In this FAQ we will address two arena's of Toyota Supra performance, suspension and engine modifications, both of which will bring you great enjoyment. This particular FAQ will focus on the 1993.5 to 1998 Supra Twin Turbo models (both automatic and manual gearboxes)
I. Engine Performance
Doing the BPU (basic performance upgrade's, invented here at SupraStore.com) is generally the first place to start. In any turbo car raising the boost and freeing up the exhaust flow along with a good intake is a good start. We suggest starting with an air intake system (all we have are good). Secondly, free up the exhaust system. The Supra Twin Turbo 2JZGTE engined US Spec cars have two catalytic convertors, one is pre-cat which is used for cold start emissions and then the main CAT. We recommend replacing this section of exhaust piping with what is called a downpipe (available under exhaust section). There are two versions of the downpipe, those that eliminate both CATS (therefore for off-road use only) and those that have a built in single higher flow CAT (street legal). Expect an increase of only 5hp with the air intake, but most importantly you are supplying the turbo with more air and in most cases cleaner as well. A downpipe (cat-less) will give you around 35HP and a downpipe with a single high flow cat around 28HP, both of which are nice power adders. Since the CAT restrictions has been minimized or replaced the turbos spool up quicker and build 1-2 psi of more boost as well. In cold weather climates it is possible that at this point you may hit what is called fuel or boost cut. It is actually a factory computer instituted fuel cut that takes place around 14.5psi of boost. If this takes place, then you will need to install our GReddy BCC (boost cut controller) to eliminate this. The BCC is a standard component in our BPU 460HP package.
An aftermarket performance exhaust system completes the equation and all of them provide about the same power increase of 12-17HP. Choose based upon looks, quality, loudness and your budget. All the units we have here at SupraStore.com will fit to our downpipes or to your factory downpipe set-up and are CAT-BACK.
Now you are ready to increase the boost from the factory 11 psi to 17-18 psi by installing a boost controller. Raising the boost will give you a huge performance gain and has proven to be very reliable in street usage. Any of our manual or electronic boost controllers we list will work good with any combination of downpipes and/or exhaust systems. Make sure you purchase the GReddy BCC at this time as well as you will surely hit fuel cut. Fuel cut will not hurt the engine in any way, but it won't allow you to run the higher boost needed for 460HP+, which is what you will have with all these goodies.
Fuel economy may drop about 5% on the freeway (maximum), the benefits of fuel injected car. Failure rate on the factory twin-turbos running at 17-18psi seems to be around 2%.