In Reply to: Re: GTech comparisons (including png's 540iA) posted by Peter G. on January 17, 2000 at 01:14:38:
Thanks for cleaning up that table.
Anyway, I can't speak to the comparibility of one G-Tech to another which is really a question of the absolute accuracy of their units. I can attest to the presision and repeatability of numbers with any one G-Tech however.
Also note that, while these numbers seems slow, that is consistent with my feeling that I wasn't getting good launches. These same cars with this same G-Tech got significantly better times when I was on a stickier surface and the temperature was 40 degrees cooler.
Anyway, If you were getting 5.5 out of your stock auto 540i, then you either have a really strong car, or your G-tech is optimistic.
Regardless, I like the G-tech because it makes it easy to quantify improvements in technique or car modifications. This is a big help, for example, on my 240Z autocross car where I can tweak things like fuel mixture and spark timing.
: [ png: Let's see if I can't get this table to format right... ]
: : M5 540i M3
: : 0-60 5.1s 6.2s 6.2s
: : 1st 0.70g 0.57g 0.55g
: : 2nd 0.55g 0.42g 0.44g
: : 3rd 0.35g 0.28g 0.28g
: : (FYI, with cooler temps and better traction, I've gotten upper-mid 5 second times in both the 540 and M3 before)
: These measurements illustrate one of the weak links in the G-Tech story. I have a G-Tech Pro and a '99 540iA Sport with Dinan's cold-air intake, Stage II engine programming, and Steptronic transmission programming.
: Prior to all the mods, I was getting 5.48 and 5.49-second 0-60 readings essentially every time I did my part during the launch. (DSC off, A/C off, RPMs to about 1,500 with the brakes on, then release the brake and roll the power on just fast enough to produce a little bit of tire spin, but not too much.)
: With all the mods, I'm getting 5.30 to 5.33-second readings. Okay, great, it's just about as much faster as it ought to be given the relatively small amount of extra power added by the Dinan mods.
: But would another G-Tech produce the same results? That is, are G-Tech results repeatable, and therefore transferable, from one G-Tech to another?
: I expect that any recent 540i six-speed manual-transmission car ought to be faster than my car, regardless of the mods, but here we have evidence that my G-Tech is producing better results for my car than your G-Tech is for yours. This just isn't likely to be representative of reality.
: . png