Factory Top Speed
07-06-2002, 01:13 AM
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Factory Top Speed
Hello all, new to porsche's and the board.
question for ya all. my manual reads that the top
speed for the 84 is around 133MPH. I have many times topped 150MPH. I belive this car to be stock. What give's? did the factory under estimate? tnx for info.
question for ya all. my manual reads that the top
speed for the 84 is around 133MPH. I have many times topped 150MPH. I belive this car to be stock. What give's? did the factory under estimate? tnx for info.
07-06-2002, 01:15 AM
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I think the speedometer readings on the n/a's are a little optimistic as I too have gotten mine to read 145 mph before I shut down.. I was probably closer to 135. Also, I think that Porsche downgraded the specs just a bit in the factory readings... correct me if I'm wrong though
07-06-2002, 01:54 AM
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[quote]Originally posted by Silver84:
<strong> I have many times topped 150MPH. I belive this car to be stock. </strong><hr></blockquote>
You don't happen to be a fisherman by any chance?
<strong> I have many times topped 150MPH. I belive this car to be stock. </strong><hr></blockquote>
You don't happen to be a fisherman by any chance?
07-06-2002, 01:59 AM
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I used to have a 84 N/A and there was no way to get it above 130......but isent it limited because of the tranny???? with a turbo transmission I think you could.......downhill mabe 
07-06-2002, 02:05 AM
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[quote]Originally posted by Silver84:
<strong>haha fishermen no....i have however got the speedo to read out to alittle under the 155 hashmark. go figure?</strong><hr></blockquote>
Perhaps the car is Canadian and your looking at KPH - In which case you'd be going about 98 MPH!
Just funnin'ya - I have no idea what a 944na will do. I do know that I can't find a road that's suitable for much over 100 mph in my area. But man o man, that 951 hits that mark fast!
<strong>haha fishermen no....i have however got the speedo to read out to alittle under the 155 hashmark. go figure?</strong><hr></blockquote>
Perhaps the car is Canadian and your looking at KPH - In which case you'd be going about 98 MPH!
Just funnin'ya - I have no idea what a 944na will do. I do know that I can't find a road that's suitable for much over 100 mph in my area. But man o man, that 951 hits that mark fast!
07-06-2002, 02:07 AM
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hmmm interesting...I doubt my speedo is more then 25mph off. is it possible for it to vary accoring to speed? like the faster you go the more off it could be? It seems awful fast though I just wonder how off it could be. I really dont know to much about this car. it could be possible it's been upgraded.
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07-06-2002, 02:12 AM
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I know that on motorcycles the speedos always err on the high side.There have been several letters in the bike mags where somebody said they topped out a stock bike at 200-205 mph on the speedo where the magazine tset barely got 180mph out of it with a radar gun.
IMHO the manufacturers will have a speedo read high for their CYA-partly to compensate for tire wear and better to err on the side where the customers don't get tickets from a faulty speedo reading.
Just my $.02
IMHO the manufacturers will have a speedo read high for their CYA-partly to compensate for tire wear and better to err on the side where the customers don't get tickets from a faulty speedo reading.
Just my $.02
07-06-2002, 03:12 AM
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There was a top-speed test a while back where a 911 saw 212mph or something on the speedo? Turns out it was really only 182 or so.
"is it possible for it to vary accoring to speed? like the faster you go the more off it could be?"
Yes, that's the nature of mechanically-driven speedometers. You just can't quite get the exact number of 21.3 teeth on a plastic gear. So you pick one up or down. In which case, it gives you a fixed percentage error, say... 10%. So at 50mph your speed indicates 55mph. At 100mph, it shows 110mph. Then at 136mph, you see 150mph.
An electronic speedo like the 951, has a fixed offset, like always 5mph optimistic. This was probably intentionally programmed in since you can make it exactly right on if you wanted to. You can even account for tire-diameter growth at the higher speeds as well.
"is it possible for it to vary accoring to speed? like the faster you go the more off it could be?"
Yes, that's the nature of mechanically-driven speedometers. You just can't quite get the exact number of 21.3 teeth on a plastic gear. So you pick one up or down. In which case, it gives you a fixed percentage error, say... 10%. So at 50mph your speed indicates 55mph. At 100mph, it shows 110mph. Then at 136mph, you see 150mph.
An electronic speedo like the 951, has a fixed offset, like always 5mph optimistic. This was probably intentionally programmed in since you can make it exactly right on if you wanted to. You can even account for tire-diameter growth at the higher speeds as well.
07-06-2002, 04:10 AM
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[quote]Originally posted by Danno:
<strong>There was a top-speed test a while back where a 911 saw 212mph or something on the speedo? Turns out it was really only 182 or so.</strong><hr></blockquote>
Yeah, I have that test- I can dig it up if anyone REALLY wants me too- it has a Viper, NSX, and 993TT S. They run them each both directions and measure them w/radar. Every car showed high each way w/the NSX being the closest and the Porsche the worst. The Porsche was not only off by ~20mph(!) one way, BUT, it was off by ~12mph the other way- it wasn't even consistent! Don't know how, but.... The Porsche BTW, was the fastest overall w/a two-way average real speed (as opposed to indicated) of just over 190mph- I THINK it was like 192mph....
<strong>There was a top-speed test a while back where a 911 saw 212mph or something on the speedo? Turns out it was really only 182 or so.</strong><hr></blockquote>
Yeah, I have that test- I can dig it up if anyone REALLY wants me too- it has a Viper, NSX, and 993TT S. They run them each both directions and measure them w/radar. Every car showed high each way w/the NSX being the closest and the Porsche the worst. The Porsche was not only off by ~20mph(!) one way, BUT, it was off by ~12mph the other way- it wasn't even consistent! Don't know how, but.... The Porsche BTW, was the fastest overall w/a two-way average real speed (as opposed to indicated) of just over 190mph- I THINK it was like 192mph....