Kagan

Hi,

What is the rpm at 70 miles/hour for your 911 3.2? Is there a different differential setup for different cars produced in the same year?
thanks..

whalebird

No, to answer your question. All the Porsche owners manuals have a rpm/mph chart toward the rear in the "specifications" section. You will get your info there.

ked

eyeballed from the chart in my '87's OM (dated 6/86), where there is alot of useful info...
4th: 3600
5th: 2850

Ed Hughes

Keep in mind as we've moved on in the world of tires from the 80's, that diameters are somewhat all over the map, even for the same sized tires from different manufacturers. This will effect the final answer.

ron mcatee

Kagan, I just did a test of my car with Yokohama ES100, 16" tires on it. At 70 mph, my speedo reads 3100 rpm. As Ed stated, tires may have an impact on readings since a lot of them have different rolling radius's.

GothingNC

I wonder if it the same for the SC?

I usually cruise at 3200 RPM in 5th
16 inch fuchs

John

Ed Hughes

16" means nothing. You need aspect ratio and tire diameter/circumference to determine any sort of speed/rpm correlation.

rusnak

I was going to say the same thing. I get 3100 +/- 100 rpm in 5th.

My SC was geared much lower, so add 1K rpm to the 3.2 rpm figure.

whalebird

Maybe a garden variety GPS would help determine true speed and clarify any variations.

GothingNC

Rears are 225/50 16
Diam 24.9"
Circumference 78.09


Front 205/55 16
Diam 24.9"

Kagan

hmm I see.. I recently bought a 84 targa and I am still trying to get used to the car and trying to learn the characteristics . I know that the tire specs will affect the speed and rpm on the first hand. These are very close to what I have despite the wheel size (my 84 targa has 18 inch wheels). Thanks so much..