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bhart11

Member Since 14 Jan 2003
Offline Last Active Sep 25 2007 08:13 AM
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Posts I've Made

In Topic: Midget Safety

15 September 2007 - 01:37 PM

First of all, forgive me if available stuck throttle kill systems have already been discussed. I don't read over every post in full detail, so I might have missed somebody already mentioning where to get a stuck throttle system.

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Concerning stuck throttle kill systems:

A few years ago at the innaugural Carolina Focus seires event at Hickory (NC), we were walking around the pits checking out everyone elses equipment and noticed that a couple of cars had "something" in line w/ the throttle pedal linkage with a wire hanging out of it. When we asked about it, we were told it was a stuck throttle kill switch.

I did a little Google-ing, and as usual, I came up dry. Perhaps somebody who has installed such a system on their car could shed some light on the subject: Where you get them? How well they work? etc.

If there was an appropriate commercially available solution out there (it kind of seems like there would be), I know I would seriously consider installing it on my car. For anybody who says, it's just one more thing to go wrong - hey, it's your safety or your driver's safety at stake and that's your business.

Even the most well prepared cars around have problems with stuck throttles - sometimes, it's just a freak thing, like the incident somebody mentioned where the air box fell into the injection - you can't really plan for that.

In the series that I currently work in (one of the s@#t spec car series mentioned by the aussie) - the engine manufacturer provides a stuck throttle solution. There is a stuck throttle "switch" mounted near the pedal and in-line w/ the throttle cable. When there is tension in the cable, the switch is closed and the ECU knows that the engine throttle is open b/c the driver is pressing on the pedal. When the driver lifts, the ECU sees that the switch is open, and if the engine throttle sensor is still above a certain threshold (say 30 degrees), then the ECU starts a timer that is set to something like 1/4 [sec]. So if the pedal is not being pressed, and the engine-throttle is open more than the threshold for over 1/4 [sec], it figures that the throttle must be stuck and it kills the engine.

That is a sensible system, but new for this year, the engie mfr. has added another criteria that may trigger the stuck throttle cut. It looks to see if the engine throttle is over a threshold value, and if the brakes are on (brake pressure). In that situation, it may detect when a throttle pedal (actually the pedal, not the butterflies, linkage, etc) has become stuck and shut the engine down based on that criteria.

Ok, so midgets don't have ECU's just yet, or more than a handful of sensors for the most part, but the electronics going on within your TelTach are probably more complicated than the electronics requried to implement strictly a stuck throttle system. The only somewhat complicated thing about it is having a timer of some sort to prevent false-triggering, but not havinng put an immense amount of thought into it - maybe the logic isn't even necessary. I definitley don't think that you would absoblutely need any sensors whatsoever, just various switches would provide enough information to figure out when the throttle is stuck.

Thanks to our coutny's obsession with litigation, I could see a company having major reservations in selling such a system. You can put all kinds of use at your own risk warnings on it - if some rich guy decides that your system cost him a racecar, or worse ended his racing carrer, it would really ruin it for the rest of us, not to mention the person who is trying to do the right thing by distributing the system... but I'm not really a business man, so perhaps those concerns aren't justified.

So does the system exist? Can we get it for a midget?

Does anyone have experience w/ mounting a kill switch on the steering wheel - or I should ask, does anyone have expereience where a steering wheel mounted switch was actually used to avert disaster due to a stuck throttle in a short track application?

Brandon