Well, I had them fitted mid last month and finally had a dyno done last Friday. I'll post the graph at the end of the week. I knew I could feel a mid rpm increase in torque as the cars drivability has been noticeably increased and the graph reflected this. There was no change in peak power which as strange as it sounds, doesn't disappoint me. The other interesting benefit I've experienced is a boost in fuel economy. On Friday I filled the car at the 750km's and it still had 7l in the tank. A lot of the driving has been highway driving but previously I was lucky to hit 650km's with 10ish litres left.

Fitment was fun though. One of the primary pipes was hitting on the started motor so a small dint was placed to accomodate it. There's also a buzz noise from the flec pipe and I believe a steel strap in the right place should fix this but it doesn't really bother me. A high flow cat was fitted as well. The car also has a Lukey muffler and still uses the stock piping.

Can't wait for a dyno tune now :badgrin:

You will find all breathing mods like airfilters, CAI, extractors, exhaust will lean the motor out which is where most power increases come from. On the plus side better fuel economy results :D

You will find all breathing mods like airfilters, CAI, extractors, exhaust will lean the motor out which is where most power increases come from.
I was wondering if the factory 2.15' piping coupled with the factory snorkle would have become the restrictions. So I spoke to the guy working on my car and he said that he put his competition WRX on a dyno and removed the factory induction and filter and replaced it with a pipe sitting right in front of the fan. They didn't see any change in the power or torque curve at any point.

The absense of no top end gain is interesting, isn't it? Particularly in light of the dramatic gains you got from your pacemakers, AussieMagna (dyno discrepencies notwithstanding).

I can't imagine there's such a fundamental flaw in their design that there's no performance increase..

It'll be interesting again to see the figures once you get a piggy back, Redav. And to compare with AM's chip once fitted.

I'm saving up for an E-manage myself (next month hopefully. yay) then it's off to Alice Springs to see if Street Torque can unlock some ponies for me.

Regarding intake restrictions, I've been reading and re-reading the articles over at AutoSpeed that detail measuring the pressure drops in the air intake.. I reckon I'll be giving it a go soon to put to bed once and for all the question about how restrictive the stock airbox and snorkel are.

Edit: Oh, also considering fitting some Air/Fuel Ratio measuring gear.. either hooking up to the existing factory oxy sensor, or buying a good wide-band one.. looks like you can pick them up fairly cheaply on eBay.

Regarding intake restrictions, I've been reading and re-reading the articles over at AutoSpeed that detail measuring the pressure drops in the air intake.. I reckon I'll be giving it a go soon to put to bed once and for all the question about how restrictive the stock airbox and snorkel are.

I can't wait for the results, exellent idea :D

im thinking redav that u must be starved for fuel if theres no top end gain after extractors...how long since u had injectors cleaned and a new fuel filter.

re the CAI's for the WRX and the mgana, dyno's are notgriouos for showing very little gain compared to what people feel by seat of pants dyno with CAI's, because on the dyno there isnt the airflow characteristic that is on the road. on the other hand some open pods can show a gain on dyno and only a gain of noise on the road because on road with bonnet shut it sucks hot air but on dyno with bonnet open and big fan blowing cool air on engine it breathes cool air and makes a bit more power.

I'm saving up for an E-manage myself (next month hopefully. yay) then it's off to Alice Springs to see if Street Torque can unlock some ponies for me.

Bout time son :badgrin:

instead of the Greddy piggy back, why not talk to dallas regarding a haltech piggy back ;)

or a propper EMS unit :doubt:

or a propper EMS unit :doubt:

the problem with a full replacment is (and this is just a basic rundown)
a) can loose some standard functionality
b) may need to rewire aircon
c) you start limiting who can tune your car.

I knew I could feel a mid rpm increase in torque as the cars drivability has been noticeably increased and the graph reflected this. There was no change in peak power which as strange as it sounds, doesn't disappoint me.

Good stuff! So u finally got sick of watching them, sitting on the floor....
No hi RPM gain? Weird, mine work from 2500 up but at 3000-3500 they really make a diff.
Then again, yours are the newer design, dunno if that makes the diff. And of course different engine blaa blaa. Like the screaming sound of them?

