How to build a badass 8.8?

[FastDriver]

All,

I'm coming to the last few months of my deployment and I'm anxious to build the hell out of my rear end. I want to be able to brutally launch this rear with potentially in excess of 1000rwhp, 1.2X 60's, launching both with a manual now, and off of a transbrake in the future. I don't want to worry about everything staying together or needing to rebuild it in the future. Here's what I'm thinking I need:

Stock 8.8 plus the following:
- Gun-drilled 33-spline axles
- welded axle tubes
- 3.27 or 3.55 gears
- Spool
- 9" ends
- Brace Girdle

Here are my questions/curiosities:

This is a street car and as such going to a spool is a lesser of 2 evils. They're cheap and unquestionably durable, but I don't like the idea of tight turns or parking lot issues. What are alternatives to a spool that are unquestionably durable enough to handle the power I'm going to put down? I like the article I read about the Boss 302s torsen differential that's entirely mechanical. Is that rearend a good one for drag racing, too?

A recommendation I've heard before is taking 1/2" off of each side. What advantage is there to shortening the axles? Will it allow me to put in a bigger tire? How much should I bring the rear in?

What else should I be considering?

Should I reconsider a 9"?

Thanks,

Chris

 

[RangerJoe]

I'm sure there are plenty of guys who have made 8.8s live with that kind of power, but I have always had the understanding that the 8.8 is good for somewhere between 700-800 HP. My father-n-law built a rearend very close to what you are wanting to do. 8.8 with spool, girdle, welded tubes, 9 inch ends and 33 spline axles. He twisted a tube, which led binding and seals leaking. He was making 570hp and launching around 8000rpm. I think his rearend should have held up better, and I don't think that is typical of a rearend built that well. He rebuilt it the same way and has had no failures four years later. But, I think 1000hp is probably pushing your luck. I'm sure someone with first hand experience will chime in.

 

[FastDriver]

That's good feedback, Ranger Joe. Thanks!

 

[FastDriver]

Any reason not to bite the bullet and go with something like this?

Moser Engineering - M9 Complete Built to Order Fabricated 9" Housing & Axle Package - Complete Rear End Assemblies

Would a fabbed 9" still lose more power than a stock 8.8?

 

[tannerc91gt]

Those moser 9's are awesome. Know a few local guys running them and theyll take a beating. Friend of mine is cutting 1.4 60s on a HEAVILY braced 8.8 but with the time and money you have to put in it, personally id go with the moser. He's putting down 650is wheel, 250 shot off the line so it's pretty rough on the launch and he hasn't had any trouble yet. That's not really in the ballpark of what you're talking though. I'd love to know the specs on the motor making that kind of power.
Like i said, all things considered, id go with a shortened moser, gun drilled axles etc and not worry about it. 8.8s are a great rear end but at that level I'd always be worried it would give up the ghost

 

[tannerc91gt]

Btw, I don't see there being much if any additional power loss through the 9". One of the guys I know who runs a spooled one is behind a juiced 6.0 LSx with a T56 leaving at 7300rpm on ET drags. Rear end has never been an issue and he absolutely loves it. I've ridden in it a few times and sharp turns aren't really an issue at all aside from the annoying tire skidding, but you learn to ignore it.

 

[strattoc]

Dont want to whore but will anyways, the tracloc in my car is old and tired, would a spool be feasible in a not 1000 hp or even 500 hp car? I like having 2 wheel spin and my car now will do it if I turn left but if I turn right it will almost come to a stop because just the inside wheel spins. I'm asking from the aspect of price and dependability.

 

[FastDriver]

Dont want to whore but will anyways, the tracloc in my car is old and tired, would a spool be feasible in a not 1000 hp or even 500 hp car? I like having 2 wheel spin and my car now will do it if I turn left but if I turn right it will almost come to a stop because just the inside wheel spins. I'm asking from the aspect of price and dependability.

From what I've seen, spools are cheaper than just about anything else. You can buy them for about a hundred dollars. Of course, you'll need to install it.

I'd love to know the specs on the motor making that kind of power.

First, thank you for your feedback on the Moser 9. It looks like a nice piece, but it's obviously going to be $$$.

The basics are:

Dart blocked 331
AFR 205s
TFS Box R
FTI custrom hydro roller (600 lift)
GT42R-76mm turbo (maybe bigger later)

Peak power so far was done at 14 psi at 762rwhp. I've got a couple of kinks to work out before I go full boost:
- 10% lower compression in 2 cylinders (hopefully just a headgasket issue)
- Seeing too much pressure on the exhaust side
- essentially stock 8.8 (just 5-lug axles and a 3.73 gear)
- Tremec TKO (old school one rated to 450 ft-lbs)

When I replace the rear-end, and work out the motor-related kinks, I'm going to let her eat on the dyno and see if the TKO will take 1000rwhp, which is where I expect it to max out. See my build thread if you want more specifics about the whole combo.

