Brian Leduc

I am getting the car aligned tomorrow, and would like to confirm the proper ride height setting for a USA '90 C2 Coupe.

At the outset, I will say that, to the best of my knowledge, the car is totally stock (it only has 42K miles, so I would not think the suspension would have needed any work).

It appears to have Boge (black shocks) with adjustable perches front and rear. I also believe that the springs are black, but I have not checked them for a part number.

I know that the factory ride height measurement procedure calls for ride height measurements from the floor to a lower suspension point.

I also know that there are many articles that talk about measuring from the floor to the inner lip of the wheel opening at the top of the wheel arch.

Using the floor to fender method, I have seen mention of 25" rear, and 25.5" front as "proper" for 911.

Can anyone confirm the the "floor to fender" measurement for a stock '90 C2?

I always thought that the car looked a bit high in the front. Others have mentioned the same about their cars.

I just took some quick measurements with a tape measure, and have found that, while the rear is a little high (about 25.5"), the fronts are WAY high. I am measuring about 27.5" in the front.

I do know that the front perches are not at the bottom, however, the factory spec for the perches calls for (I think) +/- 10mm of adjustment, so I will definetly not be able to get anywhere near the 2" I would like in front, but every little bit helps.

New spings are not an option at the moment, as I need to stay legal for stock SCCA autocross.

Thanks in advance for your replies.

Brian Leduc

George Stevens

Brian

A standard euro RS is 25" front and rear so that is too low for a standard C2

The RS is 40mm (about 1¾") lower than a standard car

So I would guess standard height is about 26¾" front and rear

George Stevens

I forgot to add, the reason that 964's are often ½ an inch lower at the front is that the "top hat" suspension cones become inverted. especially with lowered and stiffened suspension.

It is not uncommon for the front suspension to packed out with washers to equal out the ride height.

I blame speed humps!!!! <img src="graemlins/nono.gif" border="0" alt="[nono]" /> <img src="graemlins/nono.gif" border="0" alt="[nono]" />

Brian Leduc

Thanks George!

I was really concerned about the 25/25.5 I have been reading about.

The rear perches have plenty of room for lowering (or raising), but there does not appear to be anywhere near as much threading on the fronts.

I expect that I should be able to get the front to be very close to 26 3/4 if I drop them fully, and I know I could actually raise the rear to match, but I don't know that I would want to do that.

I am wondering if the rear springs may have simply sagged a bit with age.

Best Regards,

Brian

Christer

Brian

the proper height at the front is 68cms. which is 26.77 inches so George is on the money. I don't know about the rear. Get the feeling my so called knowledge has holes in it?

Brian Leduc

I was able to drop the nose about 1/2 to 3/4" with the front perches (the tech opted to leave about 3 threads showing on the shock body). The fronts are now at about 26 7/8" from the floor.

They were also able to dial in the rest of the settings (toe, camber, caster) per the suggestion in Bruce Anserson's book (Euro RS settings, I believe).

We put it on scales, and right out of the box, the corner weighting looked good (this was a relief as I had been having nightmares that the car had been secretly wrapped around a tree by a PO, and was hopelessly bent!).

With me (about 195 lbs) in the car, the fronts are off be about 21 lbs (680LF, 659RF) and the rears were really close (1000LR, 996LR). We opted to leave it that way for now.

Now its off to San Diego for the SCCA Solo II National tour. We'll see how badly I get crushed by the Boxters and S2000s.

Brian