Larry Harris

I recently bought a 1994 C2 and it sits very high off the ground (much like a snow plow)Probably 3" between the top of the tire and the lowest part on the fender.

I also have a M491. Front height on the M491 is 24 1/2 inches with no rubbing -225x16 on the front.

I want the 964 to sit lower. I have a neighbor who just bought a 2000 C2 and it has been lowered considerably. I haven't had a chance to catch up with him to do any measurements.

Opinions: How low can I go, assuming stock wheels and tires, an remain functional.

Lar

JoeW

Have you figured out why it is so high? You may have to begin by correcting a problem and the method for lowering (even to stock height) would be largely determined by that. How low do you want to go? (No, this is not a limbo contest!) Why? (Cosmetics? Or?) J

Larry Harris

Joe,
Thanks for your answer. I suppose my reason is purely cosmetic. I don't want any rubbing problems so I won't go to extremes, but the car is just too high in front. I don't do DE or Ax with this car so that is not a consideration. Since posting yesterday I have heard of a suspension shop locally that I will contact today.

Lar

springer3

I had to sort out the ride height, corner balance, and 4-wheel alignment as part of changing the shocks. It is somewhat tedious getting it right, but the results are well worth the effort. Definitely pursue getting the height/corner balance/4-wheel alignment sorted out.

If you are running standard 16 inch wheels, the fender clearance will look high. There is extra room for optional 17-inch, and possibly even larger wheel/tire combinations.

On my C2, I ran out of adjustment on the spring perch threads about the same time as I hit the lower limit on the factory-specified height. Going lower means different (shorter) springs. It seems all track cars get lowered, but on the street, you risk skinning up your chin and the under carriage if you get much below stock (already low for a street car, IMHO).

The front height is measured at the crossmember bolt, which is easy to find. The rear height is measured at a crease in the rear body stamping, and it is impossible to find unless you know where it is. I fabricated height gages from 1/2' plastic pipe cut exactly the same length as the lower tolerance on height. I pressed the pipe against the datum mark, and then used a wedge to get the clearance from the ground to the other end of the pipe. It is easy to measure within a fraction of a mm using this method. The alignment guy used a tape measure, but he had the advantage of a rack that provided better access.

Changes in height change the camber at both front and rear. Height changes also change the corner balance unless you go exactly equal amounts on each side. If I recall correctly, the factory gives a tolerance of +/- 5 mm (about 1/4 inch) for side-to-side height difference, and a +/- 10 mm (1/2 inch) tolerance for absolute height. Corner balance takes precedence over height. On mine, it was easy to get balanced well within the height allowance. I had brand new tires, so I set height at the middle of the tolerance range, figuring that I would be near the bottom by the time the tread wore down.

There is a special wrench required to turn the spring perches. I fabricated one from 1/4 inch steel plate. It worked fine, but unless you enjoy metal working, it would be cheaper to buy one. Clean and lubricate the threads on the spring perches unless you are putting in new shocks, and the perches are new.

If you suspect the ride height was raised, I would get the alignment checked before changing anything. The adjustment range for camber is small. If you lower too far, your alignment person may not get the settings within tolerance. Be sure to get the alignment done at a shop that is set up for 4-wheel alignment, and make sure they have experience with 911s. This is not a job for the local Goodyear store.

BGLeduc

Ummmm, I am not sure about that. If you do a proper +1 upgrade, the 17" wheel/tire should be the same diameter (or very close) as the 16". It will look worse though because the tire sidewall height will be shorter, which visually accentuates the already high fender clearance.

You will not gain much with the perches. These are there to allow corner balance. Even spun to the lowest setting in front, you will be luck to gain 1/2 inch, usually much less.

As was mentioned, to do the job right requires correct lowering springs. Like many users, I have installed H&R progressives for my C2. I also upgraded the shocks to the Bilstein HDs at the same time.

And there's no need to split a gut measuring ride height. You can simply use a yardstick to measure from the ground to the top of the fender lip. This is certainly not the factory approved method, but it is reasonably accurate.

And as was mentioned, if you do lower the car, a full alignment and corner balance will be required. Then again, if you don't track the car, you might be able to live without a corner balance, although its is strongly recommended.

With the H&R springs on my C2, I am able to get close to the factory Euro RS ride height (IIRC, thats 25" to the fender rear/25.5" in the front). Not sure about C4's, but I expect you can get similar readings.

And I would not assume the ride height was raised. The US spec cars sit ridiculously high, IMHO. That was the case with my C2.

Somewhere on the 964 forum, someone posted pictures of a US spec C2 and a Euro RS.....the US spec car looks like an SUV in comparison.

BGL

joey bagadonuts

Yes, nice recall Brian (http://www.cupcar.net):


I believe the Cupcar is running at RS height which is actually around 24.5" front and rear--that's what my car looks like. Some might say it looks slammed and a bit low for everday use (especially with the forward rake), but that's the price for handling.

When you go with 25.5" f / 25" r, the car actually appears level when looking at the rocker panel line. For aesthetics alone, those are pretty good numbers to shoot for. And as mentioned above, you'll need to go with lowering springs to get there.

springer3

The car on the left looks like mine, which is dead on the US spec. It is hardly SUV like. The lowered car looks like it could not navigate my daily commute without scraping something.

The original post says there are 3 inches between the top of the tire and the fender lip. In the picture, the tire is about even with the fender lip. Three inches extra sounds like East African Safari or Baha height.

I would not trust a height measurement to the fender lip. The total tolerance is 5 mm. Sheet metal stamping equipment used to make the fenders can barely hold that tolerance, because every sheet has different spring back. Also consider that the front fender are bolted onto the car. If you ever take one off, there is almost 5 mm of adjustment to fit the fender to the hood and door lines. If the car has any history of fender benders, getting back to within 5 mm would be exceptional body work indeed. The factory specifies hard reference marks for a reason. Why not use their advice?

BGLeduc

No argument with that, other than its a pain in the *** to do correctly.

I think even Bruce Anderson has gone on record as saying that measuring to the fender lip is acceptable, but I do concur with your views that the accuracy is better going with the factory procedure.

Being cheap and lazy, I measured to the fender lip.

BGL

joey bagadonuts

Agreed, the Factory method is the way to go ... that's how my mechanic set up my car. The lip measurement was done after the fact.

jtkkz

Hope this helps, RS specs ride height

V=125mm
H=218mm

JoeW

Interesting. What specifically, jtkkz, are V & H measuring to? J

springer3

V and H are the factory-designated reference points for ride height. In the front, it is the bolt head for the crossmember bolt. In the rear, there is a crease in the body stamping behind the trailing arm. V and H are the distance to the ground from those points.

9caregiver

Hey that is my 4WD Paris Dakar RS America again. Who you calling high?? Took some measurements for you guys at the fender lip. Front 27" with 2.5" top of tire to lip, Rear 26" with 2" top of tire to lip. I have thought about lowering but decided to hold off. It is nice to not worry about bottoming the nose, Besides she has only 10,000 miles and does not see the track.

Best,

Don