Question for the brain trust. Where does Porsche measure " ride height " off of?

I've heard of fenders, some say specific points on the chassis .
What's correct?

Thanks in advance.

 

it's suppose to be specific point on chassis but most people refer to and use fender as measurements

 

 

Excellent - thank you!

 

that's about 40mm difference between us spec turbo vs. gt2/gt3...i didnt' know it was that much

 

Those Porsche numbers assume your are running stock size tires and the stock tire pressure. If you're running a taller or shorter tire or different air pressure, than those specs will not be correct.

I prefer to the measurement from the top of the fender lip to the center of the wheel. Assuming you haven't modified your fenders, this actually tells you what you want to know, which is the suspension geometry relative to the chassis.

The issue is I haven't seen the stock numbers in the chart above, translated to the fender to wheel center measurement. If someone with a stock car, that is set to the correct measurements could take the fender to wheel center measurement, that would be great. It would also be great if someone with stock size tires and PSS10's set to the recommended Bilstein measurement could post the fender to wheel center measurement.

This would be very useful for those of us running taller than stock tire setups.

Later, Steve

 

I just compared height to " spec" after an alignment...it's with in 3/16 of an inch or so.
Oh I readjusted tire pressure - f: 34 r:39 .. Stock 315 rears and 235 f..on pS2. Sorry as I did not check the before #.

 

Note that you can not superimpose GT2/3 rear measurements to TT due to the fact that the TT has 7mm thicker rubber subframe bushings than the solid GT bushings. In other words, if you want your TT at GT2 ride height as per the manual, you will need to set the rear TT ride height 7mm lower than the GT2. Most people don't realize this. Stock GT2 tires are also taller than stock TT tires.

 

While that rubber is between the subframe and chassis and ride height is measured from the subframe, it does not affect at all to OEM measurement style...just to wheel center to fender height.

 

It does. The official rear height measurement is off of the bottom of the rear subframe measured to the ground. The TT subframe is positioned 7mm lower than the GT2 subframe (relative to the body of the car) due to the thicker rubber bushings. As such, if you take a TT and a GT2 and they both have the same fender to ground measurement (with same size tires), then the GT2 ground to subframe measurement will be 7mm higher than on the TT.