TB bypass, flip side of the coin
 

It's been beat to death about:

1) Cheap mod - 1 to 5 hp gain
2) Don't bother - zero gain
3) It's for Alaska - so icing up doesn't stick the throttle open
4) Whatever I missed

I've never seen it discussed, however, does the coolant, under some hot ambiant temp circumstances, ever actually COOL the throttle body?

After all, the coolant is COOLING a whole bunch of other parts of the engine, right?

Maybe it's not such a smart idea to disconnect it, especially, let's say if you live in the desert SW.

Maybe that little bit is actually doing something good for performance.

What do you think? :confused:

Re: TB bypass, flip side of the coin (froggy47)
 

It doesnt cool the intake, the intake will radiate away heat faster than the coolant in the TB would carry it away. Plus the air coming in will carry heat back into the engine. Bypassing the TB just keeps that air at ambient temp (which is much cooler than the combustion chamber you know) a little longer. Try touching the heads, or the block when the engine is running warm. Then touch the intake plenum and tell me which is cooler.

Re: TB bypass, flip side of the coin (vader86)
 

Ok, here is the final skinny on what's up with the TB bypass mod.

By disconnecting the coolant lines to the TB you are attempting to cool the air that passes through the TB by cooling the the TB itself. Thetemperature of the TB, while warmer than ambient, is only going to affect the incoming air that is in direct, or near direct contact witht he TB. A small percentage of total incoming air. So, by cooling a small percentage of incoming air, the hope is that the cooler air is denser, and therby will allow more oxygen molecules to enter the combustion chamber.

The problem is that the cooler the TB, the smaller the hole is. thermodynamic expansion occurs when objects change temperature. It is moy opinion that any gain realized by denser air will be negated by the slightly smaller opening. IE, a larger opening of thinner air, will accomplish the same effect as having a smaller opening with denser air. So, the final result a waste of time. The TB bypass is worthless as far as HP is concerned. As far as a cool spot to rest yuor hand when leaning over the engine to work on it while its still hot, then its great.

So that's the final word on the TB bypass, lol. J/K, but it's my opinion, and you must admit it brings a valid point.

Re: TB bypass, flip side of the coin (neat)
 

That's simple enough. You put a shop rag on the throttle body to lean on, then you work on the engine. Or, you can wait until the engine cools down, then work on it. That reminds me of an experience I had when I took my Vette to a SMOG station. I asked the testing mechanic whether it was legal to put headers on my car and would it pass SMOG testing in California. He asked me, "Why do you want to put headers on it?" I said, "For more horsepower." His reply was, "If you're going to be running a catalytic converter and mufflers after the headers, you're not going to gain anything. You'll cut out some of the back pressure at the engine, but as soon as it gets to the catalytic converter and mufflers, it's going to be blocked up again, so what do you gain?" Comments?

Re: TB bypass, flip side of the coin (Netnarc2)
 

Well, the TB flows enough air for the engine so a little reduction in dia. won't negate effects of lower temps. And the area is cleaner and easier to work on the TB with the coolant lines disconnected.

Actually when you install FL headers with a hi-flow cat and hi-flow mufflers you will see some very nice gains. Just eliminating those pre-cats and going to a modern hi-flow cat on an L98 gives nice gains.

Re: TB bypass, flip side of the coin (froggy47)
 

Whether it is or not...the hose coming from the TB on my car sprung a leak and fixing it while bypassing the TB took a total of 5 minutes. Thats with taking my sweet time to tighten down the hose clamps and check to make sure it was not leaking a drop.

Bottom Line: If it works cool, if not....it doesn't decrease performance and takes just as long to not bypass.

Just my .02

Re: TB bypass, flip side of the coin (froggy47)
 

Here we go again! :smash:

Re: TB bypass, flip side of the coin (Netnarc2)
 

I bypassed mine and it still gets pretty darn HOT.

