Steering at high speed

[voodoo_stepchild]

Anyone have any ideas on how to slow the steering down at high speeds. My second dragstool needs something different than my first one as it is about 25 mph faster and I dont need the precision steering like our racers. The first stool is incredibly violent at high speeds and just a small bump to move your arms enough to move the handle bars and your upside down or headed straight for the wall. We have played with the lengths of our steering components on the spindles and even on the steering tube but still not slow enough. Another machinist friend of mine came up with a cam design for the cnc and we milled it out and its still not quite slow enough but much better. I dont want to get into any rack and pinion bullcrap or anything exotic just something simple that we are overlooking perhaps. We duplicated the steering on our Birel and our Tony shifter karts and again its way too touchy. Anybody got any ideas?


Voodoo

[moto1fast]

Hello, The first thing is that your wheel base being so short will cause this and if you have a solid rear axle w/ no differential that dont help either! The way these are set up (barstool Racers) will not do good at high speeds. You can do a few things to improve it but will never be great at handling at high speeds. The first thing I would do is set caster and camber to zero and put 1/8" toe in. I would run narrower front tires. Set it up like a dragster Slim tires on front. They run wide tires on rear and very narrow ones on front for high speed straight line running. But as you know they do not turn well at low speeds. If your barstool is going to be a dragster type build it like one. Hope this helps some!:smash:

[voodoo_stepchild]

Actually we have extended the frame from our normal bsr's which are 28 inches center front axle to center rear axle, to about 42 inches center to center. The front tires are junior dragster tires and the front end is junior spindles and hangers. The chassis is 4130 chromoly (1.025" tubing) and all bent on our bender and welded. We decided to weld the rear solid as we are not cornering and dont need the chassis to flex. This is the same design as out first dragstool and the chassis works excellent. I have been browsing the jr dragster sites and look like all are running a special rack and pinion for the little monsters. I ordered one this morning and should be here by friday so I can see exactly how it ticks. My buddy suggested that we may be able to machine a new gear and track for them to slow them down a little bit. According to the manufacturer it should be geared slow enough as it is we will see. We didnt want to go this route, but looks like we have no other choice.

Voodoo:cheers:

[moto1fast]

You coud make a very short A arm to make more steering movement making it less sensitive! Rack and pinion will do the job a lot better! Good Luck!:wave:

[voodoo_stepchild]

Yah we tried the a-arm being a shorty and even extended the arms off the spindles longer to slow it down and it was much better, but still a little sketchy. I think the rack and pinion off the jr dragster will fix it

Voodoo

[kkuenemann]

I agree that the rack & pinion will be the best way to go. As far as the alignment that moto1 mentioned, most Drag Race cars have MORE negative CASTER (top of the spindle set back from the direction of travel) added over what a stock vehicle would normally have. I currently have mine on my BSR at 10 degrees negative. This is to help the car stay STRAIGHT at speed and increase the effort needed to turn the wheels. JMO.

Post some pics once you get the steering worked out....

[voodoo_stepchild]

Well the rack and pinion and a few more mods to the spindles and steering components proved to be the trick. A Jr dragster rack fixed most of the major problems but we went back to kart wheels and tires

Voodoo

[Blackrat]

any possibilities of getting some pics of this setup please ?

[voodoo_stepchild]

Will do,
I will get some pics up as soon as I get a chance so you can see how we did it. We also had to limit the steering capability just to help slow down the steering. At the end of the run we remove a pushpin to allow full steering so we can manuever in the pits a litle easier


Voodoo:lush:

[CoolerRacer]

Im wondering how fast your going that your have those problems with steering? My spindle setup is all wrong on my cooler racer and I have had it to around 50mph. I would like to get it going 75-90 mph but will probably be running into the same problems u have.

[c.schulz]

Keep me informed.

Chris

[Swint]

Did you think of a chain and ssprocket set up? We have an old 70's Yazoo zero turn mower that has three wheels on it and the 2 front ones are stationary and the rear is the turning one and it has a steering wheel coming up, then it goes down and has a sprockt, then it has a chain that goes back to the sprocket on the top of the wheel that lets it trun. Its kinda hard to understand without a picture, I can try and get some pics tomorrow.