Hambone 7

hye guys, i was wanting to upgrade my stock throttle body. its gummed up with deposits that have been left from the EGR and the breather tube.(plus its ugly, and im not dropping cash for a worthless aluminum cover) i have removed both and cleaned the intake as best i could since i have had the car(!EGR & valve cover breather). Anyway, i was told by some guy on another board that you wouldnt see a gain, most likey a loss in power from installing a throttle body on a stock internal LT1. i have almost every bolt on you can have with the excption of a tb. i want the holley 52mm. opinions?

-PEPE-

iTrader: (10)

IMHO: if your running your stock 48mm tb, you'd have to port your intake while it's off for the 52 tb. I'd also recommend intake/injector porting. I'd say save your $$ and buy a cam/springs/roller rockers first then a TB. You might see a little gain with stock internals but it would better match up with having at least a cam in your lt1.

Hambone 7

im at school and cant exactly tear it apart for a cam install.

93turboLT1

Many guys stick with the stock TB up and over 400 NA horsepower. I have a stock one on my 383 LT1 works perfect, and have seen dyno graphs with 408rwhp through a stock throttle body, so personally I think it is a waste of money until your in that kind of power range....i'm with Brett, you can get a roller Cam/spring setup for the same price and see up to 75 hp gain over maybe 5 hp with that TB. save the money till you have the time.

Hambone 7

i found a hot cam kit with everything included, unused and under $400 im investing in it.

dmoor88

you dont have to port your stock LT1 intake for a 52mm TB. the stock intake is already opened to 52mm. now if you went with anything larger youll have to port it.

stock 48mm TB's are good to ~425rwhp. I personally stepped up to a 52mm TB a long time ago just cause i came across a stock ported one for a great price. for most setups, a 52mm TB is plenty

LT1 Guy

Hmm! I did not know this!

dmoor88

yessah.

ks my ss

if you are gona spend money on a new tb why not get a 58mm? i am still just boltons and jumped to the 58mm. it hasnt hurt me at all judging by my dyno #s and track times.

Gangly

58 TB wont hurt you at all, but it wont really help you much either as a bolt on car. a 52 mm tb will creat just as much power as a 58 mm tb on a bolt on car, yet both will create more than stock. many people have tested all three and many of them have come up with dramatically different results. You cant just guess at it. you need to look at your entire setup. is your cam taking huge slow gulps of air or is it taking small gulps of air but at a higher pressure? something as small as that will determine which ould be better. the 52 may allow more air into the motor because tis a smaller opening and creating a higher air velocity while the 58 mm tb is bigger which would allow more air into the intake, but at a slower speed. Your combination has to be balanced and one would serve better than the other on a different setup. ith your bsically stock setup, the 58 is too big and the 52 would prolly gain youa little bit more hp, ut if you were ever to go with a high revving, radical setup, the 58 would best suit your needs to keep from choking off the motor.

METALBEAST

iTrader: (1)

58 mm Tb is going to be overkill. Our engines displace 350 in^3 every 2 revolutions or 0.2025 ft^3. Even revving up to 7000 RPMs, that is only 7000 RPMs * (0.2025 ft^3/2R) = 708.9 CFM. The 58 mm TB our rated at 1000 CFM, 52 mm TB is rated at 750 CFM , 48 mm is rated at 550 CFM if I am not mistaken. A 52 mm would be more than sufficient.

ls1fbod

He's completley right, 52mm would be more suitable for ur LT1.

94Formula/TA

Stock TB bores on the intake are actually 54MM that's why AZS&M makes a 54MM TB. The reason why you see 52MM TB's is that going much further than that on a stock casting isnt a good idea.

I'd go for the 52MM if I were you.

Rich

TwoFast4Lv

iTrader: (8)

I and many others have dyno'd a 20-25 RWHP gain with the 58MM TB. It is domumented and argued a million times over but Dyno Sheets do not lie

Jordon Musser has a bunch of good info on this also. There is a reason he was running a Mono blade

BTW If you do decide to go with a larger TB it would be advised to re-tune the trans tables for it Many will get by ok with a 52mm but once you go larger the chance of killing the trans increases greatly

Good Luck!

dmoor88

yeah as long as you have the power to utilize a 58mm TB. a big cam and heads, I say, would be the minimum requirement for a 58mm TB. anything less would be a waste.