Well, I finally bit the bullet and bought an rpm gearbox for my LT 670 Pilot. I've wanted one of these ever since watching AKPilot build the infamous fl800 and I finally have one. I decided on a 9:1 gear ratio with 930CV joints. It should be an animal once all is finished.

The next piece of the puzzle is building the adapters for the outboard cv joints. I thought of many different ways of doing this, my first idea was to use VW sandrail micro stub axles and bearing carriers and build a ncomplete new rear knuckle. After pricing those parts I wanted to try a bit more simple and cheaper option first, building an adapter ring to bolt the 930 cv to the stock fl400 outboard joint.

Weeks before I bought the gearbox, my stepfather had ran into an old family friend that's father had an atlas lathe he remembered from back in the day. Long story short $500 later I had a lathe! This will be my first project on a lathe and I'm no machinist. I'm learning as I go with some pointers from the neighbor up the road In his 80s.

Here is where I am at. I built the first proof of concept adapter ring. The ID is .003" smaller than the OD of the outboard pilot joint. The plan is to heat the ring and press fit it over the pilot CV and weld as needed. I think with minimal clearancing I can get it to clear the pilot knuckle.

Again I'm mo machinist so it's not the smoothest work ever but for my first project I don't think it's too bad. If you do not think this will work, please let me know and tell me how you would have done it. I'm open to suggestions.

Once I have the adapter figured out and proven to bolt up to a pilot knuckle I will begin the teardown of my pilot to install the gearbox. I'm really not in a huge hurry to finish this project since I cant seem to kill a pilot gearbox even if I sorta try!

Nice gearbox and lathe. Congrats.
My first lathe was the same as that one but I had the Southbend.
You can build a lot of stuff with that. Get the old guy neighbour over as often as you can to learn. The old guy will have lots of knowledge and we don't know how long he will be around. You probably make his day every time you ask him to come over. Old people are very very lonely and don't get many visitors or are asked for advice, even though they have lots of it. I make it a point to go to my parents place every day. They are in they're mid 80's now.

Yes sir I think that's the way to go.
With .003" interference fit you should be able to freeze one part and heat the adapter ring in a toaster oven. It should fit on by hand. One thing to remember is that when ever you do a shrink fit, you only have one shot at it, so make sure EVERYTHING is ready to go. You need a plan and a back up plan. Also all of your tools need to be layed out and ready to go.
The rule of thumb is .001" to .003 is correct and .005" to .007" is extreme.

If I can offer a bit of advice, make sure you don't get the work too hot while machining it. It can throw off your interference fit. Ask me how I know..lol

The holy grail of FNR's!

Congrats on the new lathe! As CO said, you can do a ton of stuff with that lathe.

Looking at the CV plan,

The first thing that pops into my head is the pivot point of the CV?

Will it be in the same location in relation to the suspension pivots?

Does it need to be? Im not as familiar as you guys with the pilot suspension.

Most of these conversions I've seen, the cup is chopped off completely and a new flange is welded on. Usually a new inner flange after some machining. This keeps the assembly as short as possible.

EDIT: This type of flange,
https://www.mooreparts.com/empi-16-2303 ... gIe9PD_BwE

Can't wait to see this one come together!

New tools and strong go-fast parts, doesn't get much better.

That is my plan, i will freeze the stub axle and get the ring red hot, and if all goes as planned it will slip right over. If not i will be cutting it back apart!

I am not sure if I like that whole plan.
That ring might warp if you get it cherry red hot. There is not enough meat on that ring. You can get it hot with a torch if you want but not cherry hot. Use a heat gun if you have one.

the pivot point is going to end up slightly further inboard, and i am not yet sure if it should be in the same plane as the other pivot points on the suspension or not.
My original idea was to do as you say, chop the cup off and weld a new flange on like you linked, but the problem was the diameter of the 930 cv would have required some extreme modifications to the knuckle unless they were spaced out to where i have them at the end of the original cv cup.

