asupracar Posted November 28, 2004 Share Posted November 28, 2004 Just wondering what controls boost on a stock car. Is it a spring set at 0.8bar in the wastgate or is it electronically controlled by the ECU? Link to comment Share on other sites More sharing options...
Paul -C- Posted November 29, 2004 Share Posted November 29, 2004 I was under the impression the exhaust system is designed to restrict it to 0.8 bar. Link to comment Share on other sites More sharing options...
tbourner Posted November 29, 2004 Share Posted November 29, 2004 Same here, I always assumed it would boost as high as it could, as long as there are no restrictions to the exhaust. Hence a full decat and back box generally means you have to add a restrictor ring to limit the boost. Link to comment Share on other sites More sharing options...
Alex Posted November 29, 2004 Share Posted November 29, 2004 There is a wastegate which tries to control boost and keep it down to .8bar. But it get overloaded by a too free flowing exhaust on the J-spec (it's just not man enough to dump enough of the air flow). With a standard exhaust you have enough backpressure and little enough flow for the wastegate to work properly and keep the boost to .8bar Link to comment Share on other sites More sharing options...
Wez Posted November 29, 2004 Share Posted November 29, 2004 And to add to Alex comments the ECU controls the wastegate with a boost control solenoid. Basically its a combo of things. Link to comment Share on other sites More sharing options...
ardasaliah Posted January 12, 2005 Share Posted January 12, 2005 And to add to Alex comments the ECU controls the wastegate with a boost control solenoid. Basically its a combo of things. Is this true- coz I can't see no boost solenoid by the wastegate?? (Iam not gonna do this) Just intrested what would happen if I blocked of the pipe that feeds the wastgate if the car still has cats in + stock zorst. Would the boost still be at 0.8bar UK spec- or would it go crazy. Link to comment Share on other sites More sharing options...
tbourner Posted January 12, 2005 Share Posted January 12, 2005 Not a good idea, high pressure in the inlet with the valves closed on overrun, and nowhere for the unwanted boost to be let out!! Somethings gonna break I fear. Link to comment Share on other sites More sharing options...
b_have Posted January 12, 2005 Share Posted January 12, 2005 hmmmm....... Link to comment Share on other sites More sharing options...
Guest Usmann A Posted January 12, 2005 Share Posted January 12, 2005 Is this true- coz I can't see no boost solenoid by the wastegate?? Yes it is true. Also known as a Wastegate VSV in front of turbo no.1 Id have a look on the FAQ Ian C did ... Not a good idea, high pressure in the inlet with the valves closed on overrun, and nowhere for the unwanted boost to be let out!! Somethings gonna break I fear. That wouldnt be my main worry. Link to comment Share on other sites More sharing options...
hadyn Posted January 12, 2005 Share Posted January 12, 2005 so would there be a boost increase over the stock 0.8 bar with just the fitment of a cat-back exhaust???I thought a decat was the only thing to cause an increase of boost without a control device Link to comment Share on other sites More sharing options...
Scoboblio Posted January 12, 2005 Share Posted January 12, 2005 I had a cat back fitted a few days ago.... with the stock exhaust I was running a max of 0.725 - 0.75 bar, with the new one I'm hitting the 0.8 I was expecting in the first place.... The stock system seemed very restrictive in retrospect, maybe it's just me but the car seems to breath much easier now Link to comment Share on other sites More sharing options...
hadyn Posted January 12, 2005 Share Posted January 12, 2005 one thing that suprised me about aftermarket zorsts on TTs was how quiet they are from within the cabin. Supes must have very good soundproofing as I could barely hear the exhaust note that much in the cabin - a sharp contrast to my S14 where the fully decatted blitz nur spec r drowns out the stereo!! Link to comment Share on other sites More sharing options...
Thorin Posted January 12, 2005 Share Posted January 12, 2005 one thing that suprised me about aftermarket zorsts on TTs was how quiet they are from within the cabin. Supes must have very good soundproofing as I could barely hear the exhaust note that much in the cabin - a sharp contrast to my S14 where the fully decatted blitz nur spec r drowns out the stereo!! decatted hipers aren't quiet Link to comment Share on other sites More sharing options...
hadyn Posted January 12, 2005 Share Posted January 12, 2005 decatted hipers aren't quiet it looked like a dragger and made a lovely burble on idle when outside the car, couldnt hear it when booting it inside the car though. Then again anything sounds quiet after a nur spec! Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 12, 2005 Share Posted January 12, 2005 Not a good idea, high pressure in the inlet with the valves closed on overrun, and nowhere for the unwanted boost to be let out!! Somethings gonna break I fear. Methinks you're talking about the dump valve here, Trev The wastegate controls excess boost when the throttle is open (or tries to on a j-spec) The dump valve relieves the boost pressure when the throttle is closed. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now