KevinK2

http://www.quattroman.com/misc/ShiftPointsA4.xls

I wrote this to determine wot shift points for max acceleration. For a flat torque curve to redline, just redline ea gear. If torque falls enough at high rpm, calculator will show best shift points on the graph.

I ran artguy's torque curve, posted in 3rd gen forum header, and showed it was best to redline ea gear.

Just need torque curve, gear ratios, and tire spec's.

For FD:

1st 3.483
2nd 2.015
3rd 1.391
4th 1
5th 0.719
final 4.1

tire w, mm 225
asp ratio,% 50
rim, inch 16

DoingAnything

best way to determine shift points is on a dyno. Every car has a slightly different powerband and the best/most accurate way to find the best shift point is on a dyno.

KevinK2

the program uses the dyno torque curve, or published engine torque curve.

DoingAnything

i was't disputing your chart at all. I actually really like it, i printed it myshelf, I'll test the info this weekend at the track and see if it's accurate, using my set shift points on my race car(I'll be at the track on Friday, test day, so i'll have a little time to play w/ this). Very informative.

I wonder how many people will understand the #'s and how to calculate though.

SPOautos

Can you make the rpms higher than 7000??? can it go up to 8000 or 8500?

So far based on the 7000rpms max it looks like I should hold every gear to the max. I'd imagine with our cars being low tq, high rpms, with gear multiplication being so important we'd always be better off holding each gear to the max

BTW - Nice work with the spread sheet. I like it

eoph

if u ported u want to shift higher right?

KevinK2

you can change any of the 'boxed' input values. any rpm sequence can be used, and no limit on rpm.

don't bother entering rpm/torque values below 3K, as that will never be a useful rpm to shift to when flat out.

wzr27

heres a good place to go. it has a shift point graph. also has a bunch of other calculators.

http://www.bgsoflex.com/auto.html

KevinK2

his table uses two methods, 1st is where hp curves cross, like mine where tq curves cross, both give correct shift points.

the second method uses 'max area for the hp curves. This makes no sense, and gives very high shift points if you have a peaky torque curve. Not recommended. Area under the hp vs time curve would represent work done in a time interval. That is meaningful but not what he's doing with his torque * rpm^2 type area.