924Board.org

[Nein37]

In the next week I'll be upgrading my front suspension with a ground control height adjustable coilover setup, running 250lb Weltmeister springs and Bilstein HDs.

I currently have Koni sport adjustables in the rear on their softest setting.

Front sway bar is stock and unfortunately my 931 does not have a rear sway bar.

Will my car turn into an understeering freak mobile and if so how might I remedy this?
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1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.

[Cedric]

Yes probably, you could counter act some of it by adding some negative camber up front but it still will be understeering. Get a 19mm adjustable rear anti sway bar at least. MOer suitable is to change the torsion bars, not that big job, at least on my car. But this is very much coneccted to what tyre sizes you have, if you have wider at the rear the understeer will be even worse.
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1980 924 Turbo
www.instagram.com/garagecedric/

[Rasta Monsta]

[J1NX3D]

you should definitely get a rear sway bar, and if you get the turbo rear 18mm or the 968 M030 3 way adjustable, then you should do your front sway bar also.

i had a 20mm front sway bar and nothing rear on my 944. the weight transition from side to side in the twisties was horrible but I didn't realise how bad it was until i did a track day. I then put on a 26.8mm front sway from a S2 and a 18mm rear from a turbo and it felt like a new car! the awkwardness was gone and it was easier to keep power down. You should notice this difference too.
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'86 944

[Nein37]

Assuming I add a 19mm bar in the back should I also stiffen the setting of the Koni's in the rear? Or is the stiffness of the damper meaningless without revised torsion bars?

Concerning the front bar upgrade. I was under the impression that a higher spring rate in the front would require increasing the rear sway bar stiffness but not the front bar? Any thoughts on this.

BTW I'm a suspension noob... and I appreciate the help very much.

John
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1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.

[Cedric]

If you talk vehicle balance its very much roll stiffnes that is the factor. Roll stiffness is mainly from spring rate, that could be added either via springs/torsion bars or anti sway bars or both. If you add a big rear bar and an even bigger front bar you could end up with a car with same front-rear ratio and thus a car that behaves like an understeering dog again, it depends on the bar stiffenesses.

Stiffer dampers will affect the driving, in transients the car will feel more composed, and wheel control will be better. But too stiff will only be bouncy as heel without any actual performance gains.

Too bad i dont have so much time nowdays, or else i could have programmed a little matlab program for spring rate calculations on our cars..
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1980 924 Turbo
www.instagram.com/garagecedric/