My quick change FNR idea...

**JGSturbo** · 09-22-2013 12:51 AM

Big hunking 1.375 wide QC gears for forward (swap-able),
40 chain for reverse. I plan on using it in a shaft drive arrangement.
Still need shift forks/rods/linkage etc.

**nutz4sand** · 09-22-2013 05:15 AM

Might need to rethink it a bit. Sure it works on paper. But here you are using the gears for reverse and the chain for same direction. Most FNR's have a center counter gear just for this so the gears deal with the forward power all the time. The gears do all the forward work and the chain only enguages in reverse. (Edit: Unless you NEED the shaft direction to change for your specific needs???)

Also I am guessing you just did not draw it (since no bearings in the case) but you would need a bearing inside the lower sprocket/outside the shaft.

Also with the typical quick change gears since the teeth on the gears is not cut on the edge like normal tranny shifting gears you would NEED perfect alignment to shift the two gears back into play. Trying to use engine power to spin it to align them would be holy heck hard (both to do and on parts!). Quick change gears are made to be aligned carefully with no load by a human looking at them. Not slid in with a fork so mods to these gears to do this right would add up a lot of cost quick.

Ever see inside an RPM? No chain for the reverse. Might be worth a look for ideas but hard to build one for what they do.

Yah I know thats not what you want to here or what I want to say but there IS a reason RPM trannies exist. Yah I too wish for a cheaper way to have a neat lil reverse box.

The shaft in/shaft out shaft drive "only reverse boxes" (no spool/CV flange setup like the RPM) are literally only a little over 1000 dollars (Talk to Yoshi They may be 1300 now??) And by the time you did all the above you would have more. They are already built and bullet proof for the most part not to mention compact and most look pretty cool.

Not trying to dog on yah as much as point out this is not an easy thing to do to beat whats already out there. Just some food for thought so to speak.

**yoshi** · 09-22-2013 10:38 AM

Originally Posted by nutz4sand

The shaft in/shaft out shaft drive "only reverse boxes" (no spool/CV flange setup like the RPM) are literally only a little over 1000 dollars (Talk to Yoshi They may be 1300 now??) And by the time you did all the above you would have more. They are already built and bullet proof for the most part not to mention compact and most look pretty cool.

I still sell the straight through planetary setup for $1050. It's what I run in my busa smart car conversion kits.

I've never installed one in a rail, but I believe I sold one to Protodie a while back, so he may have done it......

**JGSturbo** · 09-22-2013 11:06 AM

No, Nutz this is good. I feel we've been lacking a good discussion here and various FNRs are a hot one. Actually yes I do want direction change, as I would run it like my shaft drive reverse thread with a flipped BMW diff.

-No bearings drawn in yet... want the idea to take full shape first.

-As for re-meshing gears, reverse gears are normally non synched. They just bevel the edges of the teeth. I'm thinking this would still need an input brake as the engine would be held still with the reverse dogs but the dogs need to be loose to engage the QC gears.

- Cost? Phfffff

I have spare CNC machine time (mills and live tool lathes, We make custom reamers so splines are not a challenge). The rest is bearing, cheap QC gears, sprockets, chain, etc. We even do in-house vac. heat treat. Our steel rack is full of tool steel alloy including H13 which is a tough impact resistant steel used for piston pins. I think I have that covered.

I really want to build something because it seems its something my shop could do for the $. At least I'll get to experiment with some new stuff.

I get tired of making somebody else's stuff, Shop rate is all you get if your lucky. Mfg. jgsturbo wastegates (google if you like) was my first venture and its going well so I'm free to chase some new leads.

**Duane** · 09-22-2013 11:17 AM

[QUOTE=JGSturbo;268081] Cost? Phfffff

I love that!

**JGSturbo** · 09-22-2013 11:34 AM

Sure If I counted all my time in building it I'd be cheaper doing the RPM but well that's the price of learning and the joy of building.

**JGSturbo** · 09-22-2013 11:40 AM

From the other thread.

**deaner** · 09-22-2013 11:51 AM

Now it makes more sense. I would use three smaller diameter QC gears instead of chain,and maybe gears from a transmission that had synchronizers/sliders/shift fork.