copy/paste.. I don't even know why I bother on other forums when I'm sure you guys can answer anything.
I was checking my pressures today with the brand new Motion pro gauge I bought for the track(thing is awesome!)... My pressures were WAY off but I had a question since then.
The pressures recommended on the side of the car are for stock tires, my car does not have stock tires so I was wondering if any adjustment should be made. I only drive on the street so I understand I probably will be OK with the recommended but I wanted an explanation, right now I have 225/45/18 in the front and 275/40/18 in the rear. I put 36/46 pressures cold in the tires as per the side sticker...
Should anything be done differently based on different widths?
46 is a lot of pressure. I've never run pressures that high and had awesome results. I'd be runnin like 34/32 f/r
But it might be in your best interests to keep em higher cause of potholes and stuff. But u kno how it is round here.
Anyway, what tires do u have? All these low pro performance tires have stiff sidewalls, and u can ride em nearly flat.
Ideally, the way to find the optimum tire pressure is to find some clean pavement, and do a nice burnout. I'll take video for YouTube! Look at the tire marks. If it's light in the middle, tire pressure is too low. If the middle is dark and edges light, too much pressure in the tires.
Take the rear pressure and run 2-4 more psi up front due to the added weight of the engine. Depending on weight distribution, run 2 if the car isn't too biased. Run 4 on a car like my 69 camaro which is very biased and the motor is super heavy
Are what you have on there the stock tire sizes?? I know the tires themselves have been changed, but if they're still the stock sizes I would still adhere pretty close to the mfg recommended pressures
But I will agree that 46 seems kinda high for a car, but who knows. Alot of the stuff I work on takes 65-90 psi, but that's for heavy loads and LT tires
__________________ -Jared
Black/Red '04 CBR 600 F4i - 251,500 miles and still kicking
Black '89 Accord LX-i sedan - 434,600 miles still running strong
Are what you have on there the stock tire sizes?? I know the tires themselves have been changed, but if they're still the stock sizes I would still adhere pretty close to the mfg recommended pressures
But I will agree that 46 seems kinda high for a car, but who knows. Alot of the stuff I work on takes 65-90 psi, but that's for heavy loads and LT tires
I have stock sized front tires and wider rears because my wheels are wider, 275 vs 255(stock) in the rear.
46 seemed very high as well, I was surprised when I saw it on the side of the car but I figured I'd go with what BMW recommends. Number with 4 passengers were bit lower.
My front tire is same as stock 225/45/18
My rear is 275/40/18 where stock is 255/40/18
Are what you have on there the stock tire sizes?? I know the tires themselves have been changed, but if they're still the stock sizes I would still adhere pretty close to the mfg recommended pressures
But I will agree that 46 seems kinda high for a car, but who knows. Alot of the stuff I work on takes 65-90 psi, but that's for heavy loads and LT tires
__________________
Quote:
"Multiple track days are needed every 12 month period to keep performance of the nut between bars and seat within an acceptable range. Failure to do so could result in a loss of talent in the nut. Crashing, "squidding it up" and illusions of awesomeness could occur.".
Well, drove in today at work and I def like the handling with the pressure where it is now. Before I had 31/31, now with the new pressures I feel the car handles better, pot holes don't feel as harsh and I've lost a little vibration I had at around 80mph which I was thinking was balance.
Feels a lot better. On a sadder note it feels slow as shit after going for a joy ride in a R8 last night.
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