Bigger TB Gain?
Burning Brakes
Joined: Sep 2004
Posts: 869
Likes: 1
From: Bradford Pa
i cannot comment factually, but i can say this. in order to warrant a larger throttle body on any vehicle you must first have done mods to increase the airflow beyond the capabilities of the stock unit before you will see any significant gains. I.E. heads, intake, cam, stroker, etc... or you should be utilizing forced induction. I have seen several people run perfectly fine with a stock unit on a HIGHLY modified engine.
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Originally Posted by Fubar569
i cannot comment factually, but i can say this. in order to warrant a larger throttle body on any vehicle you must first have done mods to increase the airflow beyond the capabilities of the stock unit before you will see any significant gains. I.E. heads, intake, cam, stroker, etc... or you should be utilizing forced induction. I have seen several people run perfectly fine with a stock unit on a HIGHLY modified engine.
If you put a 52mm on a stock engine, the possibility exists that all you'll do is lose some low end torque. This is because without the engine NEEDING the extra breathing capacity you'll just slow down the velocity of the intake air charge in the manifold by using a larger than necessary diameter.
Team Owner
Joined: Sep 2001
Posts: 62,171
Likes: 1,735
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
I wish people would say what YEAR and what theyve done or are planning to do to the car before they'd ask this question, since its been asked 10 million times.
In very few cases will it help a 350, doesnt matter if its LT1 or L98. I have seen a couple people with LT4's get something out of it, but then I recall many that havent. The engine cant use all that the stock 48 supplies anyway.
In very few cases will it help a 350, doesnt matter if its LT1 or L98. I have seen a couple people with LT4's get something out of it, but then I recall many that havent. The engine cant use all that the stock 48 supplies anyway.
Burning Brakes
Joined: Apr 2005
Posts: 1,110
Likes: 0
From: JUPITER FLORIDA
i have a stock throttle body on my 86' and i have bigger runners, base manifold, vortec heads and a medium cam. car runs decent right now. i am debating on weather i need one, and im gonna try to do the math to see if i can use the extra air flow. it might be a while before i get it but when i do i will let you know!b 
Racer
Joined: Mar 2005
Posts: 288
Likes: 1
From: Maple Ridge British Columbia
My stock 48mm throttle body was shot, so I'm replacing it with a 52mm from TPIS. I have to replace the TB, so I might as well do the 52 as I plan to do intake modifications down the road. However, if my stock TB was still good, I wouldn't replace it.
