Chasing feedback from AWD owners with extractors. Wanting to know which extractors you have and if there is any buzzing, fluttering or bazaar noises, notably around the front flex pipe.

I'd even like to hear from FWD owners who have similar issues.

Thanks in advance! :D

I'll go 1st lol

I made a set of extractors with 32" long primaries and the system had this flaming, rotten flutter that was nearly the death of me. It sounded like it was in the front, short, little flex joint so we swapped the single braid one for a double braid. Result: no change but added a restriction due to the bulk of the braid inside the flex bellow. Took them off in disgust and gave them to another member. Grrrrrrrrrrrr :rant:

hey!

I put HM headers on a while ago and no problems at all. I think i have some close up pics of them before they went on the car, let me know if you want them.

hey!

I put HM headers on a while ago and no problems at all. I think i have some close up pics of them before they went on the car, let me know if you want them.

Post them up. I'm interested in these as well. Ta

Chasing feedback from AWD owners with extractors. Wanting to know which extractors you have and if there is any buzzing, fluttering or bazaar noises, notably around the front flex pipe.

I'd even like to hear from FWD owners who have similar issues.

Thanks in advance! :D

Mate I have the buzz on the FWD with Pacemakers and full Redback system. But only a little and only at 1800 rpm exactly - either side of this there is nothing. The really weird part is that if I get under the car and grab the whole exhaust system and violently pull it side to side to look for the contact point:
1/ I can't find one;
2/ the buzzing goes away for 4 weeks or so then gradually comes back......spooookkyy

attached some pics of AWD Hm headers...

just an idea, would the noise be coming from the flex joints because the woven stuff has became loose??

attached some pics of AWD Hm headers...

How much was the header and how much was fitting, if I may ask.

sorry for the slight hijack....

are these the 400ish delivered jobbies from ebay?

could the buzzing just be the harmonics of the car?

yep, from ebay, though were about 650, install was about 100ish I think.....

I also have the HM headers for my AWD, and yes I had the buzzing and another strange noise. When I fitted the headers things were quite for sometime then the buzzing etc started after a few 1000k's.

I took the heat shield off the cat, and this seems to have sold the buzzing for now.

I wonder (after talking too with Graham Bell) if using uneven length primaries this buzzing can be eliminated. It seems rpm specific from what you are all saying and from talking to other people in the industry. Graham cites experience with unequal length primaried headers providing a broader torque curve verses a 'tuned' rpm torque approach. I thought the excitement of 2x pulses arriving simultaneously in the collector would be bad but Graham doesn't think this will be the case given a road spec car with a pretty sad cam profile, and the fact that no manufacturer sell 'tuned length' extractors actually states what rpm they're tuned for :doubt:

Fair call I thought. Guess I'd better have a go at making a set huh?

Yeah he has just purchased a set of HM's though me to test and whatnot so will see what he thinks of them anyways.

EZ,
I had the coated RPW racies on and they made a buzzing noise, was quite annoyed cause it sounded crap. Had a look under the car and the aluminium deflection plate was slightly rubbing on the pipes and you could just see the mark on the headers. Removed and no noise. Not saying that you are a mechanical numpty but sometimes brilliant people miss the obvious.

Bart

EZ,
I had the coated RPW racies on and they made a buzzing noise, was quite annoyed cause it sounded crap. Had a look under the car and the aluminium deflection plate was slightly rubbing on the pipes and you could just see the mark on the headers. Removed and no noise. Not saying that you are a mechanical numpty but sometimes brilliant people miss the obvious.

Bart

I'm probably somewhere in between lol

At the time I had a 3" Metalcat, and all heat shields were removed. It was beyond frustrating. So no longer any noise at any rpm or engine load? I found it worse under load leading me to believe accoustic/pulsation issues in the front flex. Wondering why a flex would even be needed there anyway - as long as there is a large flex between the cat and the extractor system the engine movement would be catered for. It's not as if the 2 heads move independantly :nuts:

that true but the heating/cooling process can cause the extractors to expand in size and length so it would therefore cause stress on the header plate and possibly crack. it doesn't happen on all extractors but they put the flex in there as a little bit of insurance. pacemakers don't do this because they have somehow overcome this problem in the many years of development through out there entire range.

Yep, after I got RPW "Race" headers fitted there was a buzzy/whistling sound. Strangely enough it seemed to quieten down over the last 6 months or so, to the point that it was barely no longer irritating (the buzzing had dissapeared, just a slight whistling sort of noise around 3-4k rpm), so I never got around to getting it fixed.

But my exhaust guy reckoned it was coming from the main flex pipe, but it seems your experience contradicts this.

oddly enough, since I got the blower fitted the whistling noise seems to have dissapeared, though maybe it's just being drowned out to the point of being inaudible now, hard to say.

that true but the heating/cooling process can cause the extractors to expand in size and length so it would therefore cause stress on the header plate and possibly crack. it doesn't happen on all extractors but they put the flex in there as a little bit of insurance. pacemakers don't do this because they have somehow overcome this problem in the many years of development through out there entire range.

Hard to see a 10mm plate cracking. Any expansion would be absorbed by the pipes flexing I would expect - that's why Pacemaker don't bother with it I suspect. Food for thought as I ask myself if I could be bothered to make a set (2nd attempt) for my ride.

i don't mean the plate will crack i mean the pipes could crack off the plate or on the collector cones. as i said it's just a little bit of insurance for them.

also are RPW race headers stainless steel??

Hard to see a 10mm plate cracking. Any expansion would be absorbed by the pipes flexing I would expect - that's why Pacemaker don't bother with it I suspect. Food for thought as I ask myself if I could be bothered to make a set (2nd attempt) for my ride.

how bout if i order you a set of HMs? at least if they crack or whatnot they are covered under warranty, for 10 years infact.

p[ersonally i find that a very good selling point for the HM's as it shows how confident they are in their product.

p[ersonally i find that a very good selling point for the HM's as it shows how confident they are in their product.

yeah they are a great product the only thing bad ive heard about them is they can tend to crack if used with forced induction, due to being SS.

yeah they are a great product the only thing bad ive heard about them is they can tend to crack if used with forced induction, due to being SS.

That's why i haven't got them ;)

Well my problem with the car these days is that when I go for the gas and put her up to 5.5k revs she starts making a blow off valve sound out of the pod filter. Very good reminder to change up.

Took a prospective for a test drive the other day and he was well impressed that he could just tramp the accelerator and not worry about wheel spin.

He had a couple of goes at trying to break traction but couldnt and the only thing that we found wrong was that the "learning computer" kept changing gears at the wrong time cause he was going to easy on the old girl.

I have not experienced any noise from the extractors since being installed. Could it be a fault in your installation? A gasket dag hanging down in the air flow? Too much flow from your head mods?