Gearbox options/experiences
#461
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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.
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.
#463
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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.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?
This is how I was thinking I'd make a rough estimate of the distance.
#465
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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.
I would think that if he is dragging a BRZ that would bode well for this trans correct?
#466
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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.
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.
#467
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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 don’t think the BRZ version has this issue because it looks like the input shaft isn’t as long.
#470
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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
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
Last edited by matthewdesigns; 11-19-2014 at 01:20 PM.
#472
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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.
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.
#473
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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.
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 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.
#479
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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.
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.
#480
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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.
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.