Driveshaft Shop Stub Axles

[magnumz]

Its in the title has anyone used their stub axles and companion flanges? Talked to them on the phone they said they will handle 1000hp. The price with companion flanges to accept 108mm cv's is about the same as other companies 39 spline 300M stubs. The stubs are 300M companion flanges are 4340.

[JMortensen]

First off, the 510 and 240 shafts are not the same size, so that kinda throws a red flag. Second, no matter what material you use, the Z stub axle is still only 1.250" diameter. 300M is not magic. It's a little stronger than 4340, and Modern Motorsports have had those out for a decade and people with a lot less than 1000 hp can break them. So basically I think their hp claim is grossly overrated.

 

Second, if you use their CVs then you're still using the rectangle flange output shafts out of the diff to attach your 1000 hp CV joints to. That's a serious weak link,

 

If you want max hp capability ouf of stock suspension and stub axles, I think Modern Motorsports setup with the 930 CVs and their own 4340 outputs from the diff are a much better choice. That's as good as it gets IMO and should be enough for almost all the people here, but still won't hold down 1000 hp, we know because we've seen them broken with less.
http://www.modern-motorsports.com/datsun-240z-280z-complete-cv-axle-conversion.html

[RebekahsZ]

There's nothing you can't break if that is your goal. Drive it like you love it and it will last longer than if you drive like you hate it.

[racerteck]

I have heard good things about the driveshaft shop etc

As has been rightfully pointed out by JM the 1.25'' diameter limits ultimate strength

We have developed a soloution to the OEM size that uses wheel bearings with a larger bore size

This allows the use of 1.5'' diameter stub shafts and companion flanges for size 21 CV joints ( commonly called 930 joints from the old factory backed racecar that used them)

our own setup uses a variation of the 9'' ford 35 spline 3rd member

 

The car that is using this setup is 427 cid turbo with 5 spd and 10.5 x 28 slicks

 

I currently do not market this and it is expensive, however if someone really need this level of strength..............

[Eric JB]

I have heard good things about the driveshaft shop etc

As has been rightfully pointed out by JM the 1.25'' diameter limits ultimate strength

We have developed a soloution to the OEM size that uses wheel bearings with a larger bore size

This allows the use of 1.5'' diameter stub shafts and companion flanges for size 21 CV joints ( commonly called 930 joints from the old factory backed racecar that used them)

our own setup uses a variation of the 9'' ford 35 spline 3rd member

 

The car that is using this setup is 427 cid turbo with 5 spd and 10.5 x 28 slicks

 

I currently do not market this and it is expensive, however if someone really need this level of strength..............

 

A part number for those bearings would be helpful.

[NewZed]

Who is "we", and where is "the rock"?

[racerteck]

The "rock" is the most eastern province of Canada

We is my racing buddy and I

The bearings are a proprietary design that uses sealed angular contact ball bearing units and spacer as are the stub shafts and flanges.

We went in this direction after starting to twist a previous design of 1.249 spline dia.

 

This all fits the OEM bearing housing and works well with AZC rear brakes, we use 1/2 screw in studs on 5 x 4/2 and had Dave do the rotor hats to match however moving out to 5 x 4.75 would be stronger.

[NewZed]

Do you mean "custom" when you say "proprietary"?  Basically, a one-off, but common design, with a larger inner hole in the inner race for the larger shaft?   Maybe smaller balls to allow material for the race strength?   Nice work.

[magnumz]

First off, the 510 and 240 shafts are not the same size, so that kinda throws a red flag. Second, no matter what material you use, the Z stub axle is still only 1.250" diameter. 300M is not magic. It's a little stronger than 4340, and Modern Motorsports have had those out for a decade and people with a lot less than 1000 hp can break them. So basically I think their hp claim is grossly overrated.

