What do you guys think about HM Headers is it worth having them or are Pacemakers the better option?

As well as, is it true that the Ralliart headers/extractors are actually "HM Headers"

i wouldn't doubt that ralliart headers are designed and built by HM as they also design and build most of the stuff for HSV and FPV.

What do you guys think about HM Headers is it worth having them or are Pacemakers the better option?

As well as, is it true that the Ralliart headers/extractors are actually "HM Headers"

ralliart headers are HM Headers one of the tech's at Hm told me so when i getting info on the magna headers.

I had HM's on my TP and they cracked over and over again. Finally could not be welded any more. Replaced them with Pacemakers and had no more probs. Also have ceramic coated Pacemakers on TF and no probs. Performance-wise I don't beleive there is much to choose between them...

I'm only asking as there is one on ebay for just over $400 brand new posted, and wanted to know more about it, i know its stainless steel and i know they can crack under extreme heat but thats about as far as knowledge about it goes.

I'm only asking as there is one on ebay for just over $400 brand new posted, and wanted to know more about it, i know its stainless steel and i know they can crack under extreme heat but thats about as far as knowledge about it goes.

the stainless HM's have a 15 yeat wty... i had them on the AWD and with the s/c they got so hot that coating came off (high temp paint) as it does with all painted pipes.... but much quicker than normal... just saying how hot they got... anyway no issues at all

power gain on the hm type short primarys isnt noticeable by seat of the pants, but combined with the full exhaust (still no seat of the pants gain) i got a 1L/100km fuel saving


pace makers with the long primarys are better for bottom end power

hm headders though are a direct bolt on and fitted straight up without needing to modify stuff or loose the egr or heatshields etc...

keep your heatshields when you install them, they are there for a reason

HM headers (perry exhausts) are actually a quite thin walled stainless compared to pacies si that's why they can crack and are louder
the main difference is that HM long headers are engineered for a performance and economy gain
my calais has a unique sound when compared to other 5L's around the scene and i have a full HM exhaust from extractors to tip

the stainless HM's have a 15 yeat wty... i had them on the AWD and with the s/c they got so hot that coating came off (high temp paint) as it does with all painted pipes.... but much quicker than normal... just saying how hot they got... anyway no issues at all

power gain on the hm type short primarys isnt noticeable by seat of the pants, but combined with the full exhaust (still no seat of the pants gain) i got a 1L/100km fuel saving


pace makers with the long primarys are better for bottom end power

hm headders though are a direct bolt on and fitted straight up without needing to modify stuff or loose the egr or heatshields etc...

keep your heatshields when you install them, they are there for a reason

i'm actually waiting for your input. because i knew you had them in the awd.

now. how do pacemaker, hm and rpw extractors compare.
im looking at getting an ecu, but first i was thinking bout doing the extractors.
just not sure what i should go for.

also it depends on the price.

i'm actually waiting for your input. because i knew you had them in the awd.
Hurry up and mod your car ffs. did you buy them yet? lol

now. how do pacemaker, hm and rpw extractors compare.
im looking at getting an ecu, but first i was thinking bout doing the extractors.
just not sure what i should go for.

also it depends on the price.

The general wisdom on this forum seems to be that Pacemakers offer more worthwhile and obvious gain at low to middle rpm (ie., where your engine spends most of its time) with some small gains further up the rev range. HM's (Perrys) don't offer that significant low end wack but deliver reasonably well high up the rev range. In either case you are wasting your time with a replacement of piggy back ECU unless you are a)supercharging or b) going for big cams and big inlet manifold. In both these cases you will want tochange fuelling and ignition settings.

So. Extractors first. Inlet mods next (ie., supercharging, cams etc). Then ECU.

Save creating a new thread i thought i would Thread mine!!!

any way I'm looking at getting a set of extractors for me TJ sports and i still can't decide on which is the best bang for your buck.

