I have been getting some replies about tires and what speeds they can do.I was just wondering what about traction? I know there is not much loss of grip on the slicks at paved road courses I am use to.Salt at say Bonneville or even El Mirage has to be different.Does or has anyone tested different tires for better traction on salt?? I know that Tires (even being able to get them for your car)seems the BIG question right now and seems justly so!! So how about the traction ??
M&Hs Frontrunners look fine for the front but look like they do not have much of a gripping tread for the rear??
Goodyears look like they have some and I just wonder if they would be better for the driving wheels ??
Lee
Ok I'm just trying to figure out what you are talking about with the traction (coefficient of friction) on the salt and how to deal with it. The end result is that you can not only spin the tires accelerating, but you can get to a point where the aero drag on the car will cause the tires to spin and you can't go any faster no matter how much you "peddle" the car.
Below is a formula that has been used for this. The trick is knowing how much HP is actually needed to run a certain speed (HP needed to overcome aero drag and rolling resistance [note: the car's weight doesn't really come into play here only when you are figuring the acceleration rates]). The other variable is the coefficient of the salt surface when you are running. I see numbers of a .6 friction coefficient for really good salt and .4 for bad (slippery) salt. I'm assuming these numbers are for a typical tire being run at b'ville with minimum tread and a narrow width. Personally I don't think you would see much difference in the tires you mentioned. And Personally I would like to see the Goodyear Land Speed tires used as the driven tires if you felt you might end up in the high 200's at some point. They are designed for this environment (driven tire at continuous high speed).
Below I picked some numbers that might be close for your car or might be a mile off.
In the first I "assumed" it would take 225 HP to run 210 mph. To the right of those numbers you can see the weight needed on the rear (or driven tires) to avoid wheel spin at .6, .5 and .4 friction coefficients. In the second case I "assumed" you could run 200 mph with 200 hp. Notice the difference in weight needed for traction. In the third case I left the speed at 200, but "assumed" a HP figure of 150 to see what the result was with the needed weight. And in the last case I went back to the 225 HP, but "assumed" we could run 250 mph with it. The weight went down from the first example.
-----------------Thrust = HP X 375 /Speed----------------------
---------------Weight needed on rear wheels--------------------
-----------------------------------------------.6 friction--- .5 Friction --.4 Friction
Thrust = HP X 375 /Speed -------------- Coefficient --Coefficient --Coefficient
402 = 225 X 375 / 210-----------------------670 lbs------804--------1004
375 = 200 X 375 / 200-----------------------625 lbs------750---------938
281 = 150 X 375 / 200-----------------------469 lbs------563---------703
338 = 225 X 375 / 250-----------------------563 lbs------675---------844
So the more aero the car is the less HP needed to go fast and the less weight that is needed on the drive wheels for traction. Good for you (with a streamliner) and bad for someone driving a brick like a roadster or a coupe and the reason those cars have to add weight or a spoiler (if allowed) to gain downforce on the drive wheels if traction becomes a problem.
A little disclaimer "I don't know how accurate any of the above is, since I'm trying to make sense of it myself at this point, so I would like input on this topic myself".
c ya, Sum