 

Second, if you use their CVs then you're still using the rectangle flange output shafts out of the diff to attach your 1000 hp CV joints to. That's a serious weak link,

 

If you want max hp capability ouf of stock suspension and stub axles, I think Modern Motorsports setup with the 930 CVs and their own 4340 outputs from the diff are a much better choice. That's as good as it gets IMO and should be enough for almost all the people here, but still won't hold down 1000 hp, we know because we've seen them broken with less.

http://www.modern-motorsports.com/datsun-240z-280z-complete-cv-axle-conversion.html

I had done some searching on the durability of the oversized chromoly stubs but hadn't found ppl talking about breaking them. I would be using an r230 diff with their adapter to fit the 930 cv's to the Nissan 6 bolt diff output which should be strong. I had thought about having the diff outputs treated in some way to make them stronger. The driveshaft shop kit is quite a bit more affordable and should be just as strong or stronger than the modern motorsports kit. Driveshaft Shop has a pretty solid reputation with high hp cv applications. 

[NewZed]

There was a thread a short while ago where we made fun of the absurdity of the 1000 HP claim on their web site.  The claim disappeared soon after, like somebody from there saw the thread.  Sounds like the guy you talked to didn't get the message.  I took a quick look and couldn't find it but it's out there.  I'll post a link if I do.

 

Here's their web page.  No 1000 HP claims there, just "big power".

 

http://www.driveshaftshop.com/import-axles/datsun

Edited October 9, 2016 by NewZed

[NewZed]

Here it is - http://forums.hybridz.org/topic/124155-cv-kit-for-sti-r180/

[JMortensen]

The problem with the shortnose R200 or R230 is that very few people make a cradle to mount them. If you mount the front of your diff to the diff strap bolts with a long mount, you're going to pull those bolts right out of the chassis, as some people have now done. I'd rather see a cradle that mounts to the front and rear diff mount bolts (could incorporate the control arm pivots) and then bolt the front and rear of the diff to that then have these setups where the mustache bar is modified and the front mount is modded but they aren't connected. My opinion is that is insufficient.

Edited October 9, 2016 by JMortensen

[NewZed]

Several people have reported problems with the quality of the 930 CV's.  There are a variety of sources for them, some not so good.

 

You might browse through SUNNYZ's and RebekahsZ's past efforts.  Both are drag racers who've been through the process.

 

 

Here's where SUNNYZ ended up but he has other threads about breaking stuff - http://forums.hybridz.org/topic/109324-ford-88-irs-conversion/

 

Her's one where RebekahsZ describes twisting a driveshaft - http://forums.hybridz.org/topic/116475-should-i-be-worried-about-my-axleshalfshafts/

[magnumz]

I thought i remembered there site claiming 1000hp then it disappeared it makes sense now. lol I would probly use the TTT r230 mount kit. i also thought adding some sort of pinion snubber that connects to the car in the trans tunnel area to reduce stress on the diff strap mount area. 

[racerteck]

The outer race is a little thinner, so far no issues with 1.28 60s and wheels up in 2 &3 but not a lot of street miles

I have  run cheep Chinese Empi joints but just changed to tighter GKN German ones to get rid of some of the backlash.

Drag racing a stick is an exercise in destructive testing............... we will see about durability

[Eric JB]

Several people have reported problems with the quality of the 930 CV's.  There are a variety of sources for them, some not so good.

 

 

 

Most of them sell 930 "style" cv's. What they really are is VW bus cv's. The original German cv's used,  will be better than new Chinese ones. I drag raced and sand duned for years with those joints and broke a LOT of parts. Never a bus  CV.

Off road racers prefer the 930 cv's because they will worker at steeper angles than the bus cv's. 

[Eric JB]

Hey Racerteck, So are you running the same 35 count, 30 degree pressure angle splines on the outer stubs and flanges as well?

[seattlejester]

I'd really love to see a full cradle as well. I forget who, but we had a forum member from down under post a picture of his holden differential cradle that tied in the control arm pivots, basically making a subframe and that made me really happy.  

 

While in this discussion, is there a fairly known number the 280z stub axles are unhappy at? I see some cars that seem like they have stock stubs pushing way more hp/tq numbers then I think they should be able to handle.

[NewZed]

The one a few pictures down on this page?   http://forums.hybridz.org/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-mount/

[seattlejester]

I think the one I saw was for a holden and was a fuller top and bottom design, I'll have to see if I can find the post.

 

Edit: Hah found it, thought I was loosing my mind for a bit, it was a picture on a link from someone on this forum

 

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

 

Post number 6

Edited October 12, 2016 by seattlejester