cranny

I plan on eventually swapping out the 10 bolt for an S60 and was curious approximately how much rwhp is lost with an S60. 10? 20? Just curious to see if anyone has dynoed before and after.

98slols1

not trying to high jack ur thread here but i have a similar question with a fabd 9. Is there possibly a write up some where on different rear ends and horsepower losses?

cranny

No problem at all. I'd be curious to see the differences compared to other rear ends.

oldguy99Z

iTrader: (2)

GMHT magazine did this back in their April 08 issue.They replaced the 10 bolts in two F bodies - one with a S60 and the other a Moser M9.They did before and after dynos.S60 car went from 412.5 to 397.9 HP-about 3.5% loss.M9 car from 441.2 to 436.6 HP -about a 1% loss.Bigger gears and axels use up some power.

bayer-z28

iTrader: (14)

^ I work with a guy that has been in the performance business for quite some time and he says the 12bolts are the better rears, efficiency wise. I was looking at a S60 also. I wanted strange, but this guy can get me a good deal on a M12b.

PAULZ98SS

iTrader: (5)

Can't beat an s60. Stout piece. I had 420rwhp on a mustang dyno stock 342 10 bolt. Year later I put in an s60 410 and also a 102 intake from an ls6 intake, came out to 420rwhp on the same dyno. Probably lost 30 and gained it back.

studderin

iTrader: (28)

if you have a t56 do not get a 12bolt.


I did 10 bolt vrs s60 dyno in my car
https://ls1tech.com/forums/gears-axl...o-numbers.html

cranny

So that 3.5% loss with the S60 isn't too bad. I'm sure the car will still be quicker going from the 3:42s to the 4:10.

PAULZ98SS

iTrader: (5)

Yep, even if your losing 30hp the car will still be quicker from the ratio. And def not a reg 12 bolt with an m6.

warriorcustoms

iTrader: (10)

in my research the 9in rear eats more horsepower than a 12bolt 14 bolt Dana 44 or Dana 60 & for one Im not much of a fan of puttin ford **** in my GM product I know ford guys need chevy parts to go fast but come on lol

wrd1972

iTrader: (12)

I really doubt the 1% loss compared to the 10 bolt with the 9" rear. The 9" rear has the pinion sitting much lower on the ring than everything else and this results in a bunch more tooth contact which results in more friction and likely more parasitic loss. Remeber this is very old technology that has never been refined. I know thats what the article says, I just have my doubts. If its truly 1% wooohooo I am glad I went with a 9". I would suspect from looking at the parts, the 9" will rob the most power of all three.

Also seems I remember the S60 had the most efficient tooth contact (power transfer) with the least amount of friction which is a plus but you then have a bunch more mass to spin with respect to the carrier, diff etc.

12 bolt was more middle of the road with respect to power transfer efficiency and rotating mass.

trik396

iTrader: (4)

I've got an S60 with 4.56's coming from a 10bolt with 4.10's. Can't tell the difference in seat of the pants power. But it's nice to know my rear end is pretty much bullet proof.