i might be usign a gslse rear axel diff and rear end on my rx3 project car, ill probably be putting a 13t can these rear ends handle power , about how much?


is there a aftermarket lsd that can be put into it to hold more power?

 

What are you using it for, if you're going to drag it no way, if its for street and you dont light up the rear a lot maybe.

 

Ive been running about 300HP out of my S5 13BT into an SE rearend for years with no failures.The factory LSD actually grips harder when you put more torque into it.
My LSD is pretty worn,I know because it almost feels like an open diff when you jack up the rear tires and spin them independantly.Theres almost no resistance.But when you apply all the torque my motor can make through the LSD,the clutch plates have no choice but to grip.Thats how they work,the more power goes into the carrier,the harder the pins push out on the clutch discs,which increases the locking effect on the 2 axles.
The actual mechanicals of the rearend,like ring and pinion and the alxes have not had any problems holding up to the power.Even with grippy 245/17 Falkens out back, Ive never twisted an axle or popped a gearset.


The SE trans is another story.They,like all the TypeM trannies arent known for their strength.They can take a bit of abuse,but most are pretty tired after 20+ years and they tend to break often.The TypeR TII boxes are just as well known,except their's is a reputation for strength.They were built to handle torque being made for a turbo engine.Plus being from 87 and newer cars,they often have less miles on them than most FBs.

 

Steve, your car looks a little tweek in the rear?

 

300 wow thats dope , i guess ill use it then if its good enough.

i found the whole rear end for 300 with brakes and everything so i think ill get it.
thanks

 

If you mean it looks crooked,its just the camera angle.She sits nice and level.

See!


Squagles,Id say the FB's rearend is adequate so long as its in decent shape already.Obviously,a 175K old rearend is usually gonna fail sooner than a 50K one.And if you can score a rearend from an AT car,its very likely to be in good shape.
I dont normally abuse my car,but it gets full throttle at least a few times,everytime I drive it,which is usually every day.My SE rearend had 100K on it when I pulled the thing from the wrecking yard.The SE it came off was very clean,but wrecked up front,so I guessed it was in good mechancial shape.Heres the ring and pinion after another 20K miles of TII power.I only changed the pumpkin out because of a carrier bearing that was getting louder.The axles have no twist and the R&P have a nice pattern.I always run Redline 75-90W.
My power also comes on relatively easy because I run a larger turbo than stock.Its got a bit of lag in 1st gear,which keeps the torque loading down.She doesnt start to really scream until about 3500,by which time,the cars already going a bit.A twin turbo 13B or 20B with a lot of quick,down low punch could probably scatter an FB rearend a lot easier.....

 

ya i know what you mean by getting a non beaten up one.
thanks ill look into the amount of k's on the one i might get.

 

Man steve would you quit posting pics of your 7!!!! Man evertime I see that freaking car O O O O O O ahhh, well I can't help it that car is freaking sweet.
Only to see her in person and get a ride in it would be as good as sex!
I hope my S5 TII motor going into my 79 will give me the same feeling one day.

 

is a gslse rear end and a gls rear end the same thing?


i can get a gsl rear end for 200 canadian i might get it if its good.

 

Pretty much yea.
The SE has a lower gear ratio and bigger brakesl, but its no stronger.
The housings are the same,but the bearings and axles got bigger on all 84-85 cars.

 

I think that statement is a bit confusing. All 84-85 cars have the same axle housing but the large (84-85) axle housing are not the same as the small (79-83) axle rear ends. The smaller axle rear ends are, ironically, stronger due to the stiffer axle housing. There were GSL rear ends from 81-85, so they come in both small and large axle varieties; the GSL-SEs were only around from 84-85, so they are all large axle. 83 is an odd year because it was a small axle with a large companion flange (same as large axle rear ends, the following years).

I've never had much problems with the rear ends taking power, even in drag launches. NA tranny output shafts are the biggest weak link. I drag raced a peripheral port 13B powered 1st gen with puck clutch, turbo tranny, TII driveshaft, '83 small axle rear end (reinforced) with 4.88 LSD diff on giant wrinkle-wall slicks without a problem. Of course, wrinkle wall slicks are actually easier on the driveline because the torque is absorbed and released more slowly. Drag radials can impart a huge shock on the driveline and break just about anything. I broke an NA tranny output shaft with a drag launch on a streetported 13B GSL-SE with a puck clutch and drag radials. Nowhere near the power of the PP13B setup, but far more shock to the driveline with a weaker tranny.

 

Remember to get the drive shaft incase it is a different year than your car.

81-83 use the same drive shaft and the 84-85 use the same drive shaft so if you have a 82 rx7 and buy a 84 rear end you will need the 84 driveshaft.

 

nice exhoust outlet!!^^^^ whats the reason for it,

but about the se rearend, some more things that should be considered when your estimating how much power your rearend can take, horsepower, obviousely, traction, also whether or not your running drag radials or wrinkle walls, as mentioned by blake... how your going to drive it. hard all the time or just sometimes, and also how much your car wieghs, if your car is 2800lbs compared to 2000 theres gonna be allot more torque applied to the rearend even if the horsepower and amount of traction is the same...

by the way steve84 gs tII how much does your car wight?? and blake what about you im just curious...

Paul

 

Huh.
Thanks for the info,Blake.
I wasnt aware the HOUSINGS were different.My old Mazdatrix catalog does list different part numbers,guess I just never paid attention.
My car is about 2700lbs.Its still basically a 1st gen GS,but the TII powertrain does add some weight.
Stock SE rearend and gears,245/35-17 Falken FK451 rears,which are very good street tires,though not at all considered track or drag tires.They grip well,but my power can break them both loose easily in 1st and 2nd if I dont back pedal a little.
Ive never experienced any wheel hop,which I think is a BIG contributor to rearend failures.Even if I dump it on a launch,the tires will spin cleanly until they hook,so theres not much stress in the drivetrain.I guess its just because my car is light and the engine makes good off boost torque since I went with a S5 engine.

 

i do agree with steve about the rearend but like he said what are you gonna use it for and how hp are you gonna push with what kind of tires . i have an se rear in my 84 and pushing 446 on the back wheel , now with the regular tires i need not to worry about the rearend because i just smoke the tires but when i put the stickier tires i feel the rear starting to strain a little .
steve you should shim the clutches on you diff , mine was just like yours and i shimmed it and now its almost like lockers but not the same especailly on turns it does not jump around like lockers do but the grip is amazing

 

I had thought about rebuilding my LSD,but then agan...its never gone 1-legger on me,so why bother?
As worn out as I know it is,the diff still always delivery even power,itll kick out and power oversteer everytime and never once have I gone up in smoke on only one wheel.

 

I have put 250 RWHP and 250 ft lbs of tourque through a NA 1st gen tranny into an 83 gsl rear with no problems. I run small 205 wide tires and dont launch it, the car has been run on the turbo engine and same rear for years. If you dont drag launch it, it will last forever.

CJG