I was also thinking about removing the heater hoses that go to the throttle body so that the air is not heated going into the intake. I am afraid that this will cause a major lean condition, but any input would be greatly appreciated... 8)
I was going to try that also. I was told it wouldn't make enough of a difference to even bother.
Well if we have a big problem with knock because the air is not cooled enough, I would think that a heater on the throttle body would defeat the purpose of having an intercooler... 8)
I did this mod on my firebird and there seemed to be no difference. Intake temp stayed the same and my intake air temp. sensor is in the plenum so if there was a change it would have picked it up.
It's funny that GM actually MAKES the parts to do the heater by-pass.
http://www.v6z24.com/mods/howto/?page=heaterbypass
I've talked to a number of TPI folks who have try'd removing the bypass from the throttlebody, and could'nt see much difference 'til cold weather set in, then they couldn't wait to hook it back up. The place you'll notice it being gone is when the throttlebody ices up and leaves you dead and no-start in the middle of an intersection in busy traffic at 7:30 in the morning. Not fun at all!!
I've also see a setup where they use a valve (some late 80's F-body's have them on the heater) that is actuated by a switch to bypass the throttle body, cabbage one from a junkyard and set up to a toggle switch on/under the dash, labeled summer/winter. The bypass valve off f-Body's is a 2 valve unit that is a diverter/bypass that feeds the heater core when the dash control is set to heat or defrost, otherwise it bypasses the heater core to keep the cabin cooler in the hot summer weather. God knows, those things need all the cooling they can get, the AC is not worth a shit!
Quote from: TGPilotI am afraid that this will cause a major lean condition, but any input would be greatly appreciated... 8)
I don't quite understand how this would cause a lean condition. Also I dont think iceing would be an issue with a turbo car being their intake temps are higher because the turbo heats the incoming air. Even after the intercooler I think intake temps would be high enough to keep this from happening. But FYI Sy/Ty's have the Throttle body coolent passages blocked from the factory. HTH
As far as a lean condition I suppose it would not happen because the fuel tables are controlled by the ECM. I was thinking cold air = air is more dense = lean... 8)
I'm not exactly sure on the layout of the Turbo 3.1 but if its like the Turbo 4.3 then your Intake temp sensor is in the intake manifold after the throttle body. Therefore if bypassing those coolent lines had an effect on the intake temp then the ECM would see it and change fueling and spark advance accordingly. IMO anything to get your intake temps down is good. High intake temps = knock :shock: .
I agree totally. That is why I asked about it. When people started talking about frozen throttle bodies and no improvement I forgot about it. Considering my throttle body has 195* F water running through it I think this would be a bad thing also. I am going to give it a try when I come back from a trip to Utah this weekend...see what happens sort of thing... 8)
ps...Nice Typhoon!! Daily driver or only weekends?
There may be icing problems and no improvment for N/A cars but I think Forced Induction is another story. On a forced induction car the air in naturally heated when its compressed. Not to mention that turbochargers add heat from the air comming close to the exhaust. So I think the air would be warm enough to keep this from happening.
By the way the Ty is a weekend warrior only and it is in storage for the winter. I daily drive a 93 Chevrolet Corsica....with a 3.1!
I agree! Thanks for your input!! I had plans to do this anyway for my own peace of mind... 8)
If my memory serves right, the 3100's don't have TB lines. (i could go out and look in the garage, but oh well). They don't seem to have a problem with icing, and the crossover is pretty well sheilded.
My 3100 don't have the lines.