just came acrose this fnr

[yoshi]

Originally Posted by amergin

Why did they develop this FNR? They seem to be more of a 4x4 industry developer more then anything else.

Prob. had a customer they built one for, then decided to market them. Jeffco did the same thing, he build pro street transmissions, he had a customer want a reverse diff that could hold up to a busa, after the first one was done they started offering them to other people, now he sells a lot of them......

[masterfabr]

I'm curious.Is there any info how many total FNR's are sold each year? How many jeffcos,RPMs,Transworks,copycats, etc.?

[LiveWire]

Originally Posted by dunerocket

It must not be as good as the RPM. I remember someone in a thread not long ago said it couldn't be made as good and cheaper than the RPM....

I know my comments in another thread were that a hobbyist could not make a few boxes and compete with the RPM in price. This place already makes their own gears so that gives them a leg up on any hobbyist.

I called them and they made boxes for a company that was previously using RPM boxes hence the mounting needed to be the same. They are built for lower HP engines so you would compare this box to the $1600 RPM, not the $2200 one. So the price difference is not as big as it might seem. I'm not sure if $1600 includes drive flanges from RPM, but $1500 does not with this one. So the price may be very comparable.

[Odyknuck]

What HP? Do they offer it with a limited slip option? How about different ratios?

[standfast]

Interesting. Next time I am down south I will go take a look if they let me.

[stak4x4]

I want to introduce myself, My name is Tony and I am the owner of STaK 4x4. We are a manufacturer of off road transfer cases and drivetrain components primarily for the rock crawling and hobbyist market. Just some quick info on our FNR Box. As someone stated earlier, we were approached by a manufacturer of buggys who was looking for an alternative to the RPM Boxes, but wanted to use the same mounting points. We also designed around some other specific issues that they were dealing with. They wanted a 9:1 reduction, so that is what we gave them. We have the ability to change this to as high as 3.75:1. Our case is made of billet 6061 and all of our gears are alloy 8620 hardened to 58-60Rc. Our box was designed for up to 100HP, and seems to be handling more than that with our customers race version with a Hayabusa motor. We are currently looking for feedback from the buggy community as to what options (gear ratios, input shaft variables, CV Flanges, alternator, brakes etc...) that we need to implement to help out the consumers in this market.
On a different note, i am aware that some will think we knocked off an RPM box, and I can undestand that, we deal with this quite regularly ourselves, and can assure you we made every effort to seperate our box from the RPM box while still working with the customers design parameters.

Thanks,

Tony

[Bugpac]

Originally Posted by stak4x4

I want to introduce myself, My name is Tony and I am the owner of STaK 4x4. We are a manufacturer of off road transfer cases and drivetrain components primarily for the rock crawling and hobbyist market. Just some quick info on our FNR Box. As someone stated earlier, we were approached by a manufacturer of buggys who was looking for an alternative to the RPM Boxes, but wanted to use the same mounting points. We also designed around some other specific issues that they were dealing with. They wanted a 9:1 reduction, so that is what we gave them. We have the ability to change this to as high as 3.75:1. Our case is made of billet 6061 and all of our gears are alloy 8620 hardened to 58-60Rc. Our box was designed for up to 100HP, and seems to be handling more than that with our customers race version with a Hayabusa motor. We are currently looking for feedback from the buggy community as to what options (gear ratios, input shaft variables, CV Flanges, alternator, brakes etc...) that we need to implement to help out the consumers in this market.
On a different note, i am aware that some will think we knocked off an RPM box, and I can undestand that, we deal with this quite regularly ourselves, and can assure you we made every effort to seperate our box from the RPM box while still working with the customers design parameters.

Thanks,

Tony

Excellent Introduction... Everything appears to be knocked off if its even similar, Its hard not to make something that is similar looking in the buggy world...Glad your here, looking forward to more info... Welcome to the MBN Btw...

[bdkw1]

We wan't fab porn, show us your gears!

[stak4x4]

Originally Posted by bdkw1

We wan't fab porn, show us your gears!

I'll post pics of gears and shafts tomorrow, I left the camera at home today.

Tony

[standfast]

How heavy are the cars using the gearbox thus far? I am assuming there has already been chain driven use since you mentioned the busa powered car? Any more details on that car? Also, If there is some way you could implement a brake on the opposite side of the input shaft that would awesome. A 10" ish (or biggest you can fit) vented rotor and wilwood 4 piston caliper would provide excellent braking that is gear reduced. Just pick a common (off the shelf) rotor that fits. It sounds like overkill but gear reduced braking systems need to be pretty powerful to not warp up rotors and trash brake pads prematurely. Also on the input shaft side it would be nice to have bracket to mount a small alternator to. The input shaft keyway or spline would go all the way back to the box so the pulley to drive the alternator could be just inside the sprocket and chain setup. I would probably use a old chevy alternator with the internal voltage regulator. This is probably the most common alternator ever and is easy to wire in. Plus you can buy a aftermarket high amp version or just a stocker from the local autopart store that will all fit. Plus it has a external fan that will sit right next to the chain and might help keep the chains a little bit cooler. I would say a provision for a power steering pump too but I think if these new electric power steering setups that people here are trying workout, a alternator would fit the bill to power the steering/fans/fuel pump/lights/GPS/intercom/radio/fresh air pumper etc. Thats a bit to much to ask for out of the bike generators/alternators even if you aren't using all of that. Plus trying to keep a full size battery charged up.

If you have a cad drawing or dimensions of your gearbox, I can put it all in solidworks to better show you what I mean. I am willing to help because it is exactly what I want. I have this style of alternator laying around so I have the dimensions to get it put in there for you.

Also, if you could put up pics and explain how the shifter setup works would be nice. One thing I didn't like about the RPM box was how much force it took to shift. It is really hard on cables. The one on my old car with the RPM broke while the new owner was test driving it. It really needs 2 control cables to push and pull from both sides to last.