Wolverine

Well, I've been babying my new transmission for 1200 miles, and I thought I should give it some excercise. So I went to the dragstrip and made a few runs. Unfortunately, the strip has a reputation for being very slick, and my times were poor - I was spinning the wheels in second gear. However, I did take my Gtech, and was able to calibrate it using the strip trapspeed, the Gtech speed, and the formula in the manual. With H&R springs, and EDC 'sport' my corrected pitch factor is .7 (note other H&R Gtech users). My Gtech run was 112.12 mph, and the Gtech indicated 113.44 (with a PF of 0).

So, armed with my newly calibrated Gtech, I did a number of runs on my personal strip, and discovered one very important tip: Shift at the redline in every gear - especially in the 1-2 shift. Hitting the shift right at the redline will give you 2-3 mph in trapspeed vs hitting it a few hundred rpm lower.

Here are two runs I just did:



Same day, conditions, etc, but notice the difference in shiftpoints. By shifting at redline in each gear, I picked up almost 3 mph trapspeed, and hit over 118 mph with a crummy 60' time of over 2.2 seconds. You can see the effect of hitting the 1-2 shift at redline from this graph:



Initially, both runs are equal up to the 1-2 shift. By shifting right at redline, you can see that you gain over 2 mph in speed. Each gear gains a bit by shifting later, but the biggest effect is the 1-2 shift. This actually shouldn't be that surprising. If you look at the rate of acceleration in each gear (how steep the line is on the graph), you are always accelerating faster if you are in a lower gear. By keeping the car in the lower gear a few tenths of a second, you are gaining speed by accelerating faster than you would be in the higher gear. Looking at over 30 of my previous Gtech runs, this is the case - the later shift in every gear gains speed.

With a good launch, and perfect shifts, now that my rings have set and the engine has really loosened up, I'll bet I can get close to 120 mph trapspeed.

Hope this helps.

__________________
Mike

2006 E60 M5 Silverstone II/Silverstone/Aluminum, All Options, 35% tint, Aluminum Pedals, Valentine V1 and Passport 9500i Hardwired, Blinder Xtreme M40, Michelin PS2's on 20 inch BBS RS-GT's, Winter Pirelli Sottozeros on OEM 19 inch wheels, Resonator Delete, Charcoal Filters Removed, Eibach Springs and Spacers, Active Autowerks ECU, BMC Filters, RPI Air Intakes, Evosport Pulley. Retired from track duty 10/08. Dinan diff replaced with OEM at my cost due to failure at 56,000 miles. First on the list for the upcoming F10 M5.