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Old 03-14-2007, 01:46 PM   #8
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Originally Posted by SupraDupra
I would recomend a manual transmition for any type of racing over automatic any day. Due to the way an automatic works you typicaly suffer a %5 power loss through the drivetrain. There may be a few good examples of automatics at the racetrack ,but the manuals dominate by far for a reason...
For more info on auto vs. manual at the dragstrip, please see this thread:
Any given driver in an Mkiv Supra Turbo in the 1/4 will generally be more consistent AND at least a half second quicker with an auto (vs. manual). In other words, in the Mkiv Supra Turbo world, manuals do not dominate in drag racing...they are significantly slower. This is not an opinion, it is a fact, repeatedly proven by the results of hundreds and hundreds of Mkiv Turbos at the dragstrip. Please don't forget that a bone stock mkiv tt does low 13s, and a bpu mkiv easily does 12s - I'm specifically and only referring to results achieved with this particular vehicle (i.e. not drag racing in general). Also, launching any turbo car with a manual tranny is very much an art. You're usually stuck launching at zero boost, depending only on your revs and driveline/flywheel inertia to get out of the hole. Then it instantly becomes a very fine line between spinning and gripping/bogging as boost comes up...modulated by feathering the clutch (since modulating the accelerator would almost surely take you out of boost again). It can take literally hundreds of passes down the dragstrip to get that process perfected...and in general, the 6spd looses so much time getting to the 60' that there's no way on earth to make up that lost time on the back end, even with 5% more power. Without serious drag-specific modifications like a 2-step rev limiter, nitrous, slicks, line-lock, etc. to assist him, an auto tranny would most certainly be a better choice for WhisPer if he wants to get consistently quick times at the drag strip.

Fwiw, I do agree with WhisPer that a 6spd is more fun to drive, and if you're only going to the dragstrip to have fun, then a 6spd is a fine choice. However, pretty much everyone I know that goes to the dragstrip actually does care about the times that they get. Since WhisPer hasn't purchased his Supra yet, I'd suggest he should at least understand that he'll very likely be slower in the 1/4 with a 6spd (despite the additional driveline power loss).
Originally Posted by SupraDupra
...I would also think the manual preferable for autox as well ,due to the fact that you can keep your transmition in the power band more ,ie. shift down to 3rd when going through a turn so your at the top of your gear when you come out and are in your torque curve...
Agreed, a 6spd is a much better choice than an auto for roadracing or autox. Another reason is that the auto tranny fluid will overheat if driven aggressively on a road course or autox with a high horsepower mkiv.
Originally Posted by SupraDupra
...A good suspension setup goes a long way...
Agreed. Fortunately, the oem mkiv tt suspension, along with the oem mkiv tt brakes, are very suitable for roadracing.
Phil '94 Supra Turbo, 6spd, 'APU'+
Displacement is no replacement for boost.
Life begins at 30psi.

NB: Please consider posting any help requests in a new thread instead of asking me for help privately. About 99.9+% of the time, private help requests end up covering great information that could be very valuable to other forum members. If you have a good reason for needing the help request to be private, I'll consider it. If not, then why not give everyone else the opportunity to pitch in too, and/or learn from the information? Remember, there's no such thing as a dumb question. We're all here to help within this family of Supra owners.

Last edited by pwpanas; 03-14-2007 at 02:16 PM.
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