Top speeds? GPL

What speed has everyone achieved at Spa? I just hit 207mph there JUST before the kink while I was tucked in behind an AI car. I have the replay if you want it, it's pretty cool, and I made the kink without wrecking!!! -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________

I hit 200 mph in the Eagle once heading into the Masta kink without a draft. That's my best top speed ever. Not too good but it's OK for no drafting. Dan Belcher Team Racing Unlimited

204 in the Ferrari at the same place in the same situation. On my own my best is 202 in the Eagle... Guess where? Same place.... -- Cheers! Graeme Nash http://www.karisma1.demon.co.uk ICQ# 11257824 ________________________________________________________________________________ "Sorry, my eyes were on screensaver" (Calvin & Hobbes)

In the Brabham I once made 197 mph at the end of the Masta straight, and that was without any slipstreaming! Strange how the 50>hps only make the fastest cars less than 10 mph faster than the weakest... ---Asgeir---

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> What speed has everyone achieved at Spa? I just hit 207mph there JUST before > the kink while I was tucked in behind an AI car. I have the replay if you > want it, it's pretty cool, and I made the kink without wrecking!!! > -- > Tim "Calm Down" Wheatley > ________________________________________________ > Tim Wheatley > "Yellow menacing helmet in the mirror" > http://start.at/igps_stats > IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver > http://drive.to/grandprixlegends > http://website.lineone.net/~nascar > ________________________________________________

Not strange really...That's about right, Tim. All other things being equal, the amount of power required to overcome aerodynamic drag varies with the cube of the velocity of the object. So, using your example... Power requirement = (207/197)^3 = 116% more power (for just a 5.1% increase in top speed) So if you multiply the Brabham's power output by this additional power requirement factor, what do you get? 350 x 1.16 = 406 bhp ...about the horsepower of the Lotus and the Eagle. Car-to-car variations in drag coefficients and frontal areas account for the slight variations in actual horsepower requirements. The Brabham's light weight certainly helps in the acceleration department, but has no effect on its top speed. The bottom line: Incremental gains in top speed are very expensive in terms of horsepower requirements. Jack Rambo

>What speed has everyone achieved at Spa? I just hit 207mph there JUST before >the kink while I was tucked in behind an AI car. I have the replay if you >want it, it's pretty cool, and I made the kink without wrecking!!! How do you display the speed in***pit mode? I only get it with the arcade view. Joe

Careful now, Chris. Wonder how many points on the D.L. for 170, eh? But as to top speed, even more important than frontal area is drag coefficient, where cars are much better than bikes. If your Kawasaki had the same Cd as your car, with its smaller frontal area you'd be in streamliner territory! Or maybe a low-earth orbit. :-) Steve B. Remove "edy" from address for email

Um....... ok :) Too techy for me lol -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________

You can see it on replay :o) -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________

>You can see it on replay :o) Bastids ... why not have a digital speedometer option on the bottom of the screen? Joe

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> > Careful now, Chris. Wonder how many points on the D.L. for 170, eh? > > But as to top speed, even more important than frontal area is drag > > coefficient, where cars are much better than bikes. If your Kawasaki > > had the same Cd as your car, with its smaller frontal area you'd be in > > streamliner territory! Or maybe a low-earth orbit. :-) > > Steve B. > I didn't say I'd actually *GONE* 170mph. :) My personal best is an > indicated 165mph on a deserted two mile stretch of 4-lane hiway before > I ran out of room. The way bike speedometers fudge, I'd say I > realistically hit 155-160. The bike may be able to hit 170, but with my > 6'2" self on it there's *WAY* more frontal area than desirable. Stupid > knees and elbows! :) > ----------------------------- > -Chris- | Two wheels are better | > |Proud owner of a 1998 ZX-9R| > -----------------------------

Hi Chris & Steve, I wanted to get in on this thread too! I have gone 170 mph on my bike, a '92 Yamaha FZR1000. Although the specs say it's only good for 167 so I must have had a little tailwind. I'm only 5'10" and can tuck totally behind the fairing. My experience is that staying out of the airstream is good for 500-750 rpm extra. I didn't have the guts to find out how my body effected the Cd at 170 mph. BTW the engineer in me has to comment that the Cd is a function of the frontal area (and 100 other variables). So both values are closely related. Not GPL related, but I love to talk about bikes ;) Glenn White

