inconsistent 60ft

[68camaroSS]

A couple of things pop out. I think you are right that it is the tires. First, why are you running the D.O.T. compound tires? Second, the other post was correct, why are you trying to leave at 5000 rpm on those tires? I would suggest put a set of 14 x 32's on it and go racing, leave between 3500 and 4200 RPM and let us know what happens.

[slwryde]

It is a big tire. My thinking was that the big tire would help with consistent 60ft times on a variety of track conditions. I choose the DOT tires because the car is street legal and I like to drive it on the street once in a while. I had no idea traction would still be a problem.

Rear gears are 5.13
I have changed instant center from 48" out and 10" up
to 59" forward and 9" up with no noticeable difference in results.

I have had the bottom 4 link bars "nose up" trying to achieve as high an
instant center as possible. I am starting to think maybe trying to adjust
the bottom 4 link bars so they point down slightly in the front to see if that will help.

Also I have ordered a set of slicks. When I took the DOT tires off I noticed 3 perfect muddy water stripes inside the wheel tubs!! directly above the grooves in those DOT tires.

I really appreciate every ones advice.

[trikbag406]

I'm with 'L78 Nova',Im thinking transmission temp.Im no powerglide expert,but I know the 400 turbo in my Vega was built without enough clutch stack clearance (I admit,my own doing),and as the day went on,I saw slower 60 ft times,as well as slower ET's. It turns out I was dragging the forward clutches in my trans after it got hot,and the hotter it got,the worse it was.Just my experience.-Lew.

[Bill Baer]

Originally Posted by slwryde

It is a big tire. My thinking was that the big tire would help with consistent 60ft times on a variety of track conditions. I choose the DOT tires because the car is street legal and I like to drive it on the street once in a while. I had no idea traction would still be a problem.

Rear gears are 5.13
I have changed instant center from 48" out and 10" up
to 59" forward and 9" up with no noticeable difference in results.

I have had the bottom 4 link bars "nose up" trying to achieve as high an
instant center as possible. I am starting to think maybe trying to adjust
the bottom 4 link bars so they point down slightly in the front to see if that will help.

Also I have ordered a set of slicks. When I took the DOT tires off I noticed 3 perfect muddy water stripes inside the wheel tubs!! directly above the grooves in those DOT tires.

I really appreciate every ones advice.

I think you will find that the slicks will fix 90% of the problem in my experience big street tires aren't as good as even little drag slicks.
One other thing to keep in mind is engine coolant temperature you need it to be consistent if you want the 60' & ET's consistent.
You might also want to get someone to video record your launches, paint a white stripe on the side wall and pay attention to the inital hit, if you can see the line going around it's hooking, it the line is a blurr then it's not! If the tires spin on the inital hit your 60' and in some cases your reaction times will be inconsistent.

[bottombulb]

Do you run an electric water pump and electric fan?

[slwryde]

I have an electric fan. The water pump is a stewart.

[StripeHOG]

do you have anyone on the starting line that can verify you are in the groove on every pass???? IMO thats probably whats happening!!

[1320racer]

inexperienced driver combined with a new car and there's far too many variables here to determine exactly why the car is in consistent in 60 feet.

I'd suggest having an experienced racer watch you from the moment you roll into the water through staging and launch.

I also suggest setting the tires at a psi known to work and not touching them for the rest of the day.

Others things...

length/time of burnout needs to be the same every pass, stage at exactly the same temp every pass, launch at exactly the same RPM every pass, get more seat time.

Again, way to much tire!