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Throttle Coolant Bypass - Another Question

D

DWC

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It seems to me that there might be a way to install a heater shut off valve on the coolant hose that feeds through the throttle body. I have used such a valve on a previous 1982 Corvette to shut the hot water off from the dash area in order to improve cooler temps during the summer months. Would it be feasible to install such a shut off on the longer hose in front of the throttle body. The draw back seems to be that you would have to open the valve during the winter months to get hot water into the heater core in order to run your heater. I have a 1996 and have already bypassed the throttle body. But I understand that the purpose for the flow of hot water through the throttle body is to prevent it from icing or freezing in bitter cold temperatures. Any ideas or reponses?
 
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I bypassed this on my 95, I just connected the hose to the inlet on the passenger side of the TB. The temp. has ranged from 15 to 99 since I did it. Though I was not "driving" my Vette during the winter months I did go for some test drives in the cold before the road was salted.

I found no problems, as the throttle will heat up way beyond freezing in a small amount of time weather the bypass is there or not. I would not go through the trouble of devising a system to switch the coolent flow on the fly.
 

FX GS

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I have the bypass also. Although I do not drive my car much during the winter months I have had it out in 20 degree temps without any problem. Frankly, I believe the engine throws off enough heat so you don't have to worry about freeze up
 
D

DWC

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Thanks guys for your responses. I agree with you that the engine temps should always be sufficient to take care of this concern. I usually don't drive much if the weather becomes bitter since my 96 is not my daily driver. Appreciate your replies.
 

WhalePirot

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My Corvette guy claims that ther will be little or no performance boost from bypassing the TB, as the air is moving so fast, it won't heat up much. He's usually right, but not always.

Does anyone claims a noticeable improvement?

:w
 

vigman

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When my car was HOT

The bypass made a SLIGHT difference

Vig!
 
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If you do the bypass in conjunction with a K&N air filter and an open air box lid, a throttle body air foil ,a low temp thermostat like 160, and a overide switch for the fans, you can pick up about 2 tenths in the quarter.

Considering that all the above costs about 100 bucks and you gain 2 tenths (about 30 feet at 100 mph) it is a very good performance return for a slight investment.

As for the air traveling to fast to get heated by the tb, on my car when i did not have the bypass it only took a few minutes for the entire intake manifold to get to hot to touch. (at a coolent temp of 190)Maybe the 3 inches of tb would not have an effect but if the entire length of the intake trackt is superheated it may. After the small changes the top surface of the manifod never gets that hot and with the fans on the coolent temp never gos over 185. My car also has an automatic and jumpimg the fans and lowering the coolent temp also lowers the the trans fluid temp, andhelps keeps all the rubber hoses and plastic connecters on the top of the engine from becoming brittle
 

Rob

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I would be careful about installing a coolant bypass. The reason why coolant flows through the throttle body is to help warm the TB up colder climates and prevent ice crystals from forming when air rushes in and the TB is cold.
 

Hib Halverson

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I've dyno-tested the K&N replacement filter for 90-96 C4 more than once on an engine of 500hp and there's never been a performance change. In that application, the major advantage to the K&N is that it can be reused. Interestingly, the stock C4 filter system is pretty good, once you open up the air filter top, that system, regardless of filter type poses little or no restriction. We a/b tested an open element/K&N/stock air box and no air filter assy at all and the numbers were virtually the same.

TB air foils do nothing on stock or near-stock engines

The two tenths is coming from a combination of the open-element air filter top, the TB coolant bypass and improvment to the cooling system's and, perhaps in this case, the improvment to transmission peformance by running a little bit cooler fluid.

The two tenths improvement....how many passes were made to see that average?
 

WhalePirot

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dyno-tested

TY TY TY!, Hib. Guys like you are who I have learned to listen to. My Vette mechanic is the same, as he tells the truth, from his experience, doesn't just install anything and everything that claims improvement. I stayed away from one Vette 'expert' in San Diego, who's approach to improvement was BIGGER is faster.

Debunks a lot of it all, 'eh? I notice a large degradation in hot performance as I put more miles on my 406ed "84. It just doesn't go any where near as well as when cool.

I have taken no shortcuts with this re-engine project. I now find that I more cooling capacity, which should alleviate some of the performance loss.

I think we need to 'feel' improvements with the mods we make, and genuinely think we feel them. It's nice to have scientific input.

I tried split-fire plugs very briefly (took them back) as, while they improved performance over my old plugs; a set of regular plugs performed just as well. The same felt true with the K&N (well made product) filters on my Suburban, BMWs, motor home, Corvette, etc.; nice to have a nondisposal type, but not noticeably faster.

See the Tornado thread for more BUNK.

:w
 
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I ran the the car at Raceway Park a total of 8 times in 2 weekends. 4 passes before and 4 after. The ambiant temp was 76 degrees on both days anf the relative humidity was the same.

My best tiem on a stock engine was 16.616 and after the mods. is was a 13.40. The first 4 passes were all inthe 13.6 13.7 range. The next 4 after the mods were in the 13.4 13.5 range.

After having a few Gm cars and doing air filter- air box mods I always notice a mid range performance improvement, unless the stock intake is very restrictive in the first place there is not a big improvement. Usually once the velocity of air is already high such as over 40mph. I dont know how that would be read on the dyno where engine rpm changes but incoming air velocity is constant on a stationary car.
 

WhalePirot

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If you're talking 'ram air', I doubt there's any measureable effect until well past 80.

A cooler, denser air feed would seemingly make more diff.

:w
 

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