I need to go back and re read some of AKPilots posts and see what he did. I quickly scrolled through one of his threads on my phone trying to see what he did but all of the pictures are unfortunately broken or were at the time.

Yes good call, the old timer wants to bury it in the coals of the fire. a toaster oven sounds much more controllable. I have one i use for powder coating small parts already, so i may just use that.

If I remember my millwright school stuff, the expansion rate of steel is decimal-five zeros-seven (.000007)
So that means you take .003 and divide by .000007 equals temperature.
It looks like you need 500'F to get there. You want a bit more to make sure it goes first try because it will cool rapidly because it is so small and because you need a few seconds to get the part home.

Edit: that is assuming you got an accurate .003

When you put it on it should go all the way smooth and do it fast. If it even "tries" to stick -- pull it off fast.
If you do screw it up all is not lost. If the torch was handy and ready like I suggested earlier then you can spark it up and tap the ring off "gently" so you don't deform it. Two guys with hammer taps opposites will do it. Don't go wild and deform it.
Set up, speed and temperature is the key here.

Good point on the knuckle clearance. That's where I have no experience. I would mock one up with out any welding/machining if you can. Might do some weird plunge stuff and pull/push the axle out of the comfort zone.

The travel might be short enough that you wont have any issues though.

Probably could have gotten away with the next size down CV? I think RPM offers them too. Should be strong enough on such a light car. (Kind of moot at this point)

My original plan was to go with a Type 2 CV, but Dan at RPM recommended the 930 because of the amount of travel it offers vs a type 2. The type 2 is 100mm OD with only 17 degrees of travel where the 930 is 108mm with 25 degrees.

If anyone is interested, here is quite a bit of info on the different VW/Porche style cv joints.
http://blindchickenracing.com/How_to/CV ... ts_101.htm

Why not type 4’s? In the middle of both and parts are less expensive. All the type 2 stuff I had on my buggies i upgraded to the type 4’s. I already had axles and such so maybe it is a better deal for you since you have to get “all” the pieces.

Its what Dan at RPM recommended i use, and the 930s will provide the most travel.

I finally got a chance to get one adapter ring fitted onto a pilot stub shaft. Left the stub in the freezer overnight and once I had a hot fire going in the shop I put the ring in there for about 10 minutes and it fell right together. Once I knocked the casting mark off of the hub I had clearance to tighten the axle nut and let everything spin freely. I may give it a little more clearance later on, but um happy with the way it turned out so far.


The gearbox is mounted in the frame and I'm currently waiting on a driven clutch before I make my motor (( Internal Combustion Engine ? )) mounts. I was going to try and find a random sled clutch to use, but after not finding what I wanted I broke down and purchased a new Team Industries tss-04. This will give me almost infinite tuning possibilities and is probably the piece I'm the most excited for. The stock pilot driven was never quite right with the 670 IMO.

I agree, the stock pilot driven isn’t the best but 25-45mph is in my opinion pretty good with the sled power. Power delivery seems to suffer at speed greater than that and downshifting everywhere could be improved.
Regards

Hey Matty I have Aks Pilot remember?
Let me know if you want me to take any specific pics for you mate.

I wasn't sure if you still had it or not. If you could grab some pictures of how the rear outer CVs were done I would greatly appreciate it. I still plan to continue with my current plan, but it's always nice to have a plan B if this fails. And we all know the fl800 is proven to work well!

Yes still have the infamous FL800...and not so FL550Pilot and Drakart FC 600.
I'll take some pics asap for ya.
From mem I think Jay ex ATVR welded up the axle/930 mods.

Sorry for being so late Matty.Just took these pics now Sat arvo 2:22pm nice and sunny around 30c.
Let me know if need any other angle pics.
You'll notice these have the PBR mimimax boots flange setup.
This way you can get to the bolts plus I use the 2 part Nordlock washers after constantly tightening the std spring washers don't work.

More pics

More pics