Who wants a TALLER MFactory 6th gear
 

I contacted MFactory about producing a taller (.687) 6th gear. For those with the OEM rear end this will put you at 78 mph in 6th gear at 3000 rpm. For those with shorter rear ends, do the math :)

They responded that due to their forging process it is only economical if they do a batch of 30 units. Same price as their shorter 6th, $360, and they will make it so it slides right on to the shaft without any case modifications.

I would like to get a head count of those interested. Replies of 'I might be' are not helpful...

Sounds awesome for guys with a lot of highways and long straights in their area, or big power folks trying to keep the RPM's down.

Hey Toast, that is an awesome idea - especially for those who decide to run a shorter final drive. I'll use my car with some back of the napkin numbers:

Original: 4.1 Final Drive
Gearing Torque Increase: 0%
Highway Crusing @ 70mph: 3000rpm

Current: 4.8 Final Drive
Gearing Torque Increase: 17% (all gears)
Highway Crusing @ 70mph: 3500rpm

Proposed: 4.8 Final Drive (with 0.687 / 6th Gear)
Gearing Torque Increase: 17% (gear 1-5)
Highway Crusing @ 70mph: 3150rpm

Given the usage of my car, I do like the idea of sacrificing the final gear of the vehicle as an 'overdrive' gear. Great initiative Toast!

I posted my few cents and interest in another thread (http://www.ft86club.com/forums/showt...php?p=2984138#) about a month ago. I'll commit to this.

some numbers for those who are curious ~

Final Drive 3.73:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 86mph
Stock 6th gear = 77mph
MFactory short 6th gear = 68mph


(Stock) Final Drive 4.1:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 78mph
Stock 6th gear = 70mph
MFactory short 6th gear = 62mph


Final Drive 4.44:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 72mph
Stock 6th gear= 65mph
MFactory short 6th gear= 58mph


Final Drive 4.55:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 70mph
Stock 6th gear = 63mph
MFactory short 6th gear = 56mph


Final Drive 4.67:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 68mph
Stock 6th gear = 61mph
MFactory short 6th gear = 55mph


Final Drive 4.8:1 @ 3000 rpm:
Custom 0.687 ratio 6th gear = 67mph
Stock 6th gear = 60mph
MFactory short 6th gear = 53mph

what would be the speed at 2500 rpm or 2000 rpm with the stock final drive? I've been thinking about this, 6th gear seems all wrong for US speeds. And with the final drive mods it makes it even worse.

I wished 6th, and maybe even 5th, was a bit taller for a while as my commute is mostly highway. Though I'm not sure the install time/cost is worth it to me.

78/3000=x/your target rpm. solve for x.

At 2000 rpm you would be going 52, etc

I posted on the other thread somehow but anyway, I'm interested in a taller 6th gear or even a whole gear set. But I doubt we'll get 28 other people committed.

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oh ouch, I remember those. I guess there is a reason I have a worthless non-math degree and not something actually useful.

Was there any other movement on this product? It would be awesome to get a taller 6th gear.

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Hmmm... first time I've seen this thread.

How is the quality/durability (based on experiences with shorter gears)?

I've been casually looking for an M85, IS300 LSD rear end to lower my highway RPMs. But this would affect all gears and the speedo.

A taller 6th gear is better approach. For $360, I'm in.

The speedo is off the wheel sensor. The only thing that affects it is tire size.

Oh, okay. So if this final gear thing dies, I can still go the M85 route although I would still prefer just a taller OD...

Thanks

Yep.
Change all the gears you want.
The speedo should read correct if the tire size is the same.