340Elise

I thought I would start a new thread since there was a lot of response to my original thread, and I want to make sure that all those who contributed find out what happens with my GT3. Some of you seemed very curious as to what the problem is.

Today the dealer did another alignment and it improved the straight line tracking of the car, and the steering response is definitely better, but still not right.

Also, the steering does not want to go back to center on its own. I actually performed the following test at about 6/10's driving on a tightly curved road:

I take a fairly tight corner at a decent speed and remove my hands from the steering wheel and it basically stays in the same position. I was of course very careful with this and started at lower speeds and worked my way up with my hands barely off the wheel and ready to grab it. The road that I was on did have some gravel on it from a recent snow, so I did not do any hard cornering, but enough to where I would think the wheel should have been returning to center quickly when you let go. It just sat there and barely moved, if anything at all (other than surface irregularities being transmitted through the wheel). At low corner speeds it did the same.

Unless I am losing my mind, this certainly does not feel right and is not the normal behavior of a steering system.

There is no damage to the suspension (they gave it a full look over), and there also is not anything wrong with the power steering or the rack; or so we think.

It is definitely feeling better, but is certainly not right yet. Here are my before and after alignment values. Please let me know if the caster is the culprit here. I also really wonder about the machine they are using and its accuracy based on the before values. It is a laser type alignment machine and is fairly new. Also, as I type this, I am now really wondering if maybe there is something wrong with the steering rack or power steering system. Is it possible for the alignment shown below to cause the steering wheel to behave the way it does while taking corners?

Front Left:
Before After
Camber -1.57 -2.00
Caster 8.41 8.41
Toe 0.00 0.05

Front Right:

Camber -2.03 -2.07
Caster 8.28 8.28
Toe -0.03 0.05

Rear Left:

Camber -2.49 -2.49
Toe 0.13 0.09

Rear Right:

Camber -2.45 -2.46
Toe 0.06 0.09

Notice that the front toe is now in, and that is not what I asked them to do. However, it certainly took care of the straight line tracking of the car. Also, all of this was done without rotating the struts and the shims were left as before.

Tomorrow we plan to either reduce the camber some by removing shims, OR we will try rotating the struts in addition to removing shims. We want to try to get the caster as close to 8.0 as possible. According to the alignment machine, the right caster is within spec and the left is just slightly out of spec. Is this enough to cause this odd behavior???

Brian S

You're going in the right direction, those settings should not have a car stuck in a corner like that. The very nature of the rear toe-in and front caster force the car to drive straight when cornering force is not applied. 8.41 to 8.28 isn't enough caster to be really obvious, some drivers may feel it though.

I wish my dealer didn't charge me $240 for each alignment that they do poorly or I would play with the top camber as well. My wife took the car one time with very specific instructions and they didn't even tell her it wasn't done to some random specification and still took my $240 and expect me to come in again to get it right.

NJ-GT

The alignment before was not right, especially the rear axle, having different toe readings at the back is really bad.

Forget about the caster being the problem, those caster readings are fine. These cars never read even caster at both front wheels. Manthey Racing uses a special camber plate that increases caster by 1 degree to 9 degrees, the part was designed for the 996 GT3, and they still sell it as an improvement for the 997 GT3. The higher caster improves straight line stability and reduces the need of high negative camber settings at the front axle.

I use the rear toe at 0.25 degrees per side, because 0.10-0.15 per side (.20 to .30 total) makes the car too nervous, but this is not the problem you're experiencing.

At this point, I suggest to check the power steering pump (oil level, pressure, sensors, etc).

I have driven my GT3s with the most wacky alignments, and I have never experienced the behavior you have with your car.

Even if the alignment machine is not calibrated, you should not experience the problems you have with the steering wheel.

340Elise

It could be the stering wheel then also. As I mentioned in my first thread, I replaced the steering wheel with the OMP Cup wheel. This came with a hub kit, and maybe something is rubbing and not allowing the wheel to spin freely. I will put my stock wheel back on tomorrow and try that.

Thanks so much!

997gt3north

- Sounds like a good first guess.
-I was wondering if the 997 computer was somehow freaking out and semi killing your power steering
- I know those wheels work on 996s so why not 997s but you never know
- Hope you get this sorted as I too would like to maybe try this steering wheel
- I assume you are getting an airbag light or have you found the correct resistor to mask the missing airbag

- my 2cents is I would reverse your front and rear camber to (-2.5f, -2 rear) - you will like the car better and your rear tires wil last longer
paul

Earlierapex

Problems like this are usually more simple than we like to envision. Describing your problem to an alignment guy, he would say you have a castor issue. I would suspect the alignment machine is screwed up or your tech is over his head.

