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Berg
05-24-2007, 10:54 PM
What is the purpose of running coolant through the throttle body?

I've always wondered that. Is it an emissions thing? Would there be any advantage to not having the coolant running through the throttle body?

Cheers,
Berg

T-spoon
05-24-2007, 10:57 PM
Actually, I *think* it's to keep the throttle plate mechanism from icing up in cold weather and may have a cold start benefit. Um, as far as useful to NOT have it.. if you don't have much cold weather to worry about.. there may be a tiny benefit to intake charge temperatures without it, but don't know that it would be enough to make any real difference. The biggest benefit would be fewer hoses to replace down the road if that outweighs the usefulness of them being there.

Berg
05-24-2007, 11:06 PM
Thanks. When I put my engine back together I think I will leave this out. I do have cold weather here (it snowed today!), but I dont plan on driving the car too much when it's cold out.

Cheers,
Berg

T-spoon
05-24-2007, 11:10 PM
Thanks. When I put my engine back together I think I will leave this out. I do have cold weather here (it snowed today!), but I dont plan on driving the car too much when it's cold out.

Cheers,
Berg

Well, double-check that there isn't a more important reason to have it before you decide to leave it out, I'm not 100% sure there isn't something else.

Futant3
05-25-2007, 12:13 AM
Quick google search pulled up a lot of info.

Yes it's used to keep the valve from freezing up. There are lots of cars that don't even have a coolant line through the throttle body. Found some people that have disconnected it even with winter conditions and the only thing they noticed was a little impact on the idle when engine was cold.

Theoritically disconnecting it would let you have cooler air enter the engine but the gain seems to be unnoticable. Found a thread on a VW board where the guy did a dyno connected vs. disconnected and there was no difference in performance on the dyno. But of course do thorough research before you decide...

Hiko
05-25-2007, 06:03 AM
Found a thread on a VW board where the guy did a dyno connected vs. disconnected and there was no difference in performance on the dyno. But of course do thorough research before you decide...

Outta curiosity, could you post a link? I googled it and couldn't find that thread. I ask because if the guy did a dyno run on a warm engine, then did the bypass, he's obviously not going to gain any horsepower because the throttle body would still be hot.

T-spoon
05-25-2007, 06:19 AM
Well I mean, I think the big issue here is that the throttle body sits on top of the engine and it's metal. I doubt there's going to be much difference in temperature the more I think about it between having the coolant passing through it and not having it passing through it. Once the car has been running, the throttle body will be hot. It would take actual temperature readings of the metal itself and the intake charge to see if there's a difference while operating and if that difference is going to be noticable at all. It would be interesting if having the coolant actually keeps it at a stable and on average lower temperature.

Futant3
05-25-2007, 06:54 AM
Outta curiosity, could you post a link? I googled it and couldn't find that thread. I ask because if the guy did a dyno run on a warm engine, then did the bypass, he's obviously not going to gain any horsepower because the throttle body would still be hot.

Looking for it again but not finding it, I think I searched something like "coolant through throttle body" or along those lines. Anyway he didn't really include any details about the procedure used or even charts. But you bring up a good point that a warm engine is a warm engine coolant bypass or not. I'd think that unless you've got a serious system to cool the airflow through the TB no matter what the engine temp than any difference is going to disappear as soon as the car is warm.

grayscale
05-25-2007, 12:05 PM
There is actually a bit of info about this in our own NA forum. You buy bypass kits for some cars, and some cars actually respond really well to the bypass. Nuke has touched on the subject several times, and it has been suggested that our cars respond well to it.

StockGT92
05-25-2007, 07:01 PM
I had a 5.0 Mustang that picked up 5 hp/3 ft.lb at the rear wheels from disconnecting the coolant lines going to the throttle body.

Guess what I'm going to be doing during my lunch today? ;)

I'll let you guys know how it works.

Luni
05-25-2007, 07:14 PM
Im gonna be doing this on my MR2 while the engine is out.

Im lazy tho. I KNOW Im not going to get any performance out of it. I just know thats 2 less pieces of rubber to replace that could go bad.

Berg
05-25-2007, 11:10 PM
I did a google search and found a trans am forum where some guy did this. He took it a step further and ran an air line to the front of the car to try and "ram air" cool air through his throttle where the coolant is supposed to go. Seems a little silly to me....

I just want to make things simpler.

Cheers,
Berg

Futant3
05-26-2007, 02:24 AM
Interesting that you saw a gain on the 5.0 I might have to try it on that one. Even with no gain I'm with Luni that less things to break is always good.

StockGT92
05-29-2007, 03:51 PM
Yup, it worked well on the Celica. I did it over the weekend and throttle response seemed to get a little better, and the car "felt" a little stronger. I'm not going to bother with the dyno in this case, going from 135hp to 137hp is not something I'm going to go spending money to confirm. :lolhittin

Maybe now I'll just install a little dry shot on the car.... here we go....

Conrad_Turbo
05-29-2007, 03:57 PM
Doing the delete, in my mind, would strictly improve reliability, less parts = less things to break/leak. The Hp gains would be minimal but if you live in a warm climate then I wouldn't hesitate to take that plumbing off the car, where I live...no way in hell I'd take it off. :D

StockGT92
05-29-2007, 05:21 PM
where I live...no way in hell I'd take it off. :D

Yeaahhh I'll probably hook it back up when winter comes to Chicago, although last winter it never really got too bad here. Global warming anyone?

Next thing you know, we'll be waterskiing in Saskatoon in December.

Conrad_Turbo
05-29-2007, 07:45 PM
Yeaahhh I'll probably hook it back up when winter comes to Chicago, although last winter it never really got too bad here. Global warming anyone?

Next thing you know, we'll be waterskiing in Saskatoon in December.

:laugh:

Just use a couple small inline ball valves (McMaster & Carr probably has quite a few)to shut off the flow to the TB and route it back. That way you can switch it on and off between seasons...I think I'm getting old and lazy so that's what I'd do. :D

alltracman78
05-30-2007, 01:26 AM
although last winter it never really got too bad here. Global warming anyone?

Next thing you know, we'll be waterskiing in Saskatoon in December.

Sheeit

It was REALLY cold here last winter.
And it's nice and cool right now.
We're in the 50s ATM.
Weather changes alot.

alltracman78
05-30-2007, 01:27 AM
Oh yeah, I have mine removed too.
No problems through a Boston winter.