234" Mike Bos slip joint dragster...pulling the wheels

[dparker]

Our problem is we have a 234" Mike Bos dragster with a SBC it runs 8.50s with 1.18 60ft...the car is pulling the wheels out of the beams causing the car to have inconsistant reaction times and ETs. We're up to 75lbs on the nose. We're running a 6000 stall 8" converter, and 5lbs of air in the rear tires. The car will run a 8.62 et, with a 1.18 60ft and a .498 light then run a 8.59 et, with a 1.20 60ft and a .520 light. We added a 42lb battery midchassis, it caused the car to chirp the tires down track. No redlights but took the consistancy away from the car as well.
Whats the best way to keep from pulling the wheels out of the beams. I don't like adding anymore weight up front.

[johnracer]

I'd try a little more tire pressure. If it spins a touch, it may not pull the front. I know on my FED, it would pull the front out of the beams if it tried to dead hook, and would bounce & chirp for the rest of the run....
Johnny

[hammertime]

Our problem is we have a 234" Mike Bos dragster with a SBC it runs 8.50s with 1.18 60ft...the car is pulling the wheels out of the beams causing the car to have inconsistant reaction times and ETs. We're up to 75lbs on the nose. We're running a 6000 stall 8" converter, and 5lbs of air in the rear tires. The car will run a 8.62 et, with a 1.18 60ft and a .498 light then run a 8.59 et, with a 1.20 60ft and a .520 light. We added a 42lb battery midchassis, it caused the car to chirp the tires down track. No redlights but took the consistancy away from the car as well.
Whats the best way to keep from pulling the wheels out of the beams. I don't like adding anymore weight up front.

More weight ....

How red is it going ? When a car pulls the tires out of the beam its not general only a little red normally 25-45 red. 100 lbs would be next, chip it down on the hit, loosing the converter up.

and nice to see ya posting :D

[dparker]

The last redlight was .488, or -.012..the other lights were .510 to .520.
We added 42lb battery in midchassis. figuring that would add approx. 30 more lb to the nose. But it seem to upset how the chassis worked. We have 73lb in the nose right now. Kinda running out of room in the nose. Mike Bos says to add tire pressure allowing the tires to spin approx. 1 revolution and the car will run consistant and not pull the front wheels. It just goes against everything in my head to make a car slip when your trying to run on the money...

[shawnp]

I am with you on the tire spin but BOS has been doing it a long time. Sometimes lowering the launch has the reverse effect depending on the converter RPM and how hard it may flash the converter. I would recommend a very soft hit converter that is loose for the combo. That will help some.

[hammertime]

what tire and what air pressure you running ?

[dparker]

Goodyear 15x14.5x33 #2070. And 5lb of air...4200rpm chip at lauch..

[johnracer]

I'm with you on it going against everything in your head, but I bet it'll be more consistent, 60' and et quicker with a little spin. Having a suspension makes the "dead hook" concept work.
Weight in the nose will help it spin, as will more power and higher tire pressure. I'm sure some converter tweeks will help too, but I'd still try more tire pressure......it's free.
Johnny

[dparker]

I guess next race we'll try the tire pressure..what so yall think about a 1 wheel wheelie bar?

[hammertime]

I guess next race we'll try the tire pressure..what so yall think about a 1 wheel wheelie bar?

Wheelie bar shouldnt be needed on a car slower then 7.00 without nitrous :)

[raceready148]

try 36- 3800 rpm chip, then try uping tire pressure. i ran 8.00 with hard tail car with 3600 chip and 6 psi in rear tires and 30 lbs on nose. and that fixed my problem of lifting the tires. any higher on the chip and it would pull tires up out of beams.

[dparker]

Went from 4 3/4 lb of air pressure in the rear tires to 5 1/2, we went from 40psi in the front tires to 25psi. The car went red in the second round with a .485 and ran off .02. We bought back in and I dropped the transbrake chip from 4600 to 3800, thought we had a 4200 but after checking found in had a 4600, and the car went to o lights and running right on..Went to the finals where we broke out by .008. Not to bad...thanks for all the help guys. Sometimes you just seem to run into a brick wall and the answer is easy, but you go brain dead and cant seem to come up with the answer... The new points should be out this week, probably helped my son to pass me in points, where I was currently 20 points out of first.