firin Supra Posted June 19, 2010 Share Posted June 19, 2010 Right to keep it short... Last week my car was boosting perfectly, and I was getting 0.8bar with both turbo's online as per normal. This week after putting the standard exhaust and cats back in im only seeing 0.5 bar with both online and then gradually drops down to 0.4 bar. I dont understand as all I'v done is change the exhaust. I didnt have this problem before.... Anybody shed some light on the issue? Another issue is that when revving gently and letting off u hear something which I describe as a "trumpetty" noise sent through the air filter. Is this normal as my aristo does this too? Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted June 19, 2010 Share Posted June 19, 2010 So, you had a double decat and only saw 0.8 bar?, I'd say thats wrong for a start. Decatting a tt will see the boost go way up unless you have a restrictor ring in there, (most rings hold boost around 1 bar). My guess is your boost gauge is wrong. I reckon you were seeing 1 bar when it was 0.8, then when youve put the cats back in its put the boost back to stock, which is 0.8. Your gauge is still under reading so now its showing 0.5 when it should be higher. Quote Link to comment Share on other sites More sharing options...
Homer Posted June 19, 2010 Share Posted June 19, 2010 Boost on a stock TT (stock exhaust and 2x cats) is 0.76 bar. So you should at least see unless you left the restrictor ring in place with the cats going in. I'd also go with a dodgy boost gauge reading, but there at a lot of potential causes. PS: When you had it before, did it have cats or decats? 0.8 bar is very low if it was decatted, it's pretty much the same as stock. Quote Link to comment Share on other sites More sharing options...
firin Supra Posted June 19, 2010 Author Share Posted June 19, 2010 Apologies I forgot to mention that its a uk spec tt. the boost is being read off the ebc (HKS EVC 5). Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted June 20, 2010 Share Posted June 20, 2010 Plumb a cheap mechanical gauge into the system and check the reading against it. Quote Link to comment Share on other sites More sharing options...
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