Ride Height

[pete917]

Im trying to collect some data on various ride hieght setups on our (1974-89) 911's.

I know this is not the best way to measure ride height, but if you have the info could you share your ride height as measure from the ground through the centre of the wheel to the wheel arch lip. Both front and back.

Here's mine:

Front Right: 25" (63.5cm)
Front Left: 25 1/4" (64.12cm)
Right Rear: 24 3/8" (61.9cm)
Right left: 24 3/8" (61.9cm)

There are measurements without m in the car. (some balancing to be done on the front )

Cheers guys.

[Kroggers]

Hi Pete,

I have been following your other discussion as well, and very interested in the end result. I have my car booked in for a full alignment and corner balance in two weeks time.

The current ride height on my 1978 911SC, measured to the arch lip is:
Front: 62.5cm
Rear 63cm

I am not sure how much this will change when the alignment is done though...

This is my current suspension configuration to help with your analyses:
.- Glen Sanders 23mm hollow front torsion bars.
.- Glen Sanders 33mm hollow rear torsion bars.
.- Koni Yellow adjustable front and rear shocks.
.- Elephant Racing PolyBronze front and rear bushings.
.- Elephant Racing Low-Friction Control Arm Mounts.
.- Elephant Racing Weather-Sealed Trailing Arm Monoball.
.- Elephant Racing Weather-Sealed Front Monoball Cartridge.
.- Elephant Racing ASP - Adjustable Spring Plate with ER QuickChange Splined Hub kit .
.- Tarett Adjustable Hollow Front Sway Bar
.- Tarett Adjustable Hollow Rear Sway Bar
.- Wevo Rear Sway Bar mounts
.- Turbo Tie Rods

[Talewinds]

Add photos...

Mine: 25-1/2" at all four corners.

[nesslar]

Just had an alignment done and had the ride height adjusted a bit (mainly left rear, which has always been just a touch too low.
Now I'm at about 25" rear, about 25.75" front; rocker panel "rake" is 3/4" higher at the rear, measured at tip of rocker to ground. I like it.
Side-to-side measurements at like points ground to chassis are identical front, identical rear.
Lotsa guys like 'em lower, but I like to see some "air" over the tires (about 1" or so rear, 1.5"+ front....approx. ...I'll edit for photo later...
Seems identical measurements to fender lips can be hard to obtain; years of body twisting, settling, suspension wear, whatever....one of many interesting little idiosynchrasies with these cars...including the owners, lol.

[jimbauman]

@Pete... my ride height measurements are just about identical to yours with 16" wheels ... 23/30 TB's, Koni adjustables, ERB bushings, turbo tie rods and bump spacers on the front, Bilstein Sports and SAW adjustable spring plates and bushings on the back...

JB

[Tom '74 911]

(sorry for bringing this up) I know this has been said ad-nauseum in other posts . . . but measuring from the fenders is not a great way to be accurate when measuring ride height. My car has welded on rear flares and they are off by almost 1/2" side-to-side (crappy PO welding job too). The front fenders are stock, but are off 1/4". The best way (from the factory manual even) is to measure from the centerline of the torsion bars. You can use the spring plate covers in the rear and the rear end caps in the front. This will be much more accurate (again sorry).

Tom

[Gunter]

Being that low, you have issues with bump-steer.
Did you install the spacers under the rack to lessen this problem?
If not, I suggest you do it. :

Decide what height and alignment you want before you have it done.
Some popular settings:
Fender height front 25" and rear 24.5" which gives the desired 1 deg nose-down attitude.
Castor: 6 to 6.2 degree,
Camber: front 1/2 to 3/4 degree, rear 1 to 1.5 degree,
Toe: front slight Toe-in like 1/8", rear 0 (Neutral)

The Tech doing the work will love you if you open each bolt, apply Antiseize lube and re-tighten.
If you do that beforehand, it'll save time and make things easier.

Expect things to settle, i.e., after about 1-2 weeks after adjustments, the height may settle 1/2" to 3/4" down.

Originally Posted by Kroggers

Hi Pete,

I have been following your other discussion as well, and very interested in the end result. I have my car booked in for a full alignment and corner balance in two weeks time.

The current ride height on my 1978 911SC, measured to the arch lip is:
Front: 62.5cm
Rear 63cm

I am not sure how much this will change when the alignment is done though...

