Turbo question...tell me if this makes sense

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
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Northern KY
A guy told me that i can bypass the boost control solenoid completely, and just run a hose from the same place on the T3 that's going to the BCS now, and just run that straight to the waste gate actuator and plug the rest of the ports on the turbo.....he said that this will give me 14psi as soon as the turbo can make it but that the port on the turbo actually restricts boost to 14psi because of the diameter of the opening (he said you can drill it out and get more but you need an intercooler). He said this port actually IS the boost regulator, and that the BCS basically tricks the WGA into running only 9psi until the turbo hits 4k RPM....but that bypassing it will give me the 14psi instantly...i just have to run premium (which i do anyways).

Is this BS or will this work reliably without blowing my head gasket? Is it safe to run like this until it's intercooled? (i'm not even going to put the MBC on it until then because i KNOW i'll give in and crank the boost up lol )
 
Umm...that guy is misinformed.

You don't want to just bypass the BCS without some sort of other boost controller. I can't remember exactly what it'll do...you'll either get the bare minimum boost (10 psi) or it'll have no limit and go to 20+ psi.

All that crap he was spouting about the hole in the turbine housing regulating boost and the BCS "tricking" the wastegate into anything is complete BS. The wastegate actuator is purely a boost/vacuum actuated device. The BCS just limits the amount of boost that reaches the wastegate actuator to open it, just like all other boost controllers.

Now that I think about it, if you just bypass the BCS with a vacuum hose straight to the actuator, it would probably just open at 10 psi (the lowest setting for the factory actuator).
 
The BCS system works as a pressure bleeder for the wastegate signal. The bleeder orifice is in that little 3-way tee by the compressor outlet. When the BCS is closed, it doesn't bleed any pressure. When it opens, it bleeds air through that orifice and the wastegate sees less than actual manifold pressure and opens at 14-15psi instead of 9-10.

Personally I would leave it alone until you get some form of intercooling. I believe the BCS also lowers boost in response to pinging, so that's not a bad feature to have. You do have the knock sensor hooked up, don't you?
 
Well i kept getting different stories from different people about easy/cheap ways of regulating boost and then i'd hear from someone else that it's a stupid idea...so i said screw it and ordered a Gillis valve. It should be here in about a week or so i guess.

Now i just need a decent intercooler and things will liven up a bunch :D