924Board.org

[por937]

I'm not sure how fast mine goes - I know I had it wound right up in 5th gear a few years ago and was pulling just on 6000rpm. Speedo was flicking about between the120 and 160mph mark and I didn't have time to tale my eye off the road any longer to get an accurate reading. When you moving at this speed the road is moving under you at 62 metres per second (205 feet per second) and you don't have time to look at the speedometer. My rev counter has been repositioned to the centre dial and turned so 6000 is in the straight up and down position (i.e. pointing to 12 o'clock)

I did this speed at early on a Saturday morning in the middle of our dairy farming community on the way to a race meeting. The last thing you want to be doing at this speed is spending time looking at the speedometer or rev counter to figure out how fast you’re going, as the little black shape ahead can suddenly become a herd of cows crossing the road.

I reckon I was going around the 140 mph as the 911 2.7 Carrera RS that was with me reckoned he was flat tack and they do about 140 to 145. At the time I was running 215 /55 x 16 inch rims (about 50% worn) running a boost of 12 pounds and 104 octane fuel. I also had another set of rim and tyres in the car so it was laden down a bit.

According to the calculation of gear ratios tyre size and revs I should have been pulling 152 miles and hour. Which would be nice if it was doing that but I reckon due to drag weight etc it was closer to the 140 mark (as backed up by the Carrera that was about 50 to 100 metres behind me).

[dwak]

Sure hope I don't meet you at the top of the hill coming the other way at the same speed in my special Canadian 931 over by Farmer Bob's place. Those two lane country roads really kill.
dwak the hayseed

[81turbo]

Everyone (you to Rick) I believe that you have interpreted my statements about the Canadians is a bad light. I have no problem with you guys, bad press and all. Really I could care less about your national origin. I hope that is cleared up. I even Know a good majority of your national anthem (a hockey fan in my youth) I hope you will accept this as an apology:



Also I am glad that the points I was making earlier about top speed have been reinforced and understood. I may have been missing a few calculations but I was making logical arguments w/o personal insults.

Long live Canada long live us all, now lets keep those cars under 125MPH or 205 Km/h eh. (thanks adam)




[ This Message was edited by: 81turbo on 2002-08-30 14:19 ]

[928dreams]

LOL long live Canada and you live in United States? That makes sense. I don't see why people on here praise Canada so much, I guess the weather is good, that's all I see.

But anyways, is this the longest topic on here or what, I mean top speed is great and all but how often do you all do it? I can see it on a race track but that's it, it's cool to see how fast your can go but it makes me a nervous wreck, I hear that voice in the back of my head saying your going to get pulled over and go to jail, that is why I only did it once in my '77 and didn't get pulled over but I did do engine damage. I
like low-end speed now, quarter mile and 0-60 stuff is for me. I have never ran a 924 on a quarter mile so I have no idea what it does stock, I'm guessing mid to low 15's that is what my old MR2 did completly stock.

[924 turbo]

[dwak]

I think the good thing about 924's/931's at speed is you know it versus a Jag XK8 I was driving last week was hitting 200KPH+ on a secondary highway and I was hardly aware of it. Dangerous for 'seat of the pants' driving. Difference between a good ol' sports car and a 'soft' person's car.
dwak

[Rick MacLaren]

I think the primary difficulty I had in understanding the flow of the discussion, and the concept of top speed, was in the idea of a 'restriction' due to drag at the speed of around 220 to 230 KPH. After all, we know our cars had an excellent CE of drag. A second area I had difficulty in comprehending in the discourse was the notion of weight not contributing to top speed in a significant way. Jon corrected me on these concepts. He didn't say so directly, but I gathered from his talk that there was a formulaic solution to our problem, and when you plug HP and CE(drag) figures in, you can derive the needed HP to make the car push beyond, say 220. That learning was a milestone, at least for me.

So when the writing got fast, and I saw some of the talk coming through, I was quite frustrated because I frankly did see my speedo (albeit flickering, yes) at the speeds stated. This brought about a third conceptual difficulty, namely, that my tire size was smaller, hence, the speedo error was magnified by up to 12%.

I'm sorry my talk was a piss off to all.

Who says learning is easy?

You yanks aren't too bad, as a whole. Your President is nuts, but I think you all knew that anyway.

The stuff about a 924S being faster still eluded me far into the discussion, when it came to top speed, cause the engine, at least on my car, and I'm trying not to brag here, just wasn't working that hard. Hence, it seemed as if there was more left on the throttle. There didn't seem to be anything holding the car back except for time. Now, having been better informed, I can see that drag was holding the car back, and without sufficient horsepower, no amount of weight loss is gonna let the weak horsepowered 924 'push' the car through the air. Not a sound barrier, but there's some kind of barrier at the higher end nonetheless that only raw seething horsepower can correct. Now, after all this shit, I imagine it like a light weight, large, box trying to make it up to a particular high speed when the engine is working hard - the only thing that's gonna overcome the force of air pushing back on the car is raw seething horsepower.

I'm guessing the relationship between horsepower, velocity and drag has to be a curve, not a straight line, as I'd originally imagined.

So, having been appropriately spanked, I'm gonna get back to work here and take a needed respite for a couple of days. And I get some work done at my job (that's what I do for relaxation in between writing sessions here) and when it's done, spank myself profusely again just to remember the experience!

Cheers.


[ This Message was edited by: Rick MacLaren on 2002-08-31 00:31 ]

[eturbo924]

I have had mine right around 120mph. Tests indicate that the 924 115hp cars can hit 123mph with the rear spoiler. I only had the 85mph speedo in the car when I used to go that fast.

Fastest I have ever driven. 155mph in a 1989 Carrera 4. Can't imagine what it looked like from the Bus I passed at 130mph on my way to 155. Wow does it feel slow traveling at 100 after that. That was about 9 years ago. Have not ventured that high again.

Speed is now for track... if I ever get there

Eric

[Lizard]

I would have to agree with you doing 100kmph after doing over 200kmph for awhile feels like you are crawling. you will also notice your responces aremade alot quicker.

[Paul]