When to shift

[Jay633]

Im curious, does it depend by car or specific mods, but when your driving doen the dragstrip when is it that you shift gears

[floridamtbiker99]

I believe right before red lining it. The Power band is about 3500 rpms on MKII supra. This comes from my experience drag racing in the 1980's.

[Jay633]

what about mk3 supra

[floridamtbiker99]

I believe it would be the same with any car. The usually power band really kicks in about 3.000 to 3500 rpms. It does not matter if your car is stock or build for racing, the same go to or near red line but not over.

[cre]

Shifting at redline is a horrible idea on any vehicle that's remotely stock... ESPECIALLY one that's 25+ years old (even worse if it's a '89+ MKIII). If you believe that the 7M (or any engine which came in any generation Supra) made power beyond the rev limiter you'll hopefully be wise enough to heed the rule of thumb that you should shift 5-10% short of redline as bouncing off the limiter will definitely cost you the race (and in this case quite possibly your engine).

The best point to shift is always a topic of considerable argument. The smartest thing to do would be to take advantage of modern technology, get on a dyno and check out the performance per gear and watch for overlap. The optimum shift point is going to change as you accelerate from a stop and the dynamic of the load changes. Initially you'll want to favor the optimum torque RPM and as your speed increases move the shift point north up to the peak HP RPM. Now, you don't want to shift right at the peak of the TQ curve. For example: if you shift out of 1st right at the peak or the toque curve you'll be dropping into 2nd a good deal further down the curve and have a good amount longer to get back to that peak power level. Shift out of 1st a few hundred RPM after the TQ peak and you'll only have 200RPM to get back to peak in 2nd. Torque and HP generally drop off slower than they're reached, don't ever shift at or before peak TQ and don't shift after peak HP (there's nowhere left to go but down).

Looking at a couple stock 7M-GTE dynos, the peak torque in 4th gear is around 2700-3200RPM and peak HP 5000-5500RPM. The MKIII doesn't pull for shit after the mid-upper 5000's and I wouldn't hold it past that.

[Busted Knuckles]

My stock 7M-GE (N/A) pulls very well between 3,000 and 5,500. The redline is at 6,500, according to the stock tach, but I rarely go to 6,000. Even at 24 years old and 263,000 miles on it, she rips through the RPM range like a lioness on a gazelle! I'm kinda skittish about pulling all the way to redline, so I shift a touch early, like just as the tach hits 5,500. But the close-ratio gear set in the W58 keeps it in the power band between shifts.

[pandrade]

from the few times at auto cross and street rolls iv noticed that at 5000-5500 i start to lose steam so i usualy shift at 4900-5000 but thats whith my 3in raceing exshaust and a well taken care of motor. i wouldent go past that because i dont want to risk any catastropic failure( this is where i think i shift i rarely look at tack i go by sound and feel)