Ben's Supra Page

  A stock '97 Toyota Supra Turbo has 295 rear-wheel horsepower, will do 0-60 in 5.0 seconds flat, and can finish a standing-start quarter-mile in 13.4 seconds.  That's very fast for a street car.  I was satisfied with that level of performance for about a year...
  In June '98 I brought my '97 Supra down to Rod Millen Motorsports of Huntington Beach, CA (http://www.rodmillen.com).  There, they installed the following parts:

Back on the dyno, these mods were good for an additional 70 rear-wheel horsepower, raising the total to 365 at the wheels.  The additional horsepower knocked a few tenths off the 0-60 run, to 4.7 sec, and knocked a few more off the quarter mile times, to 12.8 sec.  The freer-flowing exhaust & intake also dramatically reduced turbo lag, making the Supra easier to drive around town.  Those performance figures put the Supra in fairly rarified air -- only a handful of performance cars are faster, and all are much more expensive.  I had an entertaining year laying waste to turbo RX-7s and 3000GTs, Corvettes and Camaros and Mustangs, but then the performance bug bit again, hard.
  In July '99, the Supra went back down to Rod Millen Motorsports for some more extensive upgrades: More recently, I have upgraded the brakes in preparation for a little roadracing.  In addition, I replaced the stock driveshaft, which was beginning to fail under the strain of all the new power.  The Supra now sports: On October 2, 1999,  the Supra made 619 rear-wheel horsepower and 532 ft/lbs of torque, measured on a dynojet dyno.  This substantially exceeded my expectations for the project; kudos to Rod Millen Motorsports for their installation and tuning, and to the Supra MKIV list members for their collective wisdom and suggestions.  The link below has a large-size dyno sheet scan as well as some information about the dyno conditions.

It is interesting to compare the October 2 results with my previous results on August 22.  Since then, three things have changed:
(1) I have added the OS Giken clutch, replacing a slipping stock clutch
(2) I have adjusted the cam timing gears as detailed in the above link
(3) I have replaced the original .73 exhaust housings on the turbos with the .61 housings from Powerhouse

The net effect of these changes is clearly obvious in the next link, which shows two lower-power dyno runs: the first at 18 psi before the above changes, and the second at 17 psi after the changes.  The most dramatic change is the way the powerband has shifted downward by 500-800 rpm, boosting low-end torque.  This is particularly noticeable on the street, where the car now makes reasonable power as low as 3,000 rpm.

This link shows the three runs I did back in August, before the latest modifications.

For those interested in the actual installation, here's a chronological set of photos from Rod Millen as they installed the kit.

HKS Twin Turbo Kit teaser shots
Removing the stock turbos & exhaust manifold
More Trick Bitz
Installing the new exhaust manifolds & turbos
Installing the intake & fuel injectors
Fuel system, cam gears, pulleys
Assembly Complete!
Engine bay & FMIC shots

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