Stock 8.8 Rear End Strength??

[Darkside]

How much HP/TQ can the stock rear end take???

I know there are things that can be done to strengthen the 8.8; bracing, welding the tubes, better axles, etc. but I am not sure of any others.

With possible mods, how much HP/TQ can a 8.8 take?

At what point do you need to go with a 9" Rear

[The Bone]

The 8.8 is a strong rear end but when you improve the traction of the tires that is when things brake. I also think thet people have broke it with stock HP.I have heard of people twistinf off axels and bolwing up the gearset.
You may be better off if you get a new rear from Curry Interprises they build some strong stuff.

[Johnny Dangerously]

Iceman broke his recently.


`

[Darkside]

Originally Posted by Johnny Dangerously

Iceman broke his recently.


`

I just read Iceman's entire thread on his rear end carnage.

[6-Speed]

The CobraJet has a beefed up 9" rearend; perhaps it will end up in the Ford Racing catalog some day.

[Johnny Dangerously]

Originally Posted by 6-Speed

The CobraJet has a beefed up 9" rearend; perhaps it will end up in the Ford Racing catalog some day.

Or in the BVM Store.


`

[Birdman]

Originally Posted by 6-Speed

The CobraJet has a beefed up 9" rearend; perhaps it will end up in the Ford Racing catalog some day.

Everything on that car will end up in the FRPP catalog , you can be sure of that. That program depends upon it.

[iceman]

The stock 8.8 is pretty stout until like mentioned earlier you throw on the slicks and start to really dig in on traction. I had upgraded to a true-trac dif and it actually took the beating pretty well. I am 700 rw torque and dumped the clutch at about that peak and the car bit and the diff housing cracked but it still worked fine. I don't know to be hones if that broke it or the driving while the axle was snapped did since it was twisted it grind hard on each revolution.

My advice is at a min. get the FRPP Girdle on there asap regardless of power. It's a huge improvement and looks better too. If you want to upgrade the dif. I believe the true trac is a good choice as it is strong, quiet, and able to go to the drags, street, or road track with no issues. Also no clutch packs to burn out.

Get the axle tubes welded. It's not as important. Mine were not done (still aren't) but will be before I go to the drags again.

If you decide you have to have the baddest mother out there. There is soon to be a 9" with an air locker that is an open diff. when not locked and a full locked dif. when it is. If you just want a drag car a spool is the way to go but not for the street and I want to to be able to do all 3 areas well. I do believe I['ll eventually lose the slicks and put on the 325/50/15 MT ET Street Radials for the strip. I'd rather spin than destroy my arse again.

THe answer to your question about the stock rear and what it will handle? Probably different for everyone. If you slip the clutch rather than dump it probably it will handle quite a bit (still do the girdle though). If you beat it then not as much but the key is the traction thing. You can't break it on street tires more than likely as you will just spin all day long

[6-Speed]

Originally Posted by iceman

My advice is at a min. get the FRPP Girdle on there asap regardless of power. It's a huge improvement and looks better too.

Can you elaborate on how the differential girdle/cover helps strengthen the rearend. I know it offers some bolts that need to be torqued down; I suspect they jam against something inside.

Thanks.

[Alloy Dave]

Originally Posted by 6-Speed

Can you elaborate on how the differential girdle/cover helps strengthen the rearend. I know it offers some bolts that need to be torqued down; I suspect they jam against something inside.

Thanks.

Yes, they push against the caps that provide preload on the carrier bearings. I have no opinion as yet to it's effectiveness.

Dave

[TOMMY GUN]

Originally Posted by 6-Speed

Can you elaborate on how the differential girdle/cover helps strengthen the rearend. I know it offers some bolts that need to be torqued down; I suspect they jam against something inside.

Thanks.

I added this...

TA Performance Bearing Cap Stud Kit


Along w/ the cover to help stiffen up the rear gears in hopes to keep them from flexing over time.


.

[purdueranger]

8.8s can take a beating from hell and back. The girdle kills off the deflection that kills axles and gears. The shock from the sudden driveline rotaion causes the carrier to move and bind, that is what caused Iceman's carnage. I have a girdle in my camaro and it has seen some violent launches on big slicks on a bottle.

welding your axle tubes is going to help from them sliding out and bending. Remember those axle tubes are just an interference fit.

