22 replies to this topic

[ejeff]

I'm building a hardbody Willys with the JDS Gasser chassis and ProSlot .560 big block. My aim is .999
I cannot get the car to go down the track. It jumps, it hops, it rolls over.
I have tried everything I can think of. Weight in different places, every gear ratio, every tire width.
Please help!
Thanks!

[Tom Katsanis]

How do you have the wheelie bars set on it.
I would get the rear tires trued if you have not already & set the wheelie bars set up with a small gap I have used just std card stock to set my wheelie bars gap.

I have not run a jds gasser chassis but know a few guys that run them.

With these high riding Gassers they can get unstable & be a handful.

[Pablo]

Check the axle straightness, check the axle bushings for wear or being loose in the bracket, and check the motor bushings for wear.

[ejeff]

Bushings in the chassis and motor are new. Chassis is straight, tires round, wheelie wheels set at minimum height.Everything is new.

[Tom Katsanis]

Jeffrey are you gluing the track I have had cars do some crazy stuff because they didn't get good traction off the line besides that I don't know what the problem can be.

As I said the Gassers can get unstable because of there setup I have seen a few end up on there side or upside down in the braking area I hope you get it sorted & could you post a pic if possible would love to see it.

[ejeff]

I've tried with and without glue. Bite does not seem to be an issue. Chassis is quite rigid. Wheelie bars as designed fairly short. Center of gravity very high.

[Tom Katsanis]

Maybe you can pm jds racing on Facebook they might have a better idea on what you can do.

[Bags]

Run it with the body off to see if it goes down the track. If it does , then your problem might be how the body is mounted to the chassis. Could be too tight , not enough movement or could be too much. Try and run it with the back mounting pins out if you can. Sometimes the wheels hit the body when the pins are out, be careful. If that works and the car goes down track then your problem is the back mount. The pin holes on the body can be opened up a little with a drill bit to allow movement .

I have found over the years that those Willys bodies aren’t very aerodynamic and do rock and roll a bit.

Keep em Green !

[Thom]

Some tires expand or grow like real drag slicks and hit or touch the body, also tires can come unglued from the rims which will make your run really violent.

[ejeff]

I've run it without the body, it is better but problem not solved.
I have seen nothing that leads me to believe the tires are touching the body or have come loose from the rims. I have also trimmed off the width of the tire that is not glued to the rim.

[Pablo]

If you have verified the axle is straight, I have one more super-crazy thought - mismatched pitch gears can drive ya nuts.

Gremlins come into your parts bin at night and get a sick thrill of taking 72P pinions and putting them in the 64P bin   

[ejeff]

No, dont own any 72s, all 64 pitch.

[Pablo]

The only thing you haven't checked is the rear axle. Please humor me so I can get over it.   

[Bags]

Check the solder joints and make sure the aren’t cracked or broken.  Also did you solder or glue the rear axel bushings/ bearings in the chassis  to keep them from walking back and forth ?  Make sure the front wheels don’t touch the track too.

[ejeff]

Ok I'll check those things tonight and let you know. Thanks.

[ejeff]

Had the drag guys at my shop look it over last night after the race. A couple of suggestions were longer wheelie bars, look closer at the guide and the settings for the wheelie wheels and front wheels. Tried all that today, no difference. Jig alignments good, axle's straight. Swapped the big block out for a Super 16 and played with the tire glue and it runs great. No problems.
So what the heck can you use these big block motors for?

[MSwiss]

What's a big block motor?

[ejeff]

ProSlot PS-101 .560 arm 16d Pro Sportsman motor

[BrettC]

Sounds like it’s to aggressive off the line then.

[MSwiss]

ejeff,
I just finally finished my building my drag strip, a few months ago.

I've been trying to absorb as much as I can, about drag racing.

What I'm learning is guys don't seem to mind racing 1.2, 1.3, 1.4 cars.

They seem more concerned about looks and consistency.

You never mentioned specifically it's a G20 motor.

That JDS gasser chassis is cool, but I don't think it was meant to be a 9 second car.(I assume the 9.99 you are shooting for is on a 1/4 mile track)

And I think that motor is more designed for conventional bar cars (longer wheelbase/lower stance)

Anyway, sometimes less is more.

I have adjustable power on both my lanes.

When I try running something with a Hawk 11, Phoenix, or G20, I'll try turning the power down from the 16+V, to something in the high 14 to 15V range.

I was originally a bit surprised at the great times I've turned, on the lower power.

Now I'm not.

99% hooked up on 15V is better than 89% hooked up, on 16V.

What kind of times are you getting with the S16D?

[ejeff]

Hmm, don't have adjustable power.
S16d was 1.200

[MSwiss]

1.200 seems pretty good for that chassis and a Hardbody Willys.

If you are on FB, you might try asking questions on Wes & Ben's.

There is infinitely more drag racers on that page, than here on Slotblog.

[idare2bdul]

The 41 Body can do that, especially with a hard launch. They also can get light at the top end of the strip. Make sure the back of the body mount allows float. I really miss Drag racing but my knees old me it was time to quit. Guess my stuff will show up for sale somewhere.