what's the rear end hp rating

[deception05]

just like the title says how much will the stock rearend handle? I would like to know before I try and mash on the gas. and is it true that your rear end isn't just affected by the launch but also a very high speeds?

[Sarge]

This is a tough question...some have busted at 400RWHP...some are well into 500RWHP and still going.....so much depends on your launch techniques.....M6/A4 etc....My rule....run it till you break it ...then upgrade it...

[deception05]

that is what I thought

[Liquifire]

I have seen people who broke the stock rear end with a stock motor with the M6. It usually doesn't hold up well after upgrades unless you are unusually gentle with it.

[BlackHawk T/A]

Like was said, hard launches with tires that stick can break the rear end without even touching the engine...

[GatorSS]

I'm wondering that myself. I'm at the 400rwhp threshold with my M6/3.42 and have heard that the stock rear can't handle much more (less, if abused, obviously). I don't launch it hard (with a rare exception or two) and I'm not a drag racer, but I do like to play around on the tracks when I can.

I agree with the "run it till you break it ...then upgrade it" rule. Meantime, I'll let that rear upgrade money work for me until I have to spend it.:)

[MadSeason]

When I bought my firehawk I had all previous paperwork on it, The owner before me had the rear diff replaced under warranty when it broke on the stock motor and gears. I'm toying with sticky tires and 425+ HP at the rear wheels now, will know exact dyno numbers in a week or so, whenever my heads get in... Still have the 3.43 rear, and hope it holds up long enough for me to work towards a 12 bolt with some 4.10s

[ibanez7]

Everything stated above is true.

Stock engines break stock rear-ends, while some engines making 400 and 500 rwhp are still beating on the stock rear-end.

My z28 m6 has 84,000 hard earned miles with about 400rwhp, still running the stock rearend. I have had gear chatter and a clicking noise every time I turn right coming from posi. Its made this noise since I bought 70,000 miles ago.

I’ve made many track passes(low 12s) and street races, and still haven’t nuked it!!!

The longevity of the stock rear end is a crap-shoot, no one knows how long they will last. The best bet is, to always keep some money aside or some room on the credit card because when it goes, you’re not going anywhere. Plus your better off replacing it with either a 12 bolt, 33 spline or a 9” rear-end instead of rebuilding and modifying the stocker.

[Rhino21149]

I don't think its a matter of how much HP but how much time. The rear axle is a weak point on F-bodies. If you launch hard and use a the max stock HP a lot you will probably ruin the original axle in 65K miles.

My experience: 400 HP and hard launches wears it out in about 25000 miles but its not too expensive to rebuild (like $700 parts and labor). This was our first rear end when our Camaro had about 365 RWHP.

500 HP and a few weekends at the track will trash it again. (This was above with 125 extra RWHP NOS,).

We went with a n aftermarket locker, which is a pain on the street--at least going around corners and in parking lots, but it hasn't broken at over 600.

[MadSeason]

I failed to mention in the post the stock rear broke on my car at 20k something miles

[Liquifire]

I don't think its a matter of how much HP but how much time. The rear axle is a weak point on F-bodies. If you launch hard and use a the max stock HP a lot you will probably ruin the original axle in 65K miles.

My experience: 400 HP and hard launches wears it out in about 25000 miles but its not too expensive to rebuild (like $700 parts and labor). This was our first rear end when our Camaro had about 365 RWHP.

500 HP and a few weekends at the track will trash it again. (This was above with 125 extra RWHP NOS,).

We went with a n aftermarket locker, which is a pain on the street--at least going around corners and in parking lots, but it hasn't broken at over 600.
so you spent seven hundred dollars twice and paid for an aftermarket locker, all together you could have bought a twelve bolt and had it in with no more worries and driven it comfortably on the street......When it goes kaboom.....just upgrade to the twelve bolt imho

[Rhino21149]

so you spent seven hundred dollars twice and paid for an aftermarket locker, all together you could have bought a twelve bolt and had it in with no more worries and driven it comfortably on the street......When it goes kaboom.....just upgrade to the twelve bolt imho

It made sense to us. We knew the axle was a weak point, but decided that a twelve bolt alone wouldn't do what we wanted eventually, so we just paid cheap to have the car fixed the first two times so we could keep playing with it while we learned and decided to do it right: it cost about $6 to do right once we knew what. The Strange rear end with locker and premium hardened parts was not cheap, we kept the full ABS, butreinforced the subframe, the U-joints, added traction bars, relocated some suspension parts, upgraded other parts, etc., and installed all adjustment suspension links. It really works now because we can set up the car as we want and we should not have to work about it again until we are well into the low 9s, which will be quite a well (at least at the rate we're making progress).

[deception05]

so actually what would be a good choice to go with rear end wise I heard that GM made a 9" if that is true I don't know but what is the best out there?

[bww3588]

12 bolt
a 9 inch takes more power to turn because of the pinion angle. a 12 bolt with 33 spline axles will easily stand up to 500+RWHP.

[deception05]

what about 800-900 rwhp looking into a CF driveshaft too

[bww3588]

what about 800-900 rwhp looking into a CF driveshaft too
then you probably want to start looking into a 9 inch or a professionally built 12 bolt with 36 spline axles.

[skar]

Do the after market alum, covers help at all.

[bww3588]

Do the after market alum, covers help at all.
for 1 their lighter. 2 they have a drain plug in em so you dont have to take it completly off to change the diff lube which you would run the risk of messing up offsets and tolerences in your gears. 3 it looks better. thats about it.

[Rhino21149]

. . . thats about it.

Agreed. They will not strengthen anything or help rolong the life of any components.

[MadSeason]

Agreed. They will not strengthen anything or help rolong the life of any components.

Disagreed, it is stronger than the standard cover that comes on there and you have extra support behind the c-clips. It will reduce flex in the rear and prolong the life

[t/as&dds]

Judging by everyone's responses here, I'd say the rating is about 65rwhp. I'm so excited, I can't wait until mine blows!!!