Straight rail for a noob

After 30+ years of road race karting I'm getting talked into trying the dirt. Some buddies are trying to get a KT class going on 1/4 mile out here in Nor Cal. I've got an old Emmick straight rail Express chassis. I'm told on that big of a track it can work and that I won't need a jackshaft. What I need is chassis set up info or ideas. Corner weights, rear wheel offsets, tire sizes, spindle heights and things like that. I really want to go play with these guys and help them get this thing going. I can tune the motor but have no knowledge of how to make the chassis work in the dirt. I've got lots of asphalt parts and pieces, motors and clutches. Trying to get it going on the cheap to see if I like it while not looking the fool.
I really enjoy my superkart but it's just a lot of expense and time. A Yammi kart drug around in the bed of the truck playing in the dirt sounds much simpler and like a lot of fun. Any advice would be appreciated!
 

JPMKarting

Premium User
"What I need is chassis set up info"

Get a cement block and put it under the right front tire and have the biggest person you can find or even two stand on the left rear tire. Then jump up and down on the right front tire a couple of times. Take it off the cement block and have someone sit in the seat while you try to lift the right front tire. If the right front tire is hard to pick up and the left front is sort of easier or a lot easier, then run it and see how it does.

Dont do this.

I would essentially move the seat over as far to the left as you can get it to maximize left side percentage.

Im betting the kart doesnt have much front end adjustability in terms of castor or camber. Spindle height wise, set both sides neutral as a starting point.

For tires/wheels, im not sure what compound or brand is best (probably a burris tread Tx-11). Go with the below sizes for tires/rims:

8.00 RR on a 10"x 6" wheel
6.00 LR on an 8.25"x 6" wheel
5.00 RF on a 6' x 6.5" wheel
5.00 LF on a 6" x 6.5" wheel

This should put you in the ball park. If you can find an offset chassis in CA with an adjustable front end, you will be way ahead of the game
 

01ron

Member
Paulkish, drink another cup of coffee then reread your post. You planning on compressing a cement block?
 

flattop1

Dawg 89
Not knowing the rarity of an emrick chassis .
Paul's idea of twisting the chassis could work .
Coyote actually recommended this as a way of getting your corner weights correct .
 

11jw

New member
Back in the late 80s, we had an MXK Mirage chassis that was pretty flexible and after several races it would begin to get "sway bellied" . The owner, a very inventive fellow, built a jig into the back of his trailer so we could unbolt and remove the rear bumper and attach the back of the frame to the trailer. We would then put a custom made sawhorse under the middle of the frame and with the aid of a 4 foot level we would torque it back straight again. We also used the method paul described to get corner weights where we wanted them. Karting has come a long way since then.
 
Used to have an old straight rail Coyote I ran on dirt. Camber and spindle height were the only front end adjustments that could be made to it . Don't know how or why but it was the best handling kart I've ever driven.
 

racer11x

Member
I started on a straight rail Margay, ran it for years on Dirt Ovals and it worked great. I bought it used and the machinist that had it before me had installed adjustable front end on it though.
 

nobozos

Member
If it's for fun and on the cheap no need to spend the money on a jackshaft setup. A 1/4 mile track true 1/4 mile is a good size track for a kt. have fun Chuck.
 
Top