Boost with High Compression

[Dr.Jeff]

What should it cost to make 2 similar shafts? One is 7 3/4", other is 11".

For a period I was closely following some of the "Honda into X" swap threads, thinking it might be on my list someday. There were a mix of reported costs to have the axles made. I seem to recall some as low as under $300 to others well over $600. I'm sure there may be a big difference depending on the materials used, design of it, and where you have it done. Plus yours may be less due to the shorter length? I know the 4-wheeler crowd gets a lot of custom axles made for all sorts of axle swaps. And they tend to go big on that kind of stuff. Maybe there is someone your way that is into that scene and can offer some insight.

 

[Rupunzell]

Round two, load up and tow the race car to the event only to have the car die at the start line. What was the cost and amount of irreplaceable time that was wasted with the entire event? This happened previously add that to the overall cost of a single part failure (axle)

Weld it up, assured failure again. With each progressive weld up the "hot glue" patch becomes increasingly fragile and increasingly not possible reliable. If you're interested in doing the race day prep, load up, tow to the event and die on the start line again.. do the weld fix.... makes zero difference who or what does the welding, the problem is innate to making a weld ~regardless of who or what~ does the welding.

Really a pay now or pay MUCH more later question.

Re-spline two axles from Moser Engineering is $125 plus shipping. What did the weld up assured to fail action cost?

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Bernice

 

[gene cooley]

Round two, load up and tow the race car to the event only to have the car die at the start line. What was the cost and amount of irreplaceable time that was wasted with the entire event? This happened previously add that to the overall cost of a single part failure (axle)

Weld it up, assured failure again. With each progressive weld up the "hot glue" patch becomes increasingly fragile and increasingly not possible reliable. If you're interested in doing the race day prep, load up, tow to the event and die on the start line again.. do the weld fix.... makes zero difference who or what does the welding, the problem is innate to making a weld ~regardless of who or what~ does the welding.

Really a pay now or pay MUCH more later question.

Re-spline two axles from Moser Engineering is $125 plus shipping. What did the weld up assured to fail action cost?

Shop Services | Moser Engineering

View a list of our most common shop services or send us a call or email for more detailed information | Moser Engineering

www.moserengineering.com

Bernice

I'm not disagreeing with you. I didn't have any info on the cost of reworking an axle, don't know if the unsplined section of the axle is large enough to be splined.
Up to this weekend which cost us about $600 for no runs the actual costs for the axle have been about $3. That's what it cost when I pulled it from the junkyard.
If I divide that by the 80 events over 8 years at probably 10 to 12 runs per event THAT I DID RUN I don't see where it was the piece of junk that you seem to think it was.

 

[Rupunzell]

Measure the axle spline diameter with a micrometer, then measure the axle diameter, they are often made in a way that the axle diameter is the same as the spline diameter or very close. Larger is easy to deal with as the larger diameter is simply turned down to the diameter needed on a lathe. Splines are made with a separate machine tool set up process.

This has been done a few times for the rotary powered LeMons racer with a Porsche 901 gear box, done again as we have ditch the Porsche gear box and have gone to a non-synchro gear box on the LeMons racer. This was done on the TR6 when the stock diff was replaced with a Nissan viscous LSD. Stock Nissan axles were cut to length, sent to Moser Engineering for spline cutting. This TR6 lost it's four universal joints and sliding axle, replaced with four CV joints (Saab 9000 outer, Nissan inner) and modified Nissan axles to fit the Saab CV joints. This completely ended the problems with universal joints and sliding axle that did not always slide and the power transmission is much smoother than the universal joint set up as OEM.

This is a very common modification. The solid axle folks who shorten or lengthen a "rear end" do this all the time.

CV joints have industry standard sizes and much the same with axles that work with them. Some shopping for raw axles would be where to begin. GOOD race axles from scratch cost more as the axle is made from high quality alloy steel (8640), machine work done, heat treated, inspected-tested. Really trick axles are composite, back in the 1980's Lancia and others were already using them in the WRC cars. Works good as they lower inertia of the drive line and proved tough enough to survive WRC duty. These are truly high-buck race car items.


Bernice

I'm not disagreeing with you. I didn't have any info on the cost of reworking an axle, don't know if the unsplined section of the axle is large enough to be splined.
Up to this weekend which cost us about $600 for no runs the actual costs for the axle have been about $3. That's what it cost when I pulled it from the junkyard.
If I divide that by the 80 events over 8 years at probably 10 to 12 runs per event THAT I DID RUN I don't see where it was the piece of junk that you seem to think it was.

 

[gene cooley]

Measure the axle spline diameter with a micrometer, then measure the axle diameter, they are often made in a way that the axle diameter is the same as the spline diameter or very close. Larger is easy to deal with as the larger diameter is simply turned down to the diameter needed on a lathe. Splines are made with a separate machine tool set up process.

This has been done a few times for the rotary powered LeMons racer with a Porsche 901 gear box, done again as we have ditch the Porsche gear box and have gone to a non-synchro gear box on the LeMons racer. This was done on the TR6 when the stock diff was replaced with a Nissan viscous LSD. Stock Nissan axles were cut to length, sent to Moser Engineering for spline cutting. This TR6 lost it's four universal joints and sliding axle, replaced with four CV joints (Saab 9000 outer, Nissan inner) and modified Nissan axles to fit the Saab CV joints. This completely ended the problems with universal joints and sliding axle that did not always slide and the power transmission is much smoother than the universal joint set up as OEM.

This is a very common modification. The solid axle folks who shorten or lengthen a "rear end" do this all the time.

