S14, SR Swapped with 350Z trans

[Prok0]

I've been working on getting the 350Z transmission fit into my S14 for a bit now and figured I would make quick write up just to try to provide a bit more info to those who are looking to do it as I dont recall there being a ton of good information.

I worked with Brett over at Collins performance who provided me with the adapter plate and some help along the way.

Here is the initial shot of the motor/trans bolted together using the adapter plate. (There is a chunk cut from the bellhousing for clearance that I'll explain later) I had a few MM milled off the front of the bellhousing, essentially to negate the thickness of the plate (iirc it was either 9 or 11mm)


If you are running a T2x bottom mount setup the first issue you will run into is the o2 elbow not clearing the plate/bellhousing as the housing is MUCH larger.


I remedied this by trimming the bell housing a bit, as well as the plate. There were quite a few other bolt holes for both, so I figured losing one would not present any issue since the plate was flush with the block and the bell housing was flush with the plate even without that mounting bolt.



Also for Bretts plate you need to trim the plate around the starter opening to taper the edge essentially, I tapered it and then ended up using a through bolt from the backside, drilling the starter itself out, and using a nut to hold the starter in place, and welding the through bolts to the starter. I did that because I realized once the plate/housing were bolted together you did not have access to the starter bolt holes, so instead of having to remove the transmission to change the starter I just welded a bolt to act as a stud essentially.

Also before trying to fit the transmission it is a good idea to cut this off the bell housing (casting that sticks out with the 2 bolt holes on it, I believe this is for the factory Z33 o2 sensor harness to bolt to and you dont need it) it protrudes a bit and makes removing and installing the engine/trans a bit difficult.

And on the driver side of the transmission where the back of the case bolts on I ended up sanding down the case slightly to buy a few more MM of clearance between it and the tunnel.

And here is the McKinney shifter bracket I ended up buying to use.

I ended up modifying this ( not shown in the picture ) by cutting down the actual linkeage under the bracket, making one new side to the joint directly under the vertical portion of the shifter, and drilling two new holes to move the shifter forward about 1/2 an inch.

And here was the motor ready to go in.


Once you try to install it you will notice the case itself is way bigger, I ended up hammering out the firewall a bit where the tunnel meets the front of the firewall (not entirely necessary if you put the motor in from the bottom already sat on the crossmember). The other issue is the case is really wide towards the back of the transmission, so you will notice it will hit the inside of the tunnel where the mount pedestals are.


So I ended up yanking the trans/motor out a few times, hammering things, and still could not get the clearance I really wanted so I ended up trimming the tunnel and welding a patch in. Here is the area I trimmed before I welded the patch in


Heres a shot showing the patch and the bit of grinding on the trans case.


You will also need to hammer in the tunnel around the mount pedestals like this.

Also if you want to buy yourself a bit more clearance and be able to raise the transmission up more, you can cut the bracing out at the top and hammer it up and weld it to probably buy an extra 3/8 an inch or so.

With the modifications to the tunnel done, the linkage trimmed I had the bottom of the linkage sitting like this through the factory shifter hole.


I wanted to use a factory hold down ring and rubber boot to seal the transmission so I ended up cutting the factory tunnel, moving the hole back, and welding in a patch that was about 2'' long, and then seam sealing everything and painting it.


Here is the interior placed back in to show fitment, the trans is in neutral and will shift 1-6 with the plastic trim piece and leather boot on, but I am going to make a new vertical shifter to move it forward about an inch or so, that way it looks 100% oem when the leather is on.


Heres a shot of the simple trans bracket I made, I still have to finish enlarging the holes that go to the chassis mounting point so I can recess the bolts in, then paint it.


Heres a shot showing how the transmission sits in relation to the frame rails, the rear most section hangs slightly below the rails (this could probably be remedied by trimming the extra metal from the mount pedestal that goes up and over the tunnel, welding it up and moving the mount up that extra 3/8th inch or so.


Also for the clutch line I used an auto to manual line, put the 90 degree fitting on the slave so that I can angle it forward and avoid running it under the downpipe, placed some heat sleeving on it, and am going to make a small heat shield to use to cover the slave cylinder itself. You could make a custom line and route it a bit nicer possibly, but with the slave being on the driver side you cant use a standard KA/SR short clutch line.

