Ride Height on '79 911SC

[jonbot]

Hi guys, this is my first "real" post now owning my first Porsche. The car seems to be riding too low (feels like it keeps hitting the bump stops when i go over bumps). Anybody know off hand what the euro-specs on ride height are for a wide body Porsche? Also, is this measured from the ground to the fender lip? Thanks.

Pic related:


Jon

[Gunter]

Jon:
Nice car.
Search the board, lots of info on ride height, suspension etc.
Have fun.

[Kraftwerk]

The ride height looks great. But where you live: Speed bumps and dirt roads might require an inch more of clearance. I live in NYC so my car cannot be lowered too much , unfortunately... the suspension system has to be considered as well, new bushings etc.

[FinallyGotOne]

To address the bottoming out, you probably are, but I bet that it is due to bad strut inserts. I had my car lowered to just over 24.5 inches at the fenders and it bottomed out a lot. Then popped in two new strut inserts and it does not bottom out any more. I posted the how to, it's a VERY easy job. And the inserts cost me about 3 bones. That is a nice looking SC by the way!

[jonbot]

I actually did some searching before I posted, but couldn't find any ride height numbers specifically for a wide bodied car. If anybody has any numbers, that would be extremely helpful.

Jon

[Gunter]

It doesn't much matter if you have a wide body, or regular.
If you go to low, the shocks and struts will bottom out plus you'll get a bad bump steer.
The ride height is set up with the Torsion bars so that the movement up and down is in the middle of the travel-range of the shocks.
Generally, anything lower than 25" front and 24.5" rear (Fender lip) takes away performance.
What shocks/struts do you have?
Were the big spacers on top of the struts removed?
Do you have the bump steer kit under the rack?
Were the main bushings on the rear trailing arm replaced?
Aside from the height, are you doing a 4-wheel alignment and corner balance?
Anytime the height is changed, the alignment changes.
Are you looking for performance or just looks?
If you just want looks, set it anywhere you want and live with the bumps and bad performance.

[kwm]

This is a very helpful thread. Why? Because I have all the same issues too. I was told my strut inserts would cost 1200 to be replaced. I have serious bump steer issues as well. Are suspension issues really fixable for a DIY guy who has no lift, impact tools, etc...? I lowered my car to like 22.5 or 23. Yhea it made my bump steer issues worse and VERY occasionally I do bottom out (I say very occasionally b/c I drive the same rout in the car everyday and I know what to avoid on that rout to keep it from bottoming out) but man it sure does look a helluva lot better.

[jonbot]

Originally Posted by Gunter

Generally, anything lower than 25" front and 24.5" rear (Fender lip) takes away performance.
What shocks/struts do you have?
Were the big spacers on top of the struts removed?
Do you have the bump steer kit under the rack?
Were the main bushings on the rear trailing arm replaced?
Aside from the height, are you doing a 4-wheel alignment and corner balance?
Anytime the height is changed, the alignment changes.
Are you looking for performance or just looks?
If you just want looks, set it anywhere you want and live with the bumps and bad performance.

Then I won't go any lower than those numbers, I don't want to hurt performance. I'm not sure what shocks/struts I have in there, I just got the car, I figured first priority should be to get it off of the bump stops. No bump steer kit, in fact, original tie rods I believe, not turbo tie rods. I don't think any of the bushings have been replaced. I will do a 4 wheel alignment and wheel balance, but I don't know if the shop I go to has the equipment to do a corner balance. The shop is Bridge's Wheel and Tire in Burlingame, CA. If anyone can recommend a shop near me that does the corner balance, please do, in fact, I'll start a thread asking that. My first priority is performance, I want my Porsche to handle like a Porsche, form follows function.

Thank you for all the help

Jon

[Gunter]

Jon:
Find a shop that knows the 911.
A good Porsche shop will tell you if the tie rods, or ball joints, or bushing need replacing BEFORE they do an alignment.
You also need to settle on what Camber/Toe you want.
Most people do not want the factory specs; search some more.
I suggest you settle on a reasonable ride height first, install the bump steer kit (It's an easy DIY) consider installing turbo tie rods if the old ones are worn.
Get the Bentley SC Repair Manual to learn more about your 911.
Setting the front height is easy but the rear is fairly complicated (You'll need to understand the 40/44 spline principle)
And you'll need an absolute level ground to set the height.

kwm: 22.5 or 23 is pretty bad but good for "bling."

[FinallyGotOne]

22-23 !! that is too low. That thing must handle like a nightmare??? I'd go back up to at least 24. I know for racing lower is better to allow less air under the car, but for normal driving eeks....As racing you usually replace all the bushings to stiffer, strut inserts to stiffer, brakes, weight, alignment, tires....etc...

[jonbot]

Today I had the car's ride height adjusted, and oh man, now that the suspension isn't sitting on the bump stops, this thing drives great! I'm sure the Bilsteins don't hurt either I took the car on the freeway and couldn't help but smile as I reached triple digits and left the Lexus IS300 behind me in the dust. This car is awesome!

Jon

[CT944]

let's see some pix!

[jonbot]

Originally Posted by CT944

let's see some pix!

I'll take some pics in the next couple of days

Jon