85rotarypower

Ok, this may seem like a question a n00b would ask, but I've been looking into just how much power a stock 1st gen tranny and 82 rear end will hold. Honestly, I'm getting mixed reviews on the subject. On guy says the rear will handle over 300hp and other says they are no good for anything past 150. As for the trans, its been kinda established that 200hp is about the limit, but even then people have said they can handle over 250hp. So, my question is 2 part: A) Will my tranny be able to handle the 240hp I hope to make? B) Will a small axle 82 rear end with LSD handle the same power, and how well?

I've been thinking of swapping in a ford 8.8, but really don't want to do the work of making one fit and really can't justify the cost of a granny's prebuilt 9". I'm not really against doing a tranny swap to a TII, but I would rather do both or neither. Doing both will cost me at least $1000, assuming I can find a good mustang rear end complete from drum to drum, then I don't even have wheels to fit that bolt pattern, which means either adapters or redrilled axles again. Man I wish mazda didn't cheap out on the drivetrain in these cars.

steve84GS TII

Totally depends on how you APPLY the power......driving style,tire traction,engine types.

A 250HP N/A engine is nothing like a 250HP turbo engine in regards to powerband and torque porduction.
Torque is what breaks drivetrain parts,and turbo engines make torque that N/A's cannot.....especially when you are talking rotaries.1st gear does the most torque multiplication,and of course, thats the gear that you launch and accelerate the hardest in.
The later,large axle rearends are a better choice,they can take more torque and abuse since the axle shafts are more massive.But that doesnt mean they wont break......plenty of people have broken them just redline dumping the clutch,even with the stock HP numbers.On the other hand,if you drive sanely,even a turbo 13B doesnt put down enough torque to break the large axle rearend easily.I have 7+ years of daily driving on my rearend,taking 300HP and putting it down to 245 tires.But if I installed drag slicks and started to drop the clutch,I have no doubt Id start breaking things.

Starting condition also matters.If the tranny or rearend already has 180K miles and never go regular maintenence,dont expect it to last long once you pump things up.

85rotarypower

Ok, so basically my very high mileage rear end and tranny aren't going to take much then. This is a turbo 6 port NA project, so torque should be pretty good I think. I'm thinking I'll just go ahead with a ford 8.8 and TII tranny swap. I really don't want to break anything once I get this thing tuned. I've owned the car 4 years and barely driven it as it is.

steve84GS TII

Again,it depends on the particulars.

Even a turbo rotary doesnt make ground pounding lowend torque,except for a 20B.And the 1st gen chassis is light and doesnt accept very wide tires unless you go widebody.The stock rearend has a better chance of surviving than the stock tranny,especially with a setup that is somewhat limited on power.
Not saying your 6-port turbo will be slow,its just that most people that NEED an 8.8 or 9.0" rearend are running 400-500HP Cosmo,TII or other 4 port,wild turbo engine.A good,solid 1st gen rearend will hold up if you dont constantly abuse it and it will be cheaper and easier to buy/install than the custom Ford units.

The trans is another story.The N/A units have a penchant for wearing out after all these years.At best,they have scetchy syncros by now,and it goes downhill from there.Not to say the TII unit is indestructable,but they are well overbuilt and can often be found in 3rd gens,pulling duty for the FD trans,which is said to be weaker than the TII unit.The TII trans is usually only a bit more money to buy than the non-turbo trannies if you need a new box anyways,so it makes sense to upgrade.They are also pretty simple to install and allow the use of a larger clutch and driveline,both of which are critical when boosting.

Id concentrate on the trans for now.Because of its location,and the clutch component juggling,its more work to replace once things are done if you do have a failure.The rearend can always be done later,its easy to get to and will cost the most to upgrade if it comes down to that.You can always use the downtime during the build,to pull and examine the rearend you have now for condition and potential lifespan,before buying a low milage replacement or new upgrade.

aussiesmg

iTrader: (1)

There are many 1st gen making 10 second passes with stock rear ends, drive it until it breaks then decide

85rotarypower

Ok, thanks guys. I think I'll stick with the stock rear end as at this point in time I'm only running skinny 205's in the back, and not looking to go wider either. I've got a stock TII clutch already, just need the trans, flywheel and starter. I can deal with the shifter in the stock TII location, it would work better for me anyway considering I have to sit so far back from the steering wheel. As for a driveshaft, my U joints are going anyway so a new driveshaft is in order I think.

dbragg

iTrader: (7)

if you arent going to throwing massive as slicks on it, doing high RPM launches all the time, with high torque. the stocker is fine. even then you can still use the stocker. i have heard of a team of guys in NY making close to 1000HP on a 84-85 rearend. they have the moser axles, ARP differential bolts, and gearing out of an older mazda that is a low 3.**. thats a strictly drag car.

i have faith in the big axle rearend. i wont go bigger unless i can brake one of my moser axles. the most ill do is get a kaaz and maybe cryotreat the gears. theres no point is going bigger if you don need it. youre just loosing power in the drivetrain and spending money that could go elsewhere. my main goal is torque too.

if you get scared, get a 84-85 rearend, throw some moser axles in it and youll ge fine.