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Okay, so, today, I did the throttle body bypass that ťhey say is good for approximately fifty or so horsepower. LOL I haven't posted on CF in a long time, so I thought I would do a " how to " write-up in case some noobs are interested.
Here is the hose connecter style 1/4 inch lead-free barbed coupling that I used. It was $ 3.10 at Home Depot
Disconnect the air intake at the throttle body to make space in order to work.
Disconnect the throttle body position sensor.
Disconnect the small coolant hose on the driver's side of the throttle body.
Disconnect the small coolant hose on the pasenger's side of the throttle body.
Attach both of the hoses, that you just disconnected, together, using the hose connecter style 1/4 inch lead-free barbed coupling; fastening and sealing each hose end to the brass coupling using the pre-existing OEM Corbin clamps.
Reconnect throttle body position sensor.
Reconnect air intake at throttle body.
Cover the throttle body coolant inlet and outlet ports with 1/4 inch caps or plugs.
It only takes 20 mins. Either get the hose connectot at a hardware store or buy the throttle body bypass kit online. Good luck.
So what’s your feeling on this, now that it’s done?
As for any HP gain I would say nil. But being here in Texas and in summer over 100 it has got to help keep something cool. Also to remove TB for cleaning is a snap now.
Well, thanks a lot. I was on the fence about doing this while my intake manifold & throttle body were off, and you pushed me over the edge to get it done. Unfortunately, though, my local Home Depot charged nearly $5 for the fitting! Gotta love SoCal sometimes...
Good. Glad to hear that I could be of help!
Nearly $ 5 for the fitting in SoCal? That's ridiculous. As you know, I paid $ 3.10 - that's in Canadian dollars. At today's exchange rate, it should have cost you $ 3.10 X .77 = $ 2.38 USD.
Last edited by John1990; Jul 18, 2022 at 12:00 AM.
C’mon, it’s at least worth 65 hp.
Add some E3 spark plugs and you are north of a 100 hp gain……
😊😂
Funny not too long ago I remember someone got on here and claimed his car had 500hp from bolts ons. Everyone asked what did you install. TB spacer added 30hp, KN filter 30, polish TB 100 ,etc. These were all MFG claims so he added all that from the ads and got 500hp. LOL
From: Philadelphia PA (Birthplace of the USA, UNESCO World Heritage City)
OP, thanks VERY MUCH for posting this. Here is a video before and after which shows intake air temps lowered by about 10%, and supposedly good for up to 6hp:
For anyone wondering why GM designed it this way in the first place, it was for driving in extreme cold climates of way below zero degrees freezing temps where the throttle body would "stick" on occasion (running the coolant through the throttle body would warm it up). So 99.9% of Corvettes don't need this and are better off with the bypass.
Last edited by ArmchairArchitect; Jul 26, 2022 at 03:38 PM.
From: Philadelphia PA (Birthplace of the USA, UNESCO World Heritage City)
So I went ahead and did the mod- one thing to be mindful of is how close the hose and clamps are to the water pump pulley once you connect the two hose ends; the clearance is very minimal and will probably touch/rub on the pulley occasionally when hitting bumps in the road. So I oriented the clamps to face away from the pulley, and for piece of mind, also chained two zip-ties to keep it away from the pulley:
But, instead of this you might be better off by running a new long hose all the way from the radiator to the intake manifold barb, for simplicity. But, each end is a different size apparently (radiator end is 5/16" I believe and intake manifold end is 1/4" I believe, based on research I did from other threads).
Also, FYI, I used a 5/16" barb instead of 1/4".
What did you guys use for plugs or caps on the two throttle body openings?
Last edited by ArmchairArchitect; Jul 27, 2022 at 09:51 AM.
What did you guys use for plugs or caps on the two throttle body openings?
Kinda random, but I used adhesive-lined heat shrink tubing. Nothing will get into the TB coolant lines and it wouldn't be a hassle to remove. Thinking it shouldn't degrade either, which I can't say the same for many vacuum cap options.
OP, thanks VERY MUCH for posting this. Here is a video before and after which shows intake air temps lowered by about 10%, and supposedly good for up to 6hp:
For anyone wondering why GM designed it this way in the first place, it was for driving in extreme cold climates of way below zero degrees freezing temps where the throttle body would "stick" on occasion (running the coolant through the throttle body would warm it up). So 99.9% of Corvettes don't need this and are better off with the bypass.
Nice, man. Good score.
In fact, more than a few auto manufacturers employ this method of diverting coolant through the throttle body; thus warming it; in order to prevent the butterfly valve in the throttle body from sticking open as a result of condensation from humidity around the throttle body having frozen into ice as temps fall below freezing. The practice of bypassing the throttle body has been around for awhile employed by GM, Ford, VW, Nissan, Toyota and even Lotus.
Throttle Body Bypass How To