This is my current suspension configuration to help with your analyses:
.- Glen Sanders 23mm hollow front torsion bars.
.- Glen Sanders 33mm hollow rear torsion bars.
.- Koni Yellow adjustable front and rear shocks.
.- Elephant Racing PolyBronze front and rear bushings.
.- Elephant Racing Low-Friction Control Arm Mounts.
.- Elephant Racing Weather-Sealed Trailing Arm Monoball.
.- Elephant Racing Weather-Sealed Front Monoball Cartridge.
.- Elephant Racing ASP - Adjustable Spring Plate with ER QuickChange Splined Hub kit .
.- Tarett Adjustable Hollow Front Sway Bar
.- Tarett Adjustable Hollow Rear Sway Bar
.- Wevo Rear Sway Bar mounts
.- Turbo Tie Rods

[Jerome74911S]

Originally Posted by Tom '74 911

(sorry for bringing this up) I know this has been said ad-nauseum in other posts . . . but measuring from the fenders is not a great way to be accurate when measuring ride height. My car has welded on rear flares and they are off by almost 1/2" side-to-side (crappy PO welding job too). The front fenders are stock, but are off 1/4". The best way (from the factory manual even) is to measure from the centerline of the torsion bars. You can use the spring plate covers in the rear and the rear end caps in the front. This will be much more accurate (again sorry).

Tom

Tom's is a really good point. I never thought about the fenders being off. But, there is another point that confuses me. When I am sitting in the car, then the heights are equal right to left side within 3mm (assuming the fenders are okay). Is this the right way to measure, or should there be no weight in the car?

Jerome

[Tom '74 911]

Originally Posted by Jerome74911S

Tom's is a really good point. I never thought about the fenders being off. But, there is another point that confuses me. When I am sitting in the car, then the heights are equal right to left side within 3mm (assuming the fenders are okay). Is this the right way to measure, or should there be no weight in the car?

Jerome

When you drive your car, and you're cornering and braking and testing the car's balance are you in it? : ) : ) YES!!!! The best way to take all these measurements is with you or your equivalent weight in the driver's seat. Great point.

Tom

[UK Carrera]

Final settings following a full ride height/corner weight/alignment session are (roughly):
Rear camber -1 deg 32'/-1 deg 38'
Toe +1.5/+1.8 mm


Front camber -0 deg 56'/-0 deg 58'
Toe +0.7/+0.7 mm
Castor: +5 deg 30'/+5 deg 38'

Ride heights (left/right) - measured torsion bar centre to wheel centre:
Front (before) 127/122mm Front (after) 133/132mm
Rear (before) 239/254mm Rear (after) 254/257mm

[Talewinds]

Wow, that looks perfect to me! Nice. Got any more photos from the side?

[UK Carrera]

Here you go - just about to undergo corner weighting:

[Talewinds]

Ya. Really really nice. Thanks!

[Oh Haha]

Holy Schmoly!!!!!

She is awesome!!!



Now I know what mine would look like with silver petals.


Hmmmm---it IS supposed to rain this weekend.

[ZOA NOM]

Originally Posted by UK Carrera

Here you go - just about to undergo corner weighting:

Oh my, what a beautiful car...

I'll never let either of mine go...

[UK Carrera]

Note that the wheels on my car are not painted - the centres are bare aluminium.

I have simply stripped the paint from the centres.

[pete917]

Originally Posted by UK Carrera

Here you go - just about to undergo corner weighting:

Great Pic fella. What size tyres are you running?

That side shot tells a great story with regard to ride height. Mine sits the same as yours to the rear but a little higher to the front.

Since my first post, I have managed to get a consistent reading on the inclination of my car.

I placed a block adjacent to the centre of the wheel on both front and back. Both blocks the same thickness;

I then ran a straight edge from one block to the other. The top of the straight edge now represents the angle of the car at the tyre contact points.

Next I zeroed my inclinometer on the straight edge

Then I transfered the inclinometer to to the centre point of the door sill.

I measure an inclination of 0.4 degrees (down at the front)

So, the distance between weel centres on my car is approx 231.5cm. Over that distance at 0.4 degrees there should be a difference of 1.61cm. Looking at my original readings of rear 61.9cm and front 63.5cm thats a difference of 1.6cm.

So, Porsche recommend a 1 degree gradient. This means I need a further 0.6 degrees or 2.42cm less onfront. This would make my ride heights as follows:

Rear 61.9cm
front 61.08cm.

So I have some adjusting to do

Just for reference. A 1 degree slope over 231.5cm is 4cm. So the front of the car needs to be 4cm lower than the rear. So clearly the height of the arches at the front and rear of the car are not the same....

[jimbauman]

Here's what 24"/23" ride height and 1 degree slope looks like with 15" wheels....





JB

[pete917]

She looks nice Jim. You can see te slope of the car from the side skirts.

BTW, what tyres are those?

[jimbauman]

Thx Pete - it was aligned and corner balanced this week...

Those are Nitto NT01 225/45-15's - I got those for the track to replace the Toyo RA1's when they were no longer available.

JB