T5 for Life Posted March 31, 2009 Report Share Posted March 31, 2009 I have a 1999 V70 T5 automatic. Performance mods possibly related to this include ecu flash, short ram intake, cat back exhaust, IPD HD boost control valve, upgraded CMB valve. At full boost I experience what I can only describe as a flutter or surge. 1st gear seems to work fine, it'll boost up quickly to 23lbs boost break tires loose for a sec or two when this happens the boost goes to 0 on the gauge then upon shift to second will boost up initially to about 21 and then the boost pressure will bounce back to 15 and then back to 23 and so on it will do this 2 or 3 times until shift to third and continue. Any ideas?? Any help is greatly appreciated. Thank you Link to comment Share on other sites More sharing options...
Chilled man Posted March 31, 2009 Report Share Posted March 31, 2009 CBV ? did you upgrade that yet ? if not the flutter is from that due to being ripped Link to comment Share on other sites More sharing options...
ozzimark Posted April 1, 2009 Report Share Posted April 1, 2009 Is this on the stock turbo? If so, why do you have the boost so high? The compressor is way outside of it's efficiency range by the time you get to 20psi, much less 23, you're probably overrevving the crap out of the wheel. :lol: Link to comment Share on other sites More sharing options...
GeraldJ Posted April 1, 2009 Report Share Posted April 1, 2009 Is this on the stock turbo? If so, why do you have the boost so high? The compressor is way outside of it's efficiency range by the time you get to 20psi, much less 23, you're probably overrevving the crap out of the wheel. +1 Link to comment Share on other sites More sharing options...
justjim Posted April 1, 2009 Report Share Posted April 1, 2009 i had the same prob, replaced the cbv with a viva performance upgrade (stiffer spring and stronger diaphram) and also the hose for it. cleared right up. you dont get fuel cut off with boost that high ? Link to comment Share on other sites More sharing options...
troyhyde Posted April 2, 2009 Report Share Posted April 2, 2009 Do a boost leak test. It will reveal the culprit(s). Link to comment Share on other sites More sharing options...
Dave 54 Posted April 2, 2009 Report Share Posted April 2, 2009 Might be also exceeding the limits of the stock IC, boost set to high and the compresssor is being restricted cause the IC is not designed to flow that much. Ran into it with my talon and fixed it with a dual DIY IC set up, HAD 2 3OOZ IC's mounted in the front bumper, man it looked cool with all that piping. Link to comment Share on other sites More sharing options...
johnloves850's Posted April 2, 2009 Report Share Posted April 2, 2009 you better hope you're not running waaaaaaaaaaay lean lolan ecu reflash can only help so much with afr'sget an afr gauge and turn down the boost, jeez Link to comment Share on other sites More sharing options...
randomdude Posted April 2, 2009 Report Share Posted April 2, 2009 the flutter is compressor surge. AFAIK- it is cuased by one of two things. damaged CBV diaphraghm, or the line that runs from the WG to the CBV is cracked/torn/melted. ive melted two myself and it did just this both times. replace the line, all good. Link to comment Share on other sites More sharing options...
Hellas850 T-5 Posted April 2, 2009 Report Share Posted April 2, 2009 MHI turbos have two different types of wastegate,the one is very soft,if your car has the soft one it could be from it,or you may also have a broken exhaust housing at the wastegate port,but if it is from the tune I can't say it,because I don't know,I experienced the mentioned symptons,and when I lowered the boost pressure it became better,then I tried a small spring on the wastegate actuator and it was much better. Link to comment Share on other sites More sharing options...
T5850 Posted April 3, 2009 Report Share Posted April 3, 2009 the flutter is compressor surge. AFAIK- it is cuased by one of two things. damaged CBV diaphraghm, or the line that runs from the WG to the CBV is cracked/torn/melted. ive melted two myself and it did just this both times. replace the line, all good.x2. That is a lot of boost for a stock turbo, especially if you are at sea level. I also would think you are hitting fuel cutoff. These stock turbos really tap out at 15 psi. Here in the Rocky Mtns you can run a bit more, but again, turn down your boost, and get an air/fuel meter. (wideband too) Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.