Jump to content
HybridZ

modern motorsports cv axle coversion kit


Rob L

Recommended Posts

  • Replies 50
  • Created
  • Last Reply

Top Posters In This Topic

The Z31axles change length by sliding within the CV; the 930 axles change length by sliding on the axle splines. You really can't compare them; they are apples and oranges. 

 

Opening these kinds of questions to the entire forum will yield you a lot of speculative answers. 

 

As I understand the 930 design, they can change length by both means.  The CV joint has a range, and the axle splines have a range.  Some people lock the joint on the spline and just use the CV range.  Or let the joint float for more range.  But if the joint floats on the splines then the splined surfaces become loaded sliding surfaces with all of those inherent problems.  You'd need to know how Joe built his axles to know what to worry about.

 

And comparing the range of lengths is apples-to-apples.  Too short is too short, too long is too long.  Just sayin'...

 

 

Speculative answers is why people post questions in the forums.  New ideas.  The more the better.

Link to comment
Share on other sites

I have to call him again...the first time I talked to him ..he said the kit is good up to 800 hp

I wonder who is making the "kit".  He says "the manufacture®" on the page.  [Odd, "r" in parens = ®.]

 

He seems good at collecting the right parts though.  The factory type CV shafts will probably disappear eventually as the reman market runs out of used shafts.

 

This kit is rated at 800HP by the manufacture.

Edited by NewZed
Link to comment
Share on other sites

I'll stop after this one.  The better CV shaft topic is just too interesting to leave.

 

I don't see a lot of "plunge" room on Joe's axle shafts.  Kind of suggests that he's going with the non-floating design.

 

So, "trust but verify" would be the way to go.

 

 

post-8864-0-81429500-1447966970_thumb.png

Link to comment
Share on other sites

The thing I have found is most of these are exactly that, non floating. Locked outboard by a c clip, locked inboard by a machined hard stop or a thicker center axle that is turned down to spline. Without a hard stop apparently sudden impacts or movements (a lot of off road buggies use VW motors and this type of axle) causes the axle to mushroom apparently.

 

You set the axle length where the control arms are parallel, and the axle kind of becomes a non adjustable arm. 

 

More proof of the non floating design is in the fact there are different lengths for the R160-R180 diffs and the R200 diffs. If they were floating it would be a simple manner of running the splines a little deeper and letting the CV move inboard for the bigger diff, but apparently a new axle is required for the larger diff.

 

If you are interested in how the setup came into play the DIY setup is still available and pretty well documented by 510 guys I think if you look for Mattndew, you will find the companion flanges and the write up including an axle drawing with the indicated hard stops.

Link to comment
Share on other sites

Not sure if this info might assist but here is how I adapted Porsche 930 CVs. I'm not sure if this is always the case but I found the splines on 'plunge' and 'non-plunge' CVs were different (28 Vs 27) and the after-market axles only cater for 'plunge' CV (28 splines) on both ends

 

http://www.viczcar.com/forum/topic/12048-tutorial-holden-diff-fitted-to-a-240z/

Edited by Boy from Oz
Link to comment
Share on other sites

Quite awhile ago I ended up buying this combo Modern Motorsports and custom Driveshaft Shop stage 5 axles from this member who was strictly v8 turbo drag race focused. He went this route and shortly changed over to a solid rear axle and sold the parts as a smoking combo deal. He had the Driveshaft Shop custom build the cv axles (900hp claimed), build these from 280zx turbo specs and said they are on file with them. I already had the MM billet companion flanges to finish out the whole setup.

Link to for sale on HybridZ:

http://forums.hybridz.org/topic/91419-smoking-deal-on-bullet-proof-rear-end-set-up/?hl=%2Bdriveshaft+%2Bshop

 

 

post-736-0-09022000-1448071760_thumb.jpg

post-736-0-43904900-1448071776_thumb.jpg

post-736-0-03268400-1448071796_thumb.jpg

post-736-0-28791200-1448071812_thumb.jpg

post-736-0-67593200-1448071823_thumb.jpg

post-736-0-73635200-1448071834_thumb.jpg

Link to comment
Share on other sites

I wanted to add my 2 cents to this thread in relation to the wolf creek racing "porsche style" cv axle kit. I installed these on my car and have done approximately 2000 miles since. I had always been aware/annoyed of the amount of "slop" or play in the rear end since installing these axles and the play seemed to get progressively worse with added mileage. I run new quaife 4.11 differential with chequered flag racing chromoly stubs. Diff is supported by a ron taylor diff mount on top and stock mount on bottom (no movement). Driveshaft is custom with new upgraded u -joints. This car is not drag raced and I do not do hard launches for the record.

