Used the Race Technology DL-1 data logger for the first time at an autocross yesterday along with new Hankook R-S2 Z212's (245/45-16) on the 16x7.5 Kosei K-1's (with a few hundred miles on them). Tire pressure was set at 40psi front/27psi rear and scrubbing indication was fine on both front and rears. It was a nice HOT sunny day (low humidity at least - for Houston that is!) and everone was commenting on having less traction than at the last few events. Anyways Initial impressions of the Hankooks are that I like the Kumho MX's better (225/50-16 size). The grip is fine with the Hankook's (better than the Kumho MX's IMO) but the responsiveness is not as good. I was getting way more understeer than I was expecting on transitional elements, steady state was fine. The Hankooks are a better daily driver tire than the Kumho MX's with my Tacoma - bumps are softened though still firm and better grip in wet downpours. So for the Tacoma I currently think the Hankook's aren't quite as suited for autocrossing as the Kumho MX's (though this is comparing different sizes). I will say that for a basically STS class (except for gutted interior) 1990 Acura Integra RS with 15x7 wheels the 205/50-15 R-S2 Z212's work amazingly well! Grip and instant steering response with nary a case of understeer!

I got comparable times with that Integra last event to what my SM Camaro (about to go to Prepared class) can run... So it really does matter what vehicle and tire size is run for a given tire to say if it's better or worse. '98 Extended Cab Tacoma weighing roughly 2850lbs with 121" wheelbase, with stock ride height, and 245/45-16 sized tires on 16x7.5 wheels is indeed entirely different than a '90 Acura Integra RS weighing roughly 2400lbs with 100.1" wheelbase, lowered 1.5", and with 205/50-15 tires on 15x7 wheels.

So, without further delay here is the course map for the event:



And here is where you can find the logged screen shots for each of the four runs:

DL-1 data screenshots for September Houston SCCA event with Toyota Tacoma

P.S...Oh yeah you might be interested in run times. Since times aren't availble yet from what I remember my first run was a 66.xxx. By the fourth run my best time was a 65.5xx. Came in third in STF, second place guy (newer VW Golf with Kumho MX's) was around 0.3 seconds faster and the first place guy (Nissan 200SX on Azenis was in the high 64.xxx I believe. If you could get 60.xxx seconds or less you were flying on this course.


Modified by Vracer111 at 2:01 PM 9/5/2005

 

I've been using a DL-1 for a few months now and I think it's incredible how much you can gain from data logging. One thing I've found helpful is to make an X-Y graph that overlays all runs and use distance as the X axis. You can easily see where you were faster from one run to the next. Also, set up some track markers for the start, finish and some intermediate markers to get segment times. For an autocross course where it doesn't lap over itself, be sure to clear the "use as lap marker" box when you define the track markers.

Another thing that is nice about the DL-1 is it is very portable. I loaned it to a buddy and he bought one after using it just once.

-Brian Meyer