CV joints have industry standard sizes and much the same with axles that work with them. Some shopping for raw axles would be where to begin. GOOD race axles from scratch cost more as the axle is made from high quality alloy steel (8640), machine work done, heat treated, inspected-tested. Really trick axles are composite, back in the 1980's Lancia and others were already using them in the WRC cars. Works good as they lower inertia of the drive line and proved tough enough to survive WRC duty. These are truly high-buck race car items.


Bernice

Round 2 1/2. Visual inspection of the shaft (pics show it too) unfortunately shows that the splined portion of the shaft is larger than the "normal" part. I think that's for clearance when everything is assembled and very possibly for strength. There is a slight ramp at the change in diameter. A rough measurement tells me the spline dia is 1mm bigger than the shaft. GM makes literally millions of these things so each design is optimized for the application so they make it like they want it and I have to deal with it..
That appears to leave me with a custom shaft that may only be used for 4 more events when I add the supercharger or the rules change forcing me to change everything. Or I can weld up another one for some time and about $10 and assume it will last about 300 launches.
I appreciate your help and I intend to contact Moser for their thoughts.
Anyway it's good to have so much high powered input on this-----yours; my son the Mechanical Engineer (I always blame broken parts on him); my neighbor the machinist, and last/lowest me, the Mechanical Designer.

 

[Rupunzell]

Are these splines going into a CV joint?

If yes, CV joints have industry standard spline dimensions and there are not that many of them. Figure out what size spline these CV joints are then find a matching axle longer than what is needed. Use that axle to be cut down and re-splined as needed. Rinse and repeat.

Or use a CV joint with an inner spline smaller on one end.

Custom CV joints are good when properly designed,manuactured and ... Oh BTW, don't bother drilling out the center of the axle as some folks wanna do. Unless there is a LOT of material removed, the reduction in inertia is not that significant and adds another potential failure process.

Speaking of CV axles, the longer cv axle on the Lancia Scorpiacarlo is tubular and welded (properly done it's ok, yes this means speciality welding machinery, post welding heat treatment and testing). To compensate for the difference in twist between the short solid axle and long axle, the designers decided to compensate for difference in axle twist by increasing the outside diameter of the longer axle by using a tube with the the spline ends welded on. It works. The more common modern solution is to use very similar to identical length cv axles, then apply a center support bearing system with an intermediate connecting axle. This solution has become very common in FWD power trains.


Bernice

 

[gene cooley]

Are these splines going into a CV joint?

If yes, CV joints have industry standard spline dimensions and there are not that many of them. Figure out what size spline these CV joints are then find a matching axle longer than what is needed. Use that axle to be cut down and re-splined as needed. Rinse and repeat.

Or use a CV joint with an inner spline smaller on one end.

Custom CV joints are good when properly designed,manuactured and ... Oh BTW, don't bother drilling out the center of the axle as some folks wanna do. Unless there is a LOT of material removed, the reduction in inertia is not that significant and adds another potential failure process.

Speaking of CV axles, the longer cv axle on the Lancia Scorpiacarlo is tubular and welded (properly done it's ok, yes this means speciality welding machinery, post welding heat treatment and testing). To compensate for the difference in twist between the short solid axle and long axle, the designers decided to compensate for difference in axle twist by increasing the outside diameter of the longer axle by using a tube with the the spline ends welded on. It works. The more common modern solution is to use very similar to identical length cv axles, then apply a center support bearing system with an intermediate connecting axle. This solution has become very common in FWD power trains.


Bernice

Bernice, I am running an early hydraulically controlled GM front wheel drive automatic transaxle (3T40). This was used throughout the front drive cars of the '80s and '90s.
Ours has been rebuilt with all of the normal control updates, but also has upgraded Kevlar clutches, modified shift accumulators, modified shift governor (1-2 shift @7000), overall drive ratio changed from 3.33 to 3.73, added limited slip.
When I built this I wanted stronger drive axles than those supplied with the 2.2 pushrod engine that came with the trans.
The Pontiac Sunfire GT with the 4T40 Electronic trans had these. I found these used, they had larger CV parts and a larger spline. I had the larger drive axles from the Olds, they fit the splines of the GT axles so I used them. UNTIL I found that the RH CV didn't seal in the earlier trans. Back to the yard where I found that the early 4 speed CV housing would match my upgraded axles and match the 3 speeds sealing arrangement.
Anyway, after all of that i am very reluctant to change the dimensions of any shaft or parts of the drive axles.
As noted before I will make a new welded shaft to be used for the remainder of the season. At that point, depending on rule changes or the addition of a supercharger the axles will be custom built to our current shafts dimensions. Regardless of cost.....

 

[Rupunzell]

If you're forced to make weld up axles, cut them to length required. Make a alloy steel sleeve (4130 seamless alloy steel tubing, 0.188"wall thickness ) with moderate angle cut ends (about 30 degrees or less if possible) that slightly press fits over the axle joint. Weld up the angle cut area to the axle. The sleeve can prevent the broken axle from flying around inside the power train compartment wrecking havoc with what is inside the power train area. The angle cut is done to increase the loaded area to help distribute the stress over a larger area. The previous method of turned down area to fit into a hole on the other cut axle results in a butt joint with not enough welded area to help reduce the stress loading on the joint. Even if both ends of the cut area are deeply chamfered for weld fill, the loaded area remains small with significant risk of failure.

Have the axles dynamically balanced when done as out of balance axles can cause a different set of problems. The odds of weld up axles being out of balance is pretty much assured due to the material additive process.

Not the ideal way to alter axles, better than what was previously done.


Bernice

 

[gene cooley]

Did some parts shopping for the 600 this weekend. Found that there is a good supply of axles that can be cut and resplined (40+/-) available.
Also bought a used supercharger from a 2L Ecotec.

 

[Rupunzell]

Looks like that axle could work. Cutting and related machine work on that axle might not be easy, they usually have a hard surface with a softer core.


Bernice