BJJones

Hi

I am looking for anyone with experience or views on coilover conversions on the 930 turbo.

One of the major issues that I have always had with my 930 is the antiquated suspension design/function (I expect a deluge of abuse for this statment!)

I have just bought a complete setup but would like any tips from anyone who has performed the conversion or who have a car that has been converted.

Things I would especialy like to know:

Has anyone had any issues with the extra load on the suspension turrets, especialy the front ones? I will be using a strut brace and my chassis is strengthened with a bolt in rear cage.

Did you use adjustable suspension top mounts, my spring plates are fully adjustable.

I have rose jointed spring plates to remove the stiction from the original rubber bushes and have obviously removed the torsion bars. Any experiences with setting up the rear ride height etc would be appreciated.

What were your before and after thoughts on the setup, was it worth it?

Thanks for any input you can give me.

ZCAT3

I have done this in probably the most simple way you can - using a Bilstein RSR setup. I am using the stock shock mounts in front, but may go to a monoball type mount at some point. I also have a strut brace. I would be less concerned about the front than the rear as the rear carries more weight. Setting the rear ride height is quite easy as you just have to change the spring height with the lower threaded perches.

The front springs can be noisy as they tend to preload as you turn and they may "sproing" on you resulting in a thunk. I corrected this by using an old trick suggested by Stephen at Imagine Auto - putting rubber hose on the top and bottom of the spring. This eliminated all the strange noises. Stephen would be a good person to answer your tech questions.

As for performance, the coil overs improve both ride and handling. The car reacts better to bumps and has less body roll. It is much more predictable as well. It is pretty obvious why Porsche went to this system with the 964.

I do not think anyone will argue with you that the torsion bar suspension is pretty antiquated. There are a lot of improvements that can be made to that suspension, however, to get very good performance.

BJJones

Hi Bill

Thanks, good point about the rear taking more weight. I take it you have had no problems in that department?

Are you using the standard spring plates and top mounts on the rear?

Any chance you could send me a picture of your set up?

When you say you are using the Bilstien RSR setup does that look like a re-worked version of the standard struts at the front? in other words the original struts with adjustable spring plates welded to them.

I have seen lots of posts about the torsion bar suspension and how to improve it, but I have always had it in the back of my mind that I wanted to go the coilover route. I have much more experience of this type of setup and have never been too interested in learning about the black art of torsion bars!

Thanks again

Barry

ZCAT3

Barry - these are full threaded shock bodies. Here is a picture of the rear:

ZCAT3

And here are all the parts laid out (you can see that ride height is pretty easy to set - you still need to use all the regular stuff for alignment setting though):

BJJones

Bill

Thanks very much for your help, the effort you have gone to is much appreciated.

My plans have suufered a blow, the guy I was buying the coilovers has just mailed me and told me he has sold them to someone else!

Any pointers on where I can source a new setup? my web search hasnt revealed any dealer.

Also bill, are the struts made to accept your 930 front hubs as a direct fit?

Thanks

ZCAT3

Barry - this setup is a direct bolt in to the 930. You can contact Stephen at Imagine Auto as he is the one he sold me the parts. His e-mail is porschephd@imagineauto.com. Your car sounds like it is all ready to go for this setup.

ZCAT3

Here is a picture of the front strut mounted on the car - not the greatest but you get the idea. You can just make out my nifty Elephant Racing finned oil lines in the top of the fender well.

BJJones

Good news, I had to up my bid a little but I managed to secure the coilover kit and am picking it up on Saturday.

I will keep you posted on how I get on, thanks again for your help and advice Bill.

ZCAT3

Barry - good luck and post some pictures if you get a chance.

DP935CAB - my rear towers are stock at the moment and are holding fine. Stephen at Imagine Auto had this same setup on his car for many years with quite a bit of track driving and had no issues with shock tower strength. If I see or sense any issues or start tracking the car on a regualr basis I will probably strengthen both the front and the rear - I want to go to mono-ball adjustable camber plates up front as well and may stiffen the srpings a bit (although the current setup is very good for street and DE driving).

PorschePhD

Nice pics Bill

The issue with the Coilovers is when the spring rates are set very aggressively and the car is tracked heavily. The spring rates we normally use for street/light track is fairly conservative and will not cause an issue. I ran my personal car making gobs of HP and do so for about 4 years without issue.This and the various data from the 100+ sets we have sold support this as well. There is a lot of talk that you shouldn't or can't do this. The application will fit the need. If you are making a dedicated track car and that is all you do then spring rates like 800-1000 will be a serious problem. Otherwise 800 rate is not appropriate for a street car and should be backed down. At lower spring rates the dooms day theory does not apply. Enjoy the benefits of coilovers. They really are a great setup.

ZCAT3

[QUOTE]Originally posted by PorschePhD
[B]Nice pics Bill

Well 2 of the pictures are from you -

Any suggestions for a monoball setup up front?

BJJones

Hi

Stephen & Bill, can I have your comments on this:

I have begun to install the coilovers on my car, reputed to be genuine RSR items but whoi knows.

I have had the engine and gearbox out of my car for a while now so the ride height is all over the place.

I note that the assembled rear coilover strut is about 100mm shorter than the standard strut, would this be normal, I am thinking that the springs compress less when loaded up compared to the torsion bars?

The std struts measure around 680mm the coilovers 580mm approx.

Also the kit came with rose jointed spring plates, I am concerned that with the rose joints on the lower strut mounting the whole set up including the wheel will be able to movearound quite a lot.

The trailing arm is able to move around a fair bit after you disconnect it from the std spring plate, so with a rubber mounting at the strut top, a rubber bush at the trailing arm mount, rose joints on the lower shock mount and the spring late, what holds the whole lot in line?

I am probably not thinking this through the right way, and I have not finished bolting it all up yet, due to a problem removing a snapped bolt from the standard spring plate but comments would be welcomed.

Bill are you using rose jointed spring plates? and are their rose joints on the lower shock mounting?

Thanks

Barry

ZCAT3

Barry - I am definitely not the person to provide technical support for your install. If you post some pictures here of what you have I am sure some more qualified members will chime in. On the rear install, the spring plates remain attached and are still used for alignment setting (youjust remove the torsion bars form the tube and then put everything back in place).

BJJones

Thanks Bill, I know the spring plates remain, I have new ones that are rose jointed, and are adjustable for length, they reduce stiction from the rubber bushings.

I was just wondering if you had somthing similar, sounds like you are using the standard ones.

I removed my torsion bars and fitted one side of the rear kit today, you can ignore what I said about the alignment not being kept due to the rose joints it is solid as a rock.

I will post some pics that I took today later, I also fitted some genuine 993 RS lightweight door panels today that look the dogs.