Throttle body bypass worthwhile?
Thread Starter
Advanced
Joined: Jan 2004
Posts: 96
Likes: 0
From: Yardley PA
Throttle body bypass worthwhile?
All:
Except for the cut airlid, I've never considered any of the other "free mods" worthwhile. However, lately I've been kicking around the idea of doing the throttle body bypass. In theory I agree that it makes sense - cooler air entering the combustion chamber is more dense hence more horsepower. But realistically speaking, how much can a hot throttle body really effect the temperature of high velocity air moving through it? With that volume of air I can't imaging it impacting the actual air temperature more than one or two degrees fahrenheit. With this in mind, how much are we really getting out of the throttle body bypass?
I've been wrong in the past so maybe I'm way off base here (I'm no physics major). Anyone have any evidence supporting (or disproving) my theory?
Except for the cut airlid, I've never considered any of the other "free mods" worthwhile. However, lately I've been kicking around the idea of doing the throttle body bypass. In theory I agree that it makes sense - cooler air entering the combustion chamber is more dense hence more horsepower. But realistically speaking, how much can a hot throttle body really effect the temperature of high velocity air moving through it? With that volume of air I can't imaging it impacting the actual air temperature more than one or two degrees fahrenheit. With this in mind, how much are we really getting out of the throttle body bypass?
I've been wrong in the past so maybe I'm way off base here (I'm no physics major). Anyone have any evidence supporting (or disproving) my theory?
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Originally Posted by stick91
I've never considered any of the other "free mods" worthwhile.
-JRC-
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
My major reason for doing the TB coolant bypass was similar to the reason that I did the MAT relocation into the air filter lid...convenience.
Now whenever I need to remove the TB I don't have to hassle with the coolant hoses. And of course the TB and plenum don't get quite as hot as before and both seem to cool off quicker without the coolant inside the TB.
Now whenever I need to remove the TB I don't have to hassle with the coolant hoses. And of course the TB and plenum don't get quite as hot as before and both seem to cool off quicker without the coolant inside the TB.
Drifting
Joined: May 2004
Posts: 1,543
Likes: 1
From: Levittown NY
Originally Posted by 65Z01
My major reason for doing the TB coolant bypass was similar to the reason that I did the MAT relocation into the air filter lid...convenience.
it was nice being able to take off the tb to clean it without making a mess. performance wise i don't think it does anything.
Safety Car
Joined: Jul 2001
Posts: 3,833
Likes: 0
From: Orange County California
Yes, its very worth while.... Its one of the easiest mods to do... and while you probably wont notice an performance gain. There are times when it will prove to be a difference. Besides, like they said above, it kinda makes everything in the engine compartment a little easier deal with.
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
I did it, and like the others I agree that the best gain is in the work ease and cleanup of the TB.
However, it was free and easy, so why not? I believe the accumulation of all the free mods like the TB bypass, frisbee removal and cut lid, along with a couple of cheap mods like K&N filter, TB airfoil, relocation of IAT sensor, pre-cat removal and cat gutting (if in a sniff friendly state) all add up and do make an overall difference. More so even if accompanied by a chip, high performance ignition, performance injectors, an AFPR, and some porting and removing of restrictive blocks in plenum and runners.
However, it was free and easy, so why not? I believe the accumulation of all the free mods like the TB bypass, frisbee removal and cut lid, along with a couple of cheap mods like K&N filter, TB airfoil, relocation of IAT sensor, pre-cat removal and cat gutting (if in a sniff friendly state) all add up and do make an overall difference. More so even if accompanied by a chip, high performance ignition, performance injectors, an AFPR, and some porting and removing of restrictive blocks in plenum and runners.
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
[QUOTE=stick91]All:
With this in mind, how much are we really getting out of the throttle body bypass?
QUOTE]
It is a relatively easy mod, but the gains will be pretty minimal. I don't remember the specifics, but it has been tested in a car mag/tv show with something like 5hp gain.
I have done it, but I think the gains are directly related to how hot the engine is running. If you are running a 160 stat with fan control so your motor temp is say 180 you won't see near the gain as if the motor temp is up around say 220.
Also it is kind of a proven fact that a hot intake intake system will heat the air enough to deteriorate performance, that is why racers ice their manifold between runs. Not the same thing, but feel how hot the air is coming out of the engine bay after the fans have pulled the air thru the radiator & over the engine...so I don't know the spefics, but yes a hot intake will heat the incoming air significantly.....
With this in mind, how much are we really getting out of the throttle body bypass?
QUOTE]
It is a relatively easy mod, but the gains will be pretty minimal. I don't remember the specifics, but it has been tested in a car mag/tv show with something like 5hp gain.
I have done it, but I think the gains are directly related to how hot the engine is running. If you are running a 160 stat with fan control so your motor temp is say 180 you won't see near the gain as if the motor temp is up around say 220.
Also it is kind of a proven fact that a hot intake intake system will heat the air enough to deteriorate performance, that is why racers ice their manifold between runs. Not the same thing, but feel how hot the air is coming out of the engine bay after the fans have pulled the air thru the radiator & over the engine...so I don't know the spefics, but yes a hot intake will heat the incoming air significantly.....
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Stick: If you are looking for a HP gain from a TB bypass, do not do it! However, if you would like to "clean up" a congested area of you engine, consider the bypass. As mentioned in above posts, working on the engine (in the TB area) becomes much easier.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Instructor
Joined: Aug 2004
Posts: 109
Likes: 3
From: Just North of Boston Mass
I too was skeptical. But:
LT4-Bud is exactly right do the TB bypass in conjuction with a low temp themistat and you will FEEL a big difference.
I DID! It really woke up my 85. Also take advantage of all the free mods per Skateparkdave you'll be gald you did.
LT4-Bud is exactly right do the TB bypass in conjuction with a low temp themistat and you will FEEL a big difference.
I DID! It really woke up my 85. Also take advantage of all the free mods per Skateparkdave you'll be gald you did.
Team Owner
Joined: Jul 2003
Posts: 24,650
Likes: 8
Gut and descreen MAFS
TB Bypass
Open lid, and K&N filter
Adjust TPS to 0.65v @ idle
Gut cat(s)
Performance mufflers or straight pipes
TB Airfoil....DOES NOTHING
Get a Pulley Kit <-- Future mod for me
Eliminate the AIR pump <-- Future mod for me.
Wont get a lot of HP or Torque, but I got a nice SOTP increase
TB Bypass
Open lid, and K&N filter
Adjust TPS to 0.65v @ idle
Gut cat(s)
Performance mufflers or straight pipes
TB Airfoil....DOES NOTHING
Get a Pulley Kit <-- Future mod for me
Eliminate the AIR pump <-- Future mod for me.
Wont get a lot of HP or Torque, but I got a nice SOTP increase
