Difference between Z28 and SS diff rear housing
 

Hello,

In the process of building an LS3 swapped Honda S2000. Right hand drive, all the way down in hobbit land, New Zealand. There are only two other RHD LS swapped S2Ks in total so it's a little bit of uncharted territory, especially with the LS3.

Have to source entire drive train from bellhousing to diff. Likely a T56 mag. Such things are not so common here, we don't have Camaros and LS3/t6060/etc type gear is not common. LS1s are reasonably common though.

Which leads me to the reason of this rambling post (my apologies in advance!). For the diff install, we are using an import muscle diff cradle which is for 2010-2013 Camaro diff.

However as the low mileage 3.27 HSV (your G8 GXP equivalent) diff we have here doesn't fit due to rear of the housing, we have to go Camaro. Would love to swap if possible, does any vendor do exchanges of this nature?

Or, as we have to buy new, we'd love to go helical as it's for sprints and autocrossing primarily, plus we don't want to have to worry about clutch packs under heavy use.

Thus have been eyeing up the new 2014 Z/28 diff part#23172755.

Main concern is the rear of the diff not fitting the diff cradle we have. Does anyone have, or know of measurements or pictures of multiple angles, showing Z/28 diff, or even side by side with SS diff? Concerned the transmission cooler section, if fitted, has decreased clearance, or that the housing design has changed slightly to take this space regardless of cooler kit or not.

Have attached shots of the import muscle diff cradle. Blue diff is 2010-2013 Camaro SS, new diff in stands is Z/28, other diff is HSV/G8.
But no good shots of the rear.

More diff cradle pics here with 2010-2013 camaro diff http://www.importmuscle.com/store/p/...grade-Kit.html

Also aware these helicals are not drag diffs, but I'd expect they should be able to handle being launched fairly hard for sprints or occasional strip action, especially with a ~2800 lb car! Is there any reliability data yet? Original S2000 torsen diffs are famed for being made of glass, hence a little worried. Quaife helical internals seem to hold up well but doesn't seem to be one produced for Camaro diffs.

Any help greatly appreciated,

Many thanks,

S2KIWI

The end verdict
 

Ended up finding out the answer to all the above woes.

Only major change to the upper rear housing, is the oil breather being higher up, requiring modification of the cradle we have to use.

Standard Camaro SS axles swap as per DSS. We are using 600hp DSS units designed for S2000 and Camaro diff. VE Holdens/G8s should fit also.

Pace confirmed the pumpkins are the same, also provided measurements pictured below, of the clearance area in question on the rear housing. Will be ordering through them next week, great service.

With any luck this will be the first S2000 with a Z/28 Diff and probably the only z/28 diff in New Zealand :nod:

T56 mag, sfi housing, short shifter, braided lines on their way, custom carbon kevlar 10.5" clutch + chromoly flywheel, pressure plate etc ready. Twin row chain kit, Hyd throw out bearing, cams and valve train to be sourced locally. Mounts ready to go. Still need to get rest of dry sump system, OEM guts are being ripped out next week. Plenty more left to coordinate, brakes, wheels, TCS/LC, aero.. Let the frankenhonda begin!

See you around the boards.

Cool, your S2000 project sounds like a lot of fun! Thanks for sharing the info on the housings.

why not use the zl1 diff lots around now and way better

Hey thanks for the kind words!

We have the diff now and it's mounted in the car finally. Removing bushings from a new diff was a bit weird.

Reason we went Z/28 was we wanted a complete helical type differential, with a cooler, we are using it for auto-x/track/sprints etc, also the ZL1 differential doesn't fit in our application, unfortunately too big. Would imagine it would be practically indestructible for us though. But quite a bit heavier with cast iron casing - we should be in the 2800-2900lb range with driver and fuel.

If it ever turned into a pure drag car, we'd take the tank out and look at fitting something like that though!

Will chuck a build thread up on here, when it's ready to roll and the local car mag has done its' shoot.

Cheers LS1tech!

Excellent work and thanks for the update. Those mounting brackets look BEEFY for sure. I'm with you since the chassis is that light, you obviously should have no problems with that Z28 diff holding up.

Cheers! Hoping we are right. I'm no automotive engineer but seen similar solutions working well many times.

DSS Driveshaft now in, plus have a new tank design from Aviaid, which should fit in the car perfectly, with the rest of their dry sump pump and fittings turning up tomorrow.
Cam timing, PTV etc checks coming up shortly.

Wondering if the stock chain guides need to be changed, as the manley twin row kit is quite a bit wider. They have no visible wear.

As you can see, the donor engine has been babied and gunked up.. in only 18,000miles. Hone looks good though.

Will post a thread soon with all the pics and info up to date.

Miss my s2k. One of the best cars I've ever owned. ITB's and the f22 sound amazing, but so does a LS3.

so how big is Z28 rear ring gear I know ZL1 is 9.9" and by the pics the Z28 looks almost as big compared to the SS
another problem with ZL1 is its cast iron Z28 is aluminum wonder what weight difference is?