what's an alignment worth - lap time
03-02-2009, 12:33 PM
#1
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what's an alignment worth - lap time
assuming same variables (tires/brakes/driver), on a typical 1:20-1:40 track, what's a good guess on how much lap time a good alignment is worth (-2.5 degree front-1.5 rear) vs a factory C5Z alignment? ball park? .5 sec? 3/4 sec? 1 sec? 2 sec?
03-02-2009, 02:38 PM
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Its hard to say since the starting alignment as well as other things are not known.
Bill
Bill
03-02-2009, 06:51 PM
#3
Race Director
not a lot....maybe a second, but your assumptions are part of the problem. More grip NEEDS more camber, so you have to balance the alignment to the tire. If you go to a sticky tire withough more camber, you'll go much faster, BUT the outter edge of the tires will be destroyed in no time if you don't balance the alignment to the grip.
Running -2.5/-1.5 on stock cars won't really help over a stock alignment that much....on it's own.
Running -2.5/-1.5 on stock cars won't really help over a stock alignment that much....on it's own.
HAUL ***! 
03-03-2009, 10:52 AM
#6
Burning Brakes
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St. Jude Donor '10-'11
GRM occasionally has articles where they iterate the camber settings on a car to optimal ...
Last year or so they set up a C5 FRC autox car - don't recall whether they did an article but I'll bet they did some tests ...
Last year or so they set up a C5 FRC autox car - don't recall whether they did an article but I'll bet they did some tests ...
03-03-2009, 11:01 AM
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Melting Slicks
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Not course related, but in a roughly 50-60 second auto cross course an alignment was worth an easy second, if not more. Unfortunately without instruments on track and a rack it is hard to back to back this, but pretty widely agreed upon that alignment is third behind seat time and R compounds (at least in my circle /shrug)
A worthwhile investment for HP driving.
Fej
A worthwhile investment for HP driving.
Fej
03-05-2009, 11:00 AM
#9
Melting Slicks
Well, don't know my starting point, but after two years on track, over 40 days at various
tracks, I finally got what was described at the race shop as a mild street/track alignment
and corner weighted. I think the starting front settings were under -.5 on either side
and I always ran street tires, either GY SC or Kumho MX's. Off the machine it ended with
both at -.9 in the front, btw, on a C5 coupe I think -.7 is max stock range. I'm sure the
corner weighting had significant impact as the car was much more balanced on track as
well as, I'd call it nimble. My next outing was at Buttonwillow which I only did about 2/3
times per year but usually the same configs from prior year, new config each day with Speed
Ventures. My times were 2 to 4 seconds faster and one of the guys that I previously
waved by regularly, was surprised that I was keeping up with him. Only one data point
and not meaningful given different conditions, but it made a huge difference in my car.
Randy
tracks, I finally got what was described at the race shop as a mild street/track alignment
and corner weighted. I think the starting front settings were under -.5 on either side
and I always ran street tires, either GY SC or Kumho MX's. Off the machine it ended with
both at -.9 in the front, btw, on a C5 coupe I think -.7 is max stock range. I'm sure the
corner weighting had significant impact as the car was much more balanced on track as
well as, I'd call it nimble. My next outing was at Buttonwillow which I only did about 2/3
times per year but usually the same configs from prior year, new config each day with Speed
Ventures. My times were 2 to 4 seconds faster and one of the guys that I previously
waved by regularly, was surprised that I was keeping up with him. Only one data point
and not meaningful given different conditions, but it made a huge difference in my car.
Randy
03-14-2009, 03:59 PM
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They did a good alignment article about a year ago on their Mini, not that I'm interested in Minis, but it was a great article detailing alignment changes by eliminating variables, and then showing when they finally got past the point of what would be considered the best settings for that car. Of course many adjustments would be made from there because of different driving styles, tracks, etc. but if I was a Mini guy i would've definitely used that article's spec as a baseline. Unfortunately I haven't seen them do much of anything with their FRC, but if they did one of these detailed write-ups on their car I'd like to see it.
