930 vs 934

[KLC]

Might as well go down this road, I'll start with some show and tell. I've got a 4 seater, stock LS3, HV-24, 33 Blasters and it probably weights 2500-2600lbs. The ass end is 95" wide measured outside of tire to outside of tire, I have 31" 300M Tatum axles and I use Tatum midboard hubs. I also use 930 cvs. I can destroy cheap EMPI stars in less than a season, so I switched over to Fortin 300M stars and cages 3 seasons ago and have had very good luck with them. I didn't do a complete teardown and regrease last season I only pulled the boots back and squirted in some grease a few times, this year I took them apart and cleaned them thoroughly in the solvent tank. Luckily, I only had 1 star with some pitting where the ball apparently applies most of it's torque. At $91 for a new Fortin 300M star from Kartek I'll happily continue to use my 930 gear. It's strange that only 1 of them was pitted but I'm not complaining lol. 

Now with that said, our new frame made with 1 3/4 x .120 4130 may be a bit heavier when it gets put into service and may cause some faster wear on the cv stars, but we will cross that bridge when we get to it. The swap to 934 midboards ain't cheap, I'm not even sure that's the route I'd go. I would be inclined to install outboard hubs and be done with it, however I can buy a lot of 300M stars for the $10,000 it would cost to install outboards and axles (that's a reasonable estimate taking into consideration all of my fabrication and modification is done in house) not to mention the added wear on the transaxle due to the increase in rotating mass. Why do I talk about outboards you ask? Imagine how long a cv would last living it's life at only 10 or 12 degrees of angle...

Oh and the grease, I've been using straight Swepco moly grease as it does just as good of a job as the mixes did. It seems the Bel Ray part of the mix caked up everywhere but in the joint and did nothing special. Currently I've got a couple of tubes of John Deere moly grease I'm going to use, IMO it's all moly grease in different tubes but that's a different thread haha.

Tell us about your car and cv stories, and I wasn't looking to discuss adapters of any kind. 

 

[J Alper]

if you go with 934 with LS3 power you will very rarely need to change the CV's even if they pit i still run them for some time, they are very well built, 

I am running a LS-tall Deck 468-ci with SB2 heads and the EMPI CV 934 hold up great, CV for a Empi are $120-160 ish, no more broken cages or stars, will make your car so reliable, no more CV talk around the Fire,  

 

[lincster]

3000lb car.

Supercharged LS1.

ADS Outboard hubs.

934's.

I get 3-5 years on stars.

10-13 trips a season, 3 full duning days per trip.

I run 50/50 Belray and Swepco.

Pull boots back every other trip and add grease.

I have zerks in my caps on my hubs, so that is easy.

Been doing this for 15 years.

 

[DZRTRUN]

I have had really good luck with 930 Fortin guts in my CV’s. I would service your CV’s every year and replace what is required. Honestly I do the same thing with my 934’s. I buy German 934’s super cheap and replace the stars, cages and balls with Fortin stuff. Ends up saving me about 50%. I know it’s weird but I have never broken any outer housing. It’s usually the cages or stars that break and the Fortin stuff is amazing even in 930. 

 

[Fullthrottleguy]

Everyone has an opinion - since you asked, here is mine ...

weight, tires, and driving style is everything.

930's are lighter and really help with acceleration and are easier on the trans R&P especially when combined with 33's vs 35.5 or 36's 

But they are smaller and have less surface area - like a 9" clutch vs 11" clutch ...

if you are wearing out the stars its either Grease (not likely) or simply Heat/pressure.  The star and balls in a 930 CV just have less contact surface area  so you get more pressure in smaller area - more pressure =  more heat and you get pitting, if you are not breaking cages, then your angles are good.  A good mix of BelRay/Swepco in your case will help to stop stars from Pitting, but there is just not enough area to take the pressure over time  - 934's have 200% more surface area on the ball surface area- it just spreads the load better.

the downsides of 930's

- axles are smaller and will eventually break  "faster"at the splines from  twisting with a lot of HP  - this can be Many seasons

- Stars and balls are smaller  - less surface area - they run hotter and have more wear with higher HP

- Smaller bolts 3/8" with big HP tend to loosen faster (stretch) you have to change them after a couple seasons to be safe

- Not your issue but 930's have less angle capability than 934's

If you drive well and don't dump the clutch or stay on the gas in the "air" the shock on the CV's is not an issue 

930's will just take more maintenance even if the setup is all correct

Personally I like light cars with High HP and fast accelerations - So I ran 930/30's (RCV)  in a couple cars with no issues for 6 seasons 

The reason for 930/30 was the bigger axle - the stars and cages were 300m REM polished and Cryo'd I ran Midboard and sub 24 degree angles with 2000-2100 Lb cars, 15/33 Blaster Pro's and Supercharged just under 1000 crank HP

I re-greased every trip - flushed the CV's and new grease and swapped the stars side to side in mid season - so not maintenance free

I moved to 934's on my latest car since I was buying all new  - are they better?  well they are definitely heavier, and they do not require the level of maintenance - after first season with zero maintenance they look new ....

I service a few cars that have 930's and 934's  and the 930 cars that are set up right are really reliable but the one that is not breaks parts every other trip.  The 934 cars even set up wrong, have no problems even running EMPI's and last more than 3 seasons ...all different HP and weights from 500Hp to well over 1000HP