Help me setup my 944s2 race car suspension!
05-08-2017, 10:49 PM
#16
Rennlist Member
Apologies for the confusion.
11-30-2017, 07:18 PM
#17
Burning Brakes
Thread Starter
Few updates: added some 225in/lb coil over springs to the rear (along with the 26mm torsion bars), Much more neutral bias and rear tyres now taking a lot more load as seen via tyre temps. Front springs will shortly go up to 400# from 350 as fronts still too soft. 9M torsen diff has just failed/allows only one wheel drive so is oversteering like a pig right now, so that is to be sorted. Has just been corner weighted: 1303kg with driver and 3/4 fuel!! heavy....
12-04-2017, 07:10 PM
#18
Drifting
Ahhh, still heavy understeer bias though.
As stated above, your rear Tbar is probably factory balance for for a mere 150-160# front spring and even so, anyone with a good feel for these cars will tell you that there is a built in slight understeer from the get go.
From the braking nosedive picture, you definitely need to go another 100 on the front. IMO, the 30mm bar is a good neutral match for 400# F.
If your springs are 350#, then yeah, maybe 28-9mm. That won't resolve the nose dive though.
Still, what is total weight of car....?
My son races a top of the field 944 in PCA SP2 that I setup completely myself.
400# F. It's my belief that the 1000# spring setups that some people race on these cars is way excessive, his results prove that out, but again, my opinion.
The suspension has to be allowed to work and do it's job and at these high rates, all you have working is the sidewall of the tire....again, my opinion.
I can share other setup data off line....
T
As stated above, your rear Tbar is probably factory balance for for a mere 150-160# front spring and even so, anyone with a good feel for these cars will tell you that there is a built in slight understeer from the get go.
From the braking nosedive picture, you definitely need to go another 100 on the front. IMO, the 30mm bar is a good neutral match for 400# F.
If your springs are 350#, then yeah, maybe 28-9mm. That won't resolve the nose dive though.
Still, what is total weight of car....?
My son races a top of the field 944 in PCA SP2 that I setup completely myself.
400# F. It's my belief that the 1000# spring setups that some people race on these cars is way excessive, his results prove that out, but again, my opinion.
The suspension has to be allowed to work and do it's job and at these high rates, all you have working is the sidewall of the tire....again, my opinion.
I can share other setup data off line....
T
Enjoy all your suspension setup threads. Helps me to design and evaluate my 944 2.5 L NA for suspension modifications.
Sent a PM to "share other setup data off-line. "
Thanks
Tom
Last edited by T&T Racing; 12-06-2017 at 12:30 PM. Reason: Mistake on initial
12-05-2017, 11:43 PM
#19
Three Wheelin'
Few updates: added some 225in/lb coil over springs to the rear (along with the 26mm torsion bars), Much more neutral bias and rear tyres now taking a lot more load as seen via tyre temps. Front springs will shortly go up to 400# from 350 as fronts still too soft. 9M torsen diff has just failed/allows only one wheel drive so is oversteering like a pig right now, so that is to be sorted. Has just been corner weighted: 1303kg with driver and 3/4 fuel!! heavy....
Cheers, Mike
12-06-2017, 05:04 PM
#20
Few updates: added some 225in/lb coil over springs to the rear (along with the 26mm torsion bars), Much more neutral bias and rear tyres now taking a lot more load as seen via tyre temps. Front springs will shortly go up to 400# from 350 as fronts still too soft. 9M torsen diff has just failed/allows only one wheel drive so is oversteering like a pig right now, so that is to be sorted. Has just been corner weighted: 1303kg with driver and 3/4 fuel!! heavy....
Do you know what the set up is on the lower wishbones on this car ?
From the photo, for sure the front looks too low and soft but I don't think it is , but unless the front lower wishbones and stub axles have been modified they will not be parallel to the ground
and hence the Rollcentre will be in a worst position (pivoting more than a standard car). To truly benefit from the lower centre of gravity the suspension needs to be in it's optimum static state at rest and I'm thinking it's probably not?
Which is why the front of the car Rolls excessively (Your soft explanation?)
I had this but have rectified it now, and the different is a huge improvement and I circulated a circuit recently with 170 lbs front springs, and a 968 with 350lbs springs and my car was not much different!
Scroll down to see what I did to rectify not only the incorrect static wishbone angle but also bumpsteer issues.....
http://924srr27l.co.uk/suspension/
R
12-06-2017, 06:28 PM
#21
Burning Brakes
Thread Starter
It's not too bad, my 2.7 924 is 1150kg with driver & Fuel,
Do you know what the set up is on the lower wishbones on this car ?
From the photo, for sure the front looks too low and soft but I don't think it is , but unless the front lower wishbones and stub axles have been modified they will not be parallel to the ground
and hence the Rollcentre will be in a worst position (pivoting more than a standard car). To truly benefit from the lower centre of gravity the suspension needs to be in it's optimum static state at rest and I'm thinking it's probably not?
Which is why the front of the car Rolls excessively (Your soft explanation?)
I had this but have rectified it now, and the different is a huge improvement and I circulated a circuit recently with 170 lbs front springs, and a 968 with 350lbs springs and my car was not much different!
Scroll down to see what I did to rectify not only the incorrect static wishbone angle but also bumpsteer issues.....
http://924srr27l.co.uk/suspension/
R
Do you know what the set up is on the lower wishbones on this car ?
From the photo, for sure the front looks too low and soft but I don't think it is , but unless the front lower wishbones and stub axles have been modified they will not be parallel to the ground
and hence the Rollcentre will be in a worst position (pivoting more than a standard car). To truly benefit from the lower centre of gravity the suspension needs to be in it's optimum static state at rest and I'm thinking it's probably not?
Which is why the front of the car Rolls excessively (Your soft explanation?)
I had this but have rectified it now, and the different is a huge improvement and I circulated a circuit recently with 170 lbs front springs, and a 968 with 350lbs springs and my car was not much different!
Scroll down to see what I did to rectify not only the incorrect static wishbone angle but also bumpsteer issues.....
http://924srr27l.co.uk/suspension/
R
Yes I am concerned about roll center issues - the car has standard 968 control arms with no ball joint offsets or anything, which is why I've brought the ride height up a bit lately. I'm really still working on all this stuff and learning at a fast rate; hopefully fast enough!!
12-07-2017, 02:26 AM
#22
Then at least you know whats causing your excessive roll and softness feel, another solution is to buy the Cup arms..
High Strung
https://www.facebook.com/highstrung44/
https://l.facebook.com/l.php?u=http%...OPWyCf7yZWEeOw
R
High Strung
https://www.facebook.com/highstrung44/
https://l.facebook.com/l.php?u=http%...OPWyCf7yZWEeOw
R