A New Forged Gearset
 

Hey guys,

I've been in contact with MFactory a company that makes helical diff and forged gearsets for a bunch of applications, mostly honda but other imports, even ford and mazda stuff. I'm trying to get them to put together a gearset for the 5 speed box and it would be targeted at those of us who either hate the 6 speed box but need more power than the 5 speed can put down, or need to reliably put down more power than the 6 speed box can handle, or just dont like the gear ratios from either box. They estimate the cost coming in below 4 grand.

They require 10 pre-orders to start making a gearset, and that means a 50% deposit and a 3-6 month wait time before you pay the other 50% and receive your gears. This would be for syncro engagement helical cut gears. They also do dog boxes but I doubt we could break that 10 up between dogs and syncros but if theres interest I'll ask.

This is just a thread to see if there's interest, not currently a group buy.

We get a thread like this every other month. 4 grand? lol pocket change for most miata owners.

From the looks of it most of their gearsets are 3 grand. But you've got to pay to play and for some of us its the best option. For me my only other option would be to get stuck with the crummy feeling 6 speed and the 3.6 rear end and still not be exactly what I want.

How would this be different from the Quaife gearset that was previously available?

It wouldnt have silly gear ratios, should be cheaper, and will be available in the future rather than discontinued. And I dont know if the quaife was machined for billet or forged, but this new unit will be forged and therefore have better fatigue properties than a billet setup.

Why are the Quaife/6-speed gear ratios silly?

The Quaife ratios are silly to me because they're all really short, almost like they were designed with the 4.3 in mind. The wide ratio box actually doesnt look all that bad even with a 4.10 rear gear.

And the 6 speed ratios suck for the opposite reason, if someone made a 3.4ish rear gear for the car I think they'd work out quite well. Then you'd just need some way to get over the shifter feel, supposedly the miata roadster short shifter makes it feel pretty good.

I'm genuinely confused - you say the Quaife wide-ratio gears are not too bad, but the 6-speed ratios suck? You do realize that those two gearboxes have virtually identical ratios, right?

Also I think you may have your short and tall confused. The Quaife ratios are much TALLER than stock, not shorter.

Yes, the 6 speed throws that pesky extra gear in that means I would just have to ignore that 1st existed in the 6th. The 2-3 shift is a bit trickier than the 1-2 shift. Remember, my race gear is 2nd, and if I go over 80mph the course designer messed up.

The Quaife gearing is much better suited to forced induction. Play with FM's gearing calculator to see why. I have the wide ratio gear set and, with a 7,700 rpm redline and 4.1 R&P, can do 50 mph in 1st, 77 in 2nd, 100 in 3rd, 129 in 4th and 162 in 5th.

It's an incredible box for what I have, and has proved pretty bulletproof. The only complaint I have is that it's noisy in top gear on the highway. Small price to pay, and all that.

I actually had the 4.1 in mind when I sent them the specs and the trans. Take a ride in one and you'll see. FYI, the Quaife gear set is still available.