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[poiney]

My owner's manual recommends ~ 3psi higher for the back tires for the 335 as compared to 328i, all else being equal (i.e., speed limit, loading). I assume the main risk for higher pressure is catastrophic blow out at high speed (correct me if I'm wrong). But since the manual stipulates maximum speed for both cars, it seems that tire pressure should be specified the same.

Why do they specify higher pressure for 335 for back tires?

Also, why is the pressure of the back tire generally higher than front tire?

[gos]

Biasing higher pressure in the rear (or lower in the front) is a way to induce understeer, which is generally considered safer for emergency corrections. (i.e. it's safer to run solo off the highway than it is to spin your car into traffic)

As to the 335 vs 328, are you talking about the same size of tire? Both have sport? Same wheels? etc?

Personally I run about +4 psi in the front and +1-2 psi in the rear on my car, non-staggered setup.

[poiney]

The owner's manual has different configurations, but the trend is the same: all things being equal, except for engine horsepower (i.e., 328 vs. 335), they recommend that back tires be at higher pressure for 335.

[ADHD]

well if you want to get tech get some nitrogen and run it...
I will say this! the reason why its higher in the manual on the 335 is cause were running more hp... they now the car will be pushed and the best handling for tires is to have a couple more lbs in the rear!!
I race karts competitivly and have always been told to run +2 in the rear whether im running 11/13 or 12/14.. u have to remmber oxygen expands at high speeds and the higher temps can cuase unstable higher tire pressure.

[poiney]

I think this is why too.

Is the issue high-speed cornering or high top speed?

[kujo]

I have always had great luck with tire wear.
General rule of thumb for pressures.

10% of your curb weight and +1 or 2 in the rear.

So, if your car is 3,500 lbs.... Run 35psi in front and 36-37 in the rear.

I usually run just 1psi more in the back, as you get a bit more grip/oversteer this way.

TOO much pressure in the rear will induce Oversteer, as there will be less contact patch and you'll lose grip in the back causing the back end to break loose.

ADHD, what Karts do you run ? I also Kart quite a bit.
Looking into a new Motori 7 T+G. They have a new 175cc motor, crazy....
A bit nicer than my Mari chasis and Yamaha 100cc.

kj

[a|an]

What is the ideal tire pressure for both front and back - 17" 161s mixed tires on the 325i?

[carl_d]

335 has greater unsprung mass (bigger brakes)!

Originally Posted by poiney

My owner's manual recommends ~ 3psi higher for the back tires for the 335 as compared to 328i, all else being equal (i.e., speed limit, loading). I assume the main risk for higher pressure is catastrophic blow out at high speed (correct me if I'm wrong). But since the manual stipulates maximum speed for both cars, it seems that tire pressure should be specified the same.

Why do they specify higher pressure for 335 for back tires?

Also, why is the pressure of the back tire generally higher than front tire?

[SROC3]

so for the 335i what is the correct tire pressure exactly? 35F/36R?

[SROC3]

Originally Posted by kujo

I have always had great luck with tire wear.
General rule of thumb for pressures.

10% of your curb weight and +1 or 2 in the rear.

So, if your car is 3,500 lbs.... Run 35psi in front and 36-37 in the rear.

I usually run just 1psi more in the back, as you get a bit more grip/oversteer this way.

TOO much pressure in the rear will induce Oversteer, as there will be less contact patch and you'll lose grip in the back causing the back end to break loose.

ADHD, what Karts do you run ? I also Kart quite a bit.
Looking into a new Motori 7 T+G. They have a new 175cc motor, crazy....
A bit nicer than my Mari chasis and Yamaha 100cc.

kj

Awww. You're kid's so cute bro. He looks like Formula 1 - race car driver material.