2 Questions....
 

Im making my first passes (8)in a comp dragster, and just really making those get to know you passes. Im experiencing 2 problems on minor and one major. for the small stuff, i seem to have a slight hesitation around 4000 rpm when staging on the brake. the engine comes up to 4k hesitates a split second then jumps on up to 5k where im chipped. i believe im running out of pump shot in the carb, does this sound correct? or could it be something else? for the next issue, a bit larger....im experiencing chatter then tire spin right at the top/during the one two shift causing wheel spin and having to abort the run. its actually giving me a headache after a pass or two. the launch is smooth and feels glued down to 300' or so then here comes the chatter/shift/out of shape/abort. im kind of at a loss and looking for some ideas before i go to the track again. i worked on fuel cars for some time before i started driving and 90 percent of our shake was from underpower conditions. we would raise the percentage, either nitro or blower and alleviate this issue. well i cant do that in my naturally aspirated dragster now can i. would raising my tire pressures a half pound or so alleviate this? pull the gear longer or shorter? all advise is appreciated....

230 inch brink dragster
468 bbc dart pro 1 top end single 1050
39* locked out
14.5x32 hoosier 7psi
8 inch trans king converter
launch at 5k
shift at 7200

Re: 2 Questions....
 

Don't know much about your combo but I think you have too much timing and too much psi in your tires.
Chip Johnson

Re: 2 Questions....
 

I had the same issue on the hesitation at about 4500 RPM.
Cured it by loosening the valve lash just a little and bigger squirters in the carb which was a 2 circuit holley.
If you have a three circuit carb you might also try a smaller air bleed in the intermediate circuit.
I believe my issue was with the valve lash was too tight when the engine was not warmed up good yet at the stage process time. Mine did not stumble once the engine was good and hot. I always have it at least 170 degrees at the stage time now to avoid the stumble.

On the tire shake if it is a hard tail air pressure is about all you can change.
If it is a 4 link soften it up a bunch and that will cure the shake.

Hope you cure both issues and good luck.
Rick Cates

Re: 2 Questions....
 

it is a hardtail and it is a three stage..........

Re: 2 Questions....
 

Jason

Assuming your running a 14" wide rim I would suggest tire pressure in the 5-6 # range.
P.S if it shakes your brain out "I was never here!:cool:

Re: 2 Questions....
 

Had a hardtail, on the shake, air pressure is a good help. We've run pressure as low as 4.75. Depends on the tire. Just play with it.

Also, balance them. Some people say no, but they're wrong :)

Re: 2 Questions....
 

thanks guys...ive called in a few favors from a few of my heavy friends and they called me an (idiot) for lack of the actual term used....for running so much tire pressure. theyre all in line with what ya'll are saying ,i think ill start at 5.5 and work down since im on a good smooth track. im also going to go larger on the squirters to try to take the hesitation out. thanks for the input....ill let yall know how it turns out.

Re: 2 Questions....
 

agreed they are wrong.......balance away. we balanced every set of tires every chance we got on the fuel cars.

Re: 2 Questions....
 

well we never got down the track.....but it had nothing to do with the tires or the carb. see my new thread 8 sec. mustang for zero dollars.