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| JOHN FIRTH |
| 1997 TOYOTA SUPRA TURBO |
| 6 SPEED |
| BLACK/IVORY |
| FORT WAYNE, IN. USA |
 EMAIL JOHN |
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| 9 photos |
| 3332 words |
| June 22nd '05 |
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GENERAL:
When I was still in High School, I remember reading Car and Driver when the MKIV Supra was introduced. I was impressed with the car from what I read, but never thought much else about it because I couldn't afford one and was interested more in domestic muscle at the time. I had grown up not knowing much about import performance due to my friends owning Mustangs and GM F-bodies, in addition to my father's corvettes and his stories of hot rodding when he was young. At that time, I decided when I had the money, I'd buy and build a supercharged Mustang. Eight years later I had my Mustang and built it up with a Vortech supercharger and all the supporting hardware. I was happy with the car as it ran mid 11's at 126+ mph.
Then one day, during the summer of 2002, I was reading on the internet about a Supra that made 900+ rwhp and was very impressed. I started doing more and more research and soon knew I had to have one of these incredible machines. So, I decided to sell my 2001 BMW and began looking. I came across a few twin turbos from private owners, but I couldn't purchase them because I still hadn't sold my BMW yet. After about a month of searching I came across a post on Supraforums about a 1997 Twin Turbo 6 speed for sale at a dealer about 2 hours away from me. This was my ideal situation, as I figured I could just trade in my BMW and not worry about selling it anymore.
I instantly called the dealer and put down a deposit to hold it. This was on a Thursday and 2 days later, on Saturday, I was down there for a test drive. The car was completely stock with 59,000 miles. It was in very good condition and didn't have any major flaws. After my test drive, I was hooked. I struck a deal with the salesman and took care of the paperwork that day. The salesman told me that there were at least 2 other people wanting this car badly and hoping my deal fell through, so I felt very fortunate to have purchased it. I was ecstatic and couldn't wait to take it home but would have to wait a few days before I would be able to.
The following Wednesday, I took off work to drive down and pick it up. When I showed up, the car had been detailed and looked amazing. The drive home was a blast. I couldn't believe I was able to find and become an owner of these rare beasts along with all the attention I was getting from the car. My first modification was a Tanabe Racing Medallion exhaust. This really helped to make the car more fun to drive because of the louder and more powerful sounding exhaust. A trip to the track netted me a best time of 13.4@112 in this trim. It was now starting to get cold and was time to put the car away for the winter.
I started planning out what I wanted to do with the car and knew I wanted to go with a single turbo setup. I wanted to get all the supporting modifications done first though, so I settled on a Greddy 3 row IC and an AEM computer to start with. The AEM was still new in the Supra world and I was a little skeptical, but the possibilities with it far surpassed the VPC/GCC combination that was so common. I also had to settle on a clutch to hold the power I anticipated to make. Luckily, I found a used RPS carbon/carbon clutch for sale at a good price and snapped it up. I had read that there had been updates to these clutches and sent in pictures of mine to Rob Smith at RPS to see what version of the clutch I had. Rob told me that there had been an update to the carbon/carbon series and to send it in to him. To my surprise, he offered to rebuild and update it for free! I was very impressed with his service and offer that I will be an RPS customer for life.
From there, I began contacting various tuner shops about turbo kits and decided upon a Sound Performance kit after talking with Larry @ SP and everything I have read about them. I ordered their SP74 kit and fuel system with 95lb injectors. I couldn't wait for my kit to arrive and the 8 week timeframe killed me. Larry had been very helpful and patient with me throughout the whole process and I was very grateful. During the time I spent waiting for my kit to arrive, I met two great guys that lived a few hours from me that were both into Supras. Eric Cayton and Tim Iacolli offered to come up and help me install my turbo kit once it came in and I took them up on their offer.
By the time they were able to come up to help, I already had the fuel system installed and the stock turbos off. In April of 2003 we spent an afternoon putting on the new pieces and everything went very smoothly. The Sound Performance kit fit perfectly and made the installation simple. Eric was kind enough to give me a ride in his car with a T78 and, at only 18PSI, I was extremely impressed. We weren't able to run mine that day, though, because I was waiting for my intake manifold and throttle body to come back from being polished. I had to wait another week until I was able to fire it up. Once I was finally able to start it up and drive it, I couldn't wipe the smile off of my face. I had still yet to get my clutch put in, and again, Eric and Tim came through for me.
I drove down to them this time and we spent another Saturday afternoon installing my clutch. The Carbon/Carbon is amazing, the pedal feels lighter than stock and has very good manners. I can slip it no problem and city driving is just like driving on the stock clutch. Up to this point, I hadn't run more than 14lbs of boost because I wanted to wait to turn it up until after I had it tuned. Knowing this, Tim took me for a ride in his T72 Supra at high boost. Needless to say, he scared the crap out of me on the freeway spinning the tires at 80mph and taking off like a bat out of hell. After riding in Tim's car, I couldn't wait to turn up the boost to see what my car will do, but I had to wait a few weeks until it would be tuned by Larry at Sound Performance.
