960 IRS and Ford 8.8" IRS in a 240 wagon!

[the poi]

Just kidding! 240s are for hauling stuff from the junkyard. This **** be goin in the bumpercooler. I had an absurdly productive weekend at the junkyard this weekend (half-off!). Total haul: 850 flywheel (and an M56 for someone else), complete 960 rear subframe, and Lincoln Mark VIII center section, half-shafts, and knuckles.

The point: the T56 has some high gears and the 8.8 will let me throw pretty much whatever I want in the back, along with cheap diffs. Ford racing 4.56s and a Torsen T2 diff will make for a sweet ride. My neat Lincoln diff is all aluminum, and seems to be a touch lighter than the stock 960 diff (which is iron). The markVIII/thunderbird IRS is 5x108, and the hub bearing looks to be the exact same diameter as the 960 bearing (have to press the hubs out of both knuckles to be sure).

The plan right now is to put the TBird hubs into the 960 knuckles, and then get some Raxle Tbird axles, albeit with slightly shorter shafts. Fun side note: 960 halfshafts are thicker than tbird halfshafts!

And naturally, I'll have to shove the massive diff in the subframe. It will be...non-trivial:



So here's where I'm at, subframe and diff's all cleaned





And the ol' Tremec gets to wait a bit for a rebuild and shifter, then I gotta figure out an adapter plate. Might be annoying, doesn't look like I have much room to fit an adapter plate. Meh, I'll make something work.

[dieselboy]

thats going to be cool/ straight up awesome.

[coldfusion21]

your nuts. major props for figuring all that **** out, and more so following through.

[Bigbegum69]

i don't know if the IRS will take anything you will throw at it...

4.56 gears have pretty small teeth, and first gear will be super short with a t56

the real problem will be halfshafts...

no doubt it all should be much stronger then the stock stuff.... Judging by the caliper of your car im sure you wont skimp out on the project.... you need to figure out how to make your paddle shifters work the the t56

[blkaplan]

Originally Posted by coldfusion21

your nuts. major props for figuring all that **** out, and more so following through.

doesn't look like much is figured out yet, save the props for when its in the car

[impulse922]

Originally Posted by Bigbegum69

i don't know if the IRS will take anything you will throw at it...

4.56 gears have pretty small teeth, and first gear will be super short with a t56

the real problem will be halfshafts...

you forget that 03 cobras come stock with 8.8" IRS, dont you?

my buddy has so far chalked up an 11.8 @ 122 and a 1.8 60 ft on his. all he had was a brace to reinforce the diff housing....(when putting the diff in the housing chris, you might want to check out http://www.lightningforceperformance...bra-p-361.html

[Chris_R]

Did you get the aluminum driveshaft and adjustable suspension system from the Lincoln as well?

[volvorod85]

Hopefully one of these days the car will be done, or you'll get a girl friend and the car will HAVE to run for more than a week at a time, heh heh
Mark

[Bigbegum69]

most 03 cobra guys wont drag race there cars because they break... 1.8 60 ft. isn't good for a car that is trapping 122...

[Captain Bondo]

Give me a break. The point of an IRS is not to be pounded mercilessly down the 1/4 mile- wrong tool for the job.

Regardless, it fits into the category of easy to modify/improve for faily low $$$/effort and can hold plenty of power.

Also the T56 should have a 2.95 first in it, so you're looking at ~13:1 reduction in 1st with a 4.56. That is short, but pretty standard, certainly not crazy. So I also disagree with the "super short" comment...

IMO a 4.11 or 3.91 would be better though.

[blkaplan]

Originally Posted by Captain Bondo

IMO a 4.11 or 3.91 would be better though.

agreed, especially with all the torque the 6 makes!

[volvorod85]

With a 6cyl, he can even get away with a 3.73, which i think is pretty nice, but thats with my 4 and a 3.35 gearset. a 3.91 would prolly be just right, still reasonable for the freeway, 5th is right on IMO for a 3.73, but again being a 6cyl you could still prolly push the .5 6th at 3.73

Mark

[Matt]

God, I love junkyards.

[GhengisKhan]

Originally Posted by MattW

God, I love junkyards.

Truly spoken.

[holyoly253]

I wouldn't recommend the torsen diff. My dad just did a 8.8 conversion for his bmw racecar and he did some research and talked to Sam Strano. He is a 4 time scca champ and was a torsen distributor and he doesnt run them. I guess torsen was bought out and there crap now. My Dad went with a detriot trutrac and hes had zero problems with it.

[Captain Bondo]

Originally Posted by holyoly253

I wouldn't recommend the torsen diff. My dad just did a 8.8 conversion for his bmw racecar and he did some research and talked to Sam Strano. He is a 4 time scca champ and was a torsen distributor and he doesnt run them. I guess torsen was bought out and there crap now. My Dad went with a detriot trutrac and hes had zero problems with it.

I dunno about that.. the tru-trac is still a "torsen syle" diff (helical planetary gears).

