Ride height for street & track?

[Raucky2000]

As low as you can go before the front and rear controls go past level.

[CanAutM3]

A few thoretical pointers:

Stiffer springs do not change the amount of weight transfer; front to rear or left to right. However, with stiffer springs, the car moves less (roll/ pitch) for a given weight transfer. This allows the car to take a faster set when changing attitude and allows better control of the tire position relative to the road.

Lowering the ride height will reduce the amount of weight transfer because it reduces the distance between the center of gravity and roll/pitch centers. Reducing weight transfer improves grip. This is where it gets interresting, changing the front and rear height by different amounts will change the front to rear left-right weight transfer balance. For example, lowering the front more than the rear, when in a corner, the rear will see more weight transfer than the front which increases the front grip relative to the rear (less understeer or more oversteer)

The stock M3 suspension has a pretty good anti-dive / anti-squat geometry built-in. I personaly don't find it dives too much under braking. I found my E46 much worse in that respect.

I have been tracking cars for almost 20 years, so I don't consider myself a novice anymore. IMO, the stock EDC suspension is quite capable. I run a mild r-comp (NT01) and I am pretty impressed with the suspension. For sure, better springs or a coil over will make it better. But it is pretty good out of the box .

[bigjae1976]

Originally Posted by CanAutM3

I have been tracking cars for almost 20 years, so I don't consider myself a novice anymore. IMO, the stock EDC suspension is quite capable. I run a mild r-comp (NT01) and I am pretty impressed with the suspension. For sure, better springs or a coil over will make it better. But it is pretty good out of the box .

Which is even more of a reason why sleeve-over kits are mostly a waste...IMO.

I also disagree with the first remark. It takes 21 years to shed the novice title.

[Billj747]

Originally Posted by CanAutM3

A few thoretical pointers:

Stiffer springs do not change the amount of weight transfer; front to rear or left to right. However, with stiffer springs, the car moves less (roll/ pitch) for a given weight transfer. This allows the car to take a faster set when changing attitude and allows better control of the tire position relative to the road.

Lowering the ride height will reduce the amount of weight transfer because it reduces the distance between the center of gravity and roll/pitch centers. Reducing weight transfer improves grip. This is where it gets interresting, changing the front and rear height by different amounts will change the front to rear left-right weight transfer balance. For example, lowering the front more than the rear, when in a corner, the rear will see more weight transfer than the front which increases the front grip relative to the rear (less understeer or more oversteer)

The stock M3 suspension has a pretty good anti-dive / anti-squat geometry built-in. I personaly don't find it dives too much under braking. I found my E46 much worse in that respect.

I have been tracking cars for almost 20 years, so I don't consider myself a novice anymore. IMO, the stock EDC suspension is quite capable. I run a mild r-comp (NT01) and I am pretty impressed with the suspension. For sure, better springs or a coil over will make it better. But it is pretty good out of the box .

While I agree that stiffer springs do not affect the amount of weight transfer and they make the car take a set quicker, too stiff of springs reduces contact with the ground, especially on bumpy surfaces.

Lowering the car lowers both the Cg and the roll centers. But I agree that lowering the front generally gives the front slightly more grip. However, rake (or lowering the front more than the rear) has no real impact on the cars weight distribution.

I also don't think the stock suspension is that bad on track and the car does not dive all that much under braking.

[CanAutM3]

Originally Posted by Billj747

While I agree that stiffer springs do not affect the amount of weight transfer and they make the car take a set quicker, too stiff of springs reduces contact with the ground, especially on bumpy surfaces.

Agreed its all about finding that sweet spot compromise.

Originally Posted by Billj747

Lowering the car lowers both the Cg and the roll centers. But I agree that lowering the front generally gives the front slightly more grip. However, rake (or lowering the front more than the rear) has no real impact on the cars weight distribution.

You are correct, I was confusing two things here, roll center position only has a very negligible impact on weight transfer. Here, weight transfer is reduced simply because Cg is lowered.

I may not have been clear, but I never wanted to imply that static weight distribution was altered .

Originally Posted by Billj747

I also don't think the stock suspension is that bad on track and the car does not dive all that much under braking.