What I would do is a set of moser axles, aftermarket carrier that is stonger than stock, weld the tubes and throw in a girdle.

[TOMMY GUN]

Originally Posted by purdueranger

8.8s can take a beating from hell and back. The girdle kills off the deflection that kills axles and gears. The shock from the sudden driveline rotaion causes the carrier to move and bind, that is what caused Iceman's carnage. I have a girdle in my camaro and it has seen some violent launches on big slicks on a bottle.

welding your axle tubes is going to help from them sliding out and bending. Remember those axle tubes are just an interference fit.

What I would do is a set of moser axles, aftermarket carrier that is stonger than stock, weld the tubes and throw in a girdle.

Thanks for the informative post!


What aftermarket carrier would you reccomend for a car used mainly on the street w/ a little bit of track time?

In welding the diff what type welding would work best?

The tubes are steel, but isn't the diff cast iron and hard to weld? Or are they made of something different nowadays?

I suppose all the guts need to be out when welding them up? We use to weld up truck diffs while all was in tack, but that may not have been the proper way to do it, although never had an issue.

.

[Mr. White]

Purdueranger came over here with BVM. He has a wealth of info, not to mention a Jeep that will give your GT500 a run for it's money.....

[iceman]

He sold the jeep...as part of a trade for a monster tow truck so he can take that 10 sec. streert camaro to the track on a trailer incase he breaks something....I wish he was there when I did mine. so I wouldn't have had to pay a hefty tow charge.

PR is a great sourceof info and has strong technical ability. He does pretty much everything himself and tears up that car of his regularly...He will be a nice asset over here even though he has poor taste in color and flavor of cars

[SideOilerF100]

Why not just add the *stock* KR rear cover?

My KR has the upgraded one stock. (aluminum)

[TOMMY GUN]

Originally Posted by SideOilerF100

Why not just add the *stock* KR rear cover?

My KR has the upgraded one stock. (aluminum)

Depends how far you go w/ the HP.

Stock KR has what at the wheels? 450HP?

Just a pulley, tune and driveshaft and I'm at 560hp at the wheels.

Add a TVS and that goes to 650hp.

So you add 200 HP, you gotta start beefing stuff up to take it.

.

[iceman]

I wish I took a pic. of the FRPP girdle next to the stock cover. If you see the difference in these 2 items you will know right away that you upgraded and you will be able to understand how much better off that rear end is. I'm not sure It would have helped me with my issues but I am sure it makes me feel better to have it now. I want the tubes welded but i don't think that is as important as the dif. cover on these cars. My tubes didn't spin or warp when i snapped the axle but after going through that I am going to do the right things and I'll have to work up my nerve off the line again as I'd rather sacrifice a little time than have to fix it all over again...although I know if you are racing you are likely breaking at some point so it is what it is and I'll still be racing...I hope more this year - I only made about 10 passes all of 2008.

[gr8snkbite]

i guess i just dont understand how the frpp cover can make such an impact on strength. what does it do differently than stock.

[iceman]

Well the girdle is much thicker and more solid to start with and as Purdue Ranger stated above:

8.8s can take a beating from hell and back. The girdle kills off the deflection that kills axles and gears. The shock from the sudden driveline rotaion causes the carrier to move and bind, that is what caused Iceman's carnage. True here - the axle couldn't turn and the Drive shave and carrier were stronger than the axle so Pop it went. I have a girdle in my camaro and it has seen some violent launches on big slicks on a bottle.

welding your axle tubes is going to help from them sliding out and bending. Remember those axle tubes are just an interference fit.

What I would do is a set of moser axles, aftermarket carrier that is stonger than stock, weld the tubes and throw in a girdle.

I got the mosers because I had to replace one. The stock GT500 axles are pretty stout from what I understand but the nice thing is outside of the welding you can get all this stuff through the BVM store.

1. FRPP Axle Girdle
2. Detroit True-Trac 8.8 Dif.
3. Moser 31 Spline Axles

Then go to a chasis guy and you can have the tubes welded if you want to really secure that area too. Probably a good idea but the last on my list. You could put in a locker if you wanted but I like the true trac because it is much quiter and better on the street IMO.