If the t2 ends up having issues it should get an eaton posi, end of story. If the factory clutch type dies in mine I won't think twice.

BTW it is 28 spline I assume? I wonder if you could/should go 31 spline while you are at it?

[blkaplan]

Originally Posted by holyoly253

I wouldn't recommend the torsen diff. My dad just did a 8.8 conversion for his bmw racecar and he did some research and talked to Sam Strano. He is a 4 time scca champ and was a torsen distributor and he doesnt run them. I guess torsen was bought out and there crap now. My Dad went with a detriot trutrac and hes had zero problems with it.

Truetrac is a torsen differential. Strano also runs a F stock Shelby mustang... stock as in runs with the dif that shelby equiped from the factory...

[Captain Bondo]

is there an echo in here?

[Pennybridge Pioneer]

Originally Posted by Captain Bondo

is there an echo in here?

engineers

[blkaplan]

Originally Posted by Captain Bondo

is there an echo in here?

lol apparently. i think we responded close to the same time but i had to finish an email before sending the reply out.

[2fast242gt]

awsome poi. this will be plenty strong. and very neet!!!!! i wana see it boosting.

[the poi]

Originally Posted by volvorod85

Hopefully one of these days the car will be done, or you'll get a girl friend and the car will HAVE to run for more than a week at a time, heh heh
Mark

Don't be silly. You and I both know that that will never happen.

Originally Posted by Captain Bondo

Also the T56 should have a 2.95 first in it, so you're looking at ~13:1 reduction in 1st with a 4.56. That is short, but pretty standard, certainly not crazy. So I also disagree with the "super short" comment...

IMO a 4.11 or 3.91 would be better though.

It'll get me to 50mph at 8k in first, and puts me at 2.3k at 75mph in 6th on the freeway. Anything below that, and 6th will be utterly useless. I've been playing with this: http://www.f-body.org/gears/ and the 4.56s seems to be a good match

edit:// that said, im a manual-newbie, am I missing something?

Originally Posted by blkaplan

agreed, especially with all the torque the 6 makes!

My 6 doesn't make torque out of boost . Of course, it may have something to do with my timing be retarded 6 degrees since I last fiddled with MS2. It's got a big turbo, and PC cams though, so it's not really all that torquey.

Originally Posted by MattW

God, I love junkyards.

You're telling me. Got everything for like $350

Originally Posted by Captain Bondo

If the t2 ends up having issues it should get an eaton posi, end of story. If the factory clutch type dies in mine I won't think twice.

BTW it is 28 spline I assume? I wonder if you could/should go 31 spline while you are at it?

I'm not married to the torsen at all, I just liked them in the audi I was driving a while back. The eaton posi and the torsen are the same price, so if the eaton is the hot item, that's what I'll go with. Is there a quantifiable difference in behavior between the two, or is one just "better" than the other (depending on who you ask)?

I'm gonna stick with the 28 spline. It simplifies things, and I won't be launching it on slicks (although I do intend to drive it hard with 315 street tires). I can get some Raxle (or others) upgrade axles for the Tbird axle, and just specify shorter shafts.

[Bigbegum69]

Originally Posted by Captain Bondo

Give me a break. The point of an IRS is not to be pounded mercilessly down the 1/4 mile- wrong tool for the job.

Regardless, it fits into the category of easy to modify/improve for faily low $$$/effort and can hold plenty of power.

Also the T56 should have a 2.95 first in it, so you're looking at ~13:1 reduction in 1st with a 4.56. That is short, but pretty standard, certainly not crazy. So I also disagree with the "super short" comment...

IMO a 4.11 or 3.91 would be better though.

very true.... but wouldn't the turbo motor like more load anyway? ie lower gear? maybe im crazy.

[VQ]

Awesome, the rear on a mk2 irs isn't that much different to the Mk1 rear so I can definetly take pages out of your book on this, though getting one of those diffs in Aus isn't easy so I'll more likely use a Skyline/Supra R120 or whatever it is.

[blkaplan]

Originally Posted by the poi

It'll get me to 50mph at 8k in first, and puts me at 2.3k at 75mph in 6th on the freeway. Anything below that, and 6th will be utterly useless. I've been playing with this: http://www.f-body.org/gears/ and the 4.56s seems to be a good match

Doesn't sound to unreasonable.

Originally Posted by the poi

My 6 doesn't make torque out of boost . Of course, it may have something to do with my timing be retarded 6 degrees since I last fiddled with MS2. It's got a big turbo, and PC cams though, so it's not really all that torquey.

I got a t-25 here with your name on it that will make sure you never go out of boost

Originally Posted by the poi

I'm gonna stick with the 28 spline. It simplifies things, and I won't be launching it on slicks (although I do intend to drive it hard with 315 street tires). I can get some Raxle (or others) upgrade axles for the Tbird axle, and just specify shorter shafts.

Big boy!!!! ballin.