347fairless

Here are the torque arm mount pics. He went through the ear of the pumpkin for added side to side strength. Pretty beefy.

347fairless

......

TRex

iTrader: (3)

Well, good to see he used beefy tubing for the bolt holes. I think overall he has enough metal on it, not braced the way I did, but still should work.

Make sure you heat treat it by putting it in an oven and leave it for 24 hours - leave the shaft in and it bolted into the jig if possible during heat treat. I don't have the link here but it needs to be the recommended heat treat for welding nodular iron - google it.

SUX2BU

iTrader: (14)

No offence but that looks like its going to snap the **** off. Did he use the correct preheat and cool down your supposed to when welding cast iron?
Also i hope your using an adjustable TQ arm cause that mount is WAYYYYYYYY off. the front is supposed to be parallel with the rear end yoke. and ui hope he mocked up that mount with the TQ arm ond rear end bolted in the car(i doubtr it by the way the mount is tilted WAY up) cause it looks likr when you bolt on the TQ arm its going to aim twards the right side of the car not straight forward like it should.

SUX2BU

iTrader: (14)

I did not have a huge oven to do the pre heat and cool down your supposed to do and i did not use the correct filler rod. i think your supposed to use nickel something i don't remember. I just used a heavy sduty 480V MIG welder w/ steel .045 wire and Argon gas. Knowing that my welds were going to be weak i went the route of overkill and a **** loab of reinforcement bracing so it would hold and crossed my fingers. if you look closely at my rear end now you can see hair line cracks of where my welds are cracking but since i put so much weld all over it its still holding.
here are som pics of all the bracing and reinforcement i used.

SPANKY LS1

iTrader: (24)

I still don't understand why people try and use an 8.8 in our cars. I've not seen one yet that held up at all. Isn't the reason to upgrade your rearend so that you won't have to worry about the 10 bolt breaking? I'd be just as worried about the T/A mount breaking off (like they have done on virtually 8.8 swap that I have seen) than the factory 10 bolt breaking.

FYI, you could do a 9" for about $1500, and have a rearend that wasn't pieced together and rigged up.

Shawn

SUX2BU

iTrader: (14)

EXACTLY! i belive i was one of the first few people who broke the TA mount off the 8.8 and learned this the hardway and posted up my experience so others wouldn't do the same. but i guess it didn't work.

347fairless

I guess your the only person who is allowed to experiment with an 8.8 and because you had a $hitty first gen design that broke we should all stop the advancement of this rear end and its application to F-bodies.....

Wasn't your design improved upon and fixed by the original designer of your TA mount?

TA Mount was fitted with rear in car. Fits perfect. Setup 3 deg neg.

I will have the car tomorow and already have slicks waiting to go. the builder of this rear wanted to do a custom bottom mounted torq arm that attached to the bottom 4 bolt holes like a griggs torq arm for the stangs. I said no, lets try this first. The cast ear on the rear as to snap for tis tocompletey fail.

SUX2BU

iTrader: (14)

Jeez don't get your panties in a twist. Actually mine was a fifth or sixth gen design. and no the guy never fixed it. Thats why he is no longer making them.

SUX2BU

iTrader: (14)

I guess its just an optical illusion but that looks like ALOT of angle for 3*. i'm just measuring it from the picture you posted but it looks closer to 5*.
I'm not saying it will completely fail right away. But if not welded correctly it WILL crack and the cracks will slowly spread with every hard launch. But you should be ok for a while cause those blistering high 12's probably won't be unuff to do anything.
Let me know how it does when your pulling 1.5 60 ft's in a 3600 lb M6 on a 150 shot out of the hole. thats when mine broke.

347fairless

Just bothered me how you could be interested in the project then sort of bash it. I understand you've been through alot with the rear, but it shouldn't stop others from making it work as you did. It is still cheaper than a 9 inch or 12 bolt and more reliable strength wise than the 12 bolt (once the TA mount is figured out).