I'm tossing up between

Pacemakers
HM Headers
RPW version



most of the searches I've done say that the pacemaker version is the better option, but what are other people thoughts on the other brands?

pace makers all the way

i don't know what all of your guys pacemakers sound like.. but i've heard a few cars on youtube and on the street with pacies, some sound different to others.. not as far as volume.. but smoothness some sound terrible and some sound like a tuned 350z like mine..

excuse the quality of the pics.. but here is a few pics of my modified pacemakers, made a nice little 2.25" 18 deg merge collector, to 2.5" system.. there isn't enough room for mergies on the primaries without a fair bit more work.. so we just repaired the front 2 pipes on the front bank, and cleaned them up a bit..

i didn't drive them before with the pacemakers (had Xforce ones on there) but i can tell you now, there is strong torque from about 2500 and up.. i won't go into the theory behind a merge collector google is your friend :)

mat,

Pacemakers are proven not only in Magna's but in almost every car that use them

HM are not a bad alternitive but still prefer the above

RPW, if you do not mind a crooked exhaust and the pipes hitting the floor and cross member I am sure they must have something going for them. As they say in the classics, "there is nothing to dis-like about them but then agian there is nothing to like either"

When Ralliart run the AWD Magnas in Aust Rally Championship they used HM headers. The short primary pipes only reduce low speed torque if the secondary pipes are short. HM have been around a long time and do custom exhaust work for the car makers. When Bathurst was for production cars HM did the headers for all the factory "specials" from Holden, Ford, Chrysler. Originally they were named Head Mod.

Long primary pipes don't help low speed unless the secondary pipes are made longer to compensate. Long primary pipes have more volume and so have a weaker pulse at low rpm.

The basic rule is short primaries and long secondaries for low speed power and long primaries and short secondaries(or no secondaries) for more high rpm power.

Headers help the AWD pick up 5-6kw because of the restrictive join for the rear bank. For FWD 3rd gen there isn't much gain as the rear bank join is quite good and flows well. Ralliart said power only went from 178kw to 180kw on the Ralliart engine when they added HM headers so if they only got 2kw with a modified engine a standard engine with stock heads, cams and compression isn't going to gain much, except maybe a change in exhaust "note". 2nd gen Magnas have a rear bank join like the AWD so headers help.

Have added some pictures to illustrate the problem with Magna exhaust on 2nd gen and 3rd gen AWD.

Pic 1- The 2nd gen Magna had a really restrictive rear bank join. It doesn't need headers to fix the problem. A new rear pipe and collector will do nicely. With a split exhaust headers are only much use with a pretty big cam. Save your money, just run the pipes as was done on the 3rd gen.

Pic 2 - Mitsu got it pretty close with the 3rd gen Magna. The collector can be improved but its not too bad.

Pic 3 - HM AWD header join. The HM FWD 3rd gen header is similar. Good flowing join as it should have been done by Mitsu but a waste spending money on headers for the 3rd gen FWD.

Regarding the use of stainless steel and the issue of cracking. The problem with stainless steel is that it "work hardens" so movement and vibration in particular can get the metal quite brittle and it will crack. However that said with proper fitting and vibration absorption via correctly positioned mounting rubbers there should not be an issue with cracking. Are Ralliart Magna owners reporting any problems with their HM headers? Most makers of performance luxury cars use stainless steel headers so they obviously don't see cracking as an issue. HM have been around a long time and as they give a 15 yr warranty their backup is good.

I have HM on my AWD and they fitted up very well just like a factory exhaust. The only issue is a more pronounced metallic "buzz" in the exhaust at about 1700-1800rpm. The stock exhaust tended to do this too but I think its a bit worse with the headers.

Cheers, Alan

Is the buzz a common issue, do you know what causes it? My KF 3.5 has the buzz which usually occurs just as power is applied and seems to be more noticeable when the engine is still cold.

Pacemakers are proven not only in Magna's but in almost every car that use them

HM are not a bad alternitive but still prefer the above

RPW, if you do not mind a crooked exhaust and the pipes hitting the floor and cross member I am sure they must have something going for them. As they say in the classics, "there is nothing to dis-like about them but then agian there is nothing to like either"

I bought RPW's a few months back for my AWD, nothings crooked or touching anything and the guy that fitted them said they went on well....... yes i get a bit of buzzing.

