RQ_GT3

Own a plain 7 GT3, no ceramics.

So I've had my new track 18" wheels (235/295 rubber) MSC's sitting there for a couple of weeks, by now I finally found a jack that is low enough to work.

Questions:

These MPSCs are not directional, right?

The front wheels would not roll freely, seemed to rub against the brakes. Normal?

What is the right way to change a wheel, after placing the new wheel on hand-tighten the lugs, then drop and tighten / torque? Or tighten to a certain degree before lowering?

And as a general question, what is my best venue for learning about basics such as wheel and brake pad maintenance, basic wearables for track use, etc? Any links or book references appreciated.

Oh, and what is the recommended cold tire pressure for MPSC's, 18". for track use?

Thanks in advance!

tiger 6

I don't believe the MPSC tires are directional. I have not found any arrows, lettering etc to indicate otherwise.
When I change my wheels, I jack up the car, loosen the lug nuts with my electric impact wrench, remove the tire, do what needs to be done, impact the lug nuts back on, lower the car to the ground, and torque the lug nuts.
The recommended MPSC tire pressures for the track are:
.front: 25 psi cold, 32 psi warm
.back: 28 psi cold, 36 psi warm
This is a pretty good starting point and should be adjusted according to tire wear, temperature etc.
There are a number of good threads here on suspension settings for the track. Search is your friend!
Your front wheels should turn fairly freely. If they are rubbing against the caliper, try taking the lug nuts off and putting them back on. You may have a bit of "binding" due to a slight misalignment of the wheel.

RQ_GT3

Thanks!

Re-reading my post I did not explain the "rubbing" properly - it is not the wheel that rubs against the brake, it is the rotors that seem to have some contact with the pads (front wheels) - I would have expected the wheels to turn freely but there is a bit of friction. Is that normal?

TurboCup87

Yes that is normal. There is some friction b/t pads and rotors on any disc brake car. If your car sits a few months during winter storage, ( well I have winter!) there is often enough surface corrosion to make it tougher to rotate the wheel when jacked up. Don't worry about it.

naparsei

Yes, please remember to "break" the lugs loose while the wheels are on the ground - so you don't use the torque wrench while the car is up in the air on the jack.

340Elise

I would tighten them a little more than just by hand while the car is raised. Just get them all hand tightened, and then go in a circle while skipping a lug each time and get them snug with just a regular lug wrench.

Then, after you drop the car, i would use the same procedure, but don't tighten each lug until the torque wrench clicks. Just keep going in a circle, and tighten them a bit each time until the wrench clicks on each one (you may do 7 to 12 rotations to achieve this). If you don't think you have good feeling naturally, then you can also set your torque wrench to a lower value, like 40 lbs, and go around skipping one lug each time until it clicks. Then up it to 65 lbs and repeat; and then finally set it on the correct value of about 93 lbs (I think) to do the final tightening.

I personally believe it is important to tighten them equally and consistantly at fairly equal increments until they are fully tightened.

And don't forget to retighten them all after you drive the car the first time after doing a full tightening due to wheel swap or repair or whatever caused you to take the wheel off. Also, it is good practice to check them every so often just like you check your oil and tire pressure.

Stephen

RQ_GT3

Great advice, thanks folks!