I was reading but no one said why. Why should I remove the TPI when I do this build. One of the post stated it will eat a lot of gas if you leave the TPI on the motor. If I got to replace the TPI what should I replace it with?

 

 

and your budget

 

The fuel thing is plain wrong. Yes your motor could use more fuel, but it is in no way the fault of the TPI. I would actually argue the opposite, the choking TPI will only allow so much air through and you should need less fuel than if you had a higher flowing manifold which can make more power.

If you go aftermarket, in order of easy to complicated swaps:
-big tube TPI setups
-SuperRam
-MiniRam
-FIRST intake
-BBK (if it ever comes out)
-LT1 intake
-HSR intake
-Custom Intake

 

The TPI was designed for a 305 motor. It's flow and configuration were meant to boost the 305's torque where it would still feel powerful. It was part of GM's plan to meet early 80's emissions and economy requirements.

They also ended up using it on a 350 because the torque benefits were even better with modest loss in top-end HP. To stretch that intake one step further (and mount on a 383) is really too far. The 383's displacement is so much higher than a 305 that the stock TPI tubes would be undersized. Sure, you could generate some decent torque until about 3500 rpms, then the motor would be choked and flatline. (No add'l power would be generated about that rpm level).

Depending on how you drive, a TPI can produce better mileage. The reversion waves "tuned" by that runner length help to focus maximum efficiency at a lower rpm. Many other factors are present though.

Asking someone else what YOU should do with YOUR car is the same as handing it over and saying "Surprise me!". It's a dumb question. Read up some more (using responses above as a guide), figure out what you want, where you want power, and how much you have to spend. Better questions and answers will be the result.

 

A tpi will even work on a 406 (SuperRam).

 

It is NOT necessary to replace the TPI on a 383. It depends on what your goals are. It also depends on the 383 you are building. If you want to maximize HP you will need a different intake and matching cam.

 

They will all work technically. But a SuperRam is not a TPI, it is an aftermarket TPI replacement manifold called a SuperRam, which flows much better and lets you spin much higher. (As it appears you know! Just trying to keep things clear for the OP)

You can definitely run a TPI on a 427 it would just be a waste of 70 or so cubic inches.

 

Sounds like this question should be clarified before proceeding.....

Define a TPI.

 

Tuned Port Injection - my 3.8L Buick LeSabre has it.

most people use TPI and LTR (long tube runner, the stock system on an L98) in exchange for each other, when they are really not the same thing.

Technically a SuperRam is TPI

 

Duh. The OP should define what HE means! Based the way he used it in a sentence, he means the OEM intake, not a superram, not a large-tube TPI, not an HSR, not an imaginary BBK, etc...

 

Exactly. And, likely NOT what the OP asked about.

 

Well, since the OP has a 1990 Corvette, and he asks if he should leave the TPI on it, the question seems clear enough for me.

 

I disagree, but this is semantics.

Technically lots of motors are port injection, but the L98 with its long runner intake has the common name of "TPI intake." Because it is the stock TPI V8 intake and GM's big selling point of the motor/intake was the "tuned length runners" and "port injection" = tuned port. The side molding of the Vette has "Tuned Port Injection" on it, it was the flagship model debuting this technology and has forever been referred to as the TPI intake...because it is the stock TPI intake.

Your 3.8L buick may have a port injection manifold on it too (and maybe even the molding too), but I don't think anyone, that knows anything about TPIs, would confuse it or any other manifold (SuperRam included) as the stock, TPI intake. Because it didn't come on the "TPI" motor.

LTR on the other hand. Long Tube Runner... Large Tube Runner... this is a made up term that can lead to confusion and is used incorrectly with a much higher frequency than TPI... Is it a stock Long TR (TPI), or aftermarket Large TR (AS&M/Edelbrock/ etc.)

I just thought the OP would appreciate some clarity and I did so with respect to the common lexicon used on these forums. Use whatever terminology you prefer though.

BTW, this is a LTR setup...



But it sure isn't a TPI...

 

Mopar wins the argument of "Whos got the longest runnered torque monster".