 

 

 

Fast forward to last week. The rear end was getting very annoying...letting off gas/ starting off would result in more play/slop in the rear end and there was a bit more noise from the rear end. I decided to pull the rear end and have things checked out. The diff and diff bearings are perfect...the driveshaft and joints are perfect...the diff mounts are solid. So I pulled apart the CV axles and found that the "Porsche style" CV cages were chewed up and worn/pitted badly. Took the assembly to a local CV shop that does custom work for various high performance cars. The tech advised that the CV axles had damage to the CV's in particular the cages which in his opinion were not high quality. (Wolf creek racing states on their site that they use chromoly cages with hardened races???).

 

 

I thought this would be of interest to those considering this setup. I would not recommend the wolf creek racing axle kit, especially you V8 high torque guys...

 

Here are a few photos of one of the disassembled CV's with photos of the damage and a diagram of a CV and related bits.

post-2301-0-27027400-1448071335_thumb.jpg

post-2301-0-54270100-1448071350_thumb.jpg

post-2301-0-54353500-1448071369_thumb.jpg

post-2301-0-20116700-1448071388_thumb.jpg

Edited by DREW RBZ
Link to comment
Share on other sites

Here are a few photos of one of the disassembled CV's with photos of the damage and a diagram of a CV and related bits.

Could it be that the shaft was either too long or too short?  Looks like the balls were getting forced to one side of the cage.  How does the other cage look?  And the balls.

Link to comment
Share on other sites

All four cages have similar damage.  The damage is also to both sides of the cages.  The balls themselves appear to be in fairly decent shape but do feel a little rough (very small scratches/pitting).  The star gears and outer cases show some minor sign of wear (shiny areas).  It appears that these cages are the weak link in the CV however I do not profess to be any kind of expert in this field.  Here are a couple more photos:

 

 

post-2301-0-66871900-1448122583_thumb.jpg

post-2301-0-48440200-1448122630_thumb.jpg

post-2301-0-82301300-1448122750_thumb.jpg

post-2301-0-72103900-1448122765_thumb.jpg

Link to comment
Share on other sites

Here's some good stuff on cage materials.  Apparently there's some compromising involved depending on application.  I wonder if a new cage would get you back to where you started, or if the races and balls have too much play due to wear.

 

#4.  http://driveshaftshop.com/blog/?p=567

 

The fact that the cages are worn on both sides makes you wonder also though, if there was enough travel available in the first place.  Just wondering, don't know much.

Link to comment
Share on other sites

Hi Guys, here is some info I think might help.  Made by the same manufacture that has been making my other parts.  My CV kit for the Z car actually started out as a CV kit for the Datsun 510 with a R200 that was designed to replace the weak parts in the 510.  I had it build for the Z car as good axle parts are very hard to find. Keep in mind this is a bolt in kit no modifications needed.  If you are using adjustable lower arms and your car is 1 inch wider I can get you axles 1/2 inch wider.  I have sold 3 kits for the 510 and 5 for the Z car.  I have had no contact with the customers as far as any problems what so ever. As for the CVs they are chromoly  with 300M center section.  They are not cheap you can buy cheaply made 930 CVs for $40.00 or built right for $220.00 mine are the $220.00 version. The CVs are 28 spline plunging units.  Any other questions please feel free to contact me I always answer the phone. Please keep in mind I'm in California.

 

Happy Holidays

Joe

Edited by CHEQUERED FLAG JOE
Link to comment
Share on other sites

  • 2 weeks later...

Ok so quick update here ...i have a quick comparison ....driveshaft shop quoted me 1600 for a full complete swap including the r200 stubs for 1600....so all that would be left is the outer stubs,  and those can be had for around 800.

 

So a complete full package from inner stubs to outer stubs is 2400 usd if you piece together the drive shaft shop pieces and combine it with checkered flag outer stubs.

 

OR

 

Buy the full modern motorsports kit for 3200 usd

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...