Intake manifold / throttle bodies

JoeyD · 04-01-2009, 01:28 PM

I really have to question how much an air charge could be heated by such a small section of the TB. I doubt this mod would have any significant effect. Think about how much area an intercooler uses to effect a change on a given air charge. It's huge in comparison to one tiny little section of TB. That system is there simply to keep the TB above freezing so it doesn't freeze open/shut.

wstar · 04-01-2009, 02:02 PM

Quote:

Originally Posted by JoeyD

I really have to question how much an air charge could be heated by such a small section of the TB. I doubt this mod would have any significant effect. Think about how much area an intercooler uses to effect a change on a given air charge. It's huge in comparison to one tiny little section of TB. That system is there simply to keep the TB above freezing so it doesn't freeze open/shut.

I wonder too honestly. This mod is done on many different vehicles these days, and usually the claims are "1-2hp gain", which basically means too small to accurately measure. In any case any gains would be very situational, depending on the ambient temperature, coolant temperature, etc.

However, if you live in a place where TB freezing is never an issue, and it takes all of 15 minutes and a few small pieces of rubber and hose clamps to do this, then why not. 4 fewer hoses to fight with while I'm reaching around in there doing other things is a plus too

Neo187H · 04-02-2009, 12:00 PM

Quote:

Originally Posted by JoeyD

That system is there simply to keep the TB above freezing so it doesn't freeze open/shut.

Its a system designed the warm up the intake air charge in order to get the car up to operating temperature quicker for emissions testing.

wstar · 04-02-2009, 02:04 PM

Quote:

Originally Posted by Neo187H

Its a system designed the warm up the intake air charge in order to get the car up to operating temperature quicker for emissions testing.

Really? That doesn't make intuitive sense to me. Intake air temperature isn't going to have a big effect on engine oil/coolant temperature to begin with I don't think... but that aside, the coolant won't start flowing through the throttle bodies until after the thermostat opens, at which point the engine is already warmed up. I could be wrong, but I'm pretty sure it's there to prevent the butterfly valve (throttle plate) in the throttle body from getting stuck (frozen) into place in very cold climates.

wstar · 04-02-2009, 02:16 PM

Here's a great link on this subject. It's 5 years old and from a Mazda6 forum, but the issues are essentially the same for TB coolant bypass on just about any car:

Why not to do the throttle body coolant bypass - Mazda6 / Atenza

Someone ran the numbers for the Mazda6. That car might have very different values than our car for all of the specifics in the equations, but the overall effect is likely similar. His formulas say you might gain less than 1/2 hp from such a mod. Of course then everyone else chimes in with other theories about effects that might fall outside his model, like reducing heat load in the engine bay in general by removing more hot coolant lines, etc...

wstar · 04-15-2009, 10:55 AM

Quote:

Originally Posted by Jesse

You know what would be interesting, since the throttle is controlled by the intake valves and not the TB's.... could you just remove them? besides having a cel which we could eventually tune to ignore....could we have a hybrid individual TB system? maybe create an intake to exploit the trait??

I think UpRev and other ECU tuners will likely alter the TB open/close if that makes sense, but I wouldn't remove them if I were you. The ECU probably closes them for good reason for various reasons at various times (like at engine startup, and maintaining manifold vacuum for the brakes, etc) even if VVEL is doing most of the real throttling work.

04-01-2009, 01:28 PM	#1 (permalink)
JoeyD Enthusiast Member Join Date: Jan 2009 Location: Raeford, NC Posts: 305 Drives: 09 NISMO 370Z Rep Power: 187	I really have to question how much an air charge could be heated by such a small section of the TB. I doubt this mod would have any significant effect. Think about how much area an intercooler uses to effect a change on a given air charge. It's huge in comparison to one tiny little section of TB. That system is there simply to keep the TB above freezing so it doesn't freeze open/shut. __________________ When was the last time you did 230MPH in something with 4 seats?

04-02-2009, 02:16 PM	#5 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3595	Here's a great link on this subject. It's 5 years old and from a Mazda6 forum, but the issues are essentially the same for TB coolant bypass on just about any car: Why not to do the throttle body coolant bypass - Mazda6 / Atenza Someone ran the numbers for the Mazda6. That car might have very different values than our car for all of the specifics in the equations, but the overall effect is likely similar. His formulas say you might gain less than 1/2 hp from such a mod. Of course then everyone else chimes in with other theories about effects that might fall outside his model, like reducing heat load in the engine bay in general by removing more hot coolant lines, etc... __________________ 7AT Track Car! Journal thread / Car setup details

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