Concrete vs. Asphalt set up differences
 

Hey All,
BriitB Asked this on one of the other threads and it really needs its own .

Tom can probably add to this, but I can give you some input.

In general asphalt will get "greasy" as heat rises. Since it is black it also takes on heat faster. The oils that make up the petroleum part of asphalt rise up somewhat and make you have less grip.

Concrete on the other hand has no petroleum in the make up. It is also lighter in color to reflect heat a bit.

Taking these facts into account, concrete has more grip. When you have more ambient grip then you can run a stiffer setup spring and shock wise. The tire pressures will probably end up higher too.

Think of it just like you would want a very soft setup in the rain. some folks disconnect the sway bars for a rain setup. Some have blade adjustable arms that can be adjusted from the cockpit.

The compromise on one end of the National course is a large bump in one of the runways. The setup has to be soft enough to go over the bump and firm enough not to bottom the car.

Using cars in competition is a problem solving exercise. To really get good you need to enjoy that part almost as much as driving. The driving does provide the carrot though.

Off to Road A,

Alan

Thanks Alan! You know, you and Tom are my FP heros. Someday I hope to race you at Nationals.

Hero? You're in for a let down... ;)

As far as I'm concerned there is grippy asphalt and slick concrete as well as the opposite. But yes, in general concrete will have a little better grip than asphalt. You would be better served adjusting for smoothness vs. roughness, but that requires more major changes that are not really feasible at most sites (like springs and bars). Where I race, there is only one concrete site that I encounter outside of Topeka and it's not any better than the better asphalt sites I run. Topeka on the other hand, seems to have much better grip than any other place I run.

Now, to let the cat out of the bag. I'm no master of setup... (letdown number one) and I'm basically lazy. I tend to just drive the car. I might try adjusting things once or twice a year and then just drive it. So my asphalt setup becomes my concrete setup. The big difference comes in driving style. In Topeka, you can get away with things that will get you in trouble anywhere else. I tend to overdrive the car on asphalt and suddenly in Topeka it all works.

I wish I could have made it to Topeka last year to see how the current super stiff setup (400# springs all around) works. I used to run 150# springs up front and 225 in the rear and finished as high as 4th. Everyone would always say that my car sure "moved around" a lot more than the others. I finshed a few runs at Nationals where I felt like I nearly fell out of the car, I was bounced around so much. Now I should probably wear a mouth piece to make sure my teeth don't fall out! ;)

So, I just recommend getting your car together and getting seat time and try to adjust the driver to the different conditions. It's a lot less work! :)

Tom
FP29

Spoken like a ture FP hero!:D

Did you have to change your tire pressures any for the change of track? What pressures did you normally run on those big 16s' ?