1989 Toyota Supra

Supra Picture The largest performance modification is, of course the 7M-GTE engine swap which ups the base horsepower of the car from 200 to 230, but of course I didn't stop there. Once the turbocharger is in place, the first thing that you want to do is to crank up the boost a bit, right?

Basics first. The engine needs air to make power. Removing the stock restrictive intake and replacing it with a cone filter is beyond the basics, and hardly what I'd consider a performance mod, but I did it, so...

More basics. The easier it is to get rid of exhaust gasses, the less power the exhaust system robs from the crank. Now with normally aspirated engines, there is such a thing as too large an exhaust. The exhaust needs to flow smoothly in order to maximise the scavenging effect and draw more exhaust from the cylinders. This is not so for a turbocharged engine. The more and faster you can remove the exhaust gasses, the better. The factory exhaust had to go. I upgraded to a Tanabe Hyper Medallion cat-back exhaust system and a Random Technology downpipe, with LIPP performance turbo elbow. This makes the exhaust system at least 3" in diameter all the way from the turbo back. This allows the exhaust turbine to have the maximum pressure differential, and gives the compressor the most power to work with.

Okay, so beyond the basics, there are some things that I wanted to do to make sure that cranking up the boost wasn't going to turn my engine bay into a smoking crater.

First up is the fuel system. The stock fuel system is good for a bit more boost, but I like to have more than I need. The stock 440cc injectors were replaced with a set of Performance Turbo Engineering 550cc injectors. This takes care of some additional fuel delivery.

The complement to that is to use the air flow meter from a Lexus V8. This is exactly the same electronically as the stock unit, however it has a larger chamber. In this way, we lie to the ECU, telling it that there's really less air coming into the engine than what's really there. The ECU then delivers what it thinks is an appropriate amount of fuel, and because of the larger fuel injectors, it's right. The computer has just given us more fuel, without ever realising that anything is amiss!

Copyright ©2008 Dan Gyoba