Gearbox options/experiences - Page 24 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-17-2014, 01:01 PM   #461
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by matthewdesigns View Post
We got an FRS/BRZ trans in last week to see what we can do to strengthen it. It'll probably come apart in the next week or so. Any questions about it while I can put my hands on it? I have an NB 6spd in the garage so I can make some external comparisons if anyone would like (not gonna pull it apart).

Poking around online I found the service manual here: http://www.ft86club.com/files/BRZtrans.pdf Looks like gears 1-3 are triple synchro'd...pretty nice.

I also ran across a build thread for a BRZ making 440whp/340wtq on the stock trans. Accelerated Performance BRZ-400 - Visconti Tuning - Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB Not really any higher than the NB 6spd has put up with from what I've read here, but it will feel a lot better with the triple synchros.
I see builds with high hp and say the transmission lived. But rarely do you see anybody on the track with them flogging them for seriously low lap times, the true test of durability.
bbundy is offline   Reply With Quote
Old 11-17-2014, 01:04 PM   #462
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by matthewdesigns View Post
Yep, and will do. I'll only be able to get an approx centerline dimension on the Miata 6spd as I have no plans to open it up. Do you have one apart with which direct comparisons can be made?
Im pretty sure I can pull the front bearing cover off my S15 box and put a miata front bearing cover on in its place. I will try that tonight.
bbundy is offline   Reply With Quote
Old 11-17-2014, 05:29 PM   #463
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Quote:
Originally Posted by NiklasFalk View Post
Depending on how it's designed internally, would it be possible to have a different centerline distance with the same external dimension?
I.e. are the external dimensions the same Miata/BRZ (those would be easy to measure/inspect)?

Only a little would make a difference of course, but if the castings are identical it would be surprising if there is room to move the secondary shaft, but not impossible of course.
No way to measure though the plugs?
I think repositioning one of the shafts within the housings is going to be essentially impossible. Using a V160 as an example of a similarly arranged trans, bearing seats would have to be moved in the tail and bellhousings as well as the thrust plate. It would be a huge undertaking to get things realigned. If the BRZ trans is stronger, but has the same spacing/length WRT to the shafts, then perhaps a bellhousing swap will be the easiest solution to get one into a Miata. I'll check that the bolt pattern on the midcase is close, or maybe even the same, and how the input shafts compare as well.

Quote:
Originally Posted by Leafy View Post
At least with the 5 speed you can measure the shaft distance inside the bell housing because you can see where the bearing would be in the casting. I wouldnt be surprised if you could do the same on the 6 speed box.
This is how I was thinking I'd make a rough estimate of the distance.
matthewdesigns is offline   Reply With Quote
Old 11-17-2014, 05:33 PM   #464
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Quote:
Originally Posted by bbundy View Post
I see builds with high hp and say the transmission lived. But rarely do you see anybody on the track with them flogging them for seriously low lap times, the true test of durability.

I don't know anyone around here who seriously tracks a BRZ, only open lapping days, and that certainly will be the true test of a high TQ build. There is a local BRZ making 470whp, I can talk to the owner and see if he's having any issues thus far, but he mainly drags it afaik.
matthewdesigns is offline   Reply With Quote
Old 11-17-2014, 06:47 PM   #465
Elite Member
 
Chiburbian's Avatar
 
Join Date: Feb 2008
Location: Gilberts, IL
Posts: 2,027
Total Cats: 115
Default

Quote:
Originally Posted by matthewdesigns View Post
I don't know anyone around here who seriously tracks a BRZ, only open lapping days, and that certainly will be the true test of a high TQ build. There is a local BRZ making 470whp, I can talk to the owner and see if he's having any issues thus far, but he mainly drags it afaik.
Refresh my memory, does wheel hop kill rear ends or transmissions (or both?).

I would think that if he is dragging a BRZ that would bode well for this trans correct?
Chiburbian is offline   Reply With Quote
Old 11-17-2014, 07:23 PM   #466
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Rear ends and axles from wheel hop. At least that's what we mostly see. I guess there could be some damage upstream but there's a lot to break and upgrade in between first.

