very well from stock...and I should have listened and saved a few hundred bucks:nuts:

Well 5-10kw at the engine simply aint gonna drop your 1/4 by that much..and a 10kw gain from a muffler change is unrealistic IMO. Consider that with the TJIIS the Sports and VRX only had 8kw extra...and not all of that is from the muffler, e.g they have slightly higher base timing. I would suggest the muffler is worth about 5kw, but does aid in top-end breathing, so the power drops off a bit less after peaking.


Laws of physics dictate 5kw aint gonna drop your quatermile time by 0.6 seconds...that is the sort of gain you might expect from doing doing the whole exhaust, plus manifold and piggback. if your time improved that much, I would suggest there was some other factor..different tyres, your driving, grip levels of the track on that particular day etc. Honestly I think you'd gain 2 tenths at best down the quarter mile from a muffler...
Tyres were the same, driving style was the same, track temp was actually warmer, maybe grip levels? but i can't see how grip levels could change so dramatically. The only other thing i did which i forgot to mention was remove the dust plate that goes over the grille, i seriously reckon this helped.



The Snorkel is ****house no matter how you look at it..measure the cross-section and you'll see just how restrictive it is..all those little things you can do to it don't correct a fundamentally flawed design (believe me, I've tired all of them)

Don't waste your time mucking about with it..any improvements you can make on the snorkel are marginal, and it's still way too restrictive. Ditch it for a DIY CAI and enjoy the cheapest 5-6 kw at the wheels you'll ever get, as well as dropping a bit less power after it peaks.
5-6kw at the wheels from a CAI? Has this been dyno proven?


OP: I know what I'm telling you isn't what you wanto hear, but really you have to realistic or you're gonna be wasting your money and time on the wrong things and be dissapointed when you don't get as good gains as you are expecting..Also when do you mods you've gotta take care to do it the right way, or you are wasting money/time. E.g if you get headers, make sure to get a new flex pipe done at the same time. Similarly with a high-flow cat, don't get a cheapy, i may flow even worse than a stocker..go for a 3" metal-cat. And beware, there's alot of dodgy/unknowledgable salesmen who will give you wrong expectations/info about mods..tread with caution, if something sounds too good to be true, it probably is.
Good advice, it's not just a matter of buying extractors and an exhaust, you need to research what system is good for you. Do you prefer low down torque? Or would you prefer more power in the top end?
Those questions are the main ones to ask yourself when looking into aftermarket systems.

5-6kw at the wheels from a CAI? Has this been dyno proven?

hell yeah (http://www.aussiemagna.com/forums/showpost.php?p=228010&postcount=1)

hell yeah (http://www.aussiemagna.com/forums/showpost.php?p=228010&postcount=1)
Did you notice any difference in torque? I couldn't imagine such a small thing making such a huge difference, but if you've dyno proven it then what can i say, it's got me interested :).

so its around 5 KW if i do it right, im also getting hi flow cat, pacemaker extractors, and i already have astraight through muffler, so it should make some sought of difference

better than nothing i suppose man

if your getting a hi-flow pus pus
then pay the extra and get a decent one
where are you getting it installed?
how much for the system if you dont mind me asking?

940 for everything

$940 including pacies? must be a cheap cat...

(Philcomm does pacies for $430 plus delivery)

Yes well it was 1200, but I got it cheap, because me and my mate are going together to get them done, so we got a discount.

where are you getting it installed?

?????

Mettams Mufflers

to the op,

i had a std magna with std everything, i did extractors and a wild custon hardcore fully sick exhaust lol

and on a std stock magna all i gained was a hardcore sound, like no other magna and i saved 1L/100km on fuel

in respect to intake mods, i ran at the track with STOCK intake it was the QUICKEST!

i removed the radiator dust cover and ran slower i also removed the snorkle completley and it was also slower, but sounded so awesome... sounded like it had vtek bro lol


stick with what you are going to do, as you can continue upgrading and adding on stuff later on such as cai cams piggyback inlet etc...

and the stock intake when tested on the flow bench which i red on a auto website is amongst one of the best std intakes there is


i think better thn running an additional pipe is to enlarge the opening on the std intake, rather than as many ppl have, add a pile that enters into the std cai that comes fron down at road level

talking to my local muffler bloke he was stressing the fact so bad that hi flow cats are one of the biggest marketting gymocs in the industry, he says that the stock cats on just about every vehicle are double the diameter of the exhaust pipe, and only restrict 0.2 of an atmosphere.

any comments on that from people that arent just saying what theyve been told?

