AGK512 Posted August 7, 2006 Report Share Posted August 7, 2006 Hi all For those of you that have resisted going the Miltek route with about 4 miles on the clock Mine at 2.5k miles now seems to have a slight exhaust resonance at about 2-2.5k revs. It's no way really bad but wasn't there before (pretty sure) you can feel it more than hear it and is mildly anyoing hope it clears up as the miles go on Anyone else on the oem exhaust (or am I the only one left ! ) noticed this at all. I believe the Mk4 had a similar 'feature' Cheers Quote Link to comment Share on other sites More sharing options...
rs32 Posted August 7, 2006 Report Share Posted August 7, 2006 don't recall this on mine at 2.5k miles - but I certainly have bad resonance after a long "very hot" run at 2400 rpm with the Milltek fitted - they will be seeing the car at the end of this month to investigate. Quote Link to comment Share on other sites More sharing options...
Ian_G Posted August 7, 2006 Report Share Posted August 7, 2006 Urgghhhhh yep, same problem. Milltek amplifies it and remap amplifies it again. 2400rpm is the magic number. I'm not bright enought to work out how to link to a thread but check out my experiences in Milltek / remap / haldex. I can assure you that the OEM resonance really is not that bad at all - certainly now I'm back to it. rs32, Milltek fitted an alternate centre box and rear pipe baffles on mine. Didn't help. I'm reliably informed that it is a DSG specific problem. Quote Link to comment Share on other sites More sharing options...
rs32 Posted August 7, 2006 Report Share Posted August 7, 2006 this gets interesting Ian - your situation and my recent noticing of the "feature" on mine seems to suggest that the Milltek cat-back behaves differently if the car is remapped. I can live with the sound of mine - normally fantastic. After driving it hard for an extended period though I get the severe boominess resonating through the transmission tunnel. Milltek called me back within 2 hours to offer to take the car in - can't say fairer than that and they were very interested in the fact it's a manual SA - I rememember saying to you at Castle Combe how good the exhaust upgrade is - this opinion hasn't changed and I will be happy for Milltek to resolve the problems slowly if necessary - like RR I don't work for them but it is a very good quality aftermarket part IMO Make the dealer aware of the problem with yours SA - and see how it develops between now and 10k - not worth losing the car for time spent in the garage IMHO Quote Link to comment Share on other sites More sharing options...
Maxyboy Posted August 7, 2006 Report Share Posted August 7, 2006 can someone explain resonance to me please... i might have it but dont know what it is..... then again...if i dont know then it cant harm me eh.... cheers Quote Link to comment Share on other sites More sharing options...
AGK512 Posted August 7, 2006 Author Report Share Posted August 7, 2006 for resonance read vibration Quote Link to comment Share on other sites More sharing options...
AGK512 Posted August 7, 2006 Author Report Share Posted August 7, 2006 cheers rs and iang i'll keep and ear out for any change in music ! Quote Link to comment Share on other sites More sharing options...
UKLooney Posted August 7, 2006 Report Share Posted August 7, 2006 If you think of the exhaust system as a single piece of pipe, it will vibrate at a natural frequency depending upon its length (like a slide whistle changes note when lengthend). When noise (vibration) from the engine occurs at the same (or multiple of) frequency as the exhausts natural (resonant) frequency, the pipe will resonate and cause a low frequency tone to be produced (drone) which causes vibration through the chassis. The length of the exhaust is usually tuned so that the resonant frequency is outwith the normal rpm range of the car. Could it be that VW may have miscalculated (or not considered) the length of the system, and miltek followed suit??? Quote Link to comment Share on other sites More sharing options...
Ian_G Posted August 7, 2006 Report Share Posted August 7, 2006 Resonance - an intense sound produced by sympathetic vibration. This exactly describes the effect I was getting, peaking at 2400rpm. I had the Milltek fitted first, bad, followed by a remap with a full refit of the Milltek a week later, worse. 2400rpm is exactly where the remap put maximum torque (rolling road results) RS32 - I'm not surprised Milltek called you in, it was their people who informed me that it is DSG related - I don't really believe that. I half suspect there is a fitting issue here as AMD checked out my whole exhaust system when it went back to OEM and I think it is better than before... mind you I could well have lost some hearing from the experience . Quote Link to comment Share on other sites More sharing options...
UKLooney Posted August 7, 2006 Report Share Posted August 7, 2006 [ QUOTE ] their people who informed me that it is DSG related - I don't really believe that. [/ QUOTE ] Could it be that the shift points chosen by the DSG software simply make the issue more prominent? Quote Link to comment Share on other sites More sharing options...
Ian_G Posted August 7, 2006 Report Share Posted August 7, 2006 Yes. Gentle driving in D constantly drops you into the problem zone whereas in a manual I'd generally be using more revs. Quote Link to comment Share on other sites More sharing options...
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