I saw the nice thread re: this question focusing on engine mods. But I'm interested in suspension mods. Thoughts? I was thinking coilovers, but was recently informed that involves cutting and welding, and that the trunk will get wet "whenever it rains" so not an option for a dual-duty vehicle. Or was I misinformed?

Thanks!

 

My '87 930 has coilovers and I don't have any problems as you described. I also didn't have any cutting or welding. I have heard that the strut mounts need to be beefed up but my car has been coilovered for about ten years with no problem. It might be different if you race it. It rides like its on rails and the height can be adjusted in just a few minutes. It is worth looking into but as with anything else, you can go for the race level of mods or you can go for the street level. There is obviously a big difference. Just look at a brake upgrade with Big Reds. On the street you won't feel any difference or maybe even a little less casual stopping power, but on the track they will handle much more heat and therefore not fade for a much longer time than the stock brakes. So plan any mods on how you will use your car.

 

which coilover setup do you have? The only one I've researched is the SRP/Fox system.

 

Imagine Auto sells the RSR setup.

 

I have the RSR setup from Imagine on my dual purpose 930 and love it.

Other 930 owners that have been in my car at the track are all saving their mod $$ for the coilover conversion.

 

Are the coilovers worth it if the car is going to spend 99% of its time on the street?

Are there any advantages (on the street) to having coilovers with higher HP mods?

 

There are 2 advanatges to coilovers:

1) it is easier to set ride height
2) you can run much stiffer springs (tbars only go up to ~400#)

For the street, only #1 really matters. The other difference (not really a pro/con) is that a tbar tends to act a bit like a progressive spring: softer at the beginning of the range, and stiffer at the end. Coilovers are very linear, which is better for tuning at the track.

For street, a tbar setup is fine, though you will likely find that a coilover setup may actually be the same cost.

 

arent the 930's torsion bar at the back?

 

and front

 

Stephen Kaspar said that the 911/930 would only have to be strengthened when you go over a certain spring rate. Basically the spring rate he mentioned was too high for street use. I am guessing also stiff shocks could also need a strenghthened car but you shouldn't use stiff shocks with soft springs anyway.

 

My car handles great with 31+23 mm tosion bars and polyurethane bushings and Bilstein sports shocks, and lowered ride height. I can't imagine needing much more on the street. I can drive into most any corner without slowing down at all and just twist the steering wheel, and like magic I am onto the next straight away.

Don't overdo it unless you have nothing else to do with your cash. Or if you are going to be on the track a lot, which I know I won't.

Torsion bars are pretty damn good in my opinion. I can think of some other things like my gearbox that I would rather spend money on personally.

 

This is nice to hear. When I first looked at tbars vs. coilovers, there was about $500 difference. (see earlier post by 38D) But it seems that the system at Imagine is more than my first estimate, so it's more like $800-900 difference. There's always something else to do with your money, isn't there?

Leaning more to the tbars.........

Also would consider selling my 16" 7/9 Fuchs for 9/11 Lindseys. No need to keep things original, as I already have a motor swap.

 

I think if you do go with torsion bars, get hollow ones and the weight won't add up as much. The one thing about torsion bars is that they don't weigh down your shock mounts the same way. With coilovers you probably want a strut brace to keep your stuts tied together. Most people don't seem to think you need that with torsion bars.

I am not trying to suggest that coil overs will stress your car more, I don't know that to be true. Just that you will want a strut brace to keep your front end struts from eventually becoming torqued a bit by being utilized as part of the coilover system.

Just my two cents from a guy that is happy with torsion bars. I am sure that coil overs are great too, and clearly superior on the track.

I think you should make sure you have a really first class tuning shop and they will do a good job aligning the car and maybe corner balancing it.

I think my anti sway bars are upgraded too. Elephant racing makes suspension kits, which I have not checked out myself, but I did want to mention that they sell a new type bushing which is superior to polyurethane because it has a grease fitting and won't squeak. I think it is metal instead of urethane, also. Those bushings really do help.