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this is a 2 year old manufactured sports racer not a home build!

having a problem with our two personal track cars over heating it's CV joints.
every 4 to 6 days at the tracks I need to pull the half shafts out remove the CV's clean them and repack them with new redline CV2 grease.
I learned after 9 or 10 days on the track the CV's will get so over heated they just disintegrate .
if you look at the pic of the CV adaptor flange you will see a round wear marks on both cars the inner and outer flanges all have the same marks.
the marks are from the ball bearing cages of the CV's.
I believe this is part of the reason why the CV's are getting so hot and cooking the CV's to death?
also the CV's are running at about 8 degrees at static ride height. and under full compression they go to about 6 degrees.
the VW bus the CV's are taken from do not have that steep of a angle in the bus they run at about 3.5 degrees. running them at a steeper angle I also feel is adding to the over heating problem.
I also feel that because the VW were not designed for a vehicle that can go much faster than 70 MPH and the race cars easily see speeds well above that . this too is also a part of the problem. but a small part of it.

I have plastic axle/ half shaft end stops. in fact I have to buy them in 100 quantity bags because when I clean and repack the cv's every 4 or so days on track the end caps are worn down to nothing but a bear axle end.

talking to the manufacture a few times was totally pointless. and I'm being nice about that!
my feeling is that 1 the axles are to long and under the suspensions compression that the CV's are getting pushed to hard into the CV adaptors. why it's leaving big groves.
two the CV angles are wrong .

what's the fix?

if I drop the Diff lower in the chassis but I really can't lower it more than another inch or the chain will hit the chassis then maybe shorten the half shafts that this will maybe fix the problem?
I worry about making the half shafts shorter not to run against the adaptors but them they maybe to short and get pulled apart when the suspension is at full droop or extension.
or would a two piece sliding half shaft work better?

I understand not wanting to show more pics so I won't ask.
The distance between the cv joints changes with travel. This type usually has the trans end of the shaft with a longer splined area so the CV inner can slide back and forth on the shaft as needed to prevent the thrust loading that is occuring.

CVs don't roll but skid in the grooves with any angle greater than zero so some heat is generated which is why the special grease is needed so not the issue here.

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yes as the suspension is going under compression ( on it's up travel ) the distance between the stub axle and the adaptor in the diff gets closer.
making the half shafts long enough not to pull them apart at full drop they need to be the length they are.
as the suspension goes into compression the half shafts are then to long and crushes the CV's into the stub axle and the diff adapter.

I'm thinking the fix is to drop the diff in the chassis lower. this will lessen the angles of the half shafts so as the suspension goes through it's travel the length of the then can accommodate the less distance between the inner and outer CV's.

The bug and bus style cv joints are really not speed rated. Many of the older single seat and sports racers used them at speeds of 150 mph or more. Also many used the outboard fwd cv joint which had no allowance for plunge. My sports racer the SkaytR6 used a small Rabbit outer cv and a later 100 mm inner cv running at about 6 degrees but used only 4" of total suspension travel. All of the plunge was taken up by the inner cv joint. The axles had plunge at both limits of travel. Most of the angle was related to the diff being in sfront of the rear hubs. It sounds like the car is setup to allow too much wheel travel.
You might consider a lower ride height and/or stiffer springs. Chassis mods to lower the diff might be a good consideration.
Ideally the diff centerline should be at centerline of wheel hub when at ride height or slightly above. This will minimize the plunge of the cv joints while lowering the working angle.
Miata V8 suggested allowing the axle to move inside the cv joint to get the added travel needed as this is what offroad cars do. You could add spacers to the cv joints to allow the added plunge.
Ideas to ponder. Good luck

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When you're racing, it's life. Anything that happens before or after is just waiting -- Steve McQueen from LeMans

My build log viewtopic.php?f=36&t=10658&start=0 NOW NAMED =The Wycked 7

My other build log viewtopic.php?f=18&t=15162 The Skayt'R6