Real performance difference in 71 S vs. 72 S?
 

So I own a very stock, well performing 71 S today and always curious if I should have bought a 72 S. I know all the cosmetic and mechanical differences between the two, but when you balance the 2.4 displacement of the 72 and the lower weight and higher compression of the 71 - does the 10 HP really make a difference? What is a better performer 35 years later? BTW - I chose the 71 for the chrome grill and 901 transmission - though I love that front spoiler on the 72. Thanks for anyone's learned opinions.

Interesting question......
According to Paul Frere in his book "Porsche 911 Story" the 911S 2.2L turned 0-60 in 7.0 secs, compared to the 911S 2.4L 0-60 in 6.6 secs.
1 KM standing start are very close 2.2 is 27 secs vs 26.9 secs for the 2.4.
0-99.5mph, 2.2-17 secs, 2.4-15.7 secs.
As you know the 2.2 compression is 9.8:1 requiring Premium fuel,
where the 2.4 was reduced to 8.5:1 and can run on regular fuel.
The 915 trans in the 2.4 had slightly lower mid range gears, with the same ratio in 5th as the 901 fitted to the 2.2.
So top speed was very close.
This would account for the better acelleration, along with about 10 more ft/lbs of torque to move the 100 lb. heavier 2.4.
In stock form it looks like the '72S is just a bit quicker than the '71S.
I would like to hear from those who have driven both to comment.

If you can get a copy of Frere's book(I think he's up to version 7 now) on p61 of ver6 are the hp/torque curves for both of the engines that you asked about.

If the torque cuves are overlayed, this is what you would see.
http://forums.pelicanparts.com/uploa...1159533086.jpg

What you feel in your butt when driving are these curves multiplied by transmission gearing and tires.