The speedo I am going to be running off the diff and probably running an SGi-5 box to convert the signal from the ABS sensor.

I'll try to update this as I finish the project up, but figured I would put this out there to at least give people a little bit more info on what needs to be done to get this trans to fit up

[rbs14kouki]

Thanks alot for all those info ... Now i know how to prep the chassis for my cd009 when its gona be rebuilt

[revolvedspecv05]

Do you have a driveshaft measurement?

[Yellow4g63]

Looks like fun can't wait to this next year lol.

[KoukiMonsta]

Hey, cool post. Thanks for sharing.

[defcon86nwh]

Nice info.

[fatduece]

Thanks for sharing. Btw what exhaust mani and turbo in the picture?

[revolvedspecv05]

What shift knob/shaft situation is that too? It looks amazing ha

[Prok0]

Originally Posted by fatduece

Thanks for sharing. Btw what exhaust mani and turbo in the picture?

DOC Race manifold, GTX2867 Garret .64 A/R

Originally Posted by revolvedspec05

What shift knob/shaft situation is that too? It looks amazing ha

Its a factory Z33 shifter (vertical piece) with a Tomei 90mm shift knob, and a McKinney VQ35 swap bracket and then I drilled 2 new mount holes and chopped about 3/8's off it to shorten it up further. The OEM Nissan piece that was used to mount on the selector rod of the trans I cut off like 1/4 inch of useless material and re-welded it, and then the U bracket that goes underneath the actual shifter I made a new one and moved the bolt hole and nut that holds the shifter on forward about 1/4''

Also on the driveshaft it was an overall length of 50.25'' from the face of the differential flange to the face of the rear seal on the transmission. I am using a J30 VLSD though so for non-abs style diff it would be slightly longer. I've got it all specked out with Driveshaft Shop so they have the measurements as well, but they may vary for you pending on the adapter plate you use, if you machine the bellhousing, and also if you have an ABS style diff.

[whenzigood]

they may vary for you pending on the adapter plate you use, if you machine the bellhousing, and also if you have an ABS style diff.

[brndck]

i know this is an old thread, but i've got some relatively useful information to add
http://outslidersandsmokeproduce.blo...rans-shit.html

[s14unimog]

^ Good info on the Z33 gearboxes / thanks for sharing that.

Simple question to all of those considering this, or who have already done this; why are you doing it?

What I mean to ask, what exactly is motivating this? In my experience with the SR trans, the synchronizes and the bearings are the weak link with a higher HP SR's; not the actual gear hubs (at least in my case).

[Prok0]

Originally Posted by s14unimog

Simple question to all of those considering this, or who have already done this; why are you doing it?

What I mean to ask, what exactly is motivating this? In my experience with the SR trans, the synchronizes and the bearings are the weak link with a higher HP SR's; not the actual gear hubs (at least in my case).

We would ring off 3rd gear on our SR boxes when were were making aroudn 500rwhp, destroy synchros, etc. The Z33 box has much larger physical gears, its a newer box, readily available, and the gearing can be beneficial depending on what your doing.

Also it seems like, at least to me, the actual shifting movement is much better on the Z33 boxes than the SR/KA, this could be just due to the age of components or some other variables, but I like how the Z33 feels.

[s14unimog]

Originally Posted by Prok0

We would ring off 3rd gear on our SR boxes when were were making aroudn 500rwhp, destroy synchros, etc. The Z33 box has much larger physical gears, its a newer box, readily available, and the gearing can be beneficial depending on what your doing.

Also it seems like, at least to me, the actual shifting movement is much better on the Z33 boxes than the SR/KA, this could be just due to the age of components or some other variables, but I like how the Z33 feels.

When you say "ring off" are you saying stripped or broken gear set? I imagine that happens every now and then but again it could have some to do with the age and usage of that transmission. I'm not trying to distract from this thread, but I've just had such great use out of my SR trannys that I wonder what one would be like freshly rebuilt. My 400whp SR has done nothing more to them other than accelerate the wear on already tired bearings. If left alone, other stuff will always break.

I'm sure the Z33 box is nicer and stronger - there is no doubt in my mind. It just, is it really worth ALL of that?

[brndck]

Gearing + strength are my motivations.