Hey, Glenn, the engineer in you better go back and re-read his fluid mechanics book! :) The drag coefficient (Cd) is *NOT* a function of the frontal area. It's a characteristic of the object in the airflow. Two identically shaped objects will have the same drag coefficients regardless of their relative sizes (within limits) and hence their frontal areas. It's the theory behind scale model testing in wind tunnels. Now to the extent that Chris sits up in the airflow at speed, he changes both his Cd and his frontal area, of course. Aerodynamic drag is a function of the velocity of the airflow, the drag coefficient (independent of object size), frontal area, and air density... Drag = Cd x 1/2 x air density x (air velocity)^2 x frontal area The engineer in me had to set the record straight. :) Jack Rambo

hehe, it'd be easier! -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________ > >You can see it on replay :o) > Bastids ... why not have a digital speedometer option on the bottom of > the screen? > Joe

>>Same reason my 130hp bike will hit 170mph and my 150hp car will >>only hit 120... It's small. Frontal area counts for a *LOT*. >But as to top speed, even more important than frontal area is drag >coefficient, Frontal area (A) is exactly as important as drag coefficient (cd) and air density (rho) - each factor has linear influence on air resistance (drag). -- Matthias Flatt

Jeez Jack, do you know everything? ...... What's the meaning of life? -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________

Ouch! As soon as I hit send I knew that was coming back at me! I meant to say the overall drag, not the Cd, is a function of frontal area. The Cd is a function of everything you described and is usually determined experimentally. That's what I get for trying to send a quick reply at the office w/o getting caught. Glenn

I'll address this one; "Life is really a dream & you are not really here!" Words by: "Daffy Duck"

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> Jeez Jack, do you know everything? ...... What's the meaning of life? > -- > Tim "Calm Down" Wheatley > ________________________________________________ > Tim Wheatley > "Yellow menacing helmet in the mirror" > http://start.at/igps_stats > IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver > http://drive.to/grandprixlegends > http://website.lineone.net/~nascar > ________________________________________________

no_spam.n2rif1.vcf < 1K Download

Right-O, and thanks to JR for settling the matter of drag, but I probably hit the "send" button a touch too quick myself. I suppose my point was that superbikes' top speeds are primarily limited by their abysmal Cd's (relative to autos), which, as Chris noted anecdotally, are primarily a function of their pilots' non-aerodynamic profiles. We human critters just weren't built to go 170. Doesn't keep us from trying, though! :-) Steve B. Remove "edy" from address for email

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>Right-O, and thanks to JR for settling the matter of drag, but I >probably hit the "send" button a touch too quick myself. I suppose my >point was that superbikes' top speeds are primarily limited by their >abysmal Cd's (relative to autos), which, as Chris noted anecdotally, >are primarily a function of their pilots' non-aerodynamic profiles. >We human critters just weren't built to go 170. Doesn't keep us from >trying, though! :-)

Honestly, the easiest place to see the effects of frontal area vs. Cd is in professional drag racing. It is relatively common for for funny cars with their sleek bodies to go just as fast as top fuel cars that have probably 1/3 th frontal area. -- | "Instead of letting the moon be the Bill Mette | gateway to our future, we have let Enteract, Chicago | it become a brief chapter in our

I doubt that there is a big difference in frontal area between TF dragsters and funny cars: both have 2 huge rear wheels, close together. The gap in the middle is filled by the driver plus the engine intake. The bodywork of a FC might be a little bigger, but TF have huge wings, so IMHO frontal area is more or less the same. Drag coeffizient is hard to compare, but I guess TF are very bad, despite their arrow-shaped sleek body. AFAIK, TF achieve shorter elapsed times due to the better grip at the start with the long wheelbase and at medium speeds with their huge rear wings, but at speeds over 250 mph, even the 5000+ hp engines feel the drag. FC might need some tenths of a second more for the quarter mile, but reach similar speeds, sometimes even higher. Just a peek at the records on nhra.com: TF 4.486sec 326.44 mph FC 4.788sec 324.05 mph Wow, that's racing! -- Matthias Flatt

So, if I understand you right, the F1 engine research teams are morons because they try to squeeze out those last 20 hps? Why don't they just reduce drag and frontal area instead? ;-) ---Asgeir--- PS: I do know that racing has more to it than top speed, I really do... :-) The bottom line: Incremental gains in top speed are very expensive in terms > of horsepower requirements. > Jack Rambo

Sorry, that would be cheating! They didn't have speedos in -67 (well, not in their race cars anyway)... We are purists, aren't we? Digital speedo, bah!!! HAahaha! ---Asgeir--- > >You can see it on replay :o) > Bastids ... why not have a digital speedometer option on the bottom of > the screen? > Joe

Because Rules forbid it in certain areas. -- Tim "Calm Down" Wheatley ________________________________________________ Tim Wheatley "Yellow menacing helmet in the mirror" http://start.at/igps_stats IGPS - Ferrari Challenge - UKGPL - Summer Cup Driver http://drive.to/grandprixlegends http://website.lineone.net/~nascar ________________________________________________