In May of 2003, after Larry was done with my car, we were able to get about 690rwhp out of it at 29PSI on Larry's Mustang Dyno that is calibrated to read like a Dynojet. This is all with a completely stock motor and a conservative tune. The day after getting it tuned happened to be a dyno day at a local speed shop so I took my car there to see what it would put out on an actual Dynojet. On a more hotter and humid day, my Supra put down 685rwhp and 592rwtq SAE. This was done with no changes to my AEM calibration.
At that point I was very happy with my car, to say the least, but my modifications were far from complete. I planned to install either HKS 264 or 272 cams in hopes of breaking 750rwhp, plus I had new wheels on order to replace the stockers and a S&W 8pt roll cage to install.
In July 2003 I decided it was time for the new camshafts. I was unsure whether to go with the HKS 272s or HKS 264s. The majority of top horsepower Supras were using the 272s, but there were also a few with 264s making great power as well. I was actually leaning towards a set of 264 cams when I came across a great deal on a new set of the 272s and so I went with the larger size. In addition to the cams, I purchased Crower springs and titanium retainers for an extended redline to take advantage of the increased breathing potential of the 272 cams. When it came time to install the cams and springs, Eric and Tim came through yet again. We installed them on a Saturday and everything went smoothly. Upon starting the car for the first time after the installation, I was surprised and impressed with the change in the car's sound and idle manners. Starting the car cold, it shakes a little and the exhaust note is very raspy and rough sounding, which gives the car a more powerful sound. Once it warms up, though, the idle smoothes out and you can hardly tell that it doesn't have the factory camshafts anymore. Also, since installing the cams, when using the two-step built into the AEM EMS, it would pop and bang loudly and often shoot flames out of the exhaust! Driving the car for the first time with the new cams, I could instantly notice the increased power band, which does not fall off like the car used to with the stock cams. It just keeps pulling and pulling until redline.
In August 2003, after about a month of driving with the new cams, I was able to get back on a dyno. My first dyno session I was able to put down 696 rwhp at 27 PSI, 11 more horsepower than the stock cams, but 11 more horsepower at 2 PSI less boost. I couldn't get anymore boost out of it that day, and couldn't get more than 29 PSI on the street. I knew the car had more in it and sought to increase the boost. Since I couldn't get a stiffer wastegate spring, I put a small T in the pressure line to the side port of the wastegate to keep it shut longer. This allowed me to run at least 5-6 more PSI on the street. During this time, I set up a warning light with the AEM in case I over boosted, so I would know to let out of it because I was a little worried I wouldn't have great boost control. I went back to the dyno and was able to reach about 31-32 PSI and I increased the horsepower output to 740 SAE with 621 Torque SAE. This was with a conservative tune, about 17-18° of timing and running a little on the rich side, 11.1 - 11.3 AFR. It looks like the cams netted me about 55 more rwhp, but I think there is a bottleneck somewhere now in the car.
Between 15 and 27 PSI, the car picked up 20-22 rwhp per lb of boost, but between 27 PSI and 31 PSI, only about 11 rwhp per lb of boost. I'm either the victim of a too restrictive exhaust, or head work is now needed to realize the full gains of the 272 cams, or both. At that point I thought about going to a larger dp/mp, as I anticipated that a larger dp/mp would net me substantial power gain. That will be my next thing to try, as porting the head was last on my list. I wanted to maximize my car's potential without porting the head or using nitrous. My goal was 800rwhp all turbo, and I hoped that a more free flowing exhaust would get me there.
I also received my new wheels and tires during this time, Volk GT-Cs, 18x9 and 18x10, in gunmetal along with 245/40-18 and 275/35-18 Yokohama AVS ES 100 tires. These wheels and tires, together with the more aggressive sounding motor, have pretty much marked the end of my car as a "sleeper", which is how I originally joined to4r.com.
My next changes would see power continue to increase. As of 2003 my best result had been a 10.9 @ 138mph on drag radials, using the 74GTQ. This turbo expired at the track during a pass in June 2004, during which the car ran 10.25 @ 138mph. It was replaced by a 74GTS turbo, along with a full 4" exhaust and HKS Ti cat-back. I decided to stay with a 74mm due to still having a stock bottom end and the 74GTS being able to provide ample power. By the end of 2004, my best pass was a 10.01 @ 143mph. Eventually I plan to build the motor in order to take full advantage of the 74GTS or perhaps something larger.
In April/May of 2004, it was time to update the interior. The tan carpet and tan seats are now gone, replaced with black carpet and Sparco Torino seats. My father helped me install a 6 point roll bar as well. In addition to all the welding, my father helped with bending, cutting, and re-notching some of the bars to make the S&W kit fit how I wanted it to. It has been modified to clear the Sparco seats and still allow targa storage. Because of the 6 point roll bar, the back seat has been removed and replaced with black carpet to keep things looking nice. The final addition to the interior was a driver's side 5 point harness. Under the hood, more pieces have been polished or chromed.
