Throttle Body Coolant Bypass

[jbaker]

Ok, the truth here. I've heard a few different stories, but, is it worth the couple minutes that this job takes?? With summer coming, and the real heat, I'm wondering if this should be done?? A lot of people think "if it was MEANT to be bypassed, GM would have done it that way"... But, if that were true, "mods" would never have come along, either... So I want some honest opinions..

Jeff

 

[vader86]

GM put it in to keep the TB plates from icing over in extreme cold. At any other time it would heat up the intake charge, and the plenum by conduction which also adds to the heating of the air.

Its proven to help L98s, whether or not it helped anybody with an LT1, i dont remember.

 

[Ken]

If you live and drive in a warm climate, the coolant passing through the throttle body is not necessary. It is only there to prevent icing of the throttle blades; incoming ambient air rushing past the blades chills them. It won't decrease themperature much if the throttle body is bypassed, but in racing "by-the-rules" applications, every little bit helps.


_ken

 

[Rain]

Going to do mine next week.
Also looking at the Gadget Man's rear hatch vent. Cheaper than the ones in the catalogs.

Drain kits for the rear hatch are going to be ordered as soon as I get the go ahead financially.(as well as a wind jammer)

 

[muddywaters]

TB by-pass

Hi, My neighbor has a hot little GM type truck, I think it's a cyclone, he claims it hasn't been altered at all , it has the same TB my 88 vette has, but there are no heater hoses connected, the connections are there but no hoses are routed to them. He bought the truck new and claims if the TB was by-passed it was at the factory.

 

[jeepie]

I don't know if it helps performance or not but I did it so I don't have to mess with the coolant if I remove the TB for cleaning etc. I never understood the warming the TB idea, if your motor is ice cold so is the coolant and I don't see how cold water is going to heat anything untill the engine warms up, but by then the TB will be warm from the engine heat anyway. Just my $.02.

 

[JT ZR-Won]

If you live and drive in a warm climate, the coolant passing through the throttle body is not necessary. It is only there to prevent icing of the throttle blades; incoming ambient air rushing past the blades chills them. It won't decrease themperature much if the throttle body is bypassed, but in racing "by-the-rules" applications, every little bit helps.

Ditto on what Ken said. You won't notice a difference in performance but every little bit counts. I've done this mod to both Corvettes that I have owned.

Jay

 

[Corvette-Pilot]

I don't know if it helps performance or not but I did it so I don't have to mess with the coolant if I remove the TB for cleaning etc. I never understood the warming the TB idea, if your motor is ice cold so is the coolant and I don't see how cold water is going to heat anything untill the engine warms up, but by then the TB will be warm from the engine heat anyway. Just my $.02.

It's the "venturi" effect.
It is why in small piston airplanes they have "carb heat" controls for when you come in to land. You actually are more likely to get carb icing in the spring/fall than dead of winter because there is more moisture in the air. The cold dry air of winter isn't as big a deal. Sorry got a bit off track.

As for GM, I would think it is more of a smog issue. Once the water starts to warm up it will then warm the intake air faster so the car wont run rich as long.

If a bypass helps

 

[sothpaw]

jbaker,

Keep in mind that GM needs to make a product that can be sold
in Canada or Alaska.

If you leave the car out, ie, not garaged, and start it in the
winter at 0 deg F, then you might have a problem. I would
not advise the by pass in that case.

I bypassed mine, but I start from a garage and I don't drive it
anywhere when it is substantantially below 32F.

Yes, it is does make a difference on the LT1. I proved it. I have
the drag race slips. I did the bypass and a fuel filter, and I got
like .25-.3 s faster time. Keep in mind, I also have a 160 stat
and fans on early (170? hyper tech chip).

I will only drag race the car at 180-185 F oil temp. Above that,
I will suffer performance degradation--I won't get a best time.

 

[jbaker]

Well, today I went to 3 auto parts stores, and no one had a 3/4" to 1/2" fitting to join both hoses together. They told me to go to a plumbing supply house.. Seems like SOMEONE should have one ?!!?!? I drained the fluid tonight, so it would have been a good time to do both, but oh well

 

[rrubel]

Go to Home Depot or Wal-mart and buy a garden hose splice kit... $3 for the splice and two clamps.

I may have an extra in the garage if you still have trouble finding one.
[RICHR]

 

[warren s]

You dont have to buy anything, just connect the hose like in the picture. The bypass and a 160 therm, and a fan switch (just jump the relays) will be good for at least a 10th, but the real gain is in the throttle response you will feel. When it gets hot out the car will feel as reaponsive as a coooler day.