If that clearly isn't the case, then you can start checking steering issues and other alignment issues (extreme toe-out at the front could cause this too I suppose).

Brian S

In general, going from 8 to 9 degrees of caster would give your car less slow speed initial turn-in and better steering on the mid corner to exit and slightly affect straight line stability. Decreasing it would be the opposite and provide less straight line stability (sort of) because the car is just more darty in general. I have tried 7-9 and keep going back to the factory 8.5 area unless your track is all first gear then maybe 7 is for you, no matter what my car never had a heavy steering feel. We do have power assist and speed sensitive steering for a reason.

Caster works along with camber (and toe) so the more caster you have the greater the camber change (gain on the outside) you have going into a corner. Also the more the inside wheel tends to lift the car and transfers more weight to the outside wheel which is where you get high load cornering help from.

340Elise

Paul,

I have been thinking the same think from the beginning regarding the OMP Cup wheel. Because we have that variable ratio steering, I thought that somehow the car is getting confused. But how can it know that a smaller diameter wheel is on the car? The smaller wheel is just quicker responding by allowing less movement to get the same desired steering angle change. Unless there is a plug that goes into the old wheel that lets the car know that a different wheel has been installed, but that is not the case. You have the wires for the horn, and then two sets for the two stage driver side airbag.

The OMP wheels does come with a hub that fits the Cup car steering rack, and they had to order me a different hub to fit my rack. But it fits fine and do not see an issue there. Yesterday, while at the dealer, I borrowed one of those fancy $700.00 electronic torque wrenches and reset the center steering wheel bolt to the correct value one more time. I thought maybe I had too much torque which was compressing the spring and other parts and maybe causing the whole steering to have resistance because of this.

The airbag light is easy to sort out. One way to do it is go into the PWIS (is that what they call it?) and have the dealer simply turn off the driver side airbag. In my case, i used two 2 Ohm resistors for the 2-stage plugs. One came with the hub kit, and the other I had leftover from a Lotus Exige hub and quick release kit. It was the same resistor with the same plugs; worked great!

I will tell you that once I get this steering issue fixed, that you want the OMP Cup wheel. I use it with a fairly thick hub adaptor (helps bring it closer to me), and on top of that I use a very high quality quick release system (main reason is that I had one from my Lotus days, and it gives me even more distance towards me); it is a Works Bell unit and has a ball bearing locking system with absolutely zero play in the steering wheel. Anyway, with the smaller diameter wheel, and by allowing me to bring it much closer (where I think it should be, and it gives me better car control), I think it is a great set up. I am just anxious to see how it feels once I get this steering wheel rotation issue solved.

03-turbo911

I hope it all gets sorted! Getting a second opinion on the alignment by taking it to someone else and seeing what they get on their machine might be the thing to do.

A picture of the steering wheel fitted will be appreciated! I was thinking of doing that before reading your problems.

Yargk

I can't believe it's the wheel.

fc-racer

I bet it's the steering wheel. I had a mono wheel installed on my 993 turbo that exhibited the same problem. We had to fashion a spacer to take the friction out. The steering returned to normal after the fix.

va122

I agree it could be the wheel, i have an OMP on my 996 (actually have the Momo too if anyone wants it.) and my car would pull to the right b/c the wheel was not centered.

Hope that helps.

daytonaviolet

how about put the oem steering wheel back on give it another test drive. isolate the wheel then perhaps concentrate on the alignment.

iLLM3

OMFG I think that's the problem with my car too, it always feels like after a track event or some street driving my alignment is out of spec and my toe is out because the wheel is tilted a little, meanwhile the specs are still the same, wow!

todinlaw

I would problem solve as suggested above, put your old wheel on first before you do anything else with the alignment. My two cents on the alignment, Paul is correct I would run more negative camber in front and have it about 1/2 degree more front to rear. That ratio is what works. Also the toe issue will be a continuing problem if you do not replace the OE rear toe links the are notorious for not holding the alignment. Lastly, the rear toe would not cause your problem, it will make the rear tire tire wear uneven. Keep it up you will figure it out.