Re: Radial tire question
 

If that question was intended for me, I have no idea if it's NHRA legal for stock or SS. It does not affect the manual release of the pedal with your foot, it only stops the pedal's return at a pre-determined point. Basically the same as adjusting base pressure, except that it also has a bleed that allows additional pressure to then come in at a much slower rate. That allows more slip during launch without blowing thru the clutch in high gear.
Here's a Psi graph showing what it does on a hyd throwout bearing. The vertical drop of the trace was all foot controlled. It's only after the clutch hits that pressure drop is controlled (acts on the pedal itself, also compatible with mechanical linkage)...

http://grannys.tripod.com/clutchtamergraphintro.jpg

There's an article in the April issue of NMCA/NMRA's Fastest Street Car Magazine. I have not seen it yet, but I hear they interviewed some racers that are using it.

Grant

Re: Radial tire question
 

I always thought you could not run a hyd clutch in stock super stock. Tom

Re: Radial tire question
 

Been that way for years. Maybe they will.

Re: Radial tire question
 

So, the bias slick's fundamental for traction is its deformation. > High energy losses at all frequencies. So, the bias slick is fundamentally inefficient.

The radial is the opposite, low energy loss at all frequencies. Traction at all frequencies if you can keep it from deforming. Efficient, less rolling resistance. Faster, quicker et's.

The fundamental for wheel speed we've found effective for radial tires is the same as limiting wheel stands. Prolong the period of time the shaft is neutral in, or even exiting the damper/shock main body. We run a two way rebound adjuster on a heavy 2950pd small tire radial nitrous leaf spring car to combat wheel stands. No wheely bars allowed in the class. It lays tracks 275 radial, one teen sixty foot. There's another idea, maybe smaller tire would be easier to manage, deformation. Dunno, be interesting to see who gets there first on a radial.

Re: Radial tire question
 

Mike.
We have been using wheel speed/slippage to go fast in Comp/Modified/Gas classes for 4 decades. At the time those were not bracket classes. We all know bracket guys want a dead Hook. A turn to a turn and a half after the hit on roll out usually produces the quickest ET. Watch this with no wheelie bars and a V-6. The tire slips gets it off the line. The engine stays up on the converter after the hit. Hard to dial.
https://www.youtube.com/watch?v=eZPI6eCN8pE
We didn't have computers back in the early 70's and there was a lot of trial and error to make things work. Ed Wright knows what I'm talking about. He was there, too. Glad to see you guys working on this kind of stuff. That is getting the performance instead of being one of the dead hook crowd.

Re: Radial tire question
 

Clutch hit control is what you need to make radials work with a stick.

I don't share competitive graphs, but this one had a few problems so I can show it here. It shows what a dead hook launch looks like using one of my clutch hit controllers. 302ci sealed crate engine running the spec tune, 3100lbs. Class doesn't allow radials, so this run is with a 10.5" bias slick @ 18psi...

http://grannys.tripod.com/032419.PNG

First problem was not enough delay after the hit, which caused rpm to get pulled down to about 5200 after launch. 5500 is typical.
Second problem was the PP needed to be shimmed a little more in order to control those wheelspeed spikes after the shifts.

Depending on the track/conditions, it's not unusual for the above car to be able to go above 20psi with bias slicks and still dead hook without pulling rpm below 5500.

Re: Radial tire question
 

Radials can be made to work. All of J Allen Sherman stick customers use radials except for me. I just haven’t messed with them yet. Steve Kent uses them on his AH cud’s and his bad azz SS/B Vette. Stan Holt and Jarrod Grainer run radials on both super stocker and their stick shift comp car. Go to dragracertv and watch this pass weekend runs by Jarrod Grainer 66 Chevy II and watch how it leaves on those radials. It’s a thing of beauty.

Re: Radial tire question
 

Good call. That's a bad dude. 1.38 on the back tire. Thanks for the tip. That's a clinic.

https://i.imgur.com/ke3HBvE.png