Inteligent, Fact Based Discussion: Car vs Bike

[PhoS]

So I would assume that really wouldn't make a significant difference, most street cars would be toasted on most tracks by a 600.

Most 600s were intended for track use to begin with so I would hope so.

 

[NoCompromise]

This has been one of the most civilized, fact-based threads on the subject that I've read despite the difference in viewpoints. I am especially curious about the conclusion of the 'wider tires' discussion.

 

[NoCompromise]

moar

 

[Aluisious]

Sooo...did those articles end up posting lap times?

 

[Z3n]

Sooo...did those articles end up posting lap times?

Yeah. The ZX6R in doug chandler's hands turns a 1:56 and the ZX10 turns a 1:53.

The vette does a 2:07 and the skyline does a 1:58.

I doubt any of us could ride like DC does though. Still, apparently I'm faster than a Vette driven by a pro driver around BW on my SV.

 

[tuxumino]

Sources
http://www.thunderhill.com/CurrentThunderhill_Records3_09.pdf
http://cms.scca.com/documents/Solo_Rules/solo_categories.pdf

*Perhaps I misuderstaning car categories and the data which I'll admit is a possibility.

note on the first link there is a street prepared 72 porsche that turned a 148 laptime. Cars from the early 70s are much lighter than modern cars and can be upgraded with modern bits relatively cheaply.
take that 72 pinto and put a turbo 2.3 il4 from a merkur xr4ti with it's 5 spd trans, it's a bolt in; add some springs, shocks, sway bars and good rubber on the corners and the average 600cc or 1000cc supersport rider will be faster on their favorite road in that pinto.
Take a early 70s datsun 210 put in a 240sx engine and tranny, upgrade suspension and rubber, go out and make some riders and super car owners humble.
A lot of old econboxs can be tricked out pretty easy for under 5 grand total.

back in teh day I had a 71 datsun 510 with a 1800 sss engine, 5 speed, lowered and sprung, KYBs and 14 each wheels with pirellis. total investment maybe 4 grand ( not counting speeding tickets), used as a daily driver, cheap to run, easy to work on and fun as hell in the hills.

 

[Corb]

...take that 72 pinto and put a turbo 2.3 il4 from a merkur xr4ti with it's 5 spd trans, it's a bolt in; add some springs, shocks, sway bars and good rubber on the corners and the average 600cc or 1000cc supersport rider will be faster on their favorite road in that pinto...

If thats true, its only because the average sportbike owner can't ride his way out of a wet paper bag.
It says nothing of what the machine is actually capable of.

We are either discussing machine capability or rider/driver skill.

 

[Charles R]

Maybe you didn't get what I was saying...

The coefficient of friction between a tire and pavement is a single number that can be calculated based on about a billion different variables, including...

Yep, I actually worked with a guy who took the friction data provided from Toyo tires, and then developed a computer program that would take the data you gathered from your vehicle and turn it into a graph that 'predicted' the grip at each end of the car.
We used this to prep a baseline suspension setting, (spring rates, rollbar rates, etc.) so that had the car fairly 'neutral steering' right from the start of testing.

Smart cookie that guy.

I'm coming to the conclusion that this thing about bikes having less grip than cars is pretty much bunk.

This is true too. Even with the drastic differences in contact patch between the two, as well as the patch size differences of various cars, the net result is still the same 'ballpark' number.... About 1.3G's regardless of the vehicle

The price of that level of grip from smaller contact patches, like the bike and 'undersized' car tires, is accelerated wear. A larger contact patch 'spreads' the heat load and tearing forces, and results in a longer lasting tire. Larger patches have their limits as well. Too large a patch area, and the rubber doesn't 'deform' enough into the asphault to provide the grip you're after. (as well as a few other performance robbing things)

So time and time again, we keep facing the limit of tire tech, rather than any drastic differences form the vehicle type.

In each field of course, there are truly specialized tires that can throw the curve a bit. A drag slick is a great example. My Solo2 "autocross" tires are another. Like the drag slick, they'll go from cold to proper working temp in just few seconds. But try to run them for a 20min track session, and they'll be slippy and sliding after the first lap.

Fun and games.arty