Something on Autospeed:


We haven't done any cat converter comparisons, but an easy and effective rule of thumb is to select a cat converter one size larger than the pipe diameter being used for the rest of the system. For example, use a 3-inch cat with a 2½-inch exhaust, making sure that the pipe size transitions are through tapered cones. Taking this approach almost guarantees good cat converter flow.

so would seem the stock cat is fine for the task...?

in respect to intake mods, i ran at the track with STOCK intake it was the QUICKEST!

i removed the radiator dust cover and ran slower i also removed the snorkle completley and it was also slower, but sounded so awesome... sounded like it had vtek bro lol


There is a big difference between no snorkel (drawing in warm engine bay air, most of it having past the radiator) and snorkel replaced with some large intake tubing drawing from cooler outside air.

The positioning of the stock snorkel is OK, it just has too much pressure drop. CAI isn't about making power, all it does is remove restrictions in the intake giving you some power otherwise lost.

Redav (that was/is a member on here) also had a dyno run with and without CAI and saw a 6kW at the wheel difference in favour of the CAI.

It's proven.

Redav (that was/is a member on here) also had a dyno run with and without CAI and saw a 6kW at the wheel difference in favour of the CAI.

It's proven.

on a dyno? so the car is sitting still with bonnet open? id imagine the air in the engine bay and wherever the cai runs to would be very very close in temp on a dyno so i dont see how you'd gain 6kw atw.. i really dont believe that... only time ive heard of an increase to do with air filters/cai was a car run with no air filter at all, no piping etc and gained like 2kw atw...

on a dyno? so the car is sitting still with bonnet open? id imagine the air in the engine bay and wherever the cai runs to would be very very close in temp on a dyno so i dont see how you'd gain 6kw atw.. i really dont believe that... only time ive heard of an increase to do with air filters/cai was a car run with no air filter at all, no piping etc and gained like 2kw atw...

Well Redav, Cluthlu(sp?) and I think another member have had dyno runs. And as I said in my previous post, it wasn't mostlly to do with intake temprature, but moreso with intake restriction. There was a chick on here along time ago that worked for MMAL, she dynoed a stock manual TJ exec with and without the snorkel and had a 7kW gain without the snorkel (again proving it's the intake pressure drop with the snorkel making the differnece more then the temprature of the intake air on a dyno).

Thats what they found, I myself have felt an improvment but in the end you can beleive what you want.

There is an article on aurospeed that shows how removing intake restrictions while still using a panel filter on a falcon gave consistant 3kW at the wheel improvments (article: Negative boost, revisited parts 1-5).

Well Redav, Cluthlu(sp?) and I think another member have had dyno runs. And as I said in my previous post, it wasn't mostlly to do with intake temprature, but moreso with intake restriction. There was a chick on here along time ago that worked for MMAL, she dynoed a stock manual TJ exec with and without the snorkel and had a 7kW gain without the snorkel (again proving it's the intake pressure drop with the snorkel making the differnece more then the temprature of the intake air on a dyno).

Thats what they found, I myself have felt an improvment but in the end you can beleive what you want.

There is an article on aurospeed that shows how removing intake restrictions while still using a panel filter on a falcon gave consistant 3kW at the wheel improvments (article: Negative boost, revisited parts 1-5).

fair enough... if thems the facts then thems the facts..i cant argue :)

fair enough... if thems the facts then thems the facts..i cant argue :)
Seen as you have a ralliart (and i well, ummm, have the same front bar as you :P) i was thinking of using one of the gaps as an air damn into the air box, what do you reckon?