Apparently all AWD have this "buzz" to some extent. I haven't gotten around to trying to let the exhaust "hang loose" a little bit as opposed to it being under a fair bit of tension as it is on mine with the stock rubber hangers.

It could just be the pipes vibrating. I'm also going to try clamping a short length of something like 20mm x 2mm flat plate in a couple of places and see if it helps (like touching a bell to stop it vibrating/ringing).

Something else I may give a go is pulling the heat shielding and insulation off the stock pipes and cutting and bending to fit the headers as the shielding may be more a NVH fitting rather than a pure heat shield.

Mitsubishi didn't have much budget to develop the AWD so NVH research was minimal. Maybe the block of steel added to the rear diff to try to get rid of the hum blew the budget for any more fixes!!!

Cheers, Alan

Apparently all AWD have this "buzz" to some extent. I haven't gotten around to trying to let the exhaust "hang loose" a little bit as opposed to it being under a fair bit of tension as it is on mine with the stock rubber hangers.

It could just be the pipes vibrating. I'm also going to try clamping a short length of something like 20mm x 2mm flat plate in a couple of places and see if it helps (like touching a bell to stop it vibrating/ringing).

Something else I may give a go is pulling the heat shielding and insulation off the stock pipes and cutting and bending to fit the headers as the shielding may be more a NVH fitting rather than a pure heat shield.

Mitsubishi didn't have much budget to develop the AWD so NVH research was minimal. Maybe the block of steel added to the rear diff to try to get rid of the hum blew the budget for any more fixes!!!

Cheers, Alan

ok, keep us informed on your testing......ha,wondered what that block was for...i'll be.

ok, keep us informed on your testing......ha,wondered what that block was for...i'll be.

Extra weight ! :shock:

Extra weight ! :shock:

I'LL GET THE OXY OUT TONIGHT!

I bought RPW's a few months back for my AWD, nothings crooked or touching anything and the guy that fitted them said they went on well....... yes i get a bit of buzzing.

The last set of AWD headers I fitted the engine pipe was made crooked, the flange hits the floor, the o2 sensor is in the wrong position and near hits the tailshaft and the rear flange is about 7 degrees out. The rear flange also hits the floor pan. I now have to take them apart, cut and refit them

The HM AWD headers are a far better design with a smoother curve where as the RPW ones have a surprisingly sharp curve around for the rear pipe, agian due to poor design.

Oh and I have had in the past many issues with FWD headers from there as well though no of recent times.

The last set of AWD headers I fitted the engine pipe was made crooked, the flange hits the floor, the o2 sensor is in the wrong position and near hits the tailshaft and the rear flange is about 7 degrees out. The rear flange also hits the floor pan. I now have to take them apart, cut and refit them

The HM AWD headers are a far better design with a smoother curve where as the RPW ones have a surprisingly sharp curve around for the rear pipe, agian due to poor design.

Oh and I have had in the past many issues with FWD headers from there as well though no of recent times.

They did stop selling them [awd] for a while due to 'fitting issues', but seems to be sorted now.
That broard curve in the HM's does look the part.

i got some prices today $810 for hurricanes fitted and $750 for geni fitted, i have to wait to monday for the price for the pacies

i got some prices today $810 for hurricanes fitted and $750 for geni fitted, i have to wait to monday for the price for the pacies

Got my pacemakers for $300 and $120 for fitting plus getting a tip welded on at the same time. :shock:

Ha ha lumps of metal all over the car. Those crazy NVH guru's just love those MASS DAMPERS they are every were thats why new cars weigh so much and 200 killer wasps feels so doughy.
No power gain with HM's (Ralliarts) at all some runner length (true MMAL story but they look good). Go the Pacemakers excellent value for money if you want headers/extractors.

Cheers Dave.

Lukey now do a set of headers for the non AWD magna, according to their latest parts list. There was no picture, it was just listed as new product.

confirmed. lukey do the extractors, there on the shelf too, any exhaust shop should be able to get them bout $100 less than paccy's