top speed of a 911sc?
#17
Rennlist Member
These threads always surprise me. I have an 82 SC with a rebuilt race engine, headers, straight pipes running Hoosiers at 2700lbs with me in it and the most I've ever seen on the track is 130mph - flat out at Watkins Glen on the back straight (with a draft). By the way, there aren't any 3.2's flying by me either.
I've never gone more than 130 on a track either, and that was coming out of #4 @ TMS on the ALMS course. But, while I don't make a habit of it, I've exceeded that speed on the highway a time or two.
#18
NASA Racer
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I guess my point is I don't see how anyone is getting a top speed on the street higher than what I've seen on the track. Without sounding like an @ss, there isn't a better prepped stock SC out there than mine and in ideal conditions with a hoosiers and a light car with no exhaust, I can't break 130.
#20
I guess my point is I don't see how anyone is getting a top speed on the street higher than what I've seen on the track. Without sounding like an @ss, there isn't a better prepped stock SC out there than mine and in ideal conditions with a hoosiers and a light car with no exhaust, I can't break 130.
Granted, an indicated 145 isn't an actual 145, but the accuracy of the Porsche speedo isn't so far off as to be an actual 130.
Of course, all the above is anecdotal (as is your input) without official timing slips.
However, Porsche has always, if I'm correct, been a bit conservative in their advertising claims and what they published in their owner's manuals was, as I posted:
From the factory manual that came with my '82 SC RoW (204 hp):
Max. speed = 235 km/h (146 m/h).
And, OH YEAH? Well Uncle Ferdy liked MY car best!
#21
Rennlist Member
I guess my point is I don't see how anyone is getting a top speed on the street higher than what I've seen on the track. Without sounding like an @ss, there isn't a better prepped stock SC out there than mine and in ideal conditions with a hoosiers and a light car with no exhaust, I can't break 130.
Lastly, the weight of the car or the Hoosiers don't really affect the top end speed as I'm sure you know. Top end is about HP and Cd, drag coefficient; acceleration is a function of weight and torque. The hoosiers will help with initial acceleration out of the hole and grip through the curves but I don't think loss of grip will be a problem once you're moving 100mph+. I should be so lucky to have enough HP to break my tires loose at this speed.
#22
Rennlist Member
I guess my point is I don't see how anyone is getting a top speed on the street higher than what I've seen on the track. Without sounding like an @ss, there isn't a better prepped stock SC out there than mine and in ideal conditions with a hoosiers and a light car with no exhaust, I can't break 130.
Most tracks do not have long enough straights to get up to top speed. With my SC at Road America I hit around 135-137 mph and it is still accelerating when I have to brake It is very easy to top out a car outside of the track if you have a nice clear stretch of road. Where i live, after the fields are cleared and visibility is great there are many country roads where reaching top speed is fairly easy.
#23
NASA Racer
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I guess we'll have to agree to disagree, especially since my car has been dyno'd and I know I'm well above stock (170 at the wheels). Doug, I don't know about you, but I redline at WG coming into the bustop. I brush the brakes for T11 then trailbrake the cr@p out of T1 but still take it North of 70mph and I'm flat footed from prior to the apex of T1 to the 300 brake marker for the bustop.
My point about the Hoosiers and weight is that I will get to top speed faster than a heavier stock car on street tires. And yes they help in the turns which is why I can get a top speed on the back straight and don't need 10 miles of highway.
My point about the Hoosiers and weight is that I will get to top speed faster than a heavier stock car on street tires. And yes they help in the turns which is why I can get a top speed on the back straight and don't need 10 miles of highway.
#25
Rennlist Member
I guess my point is I don't see how anyone is getting a top speed on the street higher than what I've seen on the track. Without sounding like an @ss, there isn't a better prepped stock SC out there than mine and in ideal conditions with a hoosiers and a light car with no exhaust, I can't break 130.
I'm not trying to one-up anyone, but my weight isn't far off from yours, I was at about 2700 too with my lead rollbar, and I was dynoing at 205-207 @ the wheels. So a bit higher power to weight ratio, but not immensely. My guess is it's all in the gearing. I can 'easily' (with a long straight) push high 140's; 130 is a piece of cake, so to speak. Your car shouldn't struggle hitting 130, unless it's geared lower, IMO.
#26
Burning Brakes
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In all honesty, I am too afraid to find out what the top speed of my 911 is. It gets floaty enough at 130mph.
#27
Rennlist Member
Well, we probably need to start talking about gears and such. Somewhere along the way, something may have been changed in your tranny? Having said that, I don't know if SC's had lower 5th gears for some reason from the factory than the Carreras.
I'm not trying to one-up anyone, but my weight isn't far off from yours, I was at about 2700 too with my lead rollbar, and I was dynoing at 205-207 @ the wheels. So a bit higher power to weight ratio, but not immensely. My guess is it's all in the gearing. I can 'easily' (with a long straight) push high 140's; 130 is a piece of cake, so to speak. Your car shouldn't struggle hitting 130, unless it's geared lower, IMO.
I'm not trying to one-up anyone, but my weight isn't far off from yours, I was at about 2700 too with my lead rollbar, and I was dynoing at 205-207 @ the wheels. So a bit higher power to weight ratio, but not immensely. My guess is it's all in the gearing. I can 'easily' (with a long straight) push high 140's; 130 is a piece of cake, so to speak. Your car shouldn't struggle hitting 130, unless it's geared lower, IMO.
I agree, a gear change by a PO would be the next thing I'd look at. Sean, how well does your 1st,2nd,3rd, and 4th gear speeds align to the factory quoted 30,60,90,120 mph figures? I know on my C4S, my top end is down from the stock 993 because my 3rd, 4th, and 5th gears have been swapped out, and what was 5th gear is now my 6th. Since you have a rebuilt race engine, there's a very good chance that they did not match the factory gear ratios; which would explain the top end differences. In fact, you probably have a better shifting car if they did not return to the stock ratios.
Last edited by autobonrun; 11-24-2007 at 07:55 PM.
#28
Rennlist Member
Are you dreaming? A stock 944 Turbo S can in no way come even close to 180mph. To say you hit 180 at the top of 4th has BS written all over it. Yes I like 944's, and yes I know they have a higher top speed than stock 911's....but to say you can hit 180 is pretty funny. The 944 Turbo S's are rated somewhere around 160.....just being fair here.
In all honesty, I am too afraid to find out what the top speed of my 911 is. It gets floaty enough at 130mph.
In all honesty, I am too afraid to find out what the top speed of my 911 is. It gets floaty enough at 130mph.
I am still a fan of the old air cooled 911's too and would love to have one some time in the future. Very involving cars.
#30
These threads always surprise me. I have an 82 SC with a rebuilt race engine, headers, straight pipes running Hoosiers at 2700lbs with me in it and the most I've ever seen on the track is 130mph - flat out at Watkins Glen on the back straight (with a draft). By the way, there aren't any 3.2's flying by me either.