[F32Maniac]

Hello all,

I own a 2017 f32 440i RWD, stage 2 (BM3). As you can imagine, I struggle with traction even from rolling (60km/h). The solutions im aware of include coilovers, wider/better tyres, and LSD.

I need my grip sorted before I upgrade the turbo, but dont want to spend on all of the above. If you were to rank which would contribute more to grip, which one would it be? I am leaning towards lowering the car via coilovers. Going for Trofeo R's is not an option, tread life is not a sacrifice im willing to do pre-turbo install

FYI: I am on michelin 4S Pilot sport 255/35 and 225 tyres.

Please share your grippy setups!
Thanks

[Skyhigh]

Wider tires will make things worse! You are already at the optimal width and tire brand/model! Look at other improvements.

[mmm-five]

You don't want expensive, stickier tyres as they don't wear well, but you want more grip for all the extra power?

Why are you worried about tyre longevity? Is it cost, or just don't want to change as frequently?

With all the money you're looking to spend on the turbo upgrade & other potential mods, it can't be cost...so what is the real reason you don't want to fit Trofeo-R, Goodyear Supersport R, Michelin Pilot Cup 2, etc.?

Or maybe consider a car with x-drive?

[Skyhigh]

xDrive is the ultimate solution
But in the meantime - how about torque limitation…?

[BimR]

Does no one put rocks in their trunk anymore? 😉

[MacklinUSOB]

LSD.

[not1337]

Better tires and LSD.

[njdangelo]

If your car can't handle the power it has now and you don't want to invest in "all of the above" to make the power you have usable, why would you then spend a rather significant amount of money on a turbo setup to go faster? There is no magic setup that will allow your RWD car to handle 100% of your power all the time. Think about a car like the viper... same issue, WAY too much power for what is it, which is why its an absolute death trap in the wrong hands... a fun as hell death trap but a death trap nonetheless.
Tire spin will always be a thing. You have good tires already, get the LSD, get coilovers, etc. Neither of those will allow you put all your power down from a standstill but it is the proper next step. Your car will forever make more power than the tires can handle at this point. I am also stage 2 and even with XDrive I lose traction. Physics my man, physics.

[AllaVodka]

Limited slip + improved differential brackets will help

[Billfitz]

Drive sensibly? Nah...

[F32Maniac]

Originally Posted by mmm-five

You don't want expensive, stickier tyres as they don't wear well, but you want more grip for all the extra power?

Why are you worried about tyre longevity? Is it cost, or just don't want to change as frequently?

With all the money you're looking to spend on the turbo upgrade & other potential mods, it can't be cost...so what is the real reason you don't want to fit Trofeo-R, Goodyear Supersport R, Michelin Pilot Cup 2, etc.?

Or maybe consider a car with x-drive?

Coilovers LSD and stickier tyres have a combined cost of the turbo + fuelpump upgrade. Was hoping to choose 1 out of the 3 options for grip and then transition into the turbo kit. My issue with stickier tyres is how often I need to change them and also long-term cost. Perhaps once I install the turbo the car isnt a daily anymore? Id have to drive it to find out.

[F32Maniac]

Originally Posted by njdangelo

If your car can't handle the power it has now and you don't want to invest in "all of the above" to make the power you have usable, why would you then spend a rather significant amount of money on a turbo setup to go faster? There is no magic setup that will allow your RWD car to handle 100% of your power all the time. Think about a car like the viper... same issue, WAY too much power for what is it, which is why its an absolute death trap in the wrong hands... a fun as hell death trap but a death trap nonetheless.
Tire spin will always be a thing. You have good tires already, get the LSD, get coilovers, etc. Neither of those will allow you put all your power down from a standstill but it is the proper next step. Your car will forever make more power than the tires can handle at this point. I am also stage 2 and even with XDrive I lose traction. Physics my man, physics.

Thats the knowledge im trying to acquire, whether I NEED to install all of the above or not. If one of the 3 options gives me e.g. 75% of the benefits, i'll be happy with that. If not, then I wont be going for the turbo until I install "all of the above". I am definitely not installing a turbo until my car can reasonably grip the current power. I believe ill be doing coilovers followed by LSD since coilovers have aesthetic gains as a bonus and cost less

[Skyhigh]

How are coilovers supposed to help with the grip........ on a RWD vehicle.....?
I can imagine there may be some minor benefit for FWD vehicles due to the impact on pitch, but on a RWD......

[weehe126]

Coil overs wont do jack unless you are talking about corner grip. LSD would help a little in a straight line, but again more help exiting a corner. The best option is to get wider rims and better tires. PS4S are ok, but you need a 200 tread wear tire to really have any grip. I went from 275 rear PS4S that sould spin in 3rd to RE71r that hook in second. Im only expecting 10-15k miles out of them though.

[HighlandPete]

IMO, whatever else you do, if grip is already a problem, then tires will always be the weak link. You pay, to play!

[F32Maniac]

Originally Posted by weehe126

Coil overs wont do jack unless you are talking about corner grip. LSD would help a little in a straight line, but again more help exiting a corner. The best option is to get wider rims and better tires. PS4S are ok, but you need a 200 tread wear tire to really have any grip. I went from 275 rear PS4S that sould spin in 3rd to RE71r that hook in second. Im only expecting 10-15k miles out of them though.

Thanks for letting me know!

[Polo08816]

You bought the wrong car to race from a dig.

[F32Maniac]

Originally Posted by Skyhigh

How are coilovers supposed to help with the grip........ on a RWD vehicle.....?
I can imagine there may be some minor benefit for FWD vehicles due to the impact on pitch, but on a RWD......

I thought lowering the cars center of gravity improve traction. I guess I was wrong with that one

[Skyhigh]

Originally Posted by F32Maniac

I thought lowering the cars center of gravity improve traction. I guess I was wrong with that one

Very wrong
So SUVs in your opinion have serious traction problem then

Lowering the car will improve handling and aerodynamics but definitely not traction.

[Billfitz]

Lowering the car may improve handling, but not necessarily, especially if it results in making the suspension softer. There are many suspension tweaks that I'd do before lowering, if I lowered at all. Lowering improves aerodynamics as with less air beneath the car there's less turbulence sourced drag. However, it only has a significant effect at very high speeds, higher than an amateur racer should be driving at.

[Polo08816]

Originally Posted by Billfitz

Lowering the car may improve handling, but not necessarily, especially if it results in making the suspension softer. There are many suspension tweaks that I'd do before lowering, if I lowered at all. Lowering improves aerodynamics as with less air beneath the car there's less turbulence sourced drag. However, it only has a significant effect at very high speeds, higher than an amateur racer should be driving at.

You mean the huge wing on those 120hp Honda Civics don't work well?

Lowering the car may improve handling - but I would look at how much lowering the manufacturer and respected suspension parts companies like Ohlins, AST, etc. actually provide. Lowering the car anymore may actually be detrimental to handling.

[Logicoeur]

So a lot of babbling here. Suspension not the way to go, doesn't improve grip in the situations you are looking for.

Your only options are to force the wheels to stop spinning so much, or increase the contact patch of rubber on the ground.

IMO LSD first. Without question. That will cap the amount of slip either wheel at the rear will see. Right now you are limited by the tires since there is no cap on slip with an open diff. Then once you get a feel for the car (it will change the car dramatically), decide if you want/need wider tires to increase the contact patch. Then and only then, move up to sticker tires. Eg. A max summer in 285 rubber could give you the same amount of grip that a 245-255 UHP summer tire may.

This all goes out the door if you are tracking the car. Still lsd first, but I would go stickier tire before wider.