SUX2BU

iTrader: (14)

Yeah i guess i was kinda harsh when i saw the pics sorry.
its just a sore subject what i went thru with this rear end.
the only thing that breaks on 12 bolts is the posi. if you were to get a spool in it, that would pretty much make it indestructable.
And welding steel to cast iron will never be as strong as something that is cast iron from the start.

TRex

iTrader: (3)

It is an interesting project because of the lighter weight and higher efficiency of the 8.8 vs 12 bolt.

I would strongly advise you do the recommended heat treat. Welding nodular iron forms large precipetates of carbon in the area of the weld, severly weakening the iron. Heat treating removes these precipitates and relieves the stresses in the heat affected zone. Generally recommended to heat to 1000 to 1200 degrees for at least and hour, then let it cool slowly.

If you do not do this I would not be surprised if the base metal cracks in the heat affected zone.

I would hate to see another one of these projects fail due to skipping this step.

Google on "welding nodular iron" and you will many good references.

347fairless

The rear is in the car and everything seems fine. I abused it tonigt with street tires and will be hitting the track with the slicks soon. I will keep you guys posted.

My builder did mention that the cast iron is extremely pourus. Lots of little tiny air bubbles. He said the areas that were welded were heated with a high temp torch for quite awhile. Basically, the areas looked like "Lava" he said.

glennhl

[QUOTE=TRex]I
I would strongly advise you do the recommended heat treat. Welding nodular iron forms large precipetates of carbon in the area of the weld, severly weakening the iron. Heat treating removes these precipitates and relieves the stresses in the heat affected zone. Generally recommended to heat to 1000 to 1200 degrees for at least and hour, then let it cool slowly.

Wouldn't you worry about warping the housing if you do a post heat treat? The right way would be to weld it, heat treat it, then do all the machining on the housing. Why doesn't someone just come out with a new housing for the center section?

SUX2BU

iTrader: (14)

[QUOTE=glennhl]They have and its called a 12 bolt and 9" specically made for a 4th gen f body.
It's not cheap to make a brand new cast rear end housing.

98_Formula

iTrader: (15)

where? i havent seen a 9" for under 2k...
i'm either goin with a 12bolt or 9" soon, or maybe this 8.8" dependin on how that goes

EPP

iTrader: (22)

If you just purchased the Moser 9" housing and axles, and used a used center center, you could save some money.

I just sent out a Moser 9 inch with ABS/TCS, meaning the axles were machined. It had the Detroit Locker with 35 spline axles and a 3.89 gear. Shipping included to Texas from Indiana, the total was $2,400.00 even. Bob

SPANKY LS1

iTrader: (24)

A) Call Moser or a sponsor that sells Moser products and order a "BP9HP2". It is a 9" package which includes the housing, axles, bearings, T/A bracket, and studs). Mosers price is $985, most sponsors can beat that price.

B) Option A- Find a complete, used centersection on Ebay, Corral.net, nmraracing.com, hardcore50.com, etc. Usually can find a complete centersection with good parts in it for $300-$700 depending on usage, parts used, etc. Complete rearend ~$1285-$1685 when combined with above package.

Option B- Piece together a complete 9" centersection using new parts off of Ebay (need bearing/seal kit ~$80, spool/posi ~$100-$300, gear ~$100-$150, carrier ~$25-$300, yoke ~$100, pinion support ~$30-$120) All prices vary depending on name brand, quality. For example, a $25 stock 9" carrier would be strong enough for 95% of the cars on this board, and guys usually give them away when upgrading. So, complete rearend would run ~$1400-$2000.

Option C) Shop around and buy a complete centersection from a vendor/sponsor. Many complete centersections can be had assembled ready to go with good pars in the $500-$1000 range.

Shawn

TRex

iTrader: (3)

No doubt it is the way to go for high horsepower cars. However, for cars that don't need it, it is a lot of extra weight and efficiency loss in terms of hp at the wheels.

I could afford anything I wanted, I built an 8.8 purely for the efficiency and light weight. My car is never going to be a 10 sec car. 400 rwhp is as high as I intend to build it, and 12 bolt or 8.8 is fine for that power level. 8.8 is lighter and more efficient than a 12 bolt, so that's what I decided to go with.

FYI