4 speed ka-booom !

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Weedburner
I understand your concept, your product,and the results.
My current combo has only been to the track once and for just 4 runs. The first three runs were a wash as I experimented with the launch rpm, and blew the tires off each time(bad track I guess). I then thought to myself; Howbeit I just do what I do on the Street. Which is to play the gaspedal off against the clutch. So with the line lock set, I brought the Rs up as the lights fell, and dropped the clutch as the last orange blinked on. But I didnt drop it all the way out. I just let it drag the Rs down as I flat-footed the gaspedal. Somewhere about the time the clutch was all out, it was getting to be time to shift, so I hit the engage button on the GearVendor. This resulted in zero tirespin in first. Course they lit up in first-over.
The point is my left foot was doing what your device does. Allbeit not as accurately or in any way repeatably.
So this was run 4 of the morning, and the tower-man handed me a 92.9something mph(1/8th) slip. I was ecstatic! It was the last time I drove to the track with my little 367DD.

So If I was to get into racing, I would most certainly be knocking on your door.I would put in as many discs as it takes, cuz they are cheap compared to trannys rears and D/shafts, and trailers, and a tow-vehicle.
IMO your presentation speaks for itself.
PS; The first three runs were 60footing in the 2.4s. The last run slippered in to 2.0.
 
Street suspension, very crappy old-airport-runway, almost no track prep., annual club event. They told me I was spinning my 325/50-15DRs most of the way. Some said all the way. Which was borne out by the tach being " stuuck" on 7000. I thought I blew a clutch, but back in "the pits" could not smell anything amiss. Lower tire pressures, try again. 2nd run same as the first. Lower tire pressure, 3rd run same as the first. Aw to heck with it; one more I said and I'm done. Forth run was the charmer. I didn't come to race. I came for a timeslip, cuz everyone was bugging me with "so how fast,yadayada......" .Answer? Here; how's 93 grab ya? Now stop bugging me! And with a 7.92/2.0 no less. heehee
 
j par said:
Weedburner? Shouldn't it be "clutchburner" ? I think I'd have to get a new clutch. My clutch likes grabbing, not slipping...
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We are not talking about uncontrolled slip and runaway rpm. We are talking slowing the application of clamp pressure within a clutch that has plenty of capacity to lock up after slipping...not a clutch that slips because it's operating at it's limits.

Depending on the amount of rpm change over time, it is possible to slip a clutch for a longer period of time while experiencing fewer actual revolutions of slip. Here's a comparison of slip revolutions for equal time periods…
…Setup #1- An un-damped launch from 6500 dropping to 4000 .5 seconds later at clutch lockup represents about 22 revolutions of full pressure clutch slip.
…Setup #2- A controlled release launch from 4500 maintaining 4500 rpm thru .5 seconds represents less than 19 revolutions of slip with gradually increasing clutch pressure.

Setup #2 has less actual revolutions of clutch slip, but it also has the advantage of 500 less rpm loss. Spending it's launch operating closer to it's torque peak, it reaches the shift point quicker.
 
AJ/FormS said:
Street suspension, very crappy old-airport-runway, almost no track prep., annual club event. They told me I was spinning my 325/50-15DRs most of the way. Some said all the way. Which was borne out by the tach being " stuuck" on 7000. I thought I blew a clutch, but back in "the pits" could not smell anything amiss. Lower tire pressures, try again. 2nd run same as the first. Lower tire pressure, 3rd run same as the first. Aw to heck with it; one more I said and I'm done. Forth run was the charmer. I didn't come to race. I came for a timeslip, cuz everyone was bugging me with "so how fast,yadayada......" .Answer? Here; how's 93 grab ya? Now stop bugging me! And with a 7.92/2.0 no less. heehee
Click to expand...
So what your saying here is that you ( metaphorically speaking ) brought a knife to a gun fight ?!? :poke:
 
weedburner said:
We are not talking about uncontrolled slip and runaway rpm. We are talking slowing the application of clamp pressure within a clutch that has plenty of capacity to lock up after slipping...not a clutch that slips because it's operating at it's limits.

Depending on the amount of rpm change over time, it is possible to slip a clutch for a longer period of time while experiencing fewer actual revolutions of slip. Here's a comparison of slip revolutions for equal time periods…
…Setup #1- An un-damped launch from 6500 dropping to 4000 .5 seconds later at clutch lockup represents about 22 revolutions of full pressure clutch slip.
…Setup #2- A controlled release launch from 4500 maintaining 4500 rpm thru .5 seconds represents less than 19 revolutions of slip with gradually increasing clutch pressure.

Setup #2 has less actual revolutions of clutch slip, but it also has the advantage of 500 less rpm loss. Spending it's launch operating closer to it's torque peak, it reaches the shift point quicker.
Click to expand...
So far it's looking good on paper - actually my computer.
I don't think the clutch that I have is supposed to slip at all ever. I'm likely going to try another disc.View attachment 20150811_165057.jpg
 
I used to use a ceramic disc, even they can be tamed! When you think about it, it's not much different than brake pads...they gotta be slipped as well.
 
AJ/FormS said:
And without busting stuff or huge tirespin.
The clutch is sorta acting like a TC. Sorta cuz there's no actual torque multiplication going on.
Click to expand...

You got it! Actually better than an automatic, you don't have that brief initial multiplication period messing things up.
 
I think jpar is pulling the motor. I hope he don't get carried away with changes to his combo. might be hard to figure where he went wrong. if it does.
 
fishmens67 said:
I think jpar is pulling the motor. I hope he don't get carried away with changes to his combo. might be hard to figure where he went wrong. if it does.
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I'd like to think we are looking at things with the glass half full and seeing where we're going to go right! Lol
Yup , pulled the motor yesterday. Will do 2.02's, have springs checked for more lift from 1.6:1. Rockers.
Trannys done. Rearend- got the truck dana stripped and ready to take to be shortened. Ordered e body axles ,spool, and bearings from dr.dif. Sooo, I need to finish taking the 8 3/4 out, pull the race seats to get ready to weld in the roll bar. Weld in frame connectors. Then relocate the seats and seatbelts. Bigger newer fuel line. Put calvert drag shocks and Caltracs. Lower front end and get another alignment. And if there's a boat load of money left lol LOL lol LOL!!!! I'll get an msd two step LOL !!! A man can dream !!
View attachment 20151122_105033.jpg
 
you sir, are on your way to lower et's. stick to your plan for this winter. it's a good one.
 
DC 340 said:
I agree with yellow rose on his recommendation for a Mcleod Soft Lok clutch setup -flywheel, sintered iron disc, and adjustable pressure plate. I struggled with 4-speed racing for quite some time, breaking this and that, missing shifts, etc...

In the end I was having success using the Soft Lok, Liberty pro shifted gears, and a reverse lockout on my Hurst shifter. And I still ran a braced 8-3/4, 4.86 pro gear without issue after breaking a bunch of stuff earlier. I would take the Soft Lok recommendation seriously. It's the only way to go IMO.
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Have any extra 4.86 pro gears for a 742 case 10 spline? Needing ASAP
 
I might have a 4.86 in a 489 with a spool. I haven't seen it in over 10 years but I used to have one. I can't recall selling it. It was in a narrowed rear end with Moser axles and 11" brakes, set up to fit in the framerails.
 
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