CLASS RACER FORUM - Clutch switch

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The switch behind the clutch pedal,that allows the starter to engage; is it required, per NHRA?

Re: Clutch switch

Right, wrong or indifferent, looks like Auto's yes, and Stick no. I do not know of anyone having one. It may not be a bad idea, but not a rule for a stick car.

Sean

See General Regulations 2:11.

TRANSMISSION, Automatic

Any model transmission (must be same make as car) having same
number of forward speeds (O.D. gear not required) and reverse
permitted. Transmission case must be OEM or aftermarket OEM
replica from a standard, automotive application as found in the
Official NHRA Stock Car Classification Guide. Aftermarket case
must meet SFI Spec. 4.1 and 30.1. NHRA-accepted adapter plates
permitted. Modifications to shifting patterns are permitted, provided
full shift pattern is retained. Full shift pattern must include park and
reverse. Any gear change must occur as a result of an internal
function of the transmission or from direct action by the driver.
Lockup converter permitted if OEM-equipped with lockup converter
and OEM transmission is used. Otherwise, lockup converters
prohibited. Electronic rpm controls for the electric (internal or
external to the transmission) shifting of automatic transmissions
permitted in computer-controlled vehicles only. Otherwise, any gear
change must occur as a result of an internal function of the
transmission or from direct action by the driver. Pneumatic,
hydraulic, electric, etc. controls and shifters in all noncomputercontrolled
electronic-fuel-injected vehicles prohibited. Deepened
stock or aftermarket transmission oil pans permitted. Drilling of
transmission case or rear of engine block to adapt incompatible
units prohibited. Functional neutral safety switch mandatory.
Transmission brake prohibited. Tailshaft modifications for bushing
replacement, or NHRA-accepted aftermarket tailshaft, permitted.
See General Regulations 2:12, 2:14.

TRANSMISSION, Manual

OEM or NHRA-accepted aftermarket transmissions having same
number of forward speeds (O.D. gear not required) as original, and
reverse, may be used. All gear changes must result from direct
action by the driver. Pneumatic, hydraulic, electric, etc. shifters
prohibited. Floor-shift conversion kits permitted. Clutchless
transmissions prohibited. Clutch must be used to change gears in a

conventional manner. See General Regulations 2:12.

Re: Clutch switch

We used to get asked for that a lot. Usually when you explain it's a stick shift they said OK ----Trevor

Re: Clutch switch

Thanks for the input.I got a reply from Div 1 Tech.They said,although it is a good idea, they have never seen it asked for in/on the tech line.
Hopefully that means that it is not required per NHRA

Re: Clutch switch

I`ve never been asked in Tech, besides, most older stick cars never had a clutch pedal starter switch from the factory anyhow.

Re: Clutch switch

Not needed for a stick, It is not a good Idea to push the clutch in when starting, puts pressure on the thrust bearing before the oil is circulated through the bearings

Re: Clutch switch

Without syncros, I don't think I would want to start mine in neutral with my foot the clutch pedal, then put it in gear. Could be a tad tough on things.

Re: Clutch switch

NHRA does NOT require a neutral safety switch with stick cars.

Re: Clutch switch

Personally, in the manual transmission vehicles I own, and all that I've driven.... I never have the transmission in gear when I spin the engine over. Clutch switch to me, is redundant.

Re: Clutch switch

Quote:

Originally Posted by Bill Belden (Post 327579)

Not needed for a stick, It is not a good Idea to push the clutch in when starting, puts pressure on the thrust bearing before the oil is circulated through the bearings

Bill,
Thats an interesting thought? Just couriuos, even with almost nonexistent base pressure? I can operate my clutch fork by hand. I am not doubting, just trying to learn.

Thanks
Sean

Re: Clutch switch

Aubry, you like the crunch it makes when you put it in gear? :-)

Re: Clutch switch

Quote:

Originally Posted by Sean Marconette (Post 327742)

Bill,
Thats an interesting thought? Just couriuos, even with almost nonexistent base pressure? I can operate my clutch fork by hand. I am not doubting, just trying to learn.

Thanks
Sean

One would think that with the l thousands upon thousands of standard transmission cars that come factory equipped with a clutch switch the thrust bearing thing is a non issue. I've alway put the pedal down and it's more of a habit now than any conscious reason. Having no E-Brake means I almost never shut the car off in neutral so that's probably why.

Re: Clutch switch

hi, you keep this up and NHRA will decide you need a switch. for your information, oldsmobile had troubles with thrust bearings back in 1970 with clutch switch. car had to be in reverse and clutch depressed to start.
just let it go, ok?? no switch is needed !!

Re: Clutch switch

Quote:

Originally Posted by Ed Wright (Post 327746)

Aubry, you like the crunch it makes when you put it in gear? :-)

It's not that bad Ed, once you get used to it..You just use a little finesse..
I haven't started a stick shift race car in gear ,in about 40 years..
Once you have thrust bearing issues , you won't either.

Re: Clutch switch

Quote:

Originally Posted by Mark Yacavone (Post 327795)

I've never had a thrust bearing problem in the 40+ years I've had my car. Not saying it can't happen just I haven't seen it. I never trust the fact the trans is actually in neutral even if I put it there so I'll continue to start the car with my clutch pedal down. Maybe that's because of the freezer in my parent's garage I drove into as a kid!

Re: Clutch switch

I never had a thrust bearing problem either. No soft clutches back then either. Always started them in gear, clutch down. Maybe I was just lucky?

Re: Clutch switch

Me neither, Ed... that's why I take my time putting the transmission into gear.

About this thrust bearing concern...
The only time I ever saw a thrust bearing worn for no apparent reason, was a factory 454 in front of a TH400. I've been told that these transmissions have a somewhat high internal pressure, particularily in reverse... causing the converter to push forward with substantial force.
I dunno
that's as close as I'll get to an automatic