halokiller

Hello,

I've come across many threads about the theoretical limits of the stock c5 diff and T56, but I wanted to hear some real experience from the community. I plan on running a 255/50/16 MT Drag Radial with my 510whp 416 LS3 Corvette. If I launch around 4500rpm and slip the clutch out, can I expect the stock diff and trans to live as long as I avoid wheel hop?

sr530

The answer depends entirely on how effectively the clutch's engagement is controlled. The more power you make, the more clutch torque capacity you need. The more clutch torque capacity you have, the harder that clutch can hit. The harder your clutch can hit, the more damage it can cause. Controlling clutch engagement with your leg is not precise, one screwup can put you over the edge. There are more effective/consistent ways to control the hit of the clutch than using your leg.

The simplest version consists of a one-way in-line hydraulic restriction to control the speed of clutch engagement.
Here's a link to Tilton's version... http://tiltonracing.com/wp-content/u...trol-Valve.pdf
Here's a link to ClutchMaster's version... http://www.clutchmasters.com/content/FCV2000diagram.pdf
Upsides...
...relatively easy in-line install between clutch master cyl and hydraulic throwout bearing or slave cylinder.
...protects drivetrain from excessive shock.
...eliminates wheel hop.
...makes dead hook radial launch possible without bogging the engine.
The downsides to these are...
...they require "pre-loading" the clutch prior to launch to minimize the reaction time increase.
…they cause excessive clutch slip after the shifts.
...in-line restriction can cause excess fluid to be drawn past MC piston seals, causing increasing "pump-up" effect to the clutch pedal.

The next step up adds a solenoid bypass to make the device active on launch only...
Here's a link to the Magnus Launch Controller... http://magnusmotorsports.com/product...ontrol-device/
Here's a link to a version made by MPS Racing... http://www.mpsracing.com/products/MPS/cl03.asp
Upsides...
...relatively easy in-line install between clutch master cyl and hydraulic throwout bearing or slave cylinder.
...protects drivetrain from excessive shock on launch.
...clutch engagement speed is adjustable by rotating a dial.
...eliminates excessive clutch slip after the shifts.
...less clutch release "pump-up" effect, as the solenoid can be controlled by some ecu's or a timer.
The downsides to these are...
...they still require "pre-loading" the clutch prior to launch if minimum reaction time is important.
...clutch hit is not as sharp as it could be, as you must compromise between reaction time and clutch slip duration.
...the clutch hit after the shifts is not controlled, making it possible to get wheelhop after the 1/2 shift.
...not the hot tip for keeping radials stuck after the 1/2 shift.

The next step controls clutch engagement at the pedal.
Here's a link to my ClutchTamer clutch hit controller... http://clutchtamer.com
Upsides...
...easy install if there is an application specific version for your car.
….protects drivetrain from excessive shock on launch and after the shifts.
...clutch hit is adjustable from the driver's seat by rotating a dial.
...no wheelhop on launch or after the shifts.
...no clutch pedal "pump-up" because there is no in-line restriction.
...no effect on reaction time, works great for heads-up racing and pro-tree.
...radial friendly on launch and after the shifts.
Downside...
...installation can be difficult if there is not an application specific version for your car.

Beyond the above, i'm currently working on an improvement over the typical in-line install. My "Hitmaster" valve is still in the test phase, but it basically adds driver's seat adjustable clutch hit control without any hit delay.



Upsides...
...relatively easy in-line install between clutch master cyl and hydraulic throwout bearing / slave cylinder.
...protects drivetrain from excessive shock on launch and after shifts, eliminates wheelhop.
...clutch hit is instant and consistent with no compromise, intensity is adjustable from the driver's seat by rotating a dial.
...no need to change jets in order to change clutch engagement speed.
...can be added as an upgrade to the Tilton/Clutchmasters/Magnus/MPS launch controllers.
...adding a solenoid and bypass timer eliminates clutch pedal "pump-up" by giving excess fluid time to return before the next shift.
...adding a solenoid and bypass timer also allows full clutch clamp pressure to be applied instantly after the time delay, eliminating excessive slip.
...solenoid and bypass timer can be configured to make the unit active on launch only, or active on launch + shifts.
Downsides...
...works on hydraulic release systems only.
...overall cost is higher.

Grant

halokiller

That's really interesting, thanks for the input.

nyg215

I don't see the stock dif output shafts holding up to a 4500rpm launch with drag radials for long. Mine didn't! A few passes and it was fine but one slip up and I dead hooked which broke the output shaft. Recently snapped my g-force trans output shaft due to a bump on a damn highway on-ramp. My rear got air over the bump and when it landed poof I lost all acceleration. I'm swapping in an RKT built TR6060 and c6z rear with 500m shafts. I also have a 416 ls3....love it!!