MFactory upgraded gearsets
02-25-2017, 06:20 AM
#82
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What your calling a main shaft is the actually the counter shaft, and there is some hope the existing part will fit.
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02-28-2017, 12:38 AM
#87
Performance Build Service - BRZ / FRS ? Jacks Transmissions - this provides an explanation as to potential 4th gear failure. Not Miata, but Aisin AZ-6 box from the FRS/BRZ.
To quote what Jack has written on ft86club:
I think this is in line with the broken tranmissions: they keep up for a while and then break 4th gear. So this is most likely due to thrust wear on 4th gear and not due to pure torque. I am interested in this upgraded 4th gear thrust washer as my 6 speed is not yet in my car.
As for gear ratios: I think the stock ratios with a 3.6:1 (which is standard for EUDM) works quite well for boosted cars.
I think this is in line with the broken tranmissions: they keep up for a while and then break 4th gear. So this is most likely due to thrust wear on 4th gear and not due to pure torque. I am interested in this upgraded 4th gear thrust washer as my 6 speed is not yet in my car.
As for gear ratios: I think the stock ratios with a 3.6:1 (which is standard for EUDM) works quite well for boosted cars.
Less loading on the case, yes, but far greater loading on the shafts forcing them to separate. But anyway, that's getting off topic. I'm more than happy to discuss the merits and negatives of both Helical and Straight Cut with anyone who is interested. Feel free to PM with any questions 
But yes, I agree. For the street car/weekend warrior, definitely Helical cut, as not everyone wants their transmission to rattle/whine (like what it does with Straight Cut gears). BTW (not aimed at you, as you already know this), but Straight Cut gears does not automatically mean dog engagement; you can have Helical Gears with dog engagement, just as you can have Straight Cut gears with synchro engagement. As pointed out above, most aftermarket gear manufacturers don't have the available resources to make "complicated" things, so tend to go the easy route, which is straight cut gears with dog engagement. As you are down under, I'm sure you are familiar with Albins. This company has invested a lot into the proper equipment and almost exclusively make helical cut gears as opposed to straight cut (like PPG etc)
As mentioned in my post above, one of the "fixes" that we use in our own high hp transmission builds (1000whp+ Honda drag cars) is to upgrade the shaft end bearings. This helps counter any excess axial/thrust loads, and increases the life of the transmission very noticeably.
We have a very close working relationship with Jacks, so will make it a point to bring up this topic during our next discussion.
But yes, I agree. For the street car/weekend warrior, definitely Helical cut, as not everyone wants their transmission to rattle/whine (like what it does with Straight Cut gears). BTW (not aimed at you, as you already know this), but Straight Cut gears does not automatically mean dog engagement; you can have Helical Gears with dog engagement, just as you can have Straight Cut gears with synchro engagement. As pointed out above, most aftermarket gear manufacturers don't have the available resources to make "complicated" things, so tend to go the easy route, which is straight cut gears with dog engagement. As you are down under, I'm sure you are familiar with Albins. This company has invested a lot into the proper equipment and almost exclusively make helical cut gears as opposed to straight cut (like PPG etc)
As mentioned in my post above, one of the "fixes" that we use in our own high hp transmission builds (1000whp+ Honda drag cars) is to upgrade the shaft end bearings. This helps counter any excess axial/thrust loads, and increases the life of the transmission very noticeably.
We have a very close working relationship with Jacks, so will make it a point to bring up this topic during our next discussion.
We'd much rather give our money to Mike at MFactory :-) They make a bunch of quality parts for us and are a pleasure to work with, and we've been working with them for years. @MFMike we've never personally corresponded directly as John usually handles everything re: outside sales, but feel free to PM me here if you'd like my work contact info. I'd love to get something off the ground with you guys that could work for both the BRZ/86 and Miata versions of the AZ6. A helical, synchronized gearset would also be our preference.
Our (Jacks) modifications to the 4th thrust problem will certainly bump up the power capacity of the trans but it is not a panacea. We bought a trashed Miata 6spd from BBundy last year for R&D and found that it failed due to 4th synchro gear wandering out of position...our fix keeps this from happening but the teeth are effing tiny on that gear so it's only a matter of time before they snap off under higher load. The 3-4 fork is also pretty much dead in every AZ6 we open, so we have a hard anodized, billet aluminum fork for the BRZ/86...will have to check if it will work with a Miata 6spd. We also have a double synchro 4th gear in beta testing right now, and a 3-4 sleeve detent ball modification (so they are captive and never pop out), and those should translate to the Miata platform as well.
None of that matters if people are still tearing teeth off of gears. If Jacks or the Miata community at large can work out something with MFactory on an upgraded gearset, I'll work on setting up a package deal on installation if anyone wants that to happen at Jacks. Thrust mod/billet fork/double synchro 4th/detent mod + upgraded gearset would be killer.
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02-28-2017, 01:59 PM
#89
Yep. There is 3mm of extra space built into the end of the BRZ/86 counter shaft on the front side, behind the end bearing that rests in the bellhousing. We had to engineer a workaround to extend the shaft we got for the first build and relocate the bearing for it to work properly in that trans.
I think the biggest expense with a 3/4/5 setup is going to be the output shaft...it is about 2ft long, incorporates two fixed gears, and likely won't be cheap to manufacture. This swap will also require another gearshaft...5th/input. So two shafts with integrated gears, and 3 separate gears (two floating, one fixed). Mike will have to chime in on how expensive this might get and you guys will need to decide if it is worth it.
I think the biggest expense with a 3/4/5 setup is going to be the output shaft...it is about 2ft long, incorporates two fixed gears, and likely won't be cheap to manufacture. This swap will also require another gearshaft...5th/input. So two shafts with integrated gears, and 3 separate gears (two floating, one fixed). Mike will have to chime in on how expensive this might get and you guys will need to decide if it is worth it.
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02-28-2017, 03:33 PM
#91
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02-28-2017, 05:37 PM
#93
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These are the type of things that a community can make happen if we work together rather than dispel. I knew I was not able to make it happen myself but if enough of us can work together it's a good possibility.
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03-17-2017, 02:49 PM
#94
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Out of curiosity, are there heavier than stock flywheel options for the miata?
I'm curious if they would up the death by torque level on the 6 speeds if it comes down to a peak torque spike issue.
I'm curious if they would up the death by torque level on the 6 speeds if it comes down to a peak torque spike issue.
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03-18-2017, 01:46 PM
#98
This might be a little bit off topic but I was reading through this thread and went to the MFactory site and am I really confused or is this a 3.3 ring and pinon set for Miata diffs they list on their site for $600? Pretty sure that's less than I paid for my new 3.63 I've not got installed yet. Didn't think one of these existed. I remember a lot of talk on the MSM forum about trying to have someone make them and Bill at Miataroadster had a group buy but it fell through years ago etc. Might not be the thing for the track guys but higher HP mostly street car guys might like this.
MFactory Competition Products - Performance Driveline Components
MFactory Competition Products - Performance Driveline Components
Last edited by julio; 03-18-2017 at 08:48 PM.
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03-18-2017, 04:06 PM
#100
Sounds like it to me. That's just a generic pic of a front drive final and if you click on "images" they show rear drive apps too. They list the same part for the Honda F20/22C by which I think they are meaning it fits the S2000's which share the same differential as the MSM Miata which uses the same ring and pinion as the regular Miatas. Dang. Now I'm not sure if I want to go ahead with my 3.63 or check into this.......
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