Edit: Dragging it will definitely find the weak spots on high tq cars, just not as quickly as road racing as there's typically less heat built up and sustained. And that car may be set up on boost by gear, if so it'll last longer on launch but not up top.
matthewdesigns is offline   Reply With Quote
Old 11-18-2014, 01:29 AM   #467
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by bbundy View Post
Im pretty sure I can pull the front bearing cover off my S15 box and put a miata front bearing cover on in its place. I will try that tonight.
Confirmed, The front bearing cover from a Miata bolts on the S15 tranny shaft spacing is the same. Iíd be willing to bet money the BRZ is also the same.

The input shaft on the S15 is way long. It uses a really tall throw out bearing and has a super thick heavy dual mass flywheel. If you try and use a miata belhousing on it it looks like the clutch disk may set too far back on the shaft behind where the splines end. I donít think the BRZ version has this issue because it looks like the input shaft isnít as long.
bbundy is offline   Reply With Quote
Old 11-18-2014, 01:50 AM   #468
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

I'm going to take my 6spd to work tomorrow and grab some side-by-side pics with the BRZ trans, will post up asap.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 12:10 PM   #469
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by matthewdesigns View Post
I'm going to take my 6spd to work tomorrow and grab some side-by-side pics with the BRZ trans, will post up asap.
pictures comparisons?!!!!
bbundy is offline   Reply With Quote
Old 11-19-2014, 01:05 PM   #470
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Sorry, I know that was quite a tease to dangle. I am actually working from home this morning and was planning on posting before I headed in.

In the short time I spent with them side by side, it looks like there are some differences that might rule out an entire cluster/shaft/fork/rail swap, but maybe some gears/synchros/hubs will move over to the NB 6spd. Will take pics of them once it's apart. FYI this customer says he's been at 400/360 for about a year on the trans.

Here are some resized shots. The link will take you to a Dropbox folder with the full size pics and a PDF of the BRZ trans service manual.

Edit: for reference, the shot across the face of the bellhousings was with the midcases aligned.


https://www.dropbox.com/sh/4zulo8pwe...rZfD5Uj9a?dl=0
Attached Thumbnails
Gearbox options/experiences-20141118_091016.jpg   Gearbox options/experiences-20141118_091151.jpg   Gearbox options/experiences-20141118_091943.jpg   Gearbox options/experiences-20141118_092019.jpg   Gearbox options/experiences-20141118_092228.jpg  

Gearbox options/experiences-20141118_092327.jpg   Gearbox options/experiences-20141118_092539.jpg   Gearbox options/experiences-20141118_092551.jpg   Gearbox options/experiences-20141118_093051.jpg   Gearbox options/experiences-20141118_093105.jpg  

Gearbox options/experiences-20141118_093211.jpg   Gearbox options/experiences-20141118_093326.jpg  

Last edited by matthewdesigns; 11-19-2014 at 01:20 PM.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 01:08 PM   #471
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 8,810
Total Cats: 92
Default

I mean if you dont care about breaking the seals on the trannies you're so close to just seeing if the bell and tail housings swap.
Leafy is offline   Reply With Quote
Old 11-19-2014, 01:16 PM   #472
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Yeah, I left my 6spd at work and I feel like that'll probably happen lol. I can't guarantee it'll be this week. Gonna depend on my workload and when I can actually get to the BRZ as it's a low priority there. If I'm feeling frisky I'll go in off-hours and start it.

At the very least there will also need to be an input shaft swap or rework of the BRZ shaft as it is too long.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 05:22 PM   #473
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by matthewdesigns View Post
Yeah, I left my 6spd at work and I feel like that'll probably happen lol. I can't guarantee it'll be this week. Gonna depend on my workload and when I can actually get to the BRZ as it's a low priority there. If I'm feeling frisky I'll go in off-hours and start it.

