Slowmaro95Z28

I'm pretty set on getting a Professional Product 58mm tb since I've heard nothing but good things about them and they are extremely cheap but the place I was getting it from told me they are on backorder. Does anyone know who sells these? Maybe a sponsor has them. I really need to get one soon since it's the last part I'm waiting on before i get re-tuned. I would be open to another brand if the quality and price were comparable. Thanks.

Prototype007

iTrader: (2)

I had to wait on my Prof. Prod. 58mm throttle body and I must say it was well worth the wait!!!

Schweet97Z

iTrader: (35)

I have an LPE 58mm TB for sale. I probably wont be able to match the price of a PP TB but I will gaurantee you the quality of the LPE throttle body is better than any BBK, Holley, etc... Shoot me a PM if your interested.

Slowmaro95Z28

Everyone seems to be sold out and waiting for more so I'm just going to wait for mine too. Thanks anyway. I'm very impatient when it comes to buying parts.

Cross

iTrader: (10)

Hmm I got my Holley new for 250. Seems to be less favored but looking it over it seems to be quite well made compared to some of the other TB's I have seen and used for other cars.

LT1_freak!

iTrader: (8)

problem with the holley is when you full throttle it throws an error that your throttle positioning switch is messin up and it retards your timing and it messes with your shifting points (A4 tranmissions). I HAVE that problem and so did lots of my friends.

BattleShip

Not what you want to hear, but I would run a 52MM.

The 58MM loses driveability and does not make anyore power to make up the loss of street manners. MAYBE it will make you .05 faster in 1/4 MAYBE, but I guarantee it will make the car less mannered on the street.

I have made >600 RWHP and not used a 58mm, I took it off and sold it and that was on a drag only car.

I tune my own so I can and do 'improve' the driveability, but it is never pleasant with a 58mm.

Good luck

Cross

iTrader: (10)

I am now trading my 58mm for a 52mm

BattleShip

Each setup is different. Some could make more power BUT there are no free lunches. It is the pay me now or pay me later...

If you talk to any engine builder they will say the top two mistakes people make are

1. too large of a cam
2. too large of a carb (our case TB)

Hey I lke the little bit more, but some changes don't add they subtract. My DD is a Buick Roadmaster with a home made rear turbo. I tried just a 52mm it SUCKED! Was a pain to drive would it make more power? I will check at track to see if it will pickup but my belief it won't.

And remember my tuning is free...Another bit of trivia you MUST retune for an automatic when you go to a larger TB. The pressure tables MUST change or you will damage tranny!

StealthFormula

iTrader: (35)

I would go on ebay you can find them there. I had a Prof. Products and never used it then sold it and later bought a Holley. The Prof. Products looked nice but not quite like the Holley but for the price its a nice piece. Check out byunspeed as well I know they them.

MEAN LT1

iTrader: (2)

The subject of having a too big a of a t/b has been discussed in depth before. There is no such thing as having too big of a t/b and the motor is only going suck in as much as as it needs. Now there is too small of a t/b that will affect power. Myabee your talking about driveability of some t/b's?.

kinglt-1

iTrader: (26)

What drivability issues does a 58mm cause?

Formula350

iTrader: (3)

Apparently 58mm on a motor that doesn't need that much air, you lose a bit of TQ. How much probably varies from motor to motor and is probably also why no one has said exactly how much.

And I know you know Battle, but only 94+ Autos need the programming for the trans since 93 (and 92 vettes) use the 700R4/4L60 non computer controlled tranny.

The stock 48mm TB is good for like 450hp, but that doesn't mean a 52mm won't help out. Also with the more recent (so it seems) stock TB porting of 54mm that fills a bit of a gap between the 52 and 58, as well as giving more while not having to port the intake. For 58mm you SHOULD port the intake openings. I've actually came across a few people on here who haven't and still noticed an improvement, but I would assume the ridges would cause air turbulence and I can't see that being good for efficiency and making power heh

This is my opinion on TB's (don't mind the fact I have a stock motor and 58mm, it was left over from my TPI Firebird) is this (everything from previous MM add to next):
48mm for stock to cat back, CAI and free mods, 52mm for bolt ons, smallish cam and tune, 54mm for mild cam ported intake/heads and dual exhaust 58mm for wild cam and aftermarket heads with either dual cutouts or basically open headers.

Again, my opinion, open to suggestions and not to be taken as a "fact" list. I won't get into forced induction since that isn't my area, but one guy on here ran 420hp on a completely stock motor (tb, intake, injectors all except headers and catback) that was supercharged.

kinglt-1

iTrader: (26)

^yea I agree, my car put down 426whp with the stock lt-1 w/ stock manifolds w/ a p1sc procharger on 8lbs boost. That was with 25% loss of compression on #8 cylinder. I had it dyno'd after a head gasket issue wich turned up a broken ringland.