Bout time son :badgrin:

instead of the Greddy piggy back, why not talk to dallas regarding a haltech piggy back ;)

That's always an option.. I'd forgotten about the haltech piggy back. Time to compare prices and features, methinks. Given the good job Dallas did with your E6K he's bound to do some magic with the piggy back box too.

re the CAI's for the WRX and the mgana, dyno's are notgriouos for showing very little gain compared to what people feel by seat of pants dyno with CAI's, because on the dyno there isnt the airflow characteristic that is on the road. on the other hand some open pods can show a gain on dyno and only a gain of noise on the road because on road with bonnet shut it sucks hot air but on dyno with bonnet open and big fan blowing cool air on engine it breathes cool air and makes a bit more power.

my thoughts exactly. I put the stock snorkel back in last week and went for a drive. I am certain the car felt more asthmatic, especially in mid to high revs. I put the intake back in and it was back to a nice free-flowing, free-revving magna :D i swear by it, and even have 1/4 mile times to prove its effectiveness, IMO a better test for a CAI than a dyno :)

My immediately post fitting, and with a busted gasket dyno run showed bugger all change to the dyno curve with the race headers fitted..

But my seat of the pants how much can I beat a V6 commodore by dyno has made a dramatic improvement. Haven't found a V8 willing to drag in the last 3 months :(

But hell, it's almost worth getting these extractors fitted just for the change to the exhaust note lol

Good stuff! So u finally got sick of watching them, sitting on the floor....
Yeah, they weren't making much of a difference there :D.


No hi RPM gain? Weird, mine work from 2500 up but at 3000-3500 they really make a diff.
Then again, yours are the newer design, dunno if that makes the diff. And of course different engine blaa blaa. Like the screaming sound of them?
Yeah, dunno. I do know that headers are designed for a specific rpm band. I'm just happy that as the pipes are slightly larger than Pacemaker's and the car's a 3.0, (not the 3.5 they were designed for), I didn't experience any loss of torque. They scream nicely. No increase in cabin noise and the buzzing isn't audiable with the windows up.


im thinking redav that u must be starved for fuel if theres no top end gain after extractors...how long since u had injectors cleaned and a new fuel filter.
Last service was a major one so I'm sure that they would have done the fuel filter. Don't have the invoice handy. I'll enquire tomorrow as I'm having it serviced again. I had the AFR's graphed and it didn't show up any problems.

I'm thinking I'll try swapping the piping for 2.5 stuff with the same hardware setup and see what happens. I'll do it as a bolt on operation just in case it drones too much.

the problem with a full replacment is (and this is just a basic rundown)
a) can loose some standard functionality
b) may need to rewire aircon
c) you start limiting who can tune your car.

but not everyone can tune a interceptor unit either

but not everyone can tune a interceptor unit either

charade your constant negative posts are annoying, how about you **** off?

what is rpw ?

what is rpw ?
http://www.rpw.com.au/

glad that you are happy with the RPW race header. I have always maintained the opinion that their design is very good and people have noticed more torque and response from it.
Also smoother power curve.

charade your constant negative posts are annoying, how about you **** off?
Um... he's right. Just ask Velocity.


glad that you are happy with the RPW race header. I have always maintained the opinion that their design is very good and people have noticed more torque and response from it.
Also smoother power curve.
Yeah. I think I will carry out an experiment to see if the factory 2.15' piping has become a restriction. I'm also wondering if my muffler also is a restriction. Yup, it's a Lukey and probably flows the best of their's available but the inlet pipe is about the same size as the factory piping. Need to chat to an exhaust pro, not the usual exhaust salesman.

So, how much would one expect to pay for a set of these babies?

Retail when I bought mine was $660 inc. Check with David or even Anthony for current pricing. HPC coating will nearly double the price.

Retail when I bought mine was $660 inc. Check with David or even Anthony for current pricing. HPC coating will nearly double the price.

Yours is similar spec to mine. Do you think they were worth it, or would a set of Pacemakers be a better option?

I've never driven a car with pacemakers installed, so I can't comment from that regard. Search around and you'll be able to find some pics of the race headers in a thread I started.. Bain also started a thread and posted pics of the pacemakers so you can look at any shape differences, though I expect them to be negligable.

One thing I will say for the RPW headers is that they have larger primary pipes which means that potentially they can flow more than pacemakers, so if you're going to do more mods down the track like induction mods, cams, supercharger, etc.. then the RPW ones might be the go for that extra head room.

Edit: I consider my RPW headers a good investment and was happy to pay the dollars for the full genuine HPC coating treatment.. but whether they are worth twice the value of the pacemakers.. I'll tell you once I get my piggy back tuned ;)

Here's how they look...