I'm actually starting to lean towards the custom fabbed 9" from Moser. I like the idea of having an indestructable rear. I just wonder if it will bolt up as-is and whether all of the suspension angles are correct with the components I'm using. I think I'll give them a call tomorrow.

Chris

 

[Rick 91GT]

There is no reason a built 8.8 wont take all the abuse your talking about and your on the right path for components.

Basically what you listed was my rear I built for NMRA Drag Radial action: I used the Moser stuff since Im a dealer and could save a little money, there is nothing wrong with Strange (which I can now get) or Mark Williams Stuff.

33 spline gun drilled and flanged axles, 5/8" studs (could also do 35 spline)
9" bearing ends, late model 9" (style will depend on your rear brake set-up)
Lightened spool
Welded tubes
Rear girdle cover
Axle bracing
Front yoke, (not the flat stock like flange set-up)
Spherical Bearings (I run a Team Z relocated upper arm so they feature solid bushings)
I also weld all brackets fully to the rear, and upgrade to larger hardware at times, depends on your control arms.

9" Pro and Cons, quick change important to some drag set-ups, good stronger center sections will cost well over $1000.00 however. When Moser came out with the 9" housing it helped lower the cost slightly since it had all the attachment points. However a cheap 9" using there housing is in the $1700+ range when your done, that is the bottom barrel center section.


Chris, FWIW my rear is 2" short each side, mini tubs, 15" x 12" 6.5" will not have that super tuck drag look, tires come out to look normal but will not hit my rolled quarterpanels. Depends on your exact rear set-up, brake set-up and wheels. You'll need a true rear coil over, not cheap but its the right thing to do, a few extra bars welded in that area between the frame, if you want to add a chute mount that would be the time. The mini tub will allow you to safely put a large tire and the proper width rim under the car and set the car where it needs to be for correct geometry, you will need to trim the interior plastics but it isn't a huge deal. Depending on the rear bars on your cage you may need to revamp the design with the mini tub, not really a big deal and you can add some stiffness that car will need.

I would rather not have a spool on the street since one tire will scuff slightly under power but you dont have a choice on a 33+ spline axle. Tire shake is a killer on axles and the issie with c clip eliminators is the axles is actually smaller at the flange to accomadate them, the 9" ends allow the axles to be large all the way to the large fillet at the flange.

Ive had a MMR TKO900 take 1200RWHP

 

[softballnrd27]

I am having the same dilema as you are, the only difference is I got a 7.5 in mine right now so I have to start from scratch either way. I am leaning heavily towards the 9" bc I have 1 in the garage that I can cut down and swap in for relatively cheap. I have also looked at the Moser Fab 9 housing and axle package to use with my center section and then upgrade the center section later. I just have too many options.

 

[FastDriver]

Awesome response, Rick. PM your phone number and let me know what time is the earliest I can contact you tomorrow. If you were within 200 miles of my car in FL, my car would already be in your shop. We need to figure this out, ASAP. If I got this car to you, you'd have some work cut out for you... that I can guarantee. Have you got a buddy that goes down to races in FL? Maybe with a trailer, he can haul my heap back up to you for a more reasonable fee than the auto-shipping quotes I was getting at the beginning of the deployment.

I don't like the idea of shipping rear-ends back and forth, but I'm not sure if I have any alternative to that working with you. I also would feel more confident with someone like you ensuring that the suspension geometry and components are what I need and installed correctly. Team Z posts on other forums, and I've become a fan in the last couple of days of reading those posts. They seem to have their stuff together, and it looks like they make some good parts. One of the things a Team Z guy specifically stated was that 8.8s above 1000rwhp cause breaks/failures.

As far as which way to go on the rear end, money is not the issue. I don't want to break stuff. Spending $2k twice on the same part is never as good as spending $4k once. When someone asks me what the weak link in my drivetrain is, I don't want to have the answer (kinda like I built the engine). I also don't like building things twice. I'm certain I'll be maxing this turbo out, soon. I might be completely satisfied with the setup or I might choose to try out a 91mm turbo and a solid roller cam in the future. I want to build the rear right today to support it. That's why I'm sort of thinking that Moser 9 looks pretty sexy. It also sounds like mini-tub is the way to go. Think about these things, and we'll chat tomorrow (as long as there aren't any SIGACTs going on in my AO).
Chris

 

[Rick 91GT]

Ill pm you my number later, can't do it in the mobile an version.

Rears are more fun then this lt1 canaries im doing cap, plugs, wires and waterpump in...Damn ****s tight

 

[Rick 91GT]

Chris, try me now if you see this...