At the very least there will also need to be an input shaft swap or rework of the BRZ shaft as it is too long.
The S16 shaft is too long as well. So long I think if you did use a Miata belhousing on it you would have to add a spacer to the belhousing to keep the clutch disk on the spline section of the shaft if you did shorten the end of the shaft.

The casting on the center section of the S15 is Identical to the Miata however. Looks like there are some differences with the BRZ center casting and maybe some shift rods are in different places.
bbundy is offline   Reply With Quote
Old 11-19-2014, 06:13 PM   #474
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

Quote:
Originally Posted by bbundy View Post
Looks like there are some differences with the BRZ center casting and maybe some shift rods are in different places.
These are the first things I saw as well. Looks like those 3 sleeves in the bellhousing for the rods are a deal breaker on that end.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 06:32 PM   #475
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 8,810
Total Cats: 92
Default

Quote:
Originally Posted by matthewdesigns View Post
These are the first things I saw as well. Looks like those 3 sleeves in the bellhousing for the rods are a deal breaker on that end.
it kind of look like the miata has those 3 bumps they're just obscured by the fact that the clutch pivot boss is there, unless we're talking about a different feature.
Leafy is offline   Reply With Quote
Old 11-19-2014, 09:08 PM   #476
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

I've added to the dropbox folder a closeup of that area on the NB trans where the difference is more obvious. I was hoping that the end plate on the NB housing was thick enough to hide the ends of the sleeves and accomodate the pivot ball bung, but I'm not holding my breath.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 09:10 PM   #477
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 8,810
Total Cats: 92
Default

I think it is, you can see one of the bumps right above the pivot ball, and it looks like the flat section below the pivot ball is higher up than the flat section above it, probably at the same height as the bump, or that last part could be a trick of the camera.
Leafy is offline   Reply With Quote
Old 11-19-2014, 09:44 PM   #478
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 4,754
Total Cats: 921
Default

Very fast FR-S at Super lap last Friday. Definitely not a stock gearbox. I wonder what it was.

emilio700 is offline   Reply With Quote
Old 11-19-2014, 09:48 PM   #479
Free Moustache Rides
iTrader: (8)
 
matthewdesigns's Avatar
 
Join Date: Jun 2008
Location: Colorado Springs
Posts: 1,654
Total Cats: 45
Default

The flat area from which the rail sleeve and boss protrude is the same height everywhere around those two features. However, the rail sleeve protrudes less on the NB than the BRZ, leaving open the possibility that the other two rail sleeves could be hidden in the NB casting.

I don't have the NB manual in front of me and don't know the trans internally, so I can't say for sure.
matthewdesigns is offline   Reply With Quote
Old 11-19-2014, 09:59 PM   #480
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,443
Total Cats: 109
Default

Quote:
Originally Posted by matthewdesigns View Post
The flat area from which the rail sleeve and boss protrude is the same height everywhere around those two features. However, the rail sleeve protrudes less on the NB than the BRZ, leaving open the possibility that the other two rail sleeves could be hidden in the NB casting.

I don't have the NB manual in front of me and don't know the trans internally, so I can't say for sure.
Question is are all the shift rings in the same place on the shafts. Wonder if all the shafts and rotating bits could move over and have the Miata forks and shift rods shift it in a Miata housing.
bbundy is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Removing speedo sensor from gearbox ThunderFox Suspension, Brakes, Drivetrain 2 09-10-2015 03:19 PM
Loud gearbox vibration rhysmate Suspension, Brakes, Drivetrain 9 08-12-2012 05:43 PM
DIY gearbox rx-7fd 3s with the first side oem gearbox dogits DIY Turbo Discussion 18 03-09-2011 05:18 AM
difference automatic gearbox NA Lazy_g General Miata Chat 2 04-14-2010 03:07 PM
Nissan SR-20DET engine into Miata Big Al General Miata Chat 2 05-23-2008 11:17 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:16 AM.