Here's how they performed...

Anthony, any thoughts about the power tapering off?

Here's how they look...

Redav are those headers HPc coated?

Redav are those headers HPc coated?
Yes they are.

cthulhu, have yours discoloured? Mine haven't, just got a little dusty. Someone once said their HPC went a funny colour or maybe that's when they're hot? Dunno, doesn't make sence.

Yes they are.

cthulhu, have yours discoloured? Mine haven't, just got a little dusty. Someone once said their HPC went a funny colour or maybe that's when they're hot? Dunno, doesn't make sence.

No discolouration.. just not as shiny as they started out, like yours. Dusty is probably a good word for it.

Go pacemakers, they may be lower but at least they do not need to be modified to fit, on www.madmagna.com there is an article about fitting the rpw extractors, the guy was told by dave to gride the lower control arm mount to make his fit!!

your exhuast is only as good as it's weakest part, if i were you go for a 2.5 system, hi flo cats and straight through muffler/s, and then stay with a normal snorkel if you ask me and a K&N or BMC(not sure if they sell BMC for magnas) panel filter.

I have tryed tryed a pod filter on my car ( EB Fairmont Ghia V8, i know not a magna, but i'll explain later), and it killed the power, made a good sound, but killed power, but i kept driving it to get the ECU used to it, it did get better but nothing compared to a panel filter and snorkel, i have heard it many times

What im try to say tho is simple way is just go for a panel filter, unless you want to stuff round getting the pod in the right place a little extra gain, IMO me myself if i had a N/A car and didn't want to stuff round to much but want a better air flow, i'd go panel, if i had a forced induction car i'd go for a pod and put it in the wheel arch or if you want every little kw you can get and better way for both N/A and forced induction, make an custom HPC encloser, and get a few pipes running to the custom encloser and seals running round the top to hit the bonnet when closed, it's good but alot of stuffing round, but there no way in the world i'd be leaving a pod in the engine bay with all the hot air going into it, been there done that(as many others have too), you will be sucking in hot air, which is not good for performance figures, i mean even a heat shield isn't going to do much when you got a engine bay full of hot air, it will help but only to a point.

your exhuast is only as good as it's weakest part, if i were you go for a 2.5 system, hi flo cats and straight through muffler/s, and then stay with a normal snorkel if you ask me and a K&N or BMC(not sure if they sell BMC for magnas) panel filter.




Yep...BMC do make them for a Magna...I have one in mine. If your interested, let me know and I'll get you the part no.

Nice Dyno chart dude. But those Racers' primarys don't look any much longer than my old ones do. I thought they were supposed to be "much" longer primarys.
Isn't HPC beautiful! :cool:

Hi guys,

AFAIK, my TH was used as the trial fit of RPW race spec extractors. Did not take long to fit, and nothing had to be moved/ground etc (except for the obvious existing flexpipe and street spec extractors :bowrofl: . Photos were posted on the MOGWA forum.

Oh, there was a bit of cutting to do - the rear muffler was pushed back about 1cm and would bump on the towbar support on starting the car or when the car was under a fair bit of load. 5 minutes with a gas axe fixed that.

AFAIK, my TH was used as the trial fit of RPW race spec extractors.

Didn't you pick up something insane like 10hp from the change between the streets and these, or have I rose coloured my memory? :)

Didn't you pick up something insane like 10hp from the change between the streets and these, or have I rose coloured my memory? :)

further to my previous post - 6G74 engine, manual.

The move from street to race design (and to 98 RON fuel at the same time) added a modest 4 hp to power but something like 20-30 more Nms in torque (on the same dynapack dyno, months apart, for the purists!). I don't have the graphs in front of me, so can't quote exactly the delta. The before and after curves were almost identical in shape but increased across the entire range, both HP and Nms. IMHO, the extra $s for the race design, c/w the street design, is well worth it :D .

Not only the numbers on the graph, but the 'strength' and 'driveability' of the car improved noticeably. And the sound at idle is reminiscent of V8 (as I have bored others by insisting they loiter near the tailpipe as I started the car). :)

Well that's definately better than a poke in the eye with a sharp stick.

Here's how they look...

they look sexy as. its a shame it took dave so long to get them right. After 6 months of continual nagging to RPW and constant delays/design faults/lies? etc i went the pacemakers.