Shift Points

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Dec 5, 2002 | 02:36 PM

carl [i has type-S]

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Shift Points

<center><img src="http://pictureposter.audiworld.com/32990/shiftpoints.jpg"></center><p>As promised, here is the chart I made. Basically, through looking at the chart, you choose your shift points based on where the curves intersect one another in order to maintain the highest tractive force possible.

however, with the stock 1.8T, as you can see, you don't have much of a choice...shifting at redline will give you the best acceleration, except for the 4-5 shift, which should be done somewhere between 6000 and 6500 rpm. you can really see how widely spaced 1-3 is on this chart.

the tractive force is simply torque*gear ratio*final drive/tire radius(in feet)

vehicle speed is RPM*Pi*tire diameter(in inches)/gear ratio/final drive/1056

torque curve is an estimate: 166 lb-ft from 2-5K, falling fairly linearly to ~130 lb-ft at 6500 rpm (redline)

Dec 5, 2002 | 05:34 PM

Tsle

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Very nice chart- thanks for posting. I've been experimenting w/ shifting between 5 & 7k, and...

it's good to see that stuff in a more concrete way.

Dec 5, 2002 | 06:28 PM

carl [i has type-S]

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also, for you chipped folks, i'd be happy to make and post those as well

things change a bit when you're chipped.

i played around a little with the GIAC torque curve someone posted earlier.

just give me a legible torque curve and it's fairly plug and play.

Dec 5, 2002 | 06:41 PM

carl [i has type-S]

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Here's the GIAC chip shift points

<center><img src="http://pictureposter.audiworld.com/32990/giacshiftpoints.jpg"></center><p>these curves actually overlap a lot more...however understand that this is partly due to the fact that you can rev higher with the GIAC chip than you can stock.

the last three data points on each curve are at 4750, 5500, and 6730 rpm.

nevertheless, it still shows that you should shift at or near redline. (7000 rpm redline with GIAC)

(i also chopped off several of the initial data points from some of the curves to make things a little more clear)

Dec 6, 2002 | 04:25 AM

Elberoth

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Can you plot them against RPMs ?

Dec 6, 2002 | 04:59 AM

carl [i has type-S]

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oh all right. gimme a bit.

Dec 6, 2002 | 05:06 AM

carl [i has type-S]

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wait...that doesn't work...

because then the curves don't cascade along...you have to pick the speed at which the curves cross, and then back calculate what specific RPM that is.

because i'm a super nice guy, i will do so for you.