Hi Chris,
Yes the agreed. In theory it should not make any diff but in reality
it does. How do I know ? My buddy is running the same set-up as
me but with 27mm T-Bar which equates to about the same 400lbs
rear spring that I'm running. On the same road, you can feel theres
much less jarring & twisting coming from the rear end. Another
key factor with running T-Bars is that the lower shock mounts will
have less load to carry which means longer life span for the hemi
joints.

 

? J Chen how do u feel the twisting coming from the rear end?? <please describe>

 

Stupid question for the suspensionally challenged, but what exactly is to be gained by doing this?

 

Jeff, have you ever tried to reindex the bars?

 

>>Stupid question for the suspensionally challenged, but what exactly is to be gained by doing this?<<

If you want to change spring rates takes about one hour. Try doing that with TBS.

In 1990 911 went to coil-over.

 

6 seconds at WGI.

(not exactly a direct answer to your question )

Just because I'm so damn happy with the results of switching over from the stock suspension to coilovers, I thought I'd post my results. Best lap time last year, compared to my best lap time Sunday, 6 seconds!

The difference is unbelievable. I was expecting maybe a 2-3 second gain, who says you can't buy speed?

More seat time tomorrow...

 

Hi Reno,
The rear hatch squicks much more due to flexing.

 

Hi Shiners,
Were you running T-bars of the same spring rate as your
coilovers ? If not than it is not a valid point that you're making.
Maybe you might gain another 1 sec by going back to T-Bars
of the same rate. But than again if your car has a roll cage installed
than it would not make any difference

 

the rear hatch squeaks more due tro age, not flex. The t-bars are part of the suspension, not the tub. The hatch is attached to the tub, as is the t-bar carrier.

 

If you use elephant racing spring plate bushings, this is a non-issue.

 

Ive run the same car with and w/o torsion bars using equivalent springs rates. This is on a dedicated race/track car. Generally cannot notice the difference with body flex, definitely not on the street.

Cage is not really relevant unless you have a custom built cage that ties into the rear upper shock mounts with cross bracing. If not, the cage really does not stiffen the rear chassis/tub at all.

 

Wow, the PO deleted the tbars on my car... should I expect a rear suspension collapse at any time ? This topic seems to be turning into the drilled rotor discussion: lots of speculation and hysteria... wheres the pics of these failed shock mounts?

 

Have you calculated pound-force/sq.inch with the t-bar and shock setup and compared to a coilover setup?

I would guess that the load on the mounts/bolts will be significant larger with a coilover setup. So how much beating and stress could the mounts and bolts take?
You have to remember they are not designed for this. Driving on smooth tarmac is one thing, but on circuits like the Ns, or the roads where I live (they are just as bad as at the Ns)
I would think that the stress from constant hammering and beating of the suspension would cause this to eventually fail.

But then again 4 years is a long time …

 

Unless you yump the car regularly, I wouldn't worry about it, and I don't know anyone with a lot of experience that does (around here, anyway). OTOH, all the cars I'm thinking about have welded-in cages. Changing the rubber outer torsion bar bushing for delrin, e.g., Racer's Edge (squeeky) or polybronze, e.g., Elephant Racing (expensive), is probably a good idea to get the most out of the change, though - ditto for the rubber bushings in the coil-over'd shocks - these should be replaced regularly (and really shouldn't be there, and probably aren't, and I'm guessing the lack thereof are a prime factor contributing to the difference in noise and vibration).

I still have t-bars, but that's due to rules, and also that I want to keep some rubber in the system (because I do yump the car on occasion).

As for drilled rotors, don't even go there - I have them, and I know they work better than solid or slotted - for my application.

 

Deleting the torsion bars won't hurt a thing. You can run it on a track car or a street car or a combo car. No difference.

The ONLY possible problem is when you are using a coil over shock which is not built specifically for the 944. Shocks that are not built specifically for a 944 require the use of spacers between the shock and the control arm along with a longer bolt (referring to the lower mounting point).

When you use a spacer to push the shock away from the conrol arm, you change the load placed on the bolt from a sheer load to a bending load. And this is when people run into problems... and this is when bolts break. It's not often, but it happens.

But by using a shock such as the Bilstein Escort shock (which was built specifically for the 944), with its offset mounts, combined with the placement of the spring, and its factory rubber mounts, you see that the fit is factory correct, the shock mount is butted up to the control arm (no spacers to push the shock out), the stock shock bolt is used, and you will NEVER see a broken shock bolt.

The key here is using a shock that is built for the 944.

DO NOT USE SPACERS to push the shock out from the control arm. If you have to do this, then you need to rethink your purchase.

TonyG