ZF6 with McLeod Street Twin clutch
Tired of breaking spindles / half shafts, not yet wanting to spend cash on solid rear.
Thinking of doing Summers Brothers Racing spindles and Denny's Nitrous Ready half shafts.

I was wondering if it would be possible to fab up an air bladder that would sit above the rear diff, allowing one to add air (for track purposes) and then just deflate the bladder afterwards.

Basically, the clutch transfers power before the rear can squat and aligning the half shafts and the diff. It is transferring power through angles which are the breaking points.



I was wondering if the inflatable bladder above the diff could align the rear suspension to look something like this.



And would this prevent power through odd angles and greatly reduce broken parts?

 

Could you just add higher rate springs?

 

I think you have a misconception that the car squatting down is actually transfering weight.

That IMO is wasted motion.

Weight transfer has to do with getting more weight on the rear tire and if the rear spring is so soft that it allows the body of the car to drop down without applying all that energy to the tire, then it's wasted.

An air bag would increase spring rate which IMO is a good thing for drag racing with Corvette IRS... but I have to state that just using a stiffer rear spring is a simplier option... but I'm getting ahead of myself here.

I don't think your breakage problem has anything to do with suspension/halfshaft alginment. It's most likely because of how harsh the dual disk clutch applies load to those componets. Drag races call that "The Hit".

I have my opinions on this stuff and I didn't figure this stuff out in a day. I've broken more rear end **** than most people and I often talked with another member who broke more rear end **** than I did about what we were doing, what we were doing right or wrong and how we thought could fix the wrong... lots of trial and error and thats where my info comes from.

My 92 6spd has a SPEC Stage 3 clutch. 383 LTX based engine that is early 500RWHP. The car has run some 1.70 60fts on 315/35R17 MT drag radials slipping the absolute dog **** out of the clutch. I have broken a number of halfshafts, u-joints and outer stub axles on that car comming out on the clutch too hard.... Didn't matter what I did.... I built extended snubbers to keep the halfsahfts level when it launched and I could still bust the u-joints in the halfshaft anytime I wanted by comming out on the clutch too hard if the car hooked. Tried and tried, breaking everything for 4yrs to better 1.70 60fts... My solution was to slip the clutch and be happy running 1.70 60fts... once this clutch is done, I'm going to buy something that hits softer... like a SPEC stage 2+...

Now my friend with his 91 6spd. 383 420RWHP. He had the same dual disk clutch you have. He ended up with the extended snubbbers, Summers Bros stub axles, spool in the D44 and steel halfshafts. Made the car suck to drive on the street.... the Summers Bros bored out rear wheel brgs constantly went bad driving on the street.... Eventually he sold all of that **** and just went with a softer hitting clutch (Centerforce DF) and made sure he cooled the clutch down good between passes.

Now my 84 Real Street class car. I built this car to prove a point about IRS C4 Corvette drag cars. Car has a pump gas 427SBC. 603HP on motor with an 82 N jet in a BG Nitrous Works plate kit - about 200HP. TH350 with a PTC 4500 stall converter. 8" foot brake "soft hit" converter. d44 with a 3.90 gear and a spool. 28X10.5 "stiff sidewall" slicks. This car runs 1.20 60fts on all stock rear end stuff.... I MEAN STOCK! Stock outer stub axles, stock halfshafts with SPICER u joints. Stock Z51 rear spring and all stock 101K mile rubber bushings.

75+ passes on this car this racing season without a failure.

It's all in how you manage the "hit" that the drive train see's. I can run 1.20 60fts all season with 800hp and never break anything in the 84 but with only 580hp and a hard launch I can bust everything under the rear end in my 92.
Will

 

I have broken parts on the street with regular street tires and every time I put anything sticky on the rear, I'm spitting out parts with the McLeod.

Previously I have ran a CF Dual Friction clutch. Actually I have ran 2.
The first one started slipping (no fault of CF, some form of oil or whatever contacted surfaces and it all went bad). I replaced it with another one and in between engines (stupid me and not checking coolant level in the winter, it was mostly water and it cracked my damn block!) I put together a new engine and the mechanic told me that my clutch and flywheel were showing signs of uneven wear and he didn't feel confident putting it back in, even though there wasn't a whole lot of use on it.

So, I got to the point where I wanted a clutch that wouldn't fail me and could handle all I could throw at it. This led me to McLeod.

Your friend's 91 sucks to drive on the street you say, is that because of the spool? I was thinking of going that route minus the spool.

 

No, the spool wasnt a big deal to him.... constantly replacing rear wheel brgs and having to send them to Summers Bros to be bored out for the bigger stub axle sucked.

I have a spool in my 84 also and its not a real problem for me eith as long as I have street tires on the car... very noticeable in tight turns with the slicks on thou.
Will

 

For the track ,some have replaced the rubber snubber above the spindle with a solid mount long made enough that does not allow the
half shafts to go past horizontal on launch;
thereby limiting loading up the uni's while they are binding at max angle on squat.