Forum: HoseHeads Sprint Car General Forum (go)
Moderators: dirtonly  /  dmantx  /  hosehead

Was Jason wearing a HANS device? The YAHOO article mentioned "severe neck trama". Just wondering about that important detail.

yes he was. a simpson hybrid. but the hit to the wall was from the left side and he had removed the head restraints from his full containment seat allowing the neck to "whip" to the left when he hit. both bill simpson and randy lajoie said the neck restraints are only good for 30 degrees of side protection and said that had the head restraint been on the seat, the outcome would probably have been a lot different.

go to southjerseydirtracing.com and read the full post on the message board.

Loose is when you hit the wall with the rear of the
car, tight is when you hit the wall with the front of
the car. Horsepower is how fast you hit the wall and
torque is how far you move the wall.

Relatively low speed but high impact/abrupt stop hit with 120 pound driver. Equipment was analyzed by the manufacturers and deemed installed and used correctly meaning tethers were set to correct length and posts mounted properly on helmet. Stated it was rare by not unseen for clasps to fail as seen. We got lucky. Get rid of those things. They're not worth it. Not much else and not my place to say anything further.

http://vimeo.com/16786987

The greatest knowledge is to know that you know nothing
at all.

I had a RF Steel Torsion stop come off about 4 weeks ago and destroy a car... stop was in turn 3 crash happened turn 4... had to put it in a vice in order to back the nut off

https://www.youtube.com/watch?v=I6wirvjvhZo

Damn, that was bad. Glad you are ok.

This has got me thinking about the bars.When a bar is doing it's job it is twisting,and when it twist it is losing length or shortening.With soft bars and the kind of downforce a wing car is making,is it possible we are not leaving enough end play and the bar is actually pulling out of the stops? This could also be affecting the performance of the bars.I would like to see a study of how much length bars of different sizes are losing when they are twisted.

That's a great idea! If I remember right from 35 years ago, shifters on dirt bikes are/were machined like that. In the meantime, use the allthread. Just a few bucks to make your own. I use 3/8" allthread with a regular nut welded to one end and a nylock nut on the other end. A short piece of 3/8" fuel hose on each end will keep it somewhat centered in the bar. I never saw the point in Ti stops anyways. They are not unsprung weight.

Member of this message board since 1997

I agree, this would be an interesting experiment.

Some additional food for thought; I keep hearing that the RF stop is a common donominator. This is an important observation. The RF bar/stop on a track like Bridgeport isn't doing a whole lot, especially on a winged car. A track like Bridgeport generates a lot of wing speed. My guess is that the RF on Leffler's car was supporting very little, if any weight, at speed.

Unfortunately it sounds like the arm/bar slid out of place and interferred with the steering.

My point is this, if the RF arm/bar is just laying there, meaning very little load, then why is the stop falling off? If the stop is falling off because of brute force, or extreme wrap up, I would think the LR bar would be the one that cosistently fails...

Most of the time the torsion stop is tightened with a load on the bar. If the torque of the tightening process is less than the load on the bar and there is play in the splines the stop may not clamp as tight as it should. When the bar unloads the stop may become loose and slide from side pressure or vibration.

1 night at Lincoln Speedway, Fred Rahmer lost the right front bar & stop on 3 separate occasions that evening. He was in the Hamilton 77. I don not recall what type, brand or material they were made from. Obviously this result could have happened to him also. It did not.

He still won the feature without the right front stop or bar attached to the car that evening!!!

Dirts for racing asphalt is for getting there!!!

I had a RF stop that didn't get tightened before heading out for the B main. we made changes to the rf. I changed to a lighter bar, the crew got in a hurry and forgot to retorque the stop.. we pushed off and my crew tried to get the track officials to call me on the headset to get me to pull in, I started pole, the officials deemed it not important apparently?? upon yellow flag pace laps I noticed the car favor the RF more but knew we made a change and didn't think it was uncharacteristic of the change. possibly the LF was supporting the entire front axle? I dunno? on the wave of the green I got the jump, headed into turn one shallow and rolled onto the throttle only to find I couldn't straitn the wheel out to neutral position, we drove up the track exactly like the gentamans video on here and collected one other car, the other car rolled hard, I flew off the top of the track backwards and hit the fence with my LR, we destroyed One topwing, one set of headers,one front wing, three wheels,rear axle,torque tube, three torsion arms, two tires , you name it! a ton of stuff between two cars was tore up. lucky nobody got hurt or there wasn't any others involved in the maylay, I bruised my hip, my crew bruised their ego, a problem I hope we never experience again... I leave the gap of (at least)a nickel on my arms to the bushing, and torque and retorque to 35lbs on steel, make sure the washers are not gauled up, check the threades of your clamp bolts to make sure there is adiquit threads, grade 8 bolts,top locks or nylocks only, i recheck my nylocks if they are starting to show wear on the nylon , if I can spin them tight by my fingers I throw them away. Ive never been a fan of the aluminum threaded jobbers, alot of guys use them, there isnt enuff confidence in them for me, what retains the thread loc, other than the ductility of the aluminum,, check and recheck your stops this weekend!!

i remember a few stops falling off at lincoln and a few beat up racecars. there was a discussion about it on the grove board and it seemed like most were pointing fingers at one particular manufacturer and model. there was even a pic of a car coming at the photographer with the bar slid out of the tube and the arm about to hit the wheel......just before the wreck.

im kinda liking the explanation about why not to torque the stop bolts under load. gonna start torquing the bolts without a load on the bar......never had a stop move but it only takes one time.......

After completing blocking the car and weekly chassis lube, I tightin the stop clamp bolts with a 3/8 ratchet My crew chief does a follow up on all the wheels , stops and arms before the nights festivities (or changes) with the torque wrench, this has become routine.. I put a lot of trust in them rechecking my shop work.. Im usually satisfied with my inspection and approval in the the shop, their secondary check is just for good measure and a few times we have found a area that needed more attention, (usually this is discussed and resolved quickly). I purposely leave the stops tight,but untorqued so the concentration is left to one more set of hands and eyes pawing over the subject..(give your crewmembers a routine Job they can handel and they will stick to it like syrup to pancakes) Again, I leave a slight gap in both sides of the arm and the stop to the chassis bushing the bars will actually deflect or "worm up" in motion " hint " paint the inside of our bar with a light coat of paint, chances are it will be rubbed offafter the nights races, (this is proubly sprint 101 for some of you) for those that don't know, keep it in mind, I always give the bar a tug, it makes that sloppy side to side noise it should make (tink- tink) then set my wedge bolts at neutral (whatever you prefer) and carry on to the rest of the matinance inspection of the arms and stops is always looked over, anything odd or wore strangly is inspected again and or replaced, Ive delt with this problem before, sadly the stop was missed and I took home a destroyed racecar, as many of us have found out the hard way, I feel lucky, it could have been much much worse...

A couple of thoughts & ideas.

Why not fabricate a 2 clevice pin system thru the torsion tube where it would not let the bar slide by if the stop comes off. Inside of the left frame rail where the tubes are welded on.

No need to notch the bar as the splined ends are larger than the bar itself. You could actually make a u-clamp just to the size & spec & nut it up after after bar changes, some what like a muffler clamp look!

It would take an awful strong c-clip to withstand the pull under extreme pressure I feel & that would still be vunerable to the task at hand.