Seen as you have a ralliart (and i well, ummm, have the same front bar as you :P) i was thinking of using one of the gaps as an air damn into the air box, what do you reckon?
yeh hmm.. you thinking move pod into the front bar, or run pipe up to the box?

im scared of pods in front bars.. when tzaboy first had his pod in the front bar, he came to my place while it was raining... and the car wasnt running well as it had just had a huge drink of water through the pod... very scary!

yeh hmm.. you thinking move pod into the front bar, or run pipe up to the box?

im scared of pods in front bars.. when tzaboy first had his pod in the front bar, he came to my place while it was raining... and the car wasnt running well as it had just had a huge drink of water through the pod... very scary!
Just a pipe into the stock box, replace the snorkel with a pipe that led to the gap in the front bumper (with a new snorkel fit snug over the gap in the front bar on that side).
See attachment.

Just a pipe into the stock box, replace the snorkel with a pipe that led to the gap in the front bumper (with a new snorkel fit snug over the gap in the front bar on that side).
See attachment.


hmm interesting idea.. is there space to run pipe through??

hmm interesting idea.. is there space to run pipe through??
Damn i was hoping you wouldn't ask that :P. I haven't actually looked yet, i only just thought of it. If there's enough room to put a pipe leading down to the bottom of a stock bar, can't see why not. Will check it tonight after work.

hmm interesting idea.. is there space to run pipe through??

I tried a similar thing with my TF (different bumpers, but the metal work is the same), and there just wasn't enough room for a large pipe. And smaler pipes would be too small and have too many bends. But one can only try. :D

I'll post a picture of my setup later today if I get a chance.

well for me it didn't do **** for kw, i got 112fwkw which is basically stock 3.5l 5 speed tippy

and thats with extractors, hi flow cat, and a custom hi flow exhaust, CAI, K&N, and Barry's fuel kit using premium petrol and iridium spark plugs but i had 19's on.

but my car makes ****loads of torque and its flat all the way through and then slightly drops off.

i ran a couple 0-100 with that timing gizmo, on the 19's lowest i could get was 8.1s, on stock 17's lowest i got was 7.9s and thats with stereo n full tank, reading that a stocky verada runs 0-100 in about 9.3 i was happy. i'll be taking taking it to the drags on sunday if i can get of work, so i'll post up what i got.

when i get my system put on tomorrow, i wont be able to tell you what the KW difference is, but i can tell you if the seems to be more powerful, and next wednesday(if its not raining), ill take it down the 1/4 mile strip

on a dyno? so the car is sitting still with bonnet open?

Mine was on a dyno, and the bonnet was closed both times too. I'm pretty comfortable saying there are gains to be had with a $15 Bunnings PVC induction system.. I did already have the extractors done then, though, so it might be a cumulative thing.

Did you notice any difference in torque? I couldn't imagine such a small thing making such a huge difference, but if you've dyno proven it then what can i say, it's got me interested :).

Well I reckon I could, but then it's hard to distinguish the placebo effect from the real thing sometimes.. especially with only 5kW ATW difference.

what type of extractors did you have?

also when people say about the flexi pipe, what are you talking about? dont get angry with me, i just dont know much about the mechanical side of cars yet.lol

i just put the snorkel and paper filter back in mine the other day and its noticably slower on acelleration, no where near the torque as before with the cai n k&n.

what type of extractors did you have?

also when people say about the flexi pipe, what are you talking about? dont get angry with me, i just dont know much about the mechanical side of cars yet.lol


It's the pipe that goes from the end of the extractors to the exhust piping, as the engine moves forewards in our cars the exhaust needs to have flex so it doesnt pull the exhaust off the car

i got my pacies and hi flow cat put on this morning, and i believe it does make a difference (tried it out on great northern highway), and it sounds awsome, all need to do is my CAI now.

make sure you run that cat in
i've been told that if not run in properly it will cause the cat the clog itself and block the exhaust
so pretty much grandpa spec for about 150k's

so i have to drive like a grandpa for 150 km's, whoops i gave it to her a bit to see if it made a diff, ill be careful for a while now.

whoops i gave mine heaps when i left too bro!