Unsprung weight too low vs. torque = wheel spin?

[Ahbengdriver]

If u put light tyres, light forged rims, light brake kits, light (whatever), will u end up with 'too much of a good thing' and experience wheel spin?

Can this be overcome with, say a slightly wider tyre which will use the otherwise wasted power which causes the rear wheel to spin and put the power down on the road properly?

 

[acupunch]

Re: Unsprung weight too low vs. torque = wheel spin?

with your 335i specs, even with heavy setup it will still spin wan le.

IMO, wheel spinning mainly cause by driver who floored their throttle pedal at move off. if you can manage your right foot well, it shouldn't happen.

 

[Ahbengdriver]

Re: Unsprung weight too low vs. torque = wheel spin?

Is it possible to floor throttle n not spin, but take off like fighter jet on aircraft carrier ? keke

 

[phil]

Re: Unsprung weight too low vs. torque = wheel spin?

yes, buy drag slicks, put 90/10 shocks in the car, set up the rear as hard as possible, basically, make it a drag car

I think with turbo lag, you should gte off the line fairly quick, but i guarentee my 318 will beat you to the other side of the intersection

 

[centurion]

Re: Unsprung weight too low vs. torque = wheel spin?

If u put light tyres, light forged rims, light brake kits, light (whatever), will u end up with 'too much of a good thing' and experience wheel spin?

Can this be overcome with, say a slightly wider tyre which will use the otherwise wasted power which causes the rear wheel to spin and put the power down on the road properly?

Light unsprung weight at most reduces the overall weight of the car by like 30kg max, compared to the car's huge weight of 1680kg, with you inside 1750kg, this weight savings is only less than 2%. With 50% of the weight over the rear wheels for BMW, only 1% difference in weight over the rear wheels.

Traction can be helped by weight, eg. the 911's traction on the rear wheels is helped by the 40-60 balance with 60 over the rear wheels.

However, 1% difference does not at all affect your traction, what's more, the reduced unsprung weight improves your suspension compliance and reduces rolling inertia so that your car can overcome the inertia of the tyres and brakes quicker and with less effort.

 

[Ahbengdriver]

Re: Unsprung weight too low vs. torque = wheel spin?

Adding a rear spoiler to add downforce at the rear helps?

 

[centurion]

Re: Unsprung weight too low vs. torque = wheel spin?

If u put light tyres, light forged rims, light brake kits, light (whatever), will u end up with 'too much of a good thing' and experience wheel spin?

Can this be overcome with, say a slightly wider tyre which will use the otherwise wasted power which causes the rear wheel to spin and put the power down on the road properly?

Light unsprung weight at most reduces the overall weight of the car by like 30kg max, compared to the car's huge weight of 1680kg, with you inside 1750kg, this weight savings is only less than 2%. With 50% of the weight over the rear wheels for BMW, only 1% difference in weight over the rear wheels.

Traction can be helped by weight, eg. the 911's traction on the rear wheels is helped by the 40-60 balance with 60 over the rear wheels.

However, 1% difference does not at all affect your traction, what's more, the reduced unsprung weight improves your suspension compliance and reduces rolling inertia so that your car can overcome the inertia of the tyres and brakes quicker and with less effort.

 

[shaaz]

Re: Unsprung weight too low vs. torque = wheel spin?

yes, buy drag slicks, put 90/10 shocks in the car, set up the rear as hard as possible, basically, make it a drag car

I think with turbo lag, you should gte off the line fairly quick, but i guarentee my 318 will beat you to the other side of the intersection

If i'm not wrong there isn't or hardly any lag on the 335.

ABD
You could widen your rear track, high performance tyres would help alot. You won't wheel spin like really burn rubber la, but you'd prob hear a chip .. i don't know abt you but that always put a smile on me ..

 

[centurion]

Re: Unsprung weight too low vs. torque = wheel spin?

Rear spoiler does not help with takeoff. It hardly improves any forward traction, but a spoiler does improve side-side traction and increases stability at speed. This is an aero aid, you need AERO first.

 

[Ahbengdriver]

Re: Unsprung weight too low vs. torque = wheel spin?

If i'm not wrong there isn't or hardly any lag on the 335.

ABD
You could widen your rear track, high performance tyres would help alot. You won't wheel spin like really burn rubber la, but you'd prob hear a chip .. i don't know abt you but that always put a smile on me ..

Yeah a bit of chip sound is fine. So wider performance tyre can hor? I was watching one of those new E92 M3 videos and this red M3 left long rubber marks after spinning its rear wheels. I knew that M3 had 18" tyres and probably 255 width rear Michelin PS2 tyres.

