I just recently had a 2.5" mandrel bent exhaust system installed in my NA, which was already running some 6-2-1 extractors and is now friggin LOUD... its seriously the loudest na ive ever heard i have no idea what the hell these guys did but anyway it sounds awesome, almost too loud tho... but too the problem... it ran beautifully for a week or so after i had it done but now im getting a weird noise when i back off the throttle. Now beacuse im suddenly going to be able to hear the noises the engine is making a lot better now cus of the amplitude maybe i just never noticed this before and its fine...but when i back off the throttle the revs dont just drop straight down to about 1000 like they usually did, it hovers around and bounces up and down a bit first making sort of...spluttering noises at the same time till it returns to 1000... its hard to describe the noises almost like a V8 with a really lumpy cam would make at idle, till the revs return to 1000. This seems pretty bizarre to me and probly will have most of you puzzled too but any ideas would be much appreciated. cheers

mine does the same i think....i dont think its bad though

yeah it doesnt sound too bad...the only think i can think of is maybe the afm or something? God im sick of replacing those tho...

No offence, but I've heard lots of loud N/A's...not one sounded "good".

hahaha mate normally i would agree with you but not in this case but anyway...back to the isssue at hand Some original photos have not been recovered yet.

Have you checked your base idle and timing to make sure all that is ok.

normally if revs dont drop that easy its surging but its most likely just from your extatcors. I had my 2.5 cat back on then put extractors on, after that it made the same noise, sounds mad as, i got no tacho so wouldnt notice the revs but its fine, nearly ever vl w/extractors does it

Quote: Originally Posted by RB30-POWER Have you checked your base idle and timing to make sure all that is ok. yeah mate the car is idling normally. it used to sit at 750 and now it sits at 800 which you come to expect when completely overhauling the exhaust system. I think its probly fine, maybe the idle sensor is getting a little bit tired or its just the extractors. Either way i guess im not too fussed.

manual or auto? if its auto, does it happen in drive, or only in selected gears? mines turbo and it happens when im in selected gears only. when im in drive and back off it drops down emediately, but if im in second on 4000 and back off leavin it in second, it drops slowly and splutters its normal.

yeah its an auto and it happens in drive, but the other day i was manual shifting the auto and it did it aswell when dropping down gears.