[jr_ss]

If you launch hard with the SR tranny, it's going to blow gears up quite frequently. I'm sure you do spirited driving and road course work, but that's not real hard on the transmission in a sense.. Drag passes or hard pulls with extreme traction, generally anything that shocks the grand in high tea situations is what kills these things.

Most people swap so they won't have to continue to replace a gearbox. I'm sure a freshened one would be wonderful and may hold power for a extended amount of time, but it's inevitable that they destroy themselves. The sheer size of components just isn't designed for the abuse and trq some of these motors make.

I swapped because I didn't want to worry about blowing a gear box. I destroyed one and it's not something I particularly want to do on a Saturday.

[s14unimog]

Originally Posted by brndck

Gearing + strength are my motivations.

Originally Posted by jr_ss

If you launch hard with the SR tranny, it's going to blow gears up quite frequently. I'm sure you do spirited driving and road course work, but that's not real hard on the transmission in a sense.. Drag passes or hard pulls with extreme traction, generally anything that shocks the grand in high tea situations is what kills these things. Most people swap so they won't have to continue to replace a gearbox. I'm sure a freshened one would be wonderful and may hold power for a extended amount of time, but it's inevitable that they destroy themselves. The sheer size of components just isn't designed for the abuse and trq some of these motors make. I swapped because I didn't want to worry about blowing a gear box. I destroyed one and it's not something I particularly want to do on a Saturday.

Understandable. You guys have seen me on here for years and know that I am one of the fewer builds to actually accrue some lengthy run time on my engine at over 400whp. These days, my car sees mainly road racing track days and drift events - nothing competition. I'm not one for drag racing or wide sticky meats, but I have been hard on my drivetrain and have experienced broken half shafts, destroyed pilot bearings, and broken transmission bearing retainer plates but never an actual gear failure. I also launch my car like I would something AWD with a lot of clutch spin and am still running a single disk sprung hub. I've always feared those twin plate setups transmit too much instantaneous tq.

What's the average going rate for a total all in conversion to the Z33 trans? I've inquired with a couple dog box manufactures on one for the SR and I have to tell you, there not too far off what I believe you guys ultimately have in your setups...

[brndck]

All said and done, I'll be approaching $2k.
$650 for the Trans, $400 driveshaft, $400 for the adapter kit, $200 for a hoke shifter, $100 for a shifter since my Trans didn't come with one, + whatever the machine shop ends up charging me to mill the bell housing.

I'd still rather do this than ever go to an event and waste half the day changing a Trans.

[s14unimog]

Originally Posted by brndck

All said and done, I'll be approaching $2k.
$650 for the Trans, $400 driveshaft, $400 for the adapter kit, $200 for a hoke shifter, $100 for a shifter since my Trans didn't come with one, + whatever the machine shop ends up charging me to mill the bell housing.

I'd still rather do this than ever go to an event and waste half the day changing a Trans.

^ I hear ya on that one. Cool, so ya, about where I thought you might would say. Throwing in a good deal of labor and wheeling/dealing you're really around $3k-ish probably.

I've talked to Drenth and Quaife (they're the more reasonably priced options) and you can get everything to your spec for around 6k in a seqential - even less in an h-pattern. Not too too far off.

Holinger quoted me around $13k - but man would that be nice.

[Prok0]

Originally Posted by s14unimog

When you say "ring off" are you saying stripped or broken gear set? I imagine that happens every now and then but again it could have some to do with the age and usage of that transmission. I'm not trying to distract from this thread, but I've just had such great use out of my SR trannys that I wonder what one would be like freshly rebuilt. My 400whp SR has done nothing more to them other than accelerate the wear on already tired bearings. If left alone, other stuff will always break.

I'm sure the Z33 box is nicer and stronger - there is no doubt in my mind. It just, is it really worth ALL of that?

Yea either just break the gear itself or knock all the teeth of it.. One day I believe we went through 2-3 boxes which was not fun.

If you rebuilt it with all new components, at 400rwhp it would most likely be fine if you do not abuse it overly. You could also look into treating the gears for more strength, I just remember there being issues even with our SR box with OS Giken gears, the gears would be fine but the synchros would explode and gum up the whole box rendering it useless which is why we went to Geforce dog boxes, but thats in a bit more of an extreme race application.

Really the draw was a relatively affordable box, an extra gear to play with, tons of replacements if necessary, and its over a decade newer.