I know Tuned-Port Injection was the power-house of the 1980s, and that the TPI cars were the fastest, but is it worth keeping? I've got an '89 Firebird Formula 350, and I was just wondering. The TPI apparatus is ungodly torque-wise, as I've got a great low-end, and, off the line, I can eat almost any car, but after that I have virtually no high-end because the engine starts to bog after about 4500 RPMs. Is there an easy fix to this? I want to keep it, but having no high-end sucks bad...real bad.

 

There is no easy fix to it except cubic money

TPI was the powerhouse only compared to its options for other stock thirdgens (except those with a neato turbo). If you really want power, and emissions or fuel economy is no concern, a carb is your answer, if you're a FI head get a complete aftermarket FI intake that doesn't include any form of a LTR (long tube runner) based off ofthe TPI theory. Good intakes are LT1/miniram/stealth ram.

If you really dig that low end grunt vs a good et go for the super ram but be prepared for the nightmare some have described when it comes to assembly/disassembly


Good luck