I have no new dyno numbers for the car, but according to the trap speeds and weight of the car, it has in the area of 840-850+rwhp. April of this year saw a new personal best of 9.91 at 146mph (see below) with only a 1.58 60ft. There is still more in the car and with a much needed suspension upgrade, I feel 9.7Xs or quicker are not out of the question. As it stands now, my ultimate goal with the car is to run quicker than 9.50 and trap higher than 150mph. This will most likely require a built motor and larger turbo, but for now, I'm very happy with how the car is performing. | PERFORMANCE:
I had wanted to run a 9 second pass ever since I went to the single turbo setup and knew that I had enough power to do it. My first year of drag racing the car was done on drag radials, and which where very hard to consistantly launch well. I ran a lot of low 11s and a few high 10s on the drag radials. The following year, I borrowed the CCW drag package from my good friend Tim Iacoli and from that point on I knew that was the setup I needed and wanted to run. I didn't want to get rid of the Twin Turbo brakes, so the CCW package was pretty much my only option. After borrowing Tim's set for 4 passes, I purchased my own. After getting the CCW drag pack, I was able to beat my best drag radial elapsed time by over half a second almost instantly. I learned that the single biggest improvement you can make to a high horsepower 6 speed Supra when drag racing is a good set of tires. You can have all the power in the world, but if you can't get it to the ground, it is worthless. I continued to improve my best time every trip to the drag strip for the 2004 season. I varied launch rpm and played with minimizing boost in the lower gears to help traction. For a couple of months towards the end of the 2004 season, I was knocking on the door to a 9 second run, but just couldn't quite get there. By the end of the year, I was extremely close, with a 10.01 being my best. At this point, I knew I didn't have to make any changes to my setup to run a 9, just needed a little better launch.
Over the winter, I had a few discussions with a friend about different ideas of boost control using the AEM EMS, and when the temperatures finally warmed, I decided to give these ideas a try. I was able to get the car out to the track in mid April and luckily it was a little above normal for the time of year. The temperature was in the 70s and humidity was low, so it was a good day for racing. This was my first time out since last September, so I was a little rusty. My first 2 passes weren't very good, I didn't launch well and I missed a gear on each run resulting in me coasting to some high 10's after missing the gear. The car was not hooking up too well and was all over the track. I was not able to make a full pass during my 3 qualifying runs due to missing gears, but the car was trapping 115 in the 1/8, so I knew it was making good power. When eliminations began, I dialed in at 10.0 and hopped to make a full pass. I was bracket racing, so I had to be careful not to break out or I'd be done, and figured with how I had been driving, a 10.0 would be a safe dial. In the first round, I missed yet another gear and coasted to a 10.4. The car hooked really well and I knew it would have been a 9 second pass had I not missed the gear. Compared to my 9.91 run, I was almost a full tenth of a second quicker at the 330 mark on this pass. Luckily for me though, my opponent in the first round red lighted so I was still alive and still had a chance to run my 9 this day. For the second round, I left my dial in at 10.0 and lined up. The car launched well, but didn't feel as well as the previous run. I hit all the gears this run and at the end felt that it was just another low 10 second run. To my surprise, when I got my time slip, I saw it. I had finally ran my 9, 9.91 @ 146. I was so excited! It felt like a huge weight had been lifted, as I had been trying for a while and I knew the car had the power to do it, I just had to drive it well enough to run the time. Even though I broke out on that run, my opponent for the round red lighted again, so I was still alive. It was late though, I was tired, and I figured with the way I had been driving, I would most likely miss another gear anyways, so I decided to load the car up on the trailer. I ran my 9, and that's all I cared about. I haven't been able to get back to the track since, but I hope to make it out a few more times this year and improve my time. | THANKS:
Big thanks to Tim and Eric for the help getting my car together, and Rob Smith at RPS for the clutch update. I'd also like to thank my father for all his help and I thank my lovely wife Brenda for her putting up with my crazed obsession. |
PARTS LIST:
| ENGINE:
SP74GTS turbo
SP exhaust stainless manifold
HKS GT wastegate
HKS Racing Type II BOV
Greddy 3 row FMIC
HKS 272 cams
K&N Filter
NGK 6097 sparkplugs
4" dp/mp
HKS Ti exhaust | FUEL:
95lb injectors
Sound Performance fuel rail
-6AN braided SSLines
twin Walbro pumps
Aeromotive regulator | ELECTRONICS:
AEM EMS
HKS DLI
GM boost solenoid to control boost and FJO Wideband O2 | DRIVETRAIN:
RPS Carbon/Carbon clutch | INTERIOR:
Sparco Torino seats
black carpet
Autometer Lunar series guages
B&M shifter
S&W 8pt. cage |
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turbo: SP74
pistons: oem
rods: oem
head: oem
cams: HKS 272
boost: 32psi
injectors: 980cc
pumps: Walbro x2
fmic: GReddy 3-row
clutch: RPS carbon
nitrous:
rwhp: 840 (dynojet)
circa 988hp at the flywheel
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