First trip to a track ever

[Saleen304]

I successfully run M&H Racemaster DR's in their 275/45/18 size. They dead hook. Granted, my car doesn't make the power that yours does, but I cut 60's in the 1.62-1.67 range consistently on them. I have two friends that run the exact same tire with the same great results.

What pressure and launch rpms do you use? What kind of burn out? Do you slip the clutch or dump it? I have those tires and can't seem to be consistent. I have been low 1.6x 1 time. Most of the time I am high 1.7s.

 

[Five Oh Brian]

What pressure and launch rpms do you use? What kind of burn out? Do you slip the clutch or dump it? I have those tires and can't seem to be consistent. I have been low 1.6x 1 time. Most of the time I am high 1.7s.

I usually run 25 psi in the M&H DR's, depending on weather and track conditions. I heat them up in 2nd gear for about 10 seconds until the car chirps/lurches during the burn out. I have the 6R80 automatic, but I have a 5,000 rpm stall converter so I'm leaving the line hard like a manual letting out the clutch very quickly.

 

[shanshine]

If you can get someone to video from right behind the car next to the wall focusing on the rear wheel that will help give you an idea as to what your tires are doing. You can tell if its squatting too much (to adjust pressure accordingly) or spinning on the rim.
Also invest in a log book from summit http://www.summitracing.com/parts/sum-g5155/overview/ or keep a notebook so that you can see what the car is doing and how your times change every time you make an adjustment.

 

[GT RO]

If you can get someone to video from right behind the car next to the wall focusing on the rear wheel that will help give you an idea as to what your tires are doing. You can tell if its squatting too much (to adjust pressure accordingly) or spinning on the rim.
Also invest in a log book from summit http://www.summitracing.com/parts/sum-g5155/overview/ or keep a notebook so that you can see what the car is doing and how your times change every time you make an adjustment.

Great advice right there

 

[JoshK]

Hopefully these will help.....

 

[JoshK]

I think I may have found an issue with the traction problem. I just went out to the car to start putting on the new wheels. The above pics are with the car on an older set of BMR springs. These springs lowered the car much more than I thought that they would. Well I decided to look under the car, and the damn thing is sitting ON the bump stops. I didn't trim them, but should it actually be sitting down on the bump stops? I will get a pic.











Is it just me or do these springs look like they are already compressed the max that they should be? The car has less than a 1/2 a tank of gas in it here.

 

[JEWC_Motorsports]

Josh my car on BMR springs was pretty close to sitting on the bump stops. I trimmed them down and havent had any ride or traction issues.

 

[JoshK]

I put the tires on and when the others were off I trimed the bumpstops down. Here is the final product. I think it will work, just hope it doesn't squat too hard or it will hit the fenders. Nitto 305/45-18s vs the 325/50-15 Hoosiers also.

 

[Mike K]

Those should help.

 

[JoshK]

I swapped a set of Roush springs onto the car yesterday. Also running the set of Hoosier Drag Radials pictured above. I just took the car out to test everything out. Just normal driving the car is fine, but at WOT after about 50mph the whole car is basically trying to swerve side to side. Any ideas what the problem might be. Tires were set to 18psi cold and didn't warm them up. I have a drag racing event at an airstrip coming up so I am testing to get the car to hook on the street. Is this too low of air pressure for these tires?

 

[skwerl]

Josh, are your front tires radials or bias plies? If you're running radials out back then you can't run bias plies up front or else you get tracking/sway issues.

 

[JoshK]

I only change the rears. Fronts are Michelin Pilots.

I raised the pressure to 22lbs cold and most of the sway went awat, but traction seemed to definetly fall off also.

 

[itsslow]

How wide are the 15'' wheels? I've always had issues with my slicks bulging but i got used to it. How bad is it if you ran 20psi?

Side note: Stick shift cars don't like drag radials. Drag radials work best with automatic cars.

 

[JoshK]

Wheels are 15X10

 

[rcm90]

It's the front/rear tire combo. Like skwerl said, you cant run a bias ply with a front radial without sway issues. Get some littles for the front and the issue will go away.

 

[JoshK]

But the rears are a drag radial? They are not the QTPs

 

[rcm90]

Correct, but the sidewalls are still soft like a slick, they are "belted" around the circumference of the tire.

They were made to be more forgiving and easier to recover than a normal drag radial.

 

[JoshK]

well crap, I'm not going to be able to get some front runners before the races on the 4th. At least its just an 1/8 mile. Guess i will just have to run a little more air in the rear.