ben_harmer32 Posted September 20, 2015 Share Posted September 20, 2015 Does anyone know the ratio of the rear diff on the supra. Are the auto and manual the same? Cheers! Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted September 20, 2015 Share Posted September 20, 2015 They're on the forum gear and tyre calculator Quote Link to comment Share on other sites More sharing options...
David P Posted September 20, 2015 Share Posted September 20, 2015 (edited) Unless I was subscribed to that thread, it would be a bar steward to find, after 31 posts, ben_harmer32 N/A or T.T? stands even less of a chance and then requires a program that I don't have to open it. Here it is. http://www.mkivsupra.net/vbb/showthread.php?225050-Supra-specific-gear-diff-ratio-and-tyre-size-calculator This site gives transmission and differential specs, 4AT, 5MT & 6MT, N/A and/or T.T. http://mkiv.supras.org.nz/specs.htm Edited September 20, 2015 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
ben_harmer32 Posted September 20, 2015 Author Share Posted September 20, 2015 Cheers guys. Was just wandering if the auto rear diff was better for acceleration. I'll have a look at the spread sheet at work tomorrow. Quote Link to comment Share on other sites More sharing options...
V8KILR Posted September 21, 2015 Share Posted September 21, 2015 I recently ran the numbers with this calculator http://www.wallaceracing.com/drag-sim.htm and surprisingly, for drag racing it is slower to use an auto diff (3.769 or 3.538) vs a manual diff (3.266 or 3.133). The calculator assumes you can slip the clutch to a higher mph for the manual diff ratios, so it may not match what would occur in a real world test. I switched to the 3.538 diff a while back thinking it would give me quicker time on the 1/4 mile, so I'm hoping it actually does. Quote Link to comment Share on other sites More sharing options...
bignum Posted September 21, 2015 Share Posted September 21, 2015 My auto diff makes the 6 speed box more useable on the track. Quote Link to comment Share on other sites More sharing options...
V8KILR Posted September 22, 2015 Share Posted September 22, 2015 I also used to have the 3.769 diff in mine years ago and it made it much easier to drive on the street as well. Quote Link to comment Share on other sites More sharing options...
ben_harmer32 Posted September 22, 2015 Author Share Posted September 22, 2015 I was curious as previously I’ve had a Nissan Skyline and on that the auto diff and manual diff had different drive (4.1:1 auto version and 4.3:1 manual version). Using the auto diff would give better acceleration than the manual one. Was wandering if the Supra was the same? Quote Link to comment Share on other sites More sharing options...
V8KILR Posted September 22, 2015 Share Posted September 22, 2015 You definitely feel much better acceleration in each gear with the 3.769 diff, but there are other things that offset that advantage. With the 3.769 diff, it required changing into 5th at the drags back when I had the stock rpm limit, so it was no quicker then the 3.266 diff was on the 1/4 mile due to the extra gear change. A higher rpm limit would probably fix that issue though. Also as you change from 1st to 2nd (and all other gear changes), it is at a lower mph, so the same time (say 0.5 sec for the gear change) not accelerating is worse for elapsed time. This is because you are going at a lower mph when you change gears so you cover less distance during the gear change time. Quote Link to comment Share on other sites More sharing options...
ben_harmer32 Posted September 22, 2015 Author Share Posted September 22, 2015 So if i wasn't interested in top speed and just acceleration i would be better off with the 3.769 diff? Quote Link to comment Share on other sites More sharing options...
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