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When I got the Supra, it was a pretty crisp car. It had an automatic transmission that would get second gear chirps. That was pretty cool for stock. I would go against other Supras at the stop light and every time the other guy would shift, they got further and further back. I coudn't believe my automatic Supra was taking out 5-speed Supras!
Of course, I had to mess with a good thing. The first mods to the car was a set of HKS camshafts, a Doug Thorley header, and a K&N air filter. I also opened up the air flow meter and tightened the spring a couple of clicks. The Supra ran better, was a little faster and had a distinctive tone. But it was still nothing to get excited about.
The next upgrade was a TRD suspension kit. It had higher rate springs, high pressure shocks, front and rear sway bars, and urethane bushings. Now this was noticeable! I was now taking freeway interchanges at 90 MPH and yawning. I feel that every enthusiast should upgrade their suspension, as it makes driving safer and more predictable.
Of course, all of this "spirited" driving took its toll on the automatic tranny. Knowing that I was going to punish the car more, I opted for a 5-speed. It would probably last longer than another automatic. So out went the auto and in went the 5-speed and everything else associated with it (petals, slave cyl., master cyl., flywheel, clutch, bearings). Remember earlier I said my auto was quicker than 5-speed Supras? Well, thats what happened to mine. So I searched around and found a factory rear end with a 4.30 ratio. (props to Jeff @ Toyotas Only) That took care of that.
Still not satisfied, (here we go) I went back to HKS. With a pocketful of cash, I bought the Stage III turbo system seen below. Complete with EVC (HKS' electronic boost control). This kit was complete, right down to the last nut and bolt. Too bad they don't sell it anymore. Now my Supra was rippin the road up! I was smoking 911's with ease. The car was running 13 pounds of boost and felt 1500 pounds lighter. |
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After I put the kit in, I pretty much drove it like that for a couple of years. There were a few minor mishaps, but were figured out and squashed. There was one thing that kinda bothered me however. From time to time a piston would get taken out. I finally found out what it was. The pulley for the crank would move and would cause timing to shift when tuning. This led to overadvance and detonation. But it was really minute, not killing the piston quickly, but after some time. The pulley was wobbling on the crank, and wore out the keyway. So after remachining the nose of the crank, I found that it was the bolt keeping the pulley on the crank was the culprit. It was stretched out from what I figure was too many timing belt changes. The bottom of the bolt was bottoming out on the inside of the crank, causing the pulley to not secure properly. I put in a new bolt and the pulley didn't move from there on. While I had the crank machined, I had the whole rotating assembly balanced. I also had the stock rods shotpeened and fitted with Chevy big block ARP bolts. A set of Arias forged pistons .080 overbored also went in. I ported the head myself and lapped the valves. |
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While the engine was down, I went to Turbonetics and had my TO4B turbo upgraded. This time the turbo turned into a 60-1 with a P-trim turbine. Compressor map shown to the left. Rick Head asked what I required out of the turbo. I told him I was going to drive it on the street. I also told him I wanted 550 HP @ 20 pounds of boost. He replied, "This will give you more than what what you want." |
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So eventually the car got going again with some help from parts from different shops. Some turbo suggestions came from Dave at Options, along with a fuel pump,head gasket, and a HKS fuel pressure regulator. The DFI ECU orginally came from Vinnie at AEM. Twelve injectors came from RC Engineering. A staged DFI ECU mod came from BDS. The staged injector firing is to accomodate the wide demands of a street driven turbo motor. Half of the injectors are used until they are at 80% of their capacity. After that all the injectors are used but the amount of time the injectors are on, is cut in half. Harv's Performance Center wired the DFI for staged injector duty. The Supra was then tuned on the street via laptop. The Supra ran great with more power than before. It was now up to 17 PSI. The 2-bar MAP sensor was now maxed out. I drove the car like this for about a year when I was curious what it would do on the dyno. The car was put on Harv's Dynojet and taken to limits not previously found on the street. Unfortunately the Supra started to fill the area with smoke. The car went lean and took out four pistons. I later found that the stock fuel pump mounted inline with the Bosch pump was a restriction. Even at that, the car made 325 HP at the rear wheels @ 13 PSI with four melted pistons. So after some procrastination, I decided to put in a 7MGTE engine from a Japan spec 91 Supra. |
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