(Acceleration:
This time, Mike made a total of six acceleration runs to try and get the best results. He has been honing his launch technique, and I have to tell you that 3000GT really lunges when it comes on boost! As before, the challenge in launching any AWD/4WD car is that there is often too much traction, especially with a turbo motor to delay the power delivery. This time around Mike was able to launch harder and get some very nice results!
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Mike was very consistent and fast. His runs ranged from an uncorrected 14.5 second quarter mile to a 14.0. Four of the six runs were all between 14.0 and 14.1 seconds, and the trap speed was about 100mph. His 0-60 mph times ranged from about 5.9 to 6.4 seconds, most of which ended up being 5.9 to 6.0 seconds. Again, fast and consistent!
Also, Mike gets into the record books with the most forward acceleration to date: 1.0 Gs! (All right, 0.98 Gs.) If you're going against an AWD/4WD car with similar power, you better not count on beating him in a holeshot. The 3000 GT's best 0-60' time was a blazing 1.96 seconds, which beats all comers. My G35 posted a best of 2.17 seconds, and Jim's wife's Mustang posted a 2.16 seconds for comparison.
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Power:
In addition to the acceleration runs Mike also did completed one full power run, which yielded a measured 234bhp @ 5400rpm, and 261lb-ft of torque @ 4000rpm. The torque peak could actually be lower and closer to the stock specs of 2500rpm, but with a turbo motor and the G-Tech it was impossible to get maximum boost at 2500rpm. The fastest two acceleration runs gave a measured average of 242bhp @ 5700rpm, with 265 lb-ft of torque on tap. This power peak is interesting since the Mike said his turbos couldn't handle 14 PSI past 5500rpm or so, which means getting larger turbos would yield an immediate benefit right towards the 6000rpm stock power peak, regardless of higher boost!
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As I mentioned before, my new v1.4 spreadsheet is using a modified SAE standard correction, which essentially adds the boost pressure of the turbo to the ambient atmospheric pressure, which then measures an actual intake pressure to the engine and allows the SAE correction to be accurate against artificially- and naturally-aspirated engines. Using these corrections (plus estimated driveline losses, etc.) the calculated output of Mike's motor is about 315bhp @ 5800rpm, with 340 lb-ft of torque available at 4000rpm. I think this output is probably a bit low, perhaps 325-330bhp is more likely. However, since my AWD versus RWD driveline loss estimate is pretty simplistic the spreadsheet is showing a bit lower than I suspect the car is delivering. That's a nice 75-90bhp gain after fixing his boost problems!
Again on the subject of naturally- versus artificially-aspirated engines: it is well documented that turbo motors are able to handle low pressure or high temperature/humidity better than normal motors, since their turbos just wad up the air and shove it into the engine nearly as effectively as normally. Given the temperature and humidity from Mike's runs, a normally aspirated engine would have been down on power about 4.5% (and therefore have a compensating adjustment "upward".) In the 3000GT's case, the turbo mitigated it to only about 2.4% loss, and consequently had a smaller adjustment.
Technique:
This year Mike vowed to get his 3000GT up and moving as quickly as possible, so he strapped in and used a lot of revs and a bit of clutch slip to really launch that car! As you can see from the RPM and G launch comparison, the more RPMs Mike uses the more the 3000GT rips. Launches of 5000-5500rpm yield runs with a peak of 0.9 to 1.0 Gs forward acceleration, which is just cool to feel. :) When you compare this year's runs to last years, you can see both the additional RPMs and also the higher boost really give him a 20-25% advantage. Very nice!
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For most of his runs Mike shifted at 7000rpm. This seems high, since a stock 3000GT's power peak is 6000rpm, and his is 5800! However, what we found is that since the boost falls off so much between shifts, virtually any extra "boost time" yields faster runs. A run using 6500rpm shifts was a few tenths slower!
Also, you can see that Mike's shifting was fairly slow. This is due to the shifter being a pretty long throw and a bit notchy. Since his shifts were nearly one second long (compared to 0.6 seconds for my G35 or Tim's Prelude), the boost had completely dropped off and really slowed things down. Anything he can do -- a new shifter, etc. -- to speed this up will net an immediate benefit of a tenth or two. He may also want to consider powershifting (keeping the throttle on to some extent while shifting) to minimize boost loss.
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So, speed up the shifts a bit and you could trim a tenth or so off it. Otherwise, excellent technique and formidable results!
Corrections and Other Factors:
As discussed before, I used new corrections to normalize the atmospheric differences, plus the standard removal of extra weight from myself as passenger and an extra half-tank of gas.
And now the moment of truth! Will the 3000GT's corrected runs push Brian's Mach 1 off the top of the G-Tech heap? Brian's best run resulted in a 13.69 second, 103.3 mph quarter mile run. Mike's best run netted a 13.64 second, 103.0 mph quarter mile! The quarter mile king is dead, long live the 3000GT!
| Recorded Data | Corrected Data | |
|---|---|---|
| Best Run | 0-1/4 mile in 14.0 secs @ 100mph | 0-1/4 mile in 13.6 secs @ 103mph |