NISSAN S15 6 speed transmission Swap.
#1
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NISSAN S15 6 speed transmission Swap.
Ok got a transmission so I can playing with to see what is possible up close withone of these.
First things Observable now that I have them side by side; 1)Input shaft splines extend a full 2-1/8” further from the front of the center section of the transmission. that will take some thought to make work. 2)The output looks like it sticks aft of the center section the same amount but the splines are much larger than on the Miata, custom drive shaft will be required.
First things Observable now that I have them side by side; 1)Input shaft splines extend a full 2-1/8” further from the front of the center section of the transmission. that will take some thought to make work. 2)The output looks like it sticks aft of the center section the same amount but the splines are much larger than on the Miata, custom drive shaft will be required.
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I suspect it would be fairly simple for someone skilled with a good lathe to machine the input shaft back probably what I will pursue I had thought about spacing the transmission back assuming it might be less than an inch or so. but 2-1/8” is a lot back.
The Pilot bearing is also bigger diameter. Actually the Nissan uses a bushing instead of a bearing for the pilot.
The 1” X24 splines instead of 15/16 X 22 on the input is pretty easy to get a clutch disk for. One for a Subaru or a FRS will fit in with a 1.8l Miata clutch and I found one for a 74 Datsun 510 would work in a 1.6l size clutch.
The Pilot bearing is also bigger diameter. Actually the Nissan uses a bushing instead of a bearing for the pilot.
The 1” X24 splines instead of 15/16 X 22 on the input is pretty easy to get a clutch disk for. One for a Subaru or a FRS will fit in with a 1.8l Miata clutch and I found one for a 74 Datsun 510 would work in a 1.6l size clutch.
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The flywheel that came with this is pretty amazing the sprung center clutch disks like on a Miata will wind up maybe 10 degrees or so before the springs bottom out. This thing uses a ridged clutch disk but the two piece flywheel I can wind up 10 degrees with just my hand force. It will twist up well over 45 degrees maybe 90 without bottoming the springs and it moves smoothly.
#6
The flywheel that came with this is pretty amazing the sprung center clutch disks like on a Miata will wind up maybe 10 degrees or so before the springs bottom out. This thing uses a ridged clutch disk but the two piece flywheel I can wind up 10 degrees with just my hand force. It will twist up well over 45 degrees maybe 90 without bottoming the springs and it moves smoothly.
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Makes me wonder about the BRZ/FRS transmission I think it is the same gears but it doesn’t use the big dual mass flywheel. Maybe the input shaft is not so long.
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No need to dual mass flywheel with the clutch you have... its just more shock into the driveline.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
#10
No need to dual mass flywheel with the clutch you have... its just more shock into the driveline.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
#14
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No need to dual mass flywheel with the clutch you have... its just more shock into the driveline.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
I ran a solid hub clutch in my Miata an a few other cars... once your used to it, its pretty awesome actually.
The clutch shift speed happens a bit faster (and a little harder) being that its a lot less weight when you remove all of the heavy complexity that is the sprung hub. However for a street car it kind of sucks in stop and go traffic and you need to be pretty precise with your downshifting.
An option would be to have a custom clutch disc made with stronger springs if you want sprung hub with less rotational slop.
All I can say is I don’t believe sprung the sprung centers available for the Miata help longevity much when you put 300 ft-lbs on them. I bet the dual mass thing like the NISSAN has would be effective at reducing drive line shock but it is not light by any means.
here is a vido showing how it goes together.
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I do think it would be possible to use the miata input shaft if you match it with a miata primary gear slid on the counter shaft. Ill be looking into that and cosidering doing that.
Some of the advantage though is the input gear ratio on the S15 box sends lower torque through the counter shaft because of the ratio. Almost 4% lower torque gets applied to 4th gear because of the primary ratio differance.
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This is very interesting! I wonder about the power output and beating they can take, judging by the drift scene it's a lot if they use stock transmissions.
How about mounting? would it need a typical trans mount and PPF delete? with Diff mount? or maybe even use s15 differential too?
How about mounting? would it need a typical trans mount and PPF delete? with Diff mount? or maybe even use s15 differential too?
This is not a strong transmission in the NISSAN scene drifters don’t use it they consider it fragile and only road racers use it to take advantage of the superior gear ratios over the much stronger NISSAN 5 speed. In theory however it should still be stronger than the Miata 6 speed.
The other thing is there are beefed up road race versions of this transmission that are available at the lower end of the price range for a very serious solution that do have claimed ratings over 300ft-lbs. closer to a Quafe gear set for the 5 speed price than a some form of sequential but with even better ratios for track performance.
#19
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My wheel hop problems also basically dissapeard when I took the sprung center out of my clutch.
#20
The Miata bell housing and tail shaft will bolt up to the center section of the S15. They are both Aisin AZ6 transmissions. So final installation should look pretty close to stock.
This is not a strong transmission in the NISSAN scene drifters don’t use it they consider it fragile and only road racers use it to take advantage of the superior gear ratios over the much stronger NISSAN 5 speed. In theory however it should still be stronger than the Miata 6 speed.
The other thing is there are beefed up road race versions of this transmission that are available at the lower end of the price range for a very serious solution that do have claimed ratings over 300ft-lbs. closer to a Quafe gear set for the 5 speed price than a some form of sequential but with even better ratios for track performance.
This is not a strong transmission in the NISSAN scene drifters don’t use it they consider it fragile and only road racers use it to take advantage of the superior gear ratios over the much stronger NISSAN 5 speed. In theory however it should still be stronger than the Miata 6 speed.
The other thing is there are beefed up road race versions of this transmission that are available at the lower end of the price range for a very serious solution that do have claimed ratings over 300ft-lbs. closer to a Quafe gear set for the 5 speed price than a some form of sequential but with even better ratios for track performance.