i'm about a month away from finally saving the money to order a rearend.....this is the mod that i've looked forward to most.....bolt-ons and cam is listed in the sig, but future plans are 100 shot of NOS, PRC "As Cast" heads, Fast 92/92, Monster Stage 3.....car is 90% street, 10% strip, planning on 4:11 gears.....i pretty much drive like an old lady on the street, but when i go to the track, i want to be able to beat on it with no worries......will the S60's extra weight make my car handle differently on the street?.....will both take 5500 rpm clutch dumps?.....which one would take more abuse?

also, what difference will a short or long torque arm make?

 

anyone?

 

I have a S60 with a detroit locker and I couldn't be happier! Yea its heavy but the car doesn't handle any different and I like knowing It'll take whatever I throw at it. Give Carl @ Central Racing Parts a call and he can give you some more info on the S60.

 

From my research I think the weaker of the two setups would be the 9" with the true trac. I want to say those are good to around 600 at the tires according to posts on here.

Some say the weight of the S60 isn't noticeable in a straight line but if you do any road racing it'd be better not to have as much weight added.

For torque arms from what I've read and been told it more or less comes down to how the car will be used. For A4 cars the shorter Tq arm shocks the tires harder on hard launches. For an M6 car the long TQ arm wont shock the tires as hard and will help the rear stay more planted after the launch. Short tq arms are also more prone to wheel hop under hard braking which makes them less ideal for road racing type stuff. There's a lot more to it than that though, you ought to do some researching on "instant center". Hopefully someone more knowledgeable than me can fill you in on the rest.

 

Do a search on tunnel mount torque arms and floor cracks. Many people have experienced floor cracks or actually breaking the spot welds that hold the brackets where the tunnel brace used to mount to the floor. The floor sheet metal is not very thick. Another factor is that under braking the torque arm pulls down on the forward mount.

I think a long torque arm used with a relocation crossmember is the most rugged setup and from what I've read it's the most street friendly in regards to noise and ride quality.

The Detroit locker can cause shifting issues with the T56 when driving normally because of the clearance between the lugs in the locker. Carl at CRP has posted that the Detroit Locker for the S60 behaves better than the Locker used in a 9 inch. I would give him a call if you are considering a Locker to find out if it's good with the M6.
I got a S-Trac with my S60 instead of a TrueTrac because Carl recommended it. I haven't had it on the road yet as I just picked it up and I store the car for the winter.

As far as the S60's weight, it weighs about 15lbs more than a 9 inch. That's as much as 2 Gallons of Gas. Not a problem.

 

Amen to that, my short arm broke one of the two stamped metal mounts off of the floor board. I then put a long arm on and was much happier plus it was much more robust and more quiet with viewer vibes.

 

thanks guppy and fly boy......that's all good info that i haven't come across yet....i've got a PM quote from Carl for the S60 with S-Trac.....i'll probably go ahead and order fom him since it seems like a pretty good deal

 

Amen to THIS. A 9" robs much more power in parasitic loss than it would take to move that extra 15lbs. Also, the weight is exactly where you want it for road racing or strip - right over the rear tires.

S60 all the way.

 

ive had my s60 with s-trac for over a year now and love it you cant tell the s-trac is their its just as smooth as the factory diff mine has 35 spline axles and 1/2 inch wheel studs its heavy but honestly you cant tell a diffrence got mine thru eric @ midwest chassis

 

i got my s60 from carl@crp perfect!!! i think the pinion angle is straighter on an s60 as compared to the lower pinion location on a 9 inch. less pinion angle to adjust out.

 

I still have the stock torque arm and before I removed my 10 bolt I measured the pinion angle, the pinion angle of the S60 installed was the same as the 10 bolt. That's what I call a 'bolt in' swap!

 

Any issue with keeping the stock torque arm?

 

The only thing I've read about stock torque arms is that when used for drag racing with a car that hooks up good they tend to bend just fwd of were they bolt to the rear end. It was a big enough nut to crack just getting the S60, aftermarket suspension parts are going to have to come later.
The car is stored for the winter and I just installed the rear so I have no driving impressions yet.
In regards to the stock torque arm and the S60, everything bolted up just like stock, in fact the whole rear went in like a stock 10 bolt. I only had to drill one hole for the drivers side brakeline bracket bolt (LT1 brake specific).

 

i ordered my s60 with 4.10s 35 spline axles with the strack and drain and fill plugs with matching strange chromoly 3"ds for 2700 shipped, that is an amazing deal. the s track weighs about 8 lbs less then the true track. s track is the same differential just stranges version. so the weight is almost identical to a 9" and like mentioned above the hp loss i believe is the same or less then a 9". i ordered from carl and he included 4 bottles of differential fluid, 2 to go in right away then you drain at 500 miles and put the other 2 bottles in. he also included poly sway bar endlinks also. he then gave me deals on front shocks and springs as well. he is an excellent guy and his customer service is the best ive ever dealt with in any product. i am so happy with this rear end, it feels so solid and is so quiet and smooth its just awesome. i have recommended the s60 to everyone i know looking to upgrade, its a awesome piece!!

 

also if your car is 4chanel that means you have abs and tc, if you take your backing plates and reluctor rings off your 10bolt and ship them to strange when they build your s60, they install it all for free. i had it all installed even tho i did abs\tc delete with the SJM kit, if i ever sell the car the next owner will ave the choice to use have abs\tc again.

 

the s60 loses some power too, it has a bigger ring gear(9.75") to turn.
http://www.carcraft.com/techarticles...o_results.html

 

yes it does but it has a larger ring gear then a 9" and loses less or around the same from all the tests ive seen done.

 

i can't wait to order an S60

when do i actually need adjustable LCA's?.....i want to replace the stockers, but are adjustable ones absolutely necessary with a rearend swap?....my car is lowered almost 2" all the way around if that matters

also, which torque arm will work best with true duals, i want to get the mount off the tailshaft of the tranny

 

if you are lowered 2" them you deff need the relocation brackets. your lca's get angled to much when you lower it so the adjustable brackets get it back to where it needs to be. if your running duals the chassis mount torque arms are not your friend ask me how i know lol!

 

i've got the relocation brackets welded on my 10 bolt....i'll make sure to add them to the S60.....but the actual LCA's themselves, do they need to be adjustable with this new rearend, or can i just grab a solid set like these
http://www.ws6project.com/user_stor/...-control-arms/

also, i was thinking about going 3 channel and keeping my abs, but deleting traction control....do you miss yours?......if i go this route, will the ASR light be staring me in the face the entire time.....i don't want dash lights