compaq888

did you look at the set up sheet in your manual??

Also on my first day driving the car with foams didn't do too good, but you need to experiment with foams and set ups and you get it right.

afm

Here in Peru we run only rubber class,8like the British BRCA Rubber Class) with great success.
The clue to our success is running PMT premounted 26mm slick rubber tires. PMT is an Italian manufacturer of rubber tires for all classes. The Tires come in 40, 45, 50, and 55 shore hardness and they work and last well on all brands of 200mm touring cars. We get an hour's race time on a set, and sometimes can use them for training after, for next race. We've tried almost all brands of rubber , and these are the best.

Check them out at www.pmt-tyres.it

AFM

Matt.C

Thanks for reply! I mix my chassis setting with factory original and generic recommended touring car setups.

My current setup:
Front toe: (out) 1 - 1.5 deg
Front camber: -1 deg
Front caster: stock
Front shock: 50 wt / stock black spring
Front tire: 42 shore / 26 mm

Rear toe: (in) 2 or 3 deg
Rear camber: -1 deg
Rear shock: 50 wt / stock black spring
Rear tire: 37 shore / 30 mm

F/R anti-roll bars are removed. Plan to experiment with rear anti-roll bar only.


I should have collaborated my question more. I am comfortable with my current setup only when foam tire are new and midly used. Once rear tires lose material past half point, I have hard time balancing some of settings, i.e. to compensate reduced rear tire diameter, I have to jack up the rear end by adjusting shock collars, and then I don't have any droop on rear and spring tension seems too high. Also, I hate adjust chassis setup every other day to compensate the reducing rear tire diameter.

I was wondering how you guys deal with this dilema and what pro's do? Do you setup chassis for new tires and forget about it or do you re-adjust every time you run?

Matt.C

Thanks for the link, I'll check it out!

Taylor-Racing

Matt.C,
There's really no way around it. If the rears are worn significantly more than the fronts you are going to be dealing with unequal drive from the front end as compared to the rear. This is what tyre truers are for.

You could use the overdrive pulley set up as per the RR or Evo. That helps maintain even F/R tyre wear a lot.

mikecatts

iTrader: (18)

hi all.
when using foams. i tend to set my car up for every heat,
ride height, droop, etc. when the foams wear down, its important to true up so they are at your optimun split, then re-set your ride height, and then droop.
mike

Tom G

I can see re-settign after every run, but I'm questioning whether re-setting droop or up-stops is necessary?

Tire diameters don't, or at least I can't see the connection, impact droop, since it's set against the wheel hubs. This logic incorrect?

^5

drfritz

You should only to have to check the ride height after each run. if you are smaking it of the boards ever other lap them, then by all means re check your settings, put in the board and go through the settings, if not, then you are just adding more work to your race day and you might end adjusting some thing in the wrong direction and not remeber what you screwed up. I know I used to do the same thing and I over tuned my self right out of a number of races.

jeffreylin

You might need to reset the droop based on tire wear. More droop for smaller tires.

InitialD

That is when the ride height maintained constant all the time.

I guess like somebody has mentioned before, droop is best set and understood according to the amount of chassis uptravel from ride height until the tires lift off the ground. If you maintain that uptravel distance to be constant all the time, then you notice that the droop screw needs to be set when the tire wears out.

2 mm of tire diameter reduction = 1 mm of droop increase

dougday

Why would the uptravel change when the tire wears? AS the tire wears it reduces the ride height , but it does not affect the up travel of the chassis.
Only if you are measuring the uptravel from the ground, i.e. the highest point the chassis can travel above the ground without the tires leaving the ground...That will change, but the upward travel of the chassis will remain the same.....that is the distance the chassis raises relative to the ride height....Whatever that ride height maybe.

my 2 cents

InitialD

I agree with you but don't you change your ride height and increase it when your tire wears down? Are you telling me that if you set the ride height of your car initially at 6 mm and the tires wear down and you get 4 mm ride height and you don't want to set it back to 6 mm??

When you set it back to 6 mm, your initial droop changes and you need to set the droop (increase it) too.

dougday

I am not sure that I understand what you are saying, because changing the ride height should not change the droop settings.

I do not change my ride height. When the tires wear down, i change the tires.

InitialD

No worries. If you do not understand, then I will not force it on ya. But on a serious note, that's how it's done. Changing ride height does change your droop settings.

You must be rich then. (j/k) What foam tire diameter do you start with and what droop settings and ride height do you start off on your car?

dougday

First I setup the car using 60 F and 62R with a ride height of 5mm F and 6mm R and droop of 0 F and 4R. For 5 min qualifiers I will run that size tires for Practice I cut the tires to 61.5 F and 63.5 rear. The car is quite good at 58F and 60R (4 & 5mm respectively). In most cases I get 2 x 5min. qualifiers with 60F and 62R.

For a 30min main, I will use 61F and 63R and still save those tires for qualifying the next raceday. I keep my practise tires also, hence I usually have quite a few small tires laying around that I can use for Qs.

BTW the car is the Vone RRR.