In typical Mike/DSPORT fashion the R33 GT-R was not raced for a almost a year, but the week before the next big drag racing event the email tennis began full of discussions of what needed to be done to the car. Not two or three weeks before, but ONE week before. Mike does occasionally drive the car around on the street, but the reality is that driving a Hollinger sequential transmission on the street isn't all that pleasant. This time the race was Battle of the Imports this past Sunday at Fontana, CA. BOTI is the oldest import drag racing event that is still going strong. It is run by my old friends Frank and Mike Choi who still throw a good event even today. It's good to see an old school street racer (Frank) succeed at what used to love doing. Frank had this RX-3 with an auto trans supercharged 13B on NOS way back in the day, but that's another story for another time. So back to ONE week before BOTI: the car was dropped off at XS Engineering for an axle change, driveshaft loop installation, fluid changes, parachute cable termination, and general look over last Monday. Peter cranked the car out and it was picked up on Thursday. Due to my schedule I wasn't able to tune it until Friday night. Actually I had to tune the GT-R on Friday because I had to go to Buttonwillow on Saturday for for a 25hr of Thunder Hill car shake down (post coming soon).
The only changes from last time was the change to VP Q16 fuel and larger air filters with aluminum suction tubes to the turbos. Previously the car had some smaller filters with small tubes (smooth and large diameter = greater flow). Peter at XS did a nice job fabricating the current tubes and filters. Otherwise there were no changes to the R33. Here is a past article on the car: DSPORT RH9 BCNR33 GT-R. Still on the car is small, gay ass motorcycle muffler that I have been sweating Mike to change for years.
I arrived at MD Automotive at about 5:30pm and only had about an hour to fine tune the car. My goal was to just make sure the engine was safe. If I had more time, I would have re-timed the cams, added more boost and spun the engine to 10,000rpm. Due to the lack of time I kept the boost at 2.65bar (38.5psig) and 9500rpm.
Twin Apexi RX-6 TCW77 turbos, Hypertune intake manifold and single throttle body, Portflow ported head, Apexi Power FC D-jetro with Eric Hsu ultra super deluxe triple throwdown hyper battle tune, Apexi cam gears, K&N air filters, Tomei 290IN/280EX camshafts, Mahle custom pistons, HKS 2.8L forged crank, Carrillo connecting rods, Gizzmo two step and boost controller, and a 75hp shot of ZEX nitrous between 3500-7000rpm create and sustain 1104hp at the wheels.
The smoothing is at ZERO here which is very important. If you are getting your car tuned on a Dynojet, always ask for the dynosheet with SMOOTHING = 0. The inertia 248 Dynojet is currently the only chassis dyno accurate enough to show potential problems in the power curve. It is accurate enough to show an imbalance of a wheel. You tuners who have been doing this shit for a while who have used inertia 248 Dynojets and newer Eddy current 4WD dynos will know what I mean. Anyhow, with the cams re-timed, a larger 4″ exhaust, and no dumb ass motorcycle muffler, the power should continue beyond 8500rpm.
Mike's day started out with a 9.8@145mph with a misfire in 5th gear. After tightening the spark plug gap, Mike went out again with a shitty launch and spun the tires in 2nd gear for a 10.1@149mph. The car only has a two step limiter for the launch which isn't really enough to get the car to 60' real good. If Mike side steps the clutch at 9500rpm on the limiter the car will still fall on its face. So in an attempt to decrease 60ft. times, I told Mike via text msg to retard the igntion timing on the two step limiter. This increased the boost at launch from 0.5bar (7.25psig) to 1.75bar (25.4psig). Unfortunately this quick parking lot psuedo anti-lag and the Power FC's fuel cut rev limiter may have hurt the engine. I think Mike's best time to date was a 9.7 which is pretty good for a 3700lb full weight car, but the 9.7 was when the engine was making only 1040whp. 9.3s was the target, but maybe next time (and with a soft igntion cut rev limiter). EDIT: the triple plate clutch was also slipping in 5th gear. Mike also believes the center differential was fried causinga 90/10 or 80/20 split. His best 60 foot time of the day was 1.62sec on the Nitto NT-05R drag radials.
For now Mike seems to be on the repair pretty quick. He has dropped off an N1 block at Cosworth and I put him in touch with Trey Cobb (yes the rich guy who owns Cobb Tuning) for a Nismo GT block. I will be sonic testing the N1 and GT blocks for a no bullshit, fuck the forum unscientific bullshit, real deal comparison on block thickness. I hope Mike stays motivated. Most of these Skyline GT-R owners lag pretty damn hard much like myself and ESPECIALLY RS Wen Lai.
Check out a near future issue of DSPORT for more details on both BOTI and Mike's car.
Here's some video that Sean took. BTW that's Mike Choi from BOTI announcing over the PA.
Here are some quotes from Mike:
“We WILL be able to get the 60-foot times into the 1.5s or better when we get the car back to the track.”
“The DSPORT RH9 GT-R will be the first true street, full-weight GT-R to run 8s on DOT radials.” and he adds “even if it's through the 80mm motorcycle muffler!”
