I'm considering ordering an aftermarket throttle body. First which kind and how large would be the best.(3.27 gears, headers). Next question, I may get an air foil first, will I still be able to use the same air foil on an aftermarket throttle body?

 

Some aftermarket TB's come with the airfoil. You should check out the one you want to buy first, and see if it has one.

 

Can you recommend one? BBK, Edelbrock, Holley? I'm new to TPI, so I need some good advice.

 

I think slp's has the air foil with it. I dont think you can go wrong with any of those brands. What is your price range?

 

You don't need a TB until you're into the heads and cam, period.

If you're going to buy an airfoil, the only worthwhile purchase is the SLP unit. It's the cheapest, and spening more money on a fancier piece isn't going to do anything more for you.

AFAIK all aftermarket TBs come w/ an integrally cast airfoil.

Interestingly, the airfoil in these TBs is a simple flat design like the SLP piece. If a big fancy fin was worth something extra, don't you think one of the TB makers would have caught on and used it, at the least as marketing fodder?

 

Good points ED, but, consider these things and tell me what you think. For one, I noticed in your signature that you have a 305 which condierable less fuel and air than a 350. So in therory, since they have the same sized stock throttle bodies, the 350 would gain more by going to a larger one than the 305 would. One example is that I noticed you are also using the smaller primary headers for the 305. Also, I am going to install a cam, but I also have a hot short block I'm building on which I am eventually going to put my TPI, so it wouldn't be a total waste to purchase and use the aftermarket one on the stock motor for now. How much is the SLP and what size IF I get one sometime would I need. Is the 52mm the best for street use in a 300-350 hp motor? Thanks for the advice, I more than likely will just go with an airfoil for now since you told me about the SLP.

 

I bought the BBK unit. You dont need and airfoil, like Ed said it comes cast in their already. Your theory sounds good on paper but in real life a bigger tb doesnt really help. The 502 made gobs of power using a 48mm tb(stock). Is your 350 gonna need as much air as a 502?
Later Barrett

 

Ha Ha, I knew someone would pull the 502 thing outta their hat!!! Well yes and no is the answer. The 48mm would make better stop light to stop light perfomance, but the bigger is better theory would hold true in th 1/4 mile. I'd lose on the bottem, but gain mph on the the top. well I guess for now an air foil will do me just fine

 

On a strong stock L98 (14.0) a TB is worth maybe a tenth if you are actually doing a fair comparison (i.e. not skewing the numbers)

You'll pick up a lot more by swapping cams, or putting the money towards good headers, heads or intake stuff. And don't forget a torque converter and PROM tuning equipment and just keeping it running at it's peak. Then you worry about trinkets like TBs.

I understand people like doing the easy stuff. But thats not where the gains are, especially for the money spent. If it's all part of a bigger plan, thats fine, build with that in mind and don't worry about anyone else. Normally when people ask an open ended question that also involves buying an airfoil ( ) they're not talking about heavily modded cars. And i still covered that in my post that you should be well into airflow mods if you're spending money on a TB.

 

cool....well like I said I have a serious big boy engine on the stand in my garage, but I just got this car, and A.) It's an '88 with only 100k(still runs strong), so no need for the engine yet, B.)Before I do the engine, I wanna get all the other things in line such as bolt-on's, and C.) I'm spending a grand on a tranny for it so I will be broke for awhile anyway Thanks for the good advice, you have made me reconsider my plan of attack. I'm new to TPI so tell me if this sound good for now?

I will settle on doing a homemade cold air kit, a TPI foil, a good cat back(has dynomax but rusted out), a cool fan switch, adjustable pressure regulator, Taylor wires, hollow cat, and an off the shelf stage II chip(don't burn'em myself for now).

The car already has: G92 axle code, hooker headers, pulleys, accel super coil, brass cap & rotor, NGK v-power plugs, and some good suspension mods. The new tranny is corvette calibrated with a shift kit and 2100 vette stall.

Finally Ed, do I NEED 24lb injectors and a 255lph pump on this motor if do all the mods listed and maybe even the Throttle body and runners but keep the L98 and stock cam for awhile? I need some more input, I have no real world experience on MPI/TPI except on my 5.9 Limited and my roomate's Mustang. No TPI knowhow except what I have read.