Spring rate for rear coilovers

[evilC]

Originally Posted by ricola

I ordered my coil-overs today, if using with steel arms make sure you get the smaller diameter springs (1.9") or they may foul on the trailing arm. I bought pro-techs and have in the past, much better than previous AVO and GAZ from my personal experience in quality and value for money (they are all ally bodied and retail at £80+VAT each but easy to get money off). They also build them to your exact spec for the standard price, today I was offered options on length, bushing type and size (rubber/spherical) as well as rod diameter 10/16mm

http://www.protechshocks.co.uk

I'll receive them on tuesday

Great link Rich, I will lock it away in the brain cell for future reference!

Originally Posted by Obiwan

Thanks guys for your feedback. It's really appreciated.

Regarding rear axle reinforcement, I've got the Eyeball engineering torque bar.
http://eyeball-engineering.net/TorqueBar.html

Intrax answered to my questions. They can build specific coilovers based on 944 ones on my desires. Nevertheless the price is too HUGE for me (2350€). A bilstein cup set is about $2000.

UK Pro-Tech coilovers can also be a good alternative regarding the price of an equivalent set. Especially if it possible to select coil overs with off-set lower eye mounts.

The Eyeball Eng. torque bar is not suitable IMO for a full coil over conversion. The unit should be no less than a 5-bar Kafer Cup brace set that fully triagulates the the top fixing position for the coilover unit. The EE torque bar won't prevent the top fixing from moving upwards or sideways. The EE torque bar may resist the frame horns from moving downwards under torque but the bar is under a point load bending moment that also has a bolted joint at its maximum bending moment position. It all goes against the very basic principles of structural engineering although you can make anything strong enough if you add enough weight.

Offset eye mounts on dampers should be avoided at all costs since they will impart a side load to the internal seals that will fail all too quickly.

Clive

[Obiwan]

Thanks Clive for your explanations on the EE torque bar limitations. I'll sell it & look for a 5-bar Kafer Cup brace set.

Regarding your "general" comment on the offset eye mounts, I understand your point of view but I'm also confident in Bilstein engineers that designed the escort cup set with the an offset eye mounts for the rear coiloovers. Until now I've not seen such complaints or issue on this bilstein set on sevrals Porsche 944 dedicated forums.

[evilC]

Originally Posted by Obiwan

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Regarding your "general" comment on the offset eye mounts, I understand your point of view but I'm also confident in Bilstein engineers that designed the escort cup set with the an offset eye mounts for the rear coiloovers. Until now I've not seen such complaints or issue on this bilstein set on sevrals Porsche 944 dedicated forums.

I don't doubt Bilstein's expertise on this one its just that it kinda goes against the grain. The dampers that Bilstein supply are presumably set for 2.5" coils? with the threaded section that goes low down on the damper body so the potential for the coil to foul the arm is pretty high. If you use Rich's 1.9" coils and carefully select the spring length then there is a better chance of acheiving the clearence.

It occurs to me that offsetting the eyelet to get better clearance is just the same as putting a spacer on the bolt and using the standard eyelet. Assuming that the bolt is long enough, the load position and hence the BM will be the same for both the offset eyelet and the standard eyelet with spacer, although the angle at which the damper operates will be less vertical than normal but should be still within the ability of the bushes/bearings.

Clive