pstoppani

As requested in another thread, here is some data from my DL1 data logger showing the performance of my 993TT, and for fun, also my Elise.

The TT is on 225/285 MPSC's and the Elise is on 195/225 Yokohama 048Rs; these tires are comparable R compounds. The TT has Kevin's Stage 1 upgrade and is running on 100 octane fuel which I estimate is putting down about 380HP to the wheels. The Elise is mostly stock with the Sport Package (at the time the data was collected).

First, the track layout of Pacific Raceways (formerly Seattle International Raceway), then a graph show long g's, lat g's and speed.

pstoppani

I wasn't trying to get a good 60 - 130 MPH run so all I have is one that has a right hand turn in it where I'm not going full throttle. The best time is 14.4 seconds.

The secton of the track is highlighted below and the long g's, lat g's and speed are shown in the graph at the bottom.

I'll try to remember to get some clean 60-130 runs on the straight next time...

Pete

fc-racer

Looks like 140mph into Turn 1? Turn 1 scares the sh*t out of me, especially when I've taken the bike there. Ironically, I prefer the bike on that track, it doesn't feel as narrow on the bike and you don't notice the trees as much

jmayzurk

Very cool. So how do lap times compare between the two cars?

-Jeff

dp5

try checking the 'interactive mode' box on the trackmap window. makes the display much cleaner

pstoppani

Yeah, if you can read the graphs, you can see that I slow down for T1; normally keep it around 130. Someday I may go full throttle through there

My fastest time in the Elise is a tic over 1:40 and my fastest in the TT is a bit over 1:37, but as I said above, I either brake into T1 or keep my top speed below 140 so the TT is faster than I drive it.

Jean

Thanks for posting Pete.. We should see more of these from rennlisters, it is really interesting.

So It seems like you are getting about 1G of grip with your tire setup, is that at the limit of ABS kicking in or you think you still have room to go? Almost the same in lateral Gs (maybe a bit more, not clear on the scale).. I will check my AX 22 datalogs, I believe this is consistent with my MPSC as well. I don't think one can get more than 1.2G from R compound tires.

Re. the 60-130mph you can almost never get good readings on a track, my fastest has been a 10 second or so because you are coming out of a corner between 0.4-0.6Gs while accelerating, plus usually on the track you have built a lot of heat already into the engine after a few laps.

Great stuff, thanks for posting. If anyone else has this same track, it would make a great comparison for you.

Evil Twin

I got a chance to drive a 993 TT last year at a PCA event at PIR, and your graphs fit with my memory of how the car felt. It cornered reasonably well -- neither appreciably better nor worse than my Elise -- but the engine pulls incredibly hard when the turbos spool to maximum boost.

Twin

pstoppani

Jean,

Note that I'm driving the TT at 9/10s so you won't see max G's in that data. Also, this track has the worst surface of any track that I drive on so it isn't exactly grippy. The two big sweeper corners at each end are like driving on polished gravel.

Thanks for posting your data. I find track data analysis and comparisons fascinating and very useful. These loggers are a great investment and learning tool.

Jean

Pete

The track I posted about is almost new, so the surface is excellent. Also, my car is wider than yours (GT2 flares) and the tires too, and might be lighter. But you still managed a 1.32 G which is amazing. I think this might be very close to the limit for these tires, anything beyond this is drifiting.
It would be interesting to see the Cayman some day.
Yes the tool is fantastic.
Thanks

pstoppani

I will have the DL1 in the Cayman next time I have it at the track. I'll post the results