Re: TB bypass, flip side of the coin (froggy47)
 

It's just one less place for a coolant leak and one less thing to deal with when I have to remove the intake or thorttle body. The throttle body WILL be cooler if you do this mod. That's the whole reason GM put it there was to warm the throttle body. If they felt that the throttle body got hot enough under all circumstances they wouldn't have put it on there.

Now is the temperature difference enough to give you a performance increase? Who knows, who cares? It takes 5 minutes to do. I wouldn't go spend $20 on a kit to do it when $2 from a hardware store will get you the same effect. If you ever have to pull the intake or throttle body off just go ahead and bypass it. If you don't, then don't worry about it.

Re: TB bypass, flip side of the coin (froggy47)
 

I believe the real reason for heating the throttle body is to keep it from icing and possibly sticking open in cold climates. Agree?

Re: TB bypass, flip side of the coin (honas)
 

:iagree:

Re: TB bypass, flip side of the coin (bstirn)
 

I switched mine back because the hose was crowding my IAC and TPS and adding hose to reroute it would look clumsy. I noticed the plenum cooler for the first 20 min, after that it felt as hot as before.

What is the average time that a molecule of oxygen hangs around the plenum getting all warm and toasty ?
:D :smash:

Re: TB bypass, flip side of the coin (bstirn)
 

I also though about the coolant actualy cooling down the TB.

I left it the way it is, when I put in a bigger TB "one day" I'll probably won't put them back on.

By the way, does the 52 and 58 mm TB have the coolant conectoins also?

Re: TB bypass, flip side of the coin (TheStef)
 

Yes because you re-use the same IAC housing.

Re: TB bypass, flip side of the coin (neat)
 

And MY question is, what is the difference in the TB diameters at the two temperatures? Also, the difference in air flow, at equal temps, due to the difference in diameters? I don't, "admit it brings a valid point". Besides a possible hp increase, detonation resistance is increased by a cooler inlet temp. I agree with a previous post that states it isn't worth a $20.00 kit, but if you're in there, there is no reason not to. Good luck, and...

RACE ON!!!

Re: TB bypass, flip side of the coin (CFI-EFI)
 

Quote -----------------------------------------------
Yes because you re-use the same IAC housing.
-------------------------------------------------------

I'm pretty sure I know what housing you meen... but what does IAC stand for?

Re: TB bypass, flip side of the coin (TheStef)
 

Idle Air Circuit

Re: TB bypass, flip side of the coin (Goody)
 

Idle Air Control (solenoid)

Re: TB bypass, flip side of the coin (neat)
 

[QUOTE]Ok

The problem is that the cooler the TB, the smaller the hole is. thermodynamic expansion occurs when objects change temperature. QUOTE]

I don't think you can measure the difference between a hot TB and a cold one. Both will be 48mm or 52mm or 58mm depending on the size of the TB. Temperature of the air affects it's density. The hotter the air the less dense it is. Let's look at Phoenix Airport, There are times when airplanes are grounded because the temp has driven the density so thin that the jets can't produce enough thrust to generate enough lift. It's not because the intakes are changing size. Maybe in quantum physics there is a difference, but the changing size of the TB due to temp changes won't effect the intake of air, but the number of molecules that enter your TB is dependent on temp which drives the density. I know clear as mud.

Re: TB bypass, flip side of the coin (Strick)
 

I have the perfect solution for every body,

How about we just bolt up the TB coolant Intake hose and exit hoses to a small separate electric water pump and into a separate Radiator... completely separate from the other coolant system in the engine. :D

This would definitely cool the TB and keep nice an cool, but it still doesn't stop the air from getting hot if its going through the hot plenum, hot runners, hot Intake base manifold..... I honestly don't understand why removing the coolant hoses woudl keep the TB cooler.

Has any one here even mesured the actual heat on a TB with cooland and without coolant with a Laser thermometer or just a regular thermometer?

Maybe I'll still remove the coolant hoses one day just for the heck of it and to say I have done another free mod on my car. :cheers: :cheers: