jetta-girl said:
Airing down regular street tires will actually cause them to cup in. Leaving less contact area. I did try it, before I found out about the cupping in, and it didn't do much.
I'm glad to hear about someone spraying the VHT on the tires, it makes sense that it wouldn't make a difference since the tracks are so saturated with the stuff. But, I wanted to know from someone who has done it. Or, in this case, someone who knows someone who has done it.
My 60' times are usually 2.5 to 2.7 on a particularly slippery launch.
Sounds like I just need to get better/softer tires. Any suggestions?
Regarding cupping...a good method of finding the right air pressure is to try airing them down in 1 psi increments and spinning the tires on dry pavement...look at the marks and you should be able to tell when you still have a decent contact patch...when you notice the inside of the tire not making contact anymore, go up to the previous psi when the contact patch was still good....
What size/profile are the tires? I'm a newbie here (thinking about getting a tdi...I had a 1980 diesel rabbit many, many, moons ago....)... I used to drag race a 5 litre Mustang.
If you used a "taller" profile tire, I think it wouldn't tend to "cup" as easily. The sidewall would wrinkle at a lower air pressure, instead of the tread face cupping. It takes a lot of testing to get the optimum air pressure in your tires.
Will a cheap pair of steel rims of a smaller diameter with a taller profile tire fit on your car?
You don't want to have overall tire diameter too much taller than stock, because then you would be changing the effective gear ratio...but then again, with a diesel and the torque it produces, this may not affect your times as bad as it would on a gasoline car, which would bog off the line easier....
When I ran at the track on regular radials I used BFG Radial TA's...On those regular non drag radials, my best 60' was in the 1.8's. Keep in mind, this was on a rear drive car, which transfers the weight to the back tires on launch. My ET was in the 12.5's back then.
I moved up to drag radials later and my best 60' was a 1.59. I eventually ran a best ET of 10.78 on the drag radials.
Drag radials would be your best bet, IMHO...but if you can't afford them yet, see if you could fit the steel rims/taller profile tires in your budget..perhaps look for a used set...Up here in Canada (eh!) some import racers even have used winter tires, as they're made with softer compound rubber.
Have you "pedalled" the car when you launch it? (ie, not just hammer the gas, but try to just give enough power not to spin the tires, then maybe tromp on it after you get into 2nd gear...)
The best advice is to practice, practice practice...especially when bracket racing..consistency is what wins...
(sorry for the length of my reply.....I get excited talking about drag racing....)
