manual trans and clutch quaetion

[Woodfin]

Racers, for those of you racing a manual trans.
I am considering building and racing in the Nostalgia Modified and Gassers association. This is a new program that is beginning in the North Texas service area. Other areas of the country run similar programs.

It is an index program with break out in place. The specific classes I am considering are C/G on 5.92 index or D/G on 6.09 index. It will be a relatively light weight, back half door car with a 408 LS engine so the performance will be easily attained.

My question, tell me about the clutch and transmission that will give good service life and will be relatively easy to maintain. As of now, to win the event would mean 6 or 7 passes for the day, including time trials.

NOTE: clutchless shifting is allowed.

[Adger Smith]

Following.
I'm looking a the Street roadster classes.
I have a couple G Force 5 speeds I'm going to use.
I am interested in ideas about Clutches.
Larry I'm not sure about the L/S engine platform.
Better double check on that with Kevin Hall and Tony Smith
At one time they wanted me to use iron heads like a purist modified.
I know this is evolving some..

Come on Clutch guys. Input, please.
It will have to be "Easy to Maintain" if this cripple is going to do it.

[Woodfin]

Adger, I have already talked with Kevin and the LS engine is OK. He tells me any door car or pick up that is 1979 or older is OK. I like your roadster idea.

[Woodfin]

Adger, Kevin explained to me that they relaxed the engine requirements in an effort to make it more reasonable to build a car. They are allowing the index to be the governor.

[Woodfin]

Adger, we did not specifically talk about this, but I expect, since it is basically a no electronics class, the LS or any engine will need to be carb or mechanical injection with distributor or mag.

[e vassar]

I don't know the rules for the classes, but I'll make a assumption no electronics would be delay boxes,throttle stops etc. Not engine mgnt systems.

[Rod Greene]

Originally Posted by Adger Smith

Following.
I'm looking a the Street roadster classes.
I have a couple G Force 5 speeds I'm going to use.
I am interested in ideas about Clutches.
Larry I'm not sure about the L/S engine platform.
Better double check on that with Kevin Hall and Tony Smith
At one time they wanted me to use iron heads like a purist modified.
I know this is evolving some..

Come on Clutch guys. Input, please.
It will have to be "Easy to Maintain" if this cripple is going to do it.

Call Rob Youngblood at advanced clutches. He is the best in the business.

[weedburner]

G101a and a diaphragm clutch controlled by a 'tamer. Coyote Stock cars all use this setup and are running upper/mid 9's @ 140, 3000lbs with factory sealed 302cuin naturally aspirated crate engines. Crowd pleasing 7500rpm dead hook wheelie launches are the norm, broken cars are rare. If you like people taking pictures of your car in action, screaming wheels-up launches are the way to go.

Even organic discs have been known to last a full season in Coyote Stock. Very consistent as well, field is usually as tight as NHRA Pro Stock. Here's a snip from a Dragzine article featuring Coyote Stock champ Clair Stewert, note the second to last paragraph...



With the 'tamer in place, there's no more juggling counterweight and launch rpm as conditions change. Completely eliminates the centrifugal vs base balancing act, as it allows you to adjust the launch separately without affecting high gear clamp pressure. Far simpler way to tune a clutch, and you won't need help from an expert to dial it in.
...If the clutch slips too much or not enough going into high gear, you know you need to adjust the spring pressure.
...If the clutch slips too much or not enough during launch, you dial that in with the 'tamer from the driver's seat.

The ability to control throw-out bearing position during launch can be a game changer.

[Sean Marconette]

A sintered iron setup will give long service life without having to constantly be under the car when setup correctly and last several seasons. A bellhousing that has a window to allow access for adjustments as needed, makes it faster and easier to work on. Rob Youngblood should be able to give some help on what he has to offer. I don’t have any experience with Cale’s Blackmagic clutches but they are popular too. Light base pressure is your friend and does not kill parts or your left leg!

For a trans you cannot go wrong with a G-Force.

Sean

[Rory McNeil]

I agree with Sean, I wouldn`t mess around with trying to make a non adjustable street clutch work on a drag car. In addition to my old stickshift Stocker Mustang, I have been racing my 78 Fairmont for over 35 years, the past 24 years with a stick. I ran Jerico DR4s most of that time, and have had a G Force G101A for the past 5 years. I have been using McLeod Soft Lok sintered iron clutches since 1998, and typically can go at least 2 full seasons (typically 75 to 100 low 10-high 9 second 1/4 mile passes per year). In those 24 years, I broke my Jerico 3 times,( 2 were about $300. for parts each time, once was much uglier), and I have yet to hurt the G101A. I do not have a data logger, and I have not had much need to play with counterweight, as my launch and shift RPMs are very close together, My Fairmonts Soft Lok is a 10" sintered iron disc with an aluminum flywheel, and I normally start with about 450 pounds of base pressure when new, and I am hardly "always messing with spring or counterweight adjustments ". I don`t run my clutch on the ragged edge, so I MAY adjust the spring tension 2 or 3 times a year (a 5 minute job), by 1/4 to 1/2 turn on each spring, and keep an eye on the freeplay. Other than that, it`s add some gas every 4 or 5 passes, check the tire pressures now and then, and if hot lapping, maybe charge the battery once or twice . Pretty low maintenance deal. Also, in the 24 years with the stick, I have never hurt the rearend yet,