lysol86

I have a different project of sorts going on and i needed a full irs fc rear end. I went to a junk yard and pulled the irs out of an s4 gxl w/lsd. My question is what kind of hp/tq can the n/a 7" lsd rear handle? Keep in mind i will be doing new clutches etc in it and probably go with the thicker discs. Any help is much apreciated.

Thank you
Lyle

RotaryRocket88

iTrader: (7)

At least ~ 300 rwtq., but you can break a halfshaft with much less power if you abuse it.

lysol86

Ok i was hoping it would be around that. And i would imagine it has alot to do with who is behind the wheel as well. Its not going to be too crazy to begin with but farther down the line if i go for more power i'll switch to a t2 unit. Thank you for the input

RTRY_STR

iTrader: (2)

S4 gxl diffs are really good for 300-350 WHP. S4 TII diff is what I would go with seeing as how its mechanical and not that junk VLSD that S5 comes with

lysol86

Thats what im trying to decide. I know i want s4 clutch style and not the vlsd. But im trying to find out if the n/a 7" will be good or if i should sell it and the axles and get an s4 tii 8" unit. Maybe a description of use would help. I have an 86 b2000 that im running rx7 four piston front brakes and fabbing in an rx7 irs under the rear. It will be swapped and im goin to be running it right around the 350whp mark. Its going to be a weekend cruiser/ track once in a while. Not going to be doing drag or anything like that. Just a fun vehicle to run around in and break the rears loose sometimes. As far as tires they will be street tires on 18x7.5 wheels more that likely. Still debating on what lug pattern to run.

Aaron Cake

iTrader: (1)

Torque is what kills a diff, not HP. Around 300 Ft-lbs and hard launches is where the NA diff starts to get weak. You'll break a stub shaft. If you are primarily street driving and the tires slip before the diff breaks, then you should be fine.

Acidia609

iTrader: (2)

Complete TII swap is the way to go if you plan on abussing.. But keep in mind you'll need TII Axles once you replace to TII diff since thier bolt paterns are slighty bigger... And they been on National backorder for years now at ALL autoparts stores.. People use the cost and demand and jacked these prices for axles to $300+

I ended up taking my NA and had a machinist Oblong the holes to fit my stub shafts.. I then welded reinforcement bars accross hole to hole. So far its been holding up to 312whp drift events