So I should get some 275 PS2s next time.

 

[shaaz]

Re: Unsprung weight too low vs. torque = wheel spin?

Yeah a bit of chip sound is fine. So wider performance tyre can hor? I was watching one of those new E92 M3 videos and this red M3 left long rubber marks after spinning its rear wheels. I knew that M3 had 18" tyres and probably 255 width rear Michelin PS2 tyres.

So I should get some 275 PS2s next time.

Yup, not a problem.. not that easy to get the long rubber marks unless you launch i would say. that being said you'd either have to be manual or have the launch function. So you're safe even with more torque and bhp when or if you intend to juice ur baby, you might have the DSC light here and there coming on .. but it's not going to be some what of a problem.

Buddy of mine pushing out 560NM or close to there and all i see is smiles and more smiles.. and to be honest.. the times when we're out together i never ever hear any tyre screeching or chips.. so you're safe la sir.. no prob. 275's babeh.....

 

[kenntona]

Re: Unsprung weight too low vs. torque = wheel spin?

So I should get some 275 PS2s next time.

Hahahahaha, Beng. Both Omar and Sam running on 265 rear. But Omar is contemplating on 275 rear...... then again my 235 front 275 rear is less than optimal, feeling some understeer........

 

[shaaz]

Re: Unsprung weight too low vs. torque = wheel spin?

Hahahahaha, Beng. Both Omar and Sam running on 265 rear. But Omar is contemplating on 275 rear...... then again my 235 front 275 rear is less than optimal, feeling some understeer........

Understeer is a good thing.. but if you need to make it more nuetral.. start looking at ur suspension set-up bro, play with the damper settings.

 

[acupunch]

Re: Unsprung weight too low vs. torque = wheel spin?

Light unsprung weight at most reduces the overall weight of the car by like 30kg max, compared to the car's huge weight of 1680kg, with you inside 1750kg, this weight savings is only less than 2%. With 50% of the weight over the rear wheels for BMW, only 1% difference in weight over the rear wheels.

Traction can be helped by weight, eg. the 911's traction on the rear wheels is helped by the 40-60 balance with 60 over the rear wheels.

However, 1% difference does not at all affect your traction, what's more, the reduced unsprung weight improves your suspension compliance and reduces rolling inertia so that your car can overcome the inertia of the tyres and brakes quicker and with less effort.

very logical & technical explanation le.. but I read E90 its 50:50 build chassis, not sure about E92. with jus the front roll passenger I felt good especially on high speed curvy road. with rear passenger I don't feel much lag too... BMW torque its good. I liked

 

[kenntona]

Re: Unsprung weight too low vs. torque = wheel spin?

Understeer is a good thing.. but if you need to make it more nuetral.. start looking at ur suspension set-up bro, play with the damper settings.

Ya, bro, I'd think it could also be the 5/4 settings on my coilovers. Also, was told that 245/275 might help to minimise some understeering instead of 235/275.

 

[phil]

Re: Unsprung weight too low vs. torque = wheel spin?

jesus Ken, how fast are you turning into corners? I get massive understeer on my shitbox, only cause its raining, haha!! You must have a stiff set up (no comments)

 

[Ahbengdriver]

Re: Unsprung weight too low vs. torque = wheel spin?

Ya, bro, I'd think it could also be the 5/4 settings on my coilovers. Also, was told that 245/275 might help to minimise some understeering instead of 235/275.

245/275?:woowooo: . your chia will look like a lamborghini from far...I am scared!

 

[kenntona]

Re: Unsprung weight too low vs. torque = wheel spin?

245/275?. your chia will look like a lamborghini from far...I am scared!

Boh bian. 235/265 is optimal, but rear suspect grip insufficient. 235/275 a bit understeer.

Else I must play around with (negative) camber or soften the sways.......

 

[Ahbengdriver]

Re: Unsprung weight too low vs. torque = wheel spin?

Boh bian. 235/265 is optimal, but rear suspect grip insufficient. 235/275 a bit understeer.

Else I must play around with (negative) camber or soften the sways.......

Most on E90post.com uses 235/265 leh. I think u hoot yr car too much

TripleM's E46 M3 also runs 235/265 right? How come he got no understeer

 

[rex7_vtec]

Re: Unsprung weight too low vs. torque = wheel spin?

Me running on 235/265 after adjusting camber and toe now the car is so neutral it oversteers when pushed hard