i'll make this as simple as possible...

i have an EF hatch with a GSR swap and a screwed up S1 trans.

i have a spare GSR/XSi YS1 case with a hydro B16 or ITR(gotta check, cant remember) gearset that needs rebuilt.

my question is in regards to which factory LSD/final drive i can drop in without modifications

and before i get slammed, yes, id like an MFactory/Quaife/Kaaz/Cusco etc diff. once i spend $900 on the synchrotech rebuild kit, $500 on a new clutch, and $100 for machine work, i wont be interested in spending $700+ on a high end diff to put a measly 200whp to the ground if an ITR unit will do the trick.

any positive help would be greatly appreciated

 

If you go with the OEM ITR helical LSD you will need to modify the case to make it fit. The OEM viscous B16 LSD will fit without modifications but it is a weaker design and has a different 14 bolt pattern, so you can only run the OEM 14 bolt 4.40 FD with it.

 

so if i had the case machined to fit the helical, i could use my current B16 final drive? or i have to get the final drive with the helical lsd?

 

The 10 bolt 109.8 mm hole diameter B16 FD will not fit the ITR helical LSD. You will need the 10 bolt GSR/ITR FD set with 116.8 mm hole opening.

 

Well, not sure if it means much, but you shouldn't really need to spend over $350 for a clutch to hold sub-300 whp. And not sure what machine work you're looking to do, but if it's just a flywheel being resurfaced you're looking at no more than $60. Usually under $50. So that should free up some expense at least.

Good luck! Dave here pretty much has you filled in so not much more I can add.

Really? In my head I cannot picture the YS1 housing, but I wouldn't have thought it would have required modification. Good to know, Dave. Thanks for that.

 

the last ACT kit i bought was like $400+ so i just threw $500 out there. i see i can get an Exedy stage 1 that holds 250tq for $250 so yeah thanks for mentioning that or i wouldnt have looked until it was time to buy lol

as for the machine work, my current crank, rods, pistons, crank pulley, flywheel, and clutch kit were all balanced together, so until i talk to my machinist i'll assume it all needs to be balanced together again. luckily the process only cost me $100 last time when he was assembling my engine

 

The oil fins in the bell case will rub on the OEM ITR helical LSD. You can install the ITR diff but you have to grind down the fins. It is also important to note, (for those who don't already know this) if using the ITR tapered diff bearings, the races and spacers will also need to be used from the ITR. I usually just go with the MFactory B16 helical LSD because it fits fine in the YS1 housing without all the messing around.