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02-22-2013, 01:01 AM

#2818

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Quote:

Originally Posted by fabrc68

thanks Erchn & CristianTabush, your interventios are greatly appreciated. i'l give this a try and report my considerations....

in the meantime, i have another question on the T4, altough the problem in generalized, so i try to see if the willingness to help others is still on... i race with foam tires, and i have huge problems keeping the droop to the value i want... 'cause setting the downstop (let's see to "box" values of 6 front and 5 back) alone isn't enough to set the droop... the ride height, and consequently the springs precharge, has a direct hit also...
let's say that i set the downstop to 6/5, and i set a ride height of 5/5 mm with new foam tires (65 mm)... usually that is accomplished by setting a very low spring precharge.... after some runs, the tyres wear off, let's say to 63mm, that means 1mm less ride height... if i compensate the spring precharge, increasing it a bit, to restore the 5mm ride height, the droop value lowers, cause the arms are closer to the chassis...how the hell am i supposed to measure the droop in order to keep it constant ? i don't even know where to start... i have the droop gauge to measure the downstop, but i don't have anything, but eyeball, to measure the effective droop....

someone at the track says that he sets up the downstop (6/5) with new tyres (65mm) and, in order not to have to continuosly change the downstop to adjust the droop, the set a compromise of an initial ride height of about 7mm / 7.5mm..... so they don't change it until the tyres are quite completly worn out...

my consideration on this "compromise" is that you get the "full" setup only towards the end of the tyres usage, when ride height is close to the optimal measure of about 5/5......

also, the setup book (and the various setup sheets that you can find on the net) all specify downstop values, but they never report the droop values.... where do i look to find out the "correct", initial front/back droop value for an outdoor, medium grip, mixed, asphalt track ?

sorry for the long post, but i'm sure that this issue is common for novice foam racers like me, and pro-advice would be very useful.

Fab

When we used to run foams here (US) I would true 4 or 5 sets of tires at a time all to the same size. Run them a couple times and then put them in a bag and switch to one of the other sets. After all 5 sets had been run I'd find the smallest tire and skim all the tires to match and start the process over again. When the tires started getting too small to maintain traction for the entire run I'd put them away until I was at a race where the traction was high enough that I needed to run the small tires.

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