Shifting for dummies

Keith Quistorff · **Posted:** Wed Mar 22, 2006 12:46 pm

Rich Anderson wrote:

I have included both rear axle torque (Whitney method as best I can figure it) and the HP method I use.

Okay, now I understand the disconnect between Rich's and Mike's methods. Rich's car has zero REAR axle torque :stick:

, so no wonder Mike's method won't work for him! :lol:

Graham Jagger · **Joined:** Fri Aug 29, 2003 12:53 am **Posts:** 1718

Rich Anderson wrote:

Graham Jagger wrote:

6th 0.56
Graham

Bugger. My sheet is only setup for five gears. Hmmm, guess I'll have to come up with v1.1!

Oh beleive me I will never hit 6th gear on a track. 6th is for highway to conserve gas. I can get about 29 mpg with it. I seriously doubt I will ever hit 5th on track unless it is the cool down lap and I'm coasting. Maybe VIR-F. At RA and RR I used 3-4 all the time.

Jeff sent me the dyno data files and the graph that is cleaner than my copy. I scanned a printout. I'll upload those to my website tonight or you can PM your email and I'll send that last run data file and jpg to you.

Graham

Rich Anderson · **Posted:** Wed Mar 22, 2006 1:51 pm

Keith Quistorff wrote:

Rich Anderson wrote:

I have included both rear axle torque (Whitney method as best I can figure it) and the HP method I use.

Okay, now I understand the disconnect between Rich's and Mike's methods. Rich's car has zero REAR axle torque :stick:

, so no wonder Mike's method won't work for him! :lol:

Don't tell that to the people I catch on track. :nana:

Rich Anderson · **Posted:** Wed Mar 22, 2006 4:24 pm

And on the no torque note, I just got Graham's dyno. Let's just say I had to rescale the graph a little versus my Focus. :shock:

v1.1 (six speed, I decided against seven) should be available for download soon for all you STi and T-56 Vette/Viper guys.

Rich Anderson · **Posted:** Wed Mar 22, 2006 5:21 pm

http://www.v8mongrel.com/index.php?p=howto
Version 1.1. Let us all bask in the glory that is the LS series V8.

If someone else has a dyno file that they would like done, please send it to me for version 2.0. I can extract from WinPep (Dynojet file) or you can send me a delimited text file. I think it would be better if I could put different dyno numbers in for each version.

Graham Jagger · **Joined:** Fri Aug 29, 2003 12:53 am **Posts:** 1718

You might need a v1.2 for the C5 Coupe/Vert. The Z06 and C5 coupe/vert use the same 3.42 diff. But the only gear that is the same on the 6sp is 4th @ 1.0. 1st, 2nd, 3rd, 5th the C5 coupe has longer legs. They have different diameter rear wheels and different power curves between LS1 and LS6. So the 3-4 shift would be different. They're way different in 1st and 2nd.

Rich Anderson · **Posted:** Wed Mar 22, 2006 9:37 pm

V1.1 will accomodate the different gear sets. You just need to input the data into the green cells. Same with the dyno information (which should also be colored green, btw). But once that is changed, it should work just fine for both cars. You should try it an see what effect that gearset would have on your shift points.

Ron Spencer · **Posted:** Mon Mar 27, 2006 8:23 pm

Kind of late in the thread but the best explanation of torque vs HP I've ever heard is:

HP: Determines how fast you can go (i.e. max velocity)

Torque: How quickly you can get there (i.e. acceleration). Give me the best acceleration every time!

As for shift points, I go by feel. When the car feels like the acceleration has dropped off time to shift. Yes, not at ALL scientific but then I usually don't have the time to look at the tach on track. Certainly not when autocrossing!

Or forget all that and shift at the track out point!

Ron

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