If I had a very restrictive stock exhaust. Like off a carby 3TC that was welded to a 2" dump pipe attached to a stock CT20 (3TGTEU motor, stock apart from pod filter). Would the backpressure or restriction be so severe that it would actually affect the engines ability to boost past a certain level?
The reason I ask is that I installed a Speco ("Danger to the manifold!") Boost gauge and a bleed valve on to my T18 with the above setup and from running the stock boost level, I can tell the gauge is a bit out, by about 1psi less. Anyway, I raised a the boost little by little but found it stopped just short of 10 PSI (calculated real boost not dodgy speco reading) , no matter if I adjusted the bleed more or not. I found that it actually ran heaps better after backing it off a little but the boost gauge reading did not change.
I'm thinking that if a free flowing exhaust allows a turbo to boost better, then the reverse must surely apply for restrictive exhausts.
Mon, 15 August 2005 00:23
