968 Top speed drag/redline limited?
05-15-2002, 06:39 AM
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[quote]Originally posted by kgain968:
<strong>Is our car's top speed drag limited or redline limited? Thanks</strong><hr></blockquote>
Redline, but you would need one verrrry loooong straight. Pegs out at around 256 km/h from memory. Redline in 4th is around 200km/h. 5th and 6th yet to be experienced... and of course with my limit now raised to 6850..... On the other hand I went looking for the limiter in 3rd the other day and still didn't find it at 7100!
Mark
<strong>Is our car's top speed drag limited or redline limited? Thanks</strong><hr></blockquote>
Redline, but you would need one verrrry loooong straight. Pegs out at around 256 km/h from memory. Redline in 4th is around 200km/h. 5th and 6th yet to be experienced... and of course with my limit now raised to 6850..... On the other hand I went looking for the limiter in 3rd the other day and still didn't find it at 7100!
Mark
05-16-2002, 01:59 AM
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Not too sure on the speedo, but I think it was somewhere around the 160 mph mark. This was about 2 or 3 years ago and yep it was a long staight bit of road. Hit the slip road at about 60 , 100 by the time I was on the motorway and kept it nailed until the redline approached in 5th and then 6th and 2 miles later slowed back to about 120 to take a bend I'd never really noticed before !
05-22-2002, 10:10 AM
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The owner's manual in my '94 shows a top speed of 156 mph, for whatever that's worth. If that's accurate, it wouldn't be too hard to do the math, given actual tire size & ratios for 6th & the ring & pinion.
Jim, never been there myself... mountain roads just don't work well for top speed runs..but they're a hell of a lot of fun otherwise!
Jim, never been there myself... mountain roads just don't work well for top speed runs..but they're a hell of a lot of fun otherwise!
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06-19-2002, 01:01 AM
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[quote]Originally posted by QUICK'44:
<strong>i've got the 968 gear charts right here infront of me...my charts are assuming a 25.5" diameter tire:
6th gear @ 6800 rpm = 192.7 mph,the numbers dont lie!</strong><hr></blockquote>
Somehow that does not seem correct. Sixth gear at 0.78:1 and final drive at 3.78:1. 165 - 170 MPH seems a lot closer if the engine could keep pulling all the way to that speed.
<strong>i've got the 968 gear charts right here infront of me...my charts are assuming a 25.5" diameter tire:
6th gear @ 6800 rpm = 192.7 mph,the numbers dont lie!</strong><hr></blockquote>
Somehow that does not seem correct. Sixth gear at 0.78:1 and final drive at 3.78:1. 165 - 170 MPH seems a lot closer if the engine could keep pulling all the way to that speed.
06-19-2002, 11:53 AM
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The Porsche PET shows a final drive of 3.44:1 for the 968 manual while all other info I have including the original "speed in gears" chart from Porsche shows a final drive of 3.78.
What is correct? Isn't it suposed to be one standard final drive on all 968'ers?
What is correct? Isn't it suposed to be one standard final drive on all 968'ers?
Last edited by mmmbeer; 12-21-2010 at 06:56 PM.
06-19-2002, 09:01 PM
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mmmbeer <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />
I think 3.78:1 final is correct for my '94. First gear ratio of 3.18:1 gives you a top in first of 40MPH, this seems right. 3.44:1 would give you 45MPH in first.
Road & Track 3/92 lists top speed in gears using 6700rpm as the redline of: 1st-40mph; 2nd-63mph; 3rd-87mph; 4th-114mph; 5th-139mph; estimated 6th at 6400rpm-156mph.
I think 3.78:1 final is correct for my '94. First gear ratio of 3.18:1 gives you a top in first of 40MPH, this seems right. 3.44:1 would give you 45MPH in first.
Road & Track 3/92 lists top speed in gears using 6700rpm as the redline of: 1st-40mph; 2nd-63mph; 3rd-87mph; 4th-114mph; 5th-139mph; estimated 6th at 6400rpm-156mph.
06-20-2002, 08:29 AM
#11
Would plugging in an incorrect final drive number be the reason for my low dyno hp number, as well as shifting where the torque peak is? On the Dynapack the max hp was 177, with a torque peak close to 4900 rpm.
06-25-2002, 10:10 AM
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Mathematically, 6th gear (.78) works out to 174.96 mph... assuming 25.5" dia. tire, redline at 6800, 3.78 R&P. allowing for centrifugal growth of the tire at speed, maybe a theoretical 180 mph... so apparently the 156 mph quoted top is drag limited. A 3.44 R&P would yield a higher theoretical top speed, but drag limits might actually be lower???
Jim, "Pi r square!" "No son, cornbread are square; pie are round!"
Jim, "Pi r square!" "No son, cornbread are square; pie are round!"
06-26-2002, 07:18 PM
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Thankee, kind Sir.
"Why don't we see you on 968.net?"
I dunno; I used to frequent the old board there, but it got to where it took too long to load at home ('slow connection' ain't even in it) when it hadn't been 'trimmed' for a while. I got into the rennlist habit, and only have time for one...
Jim, back to the lab... "Come along, Igor!"
"Why don't we see you on 968.net?"
I dunno; I used to frequent the old board there, but it got to where it took too long to load at home ('slow connection' ain't even in it) when it hadn't been 'trimmed' for a while. I got into the rennlist habit, and only have time for one...
Jim, back to the lab... "Come along, Igor!"
07-04-2002, 05:03 AM
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Mine's less aerodynamic than a 968 (flag mirrors, front end and fenders, etc...) but slightly lighter. It has seen 150 in my hands, I know <img src="graemlins/nono.gif" border="0" alt="[nono]" /> Anyway...
The engine and tranny are stock 968. The wheels are 16 inch 951 phone dials, don't know how the rubber compares to what the 968 had diameter wise. I still had pull and "felt" that it could reach past the listed manuals 156mph, but my moment of adolesence passed at the 150 mark. I knew I was in danger enough to get to where I was, why push faster. Indeed it was straight road. The one thing I have noticed is that the revlimiter does seem higher than listed in the manuals. Just me?
The engine and tranny are stock 968. The wheels are 16 inch 951 phone dials, don't know how the rubber compares to what the 968 had diameter wise. I still had pull and "felt" that it could reach past the listed manuals 156mph, but my moment of adolesence passed at the 150 mark. I knew I was in danger enough to get to where I was, why push faster. Indeed it was straight road. The one thing I have noticed is that the revlimiter does seem higher than listed in the manuals. Just me?