Stiffer Rear Springs Installed ..., What Else Needs to be Changed? Options

[Eddie914]

The rear shocks/springs on my teener have been changed from 185 lb/in progressive springs on Koni Red gas adjustable shocks, to 225 lb/in on Koni Yellow gas adjustable shocks with threaded collars.

What other changes will have to be made to the suspension set-up?

Most of the tracks are run counterclockwise. The rear tires wear unevenly. The outside of the right rear tire wears most. The inside of the left rear tire wears most. The front tires wear most on the outside.

My thought was that by increasing the rear spring rate, camber change in the rear would decrease. I suspect that the front anti-sway bar will need to be adjusted to a stiffer setting.

I purchased the 914/6 as a conversion with a 2.7 with 40mm Weber carburetors. The handling has always been fairly well balanced so no changes have ever been made to the suspension other than alignment and tire pressure balance. The 2.7 expired and was replaced with a stock 3.2 still using the Weber carburetors.

I believe it has the 23mm Weltmeister front anti-sway bar and no rear anti-sway bar. The front struts are matching Koni Red gas adjustable (compress and twist to adjust) struts. I do not know what front torsion bars are installed.

Thanks in advance.

Eddie

[campbellcj]

How is the static alignment set now, the camber in particular? Is it possible that things are out of whack from side to side?

If you're running radials then you most likely will want significant negative camber, i.e., 1.5-2.0+ degrees. Many 914's cannot get much more than this with the stock suspension parts/geometry.

Have you taken tire temps at the track? If not then that would be good info to have.

[PeeGreen 914]

You'd have to pull the Torsion bars and see what they are to really know what else you need. You may need a little bigger but who knows. I'd talk to Tim and see what he suggests. He seems to know the alignment and corner balance stuff better than most anyone for the 914 (Other than Greg)

[Eddie914]

I took the car to the Alfa Lapping day last Friday at Bremerton.

The morning was pretty much a rain-out. I did manage two fairly dry sessions in the afternoon.

The balance is not far off. There was a bit of loose handling (oversteer) under full throttle but the track still has spots of water.

I will try stiffening up the front anti-sway bar a bit.

The added rear spring rates seem to add a bit of precision. Oversteer is more easily catchable.

Maybe I will break down and spend a few bucks and get a corner balance and alignment.

Cheers

Eddie

[Downunderman]

One thing not to do is screw the yellow Konis up to max. All that will do is jack the suspension down and ruin everything. It is best to get the balance right with the shocks set on full soft and then when you are happy with it, mess with the shocks. Then after you have messed with them, put them back to full soft or close to it.

Cheers,

H

[sean_v8_914]

chris is barking up the right tree. sounds alignment related but tire temps will speak louder than speculation.
what tires do you run?
185 up to 225 is alot of change. if the car was previously balanced as stated then it would be loose in teh rear now. the front should be stiffened.
stiffer springs unload quicker and reward smooth fast reflexes but they will show you any driving technique weaknesses you might need to work on.
Jon mentioned your front torsions...what size are they?
front bar size?