Hey every trip I break the center star of my left lower cv, I do proper service use neo lube and it never fails the center will crack after about day 3 , Im thankful the trans axle doesnt take the hit but im getting tired of changing these things. I run an LS1 with a cam and tune, dyno says 428hp at wheel is there a tougher center center star made, I have the race cages and never have problems with them.
is there a tougher set of stars?

Sounds like you are putting too much angle on them.

Too much angle could br the problem but I had the same problem on my old car and I was running 2 degrees less than max angle and had very little if any compound angle. Later i found out that by using chromoly race cages and having the CV "race prepped" the problem would be elimiated.

Im no expert but with 600 or so hp you need to go to 934's.


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You might try Gear One 300m Stars but also what is your angle degree?

Use shorter limit straps for less cv bind/angle.

What car do you have?

Sanrail Fabricators LT, they are out of Bell gardens LA area. Great car except the breakage of cvs. Im gonna look into the gear one stars.

My straps are alredy tight due to the preload I have on the coil overs, seems when I had less preload I would bottem so I have the jam nut tightened down with about 4 inches of threads showing above.
I think the gear one 300m stars are the answer.

instead of losing travel consider half shafts w/ more angle and a higher hp rating it may be the hot ticket it was for my ride

IMO if you are running that much preload to keep from bottoming out, then you need stiffer springs, and a bit of sack dialed in. Then do what sandking said.

Whats your spring rate? Up the springs 50-100 lbs per side. I would say you have too soft of springs.
My $.02

We dont even know if your running by passes or anything..

thats to much showing above the collar for sure - but springs generally should be thought of as ride height - not the preventer from bottoming out.

what kind of car and weights are we talking about? When you say you bottom out - whats the story? when does that happen?? I agree - to much angle - but how could putting more pressure on the limit straps cause that besides stretching them out an inch.. sorten them an inch.. but still dont like that you cranked the springs like that to prevent bottoming out.

I have both of those problems (bottoming out and breaking stars), i have an X5 with an LS1 with 2.5 bypasses. I went to King last year and added about 150 to the spring rate. Chummin is right i was told the same thing the bottoming out shouldn't be fixed with spring rate and it's only for ride height. I still bottom out and i break my stars inside of my 930CV's just about every trip. I have the Kartek 930 race prep stars and they don't seem to hold up. I would agree i need to step it up to 934's. Any other suggestions for the bottoming out?

Turn in your secondary or triple tube compression until you get the desired result.

If you are bottoming out with bypass's, you need to adjust your compression. I still think the stars are breaking due to too much angle.

I agree with the stars breaking.. I was just trying to find out why he cranked them to begin with.

Its an easy cheap test.. Put a set of 2" shorter limit straps.. Just try it.. If it works great - your cost was nothing compaired to upgrading..

Then again, falling 30' out of the sky - you should expect to bottom out..

Oracle,
I have had many X5s in my shop with the same issues you have mentioned. The car overall is well built but your cv issues are due to too much combined angle. At least the cars we have worked on have been. If the previous cars are any indication of yours then you need to do the proper measurements to figure out where the angles lie and limit the rear accordingly to a safe angle. This has been the cure for the cars we have seen.

As far as bottoming out goes there are may things that can effect that. Spring rate or secondary rate nut adjustment, drivong style or bypass valving can all create that problem or cure it if they are correct.

Gentlemen,

In general, if the cv gets too much angle you will see dents in the cage, then center star chipping on the narrow edge, then cage failure and once the cage goes the star can follow it making it hard to see what happened first. If the star fails first and the cage isn't damaged then you have a loading and unloading issue or horse power shock loading into the cv. In other words the rear tires aren't on the ground, either in the whoops or jump landings on power. In jump landings you control when you lift in the air or get into the throttle on landings. On the whoops it is all suspension. Make sure it is correct, if your not sure, video helps. If that does you no good then send it to someone who knows, King, Fox, builder or a favorite shock guy. Either way, one or a combination of the two can be your issue so consider both. If these things aren't looked at then buying the Gear One 300m cv will last longer but not cure your issue, neither will 934s. Later, Justin

Something is seriously wrong with your setup if the limit straps are tight at ride height. Your car will ride like crap because there is no droop travel.

An easy way to check your limit straps is to jack up the rear of the car so the wheels are off the ground . The limit straps will be tight, now put one hand on a axle and rotate the wheel, while rotating the wheel the axle should move from the wheel to the tranny back and forth. If you feel it bind or notchy or anything but smooth tighten the limit strap and try it again. They should plunge in and out while rotating the wheel. Try and see if it binds at all doing this.

Another issue that is ignored is that the race prep cages have the Parkerized coating removed . Try a set of new stars without race prepped stars. Break them in on a high lift jack for about 10 minutes. Let them cool , then they should be ready for battle.

The stars are not usually through hardened. Just case hardened on the surface. Don't know how thick that top layer is. I can guess that the Gear One units are through hardened. Get the ones with no race prep.


The excessive clearance will contribute to the loading and unloading that Justin mentioned. (Shockloading) CV's are made to see ZERO clearance. You can buy bearings that are sized to fit to achieve no slop, or zero clearance. Don't worry about grease, it'll still lube ok. It melts and then gets everywhere.


Carl

OK, Im running 2 way bypass 2.5 with external res cduel rate coil overs. I have done some studying and I have come to the conclusion that my preload is set way too tight, I have reduced it to to 3.5 inches of thread above the nut and I will fine tune with the bypasses, I feel this will reduce the angle and I can dampen with the compression setting. oh ya the car is a sanrail fab LT weight is around 2300.

Please explain parkerized coating thks

It's the dull gray coating that looks kinda rough. Similar finish on all flat tappet camshafts. It's made to be the break-in medium/coating that "conditions" the surface for usage. It's kind of like a very fine grinding compound of sorts.

I've never asked many questions about it's properties or how it's applied. I only know that it's there for the purpose of break-in.

I could be incorrect in the name. But it's the coating that I'm describing. I know that Parkerizing is mostly used on guns. But the actual name of the process evades me now.

It's not meant to be cleanaed/ground off.
The proper way to "clearance" a CV is to use select fit ball bearings.
That's why McKenzies sells them.


Carl

428 not 600 what are you me wishises i had 600, then then that would explain the prob. I think reducing the pre load therby reducing the andle will be my trick.

I think he is referring to FWHP, which is what most of the sand engine builders refer to.

QUOTE(trawak @ Jul 19 2005, 03:20 PM)
QUOTE(swark @ Jul 17 2005, 06:12 AM)
Im no expert but with 600 or so hp you need to go to 934's.


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428 not 600 what are you me wishises i had 600, then then that would explain the prob. I think reducing the pre load therby reducing the andle will be my trick.






I think he is referring to FWHP, which is what most of the sand engine builders refer to.





YUP,,,,, thanks 1fastdsl !

And knowing your axle angle at full droop or compression might help
you do have an angle finder trawak ???????
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Ok I may be a bit fwhp? The dyno I tuned on stated hp at rw explain this fw please im intersted in learning. Also no angle of the dangle measuring device, I think I could rig something up will perform the measurments when new cvs come in and get back with you.
Up and down angle are called what?
Fwrd and back angle are called what?

FWHP.........flywheel horsepower

I got ya, seems like a way to puf up ones chest quoting the hp before it hits the ground though.