z28bryan

iTrader: (7)

Have you autoxed before? If not, don't be disappointed if you aren't competitive especially with that much power. If you autox, get the best r comps you can. If you are doing a 9 inch, I would say the aluminum center is the only way to go.

sapper_daddy

iTrader: (12)

Man as far as making a 9" like a 10 bolt...I don't know. I know the 9" is alot cheaper than the 12 bolt. But that 9 makes a lot of noise and that is the reason most people jump to the 12 bolt for the street. If you know someone who has broken the rearend on stock engines, more power to them. I know my pinion seal is leaking right now and I've seen alot of that, but that is nothing. What about a kit to keep the axles from coming out and a set of 4.10 gears? Throw in a cover man and you are good to hook. Then you can get the things you are going to need to stiffin the suspension for auto cross, like control arms, etc. Don't think I have answered anything, but I think the question you asked is realistic, I think a 9" is made for the track and isn't ever going to function like the ten bolt.

trackbird

iTrader: (4)

I broke one in an '89 Formula with a 305 and an automatic??? I had a pretty ugly shift kit in that one and it eventually broke teeth off of the 3.42 ring gear. It surely wasn't making HP. I also "hurt" the rear in my 2002 Z28 running an autocross on 315/35-17's. It was a tight course and we ran it all in first gear where we had plenty of power due to gearing. I believe it was a noisy pinion bearing, but I never checked. I advised the new owner of the noise and he was going to fix it after he bought that car. So, I still don't know what I hurt, but it wasn't 100%.

With that said, I'm going to guess that you'll be just fine with DA's in the rear. You might be fine with SA's, but DA's should cover you and then some. I even have a set or two of DA's that I'm going to part with (rears only) if you need some.

I did use the compression adjuster on my 2002 car, I used 4-5 clicks of compression damping in my car and I was faster when I was autocrossing it. I'm an oddity though because most people don't use the compression adjuster, and if they do, not 4-5 clicks of it.

Shock Hawk

I think you have it backwards. The 12 bolt whines and the 9" doesn't because of some internal pinion stuff.

Exotic Performance Plus website:
"Exotic Performance Plus strongly recommends the Moser nine inch. This rear is even tougher than the Moser 12 bolt, and the horsepower of the late model F Body cars keeps escalating every year, which requires a very strong rear. With the recent introduction of the 6.2L GM aluminum block and the excellent flowing 6.2 litre heads, the horsepower of these cars is going to just keep climbing at a very fast pace.The nine inch will handle the power, plus we prefer the way the torque arm is bolted to the nine inch in the same way the oem rear-end is attached. (This is the only good thing about the stock 10 bolt...) The Moser 12 bolt uses four short bolts to attach the torque arm, and they have a habit of loosening up, even when loc-tite is used. Why the nine inch is stronger than the 12 bolt. The 9-inch has an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads. This seems to be the major reason why the 9 inch doesn't start whining after high rpm clutch dumps, when the 12 bolt will pick up noise.The 9-inch locates its pinion gear lower on the ring gear to improve tooth contact, than the 12 bolt does.The 9-inch has a 0.125-inch larger ring-gear diameter and internal pinion support than the 12 bolt does. This is not much of a difference, but it is worth noting."

My question once again is will the DA's make a 9" (15-20lbs extra) feel like SA's on the 10 bolt?

Shock Hawk

Ok, I'm starting to lean towards the stock 10 bolt.

I'm gonna go with the 10 bolt for a while. I'm not gonna do clutch dumps, so I should be fine. I'm gonna do 3.73's until I break them and then go with 4.10's. Please tell me if 4.10's break easier than 3.73's. I'll get the Koni DA's out back just in case I ever get the 9" or someone makes a 12 bolt that can take the punishment without the whine.

What can I do to strengthen the 10 bolt? I'll get the TR2's or T2Rs or whatever they're called. Do I need an axle upgrade and I've heard something about a T/A plate or cover? What do you guys prefer as far as chassis goes (LCA, T/A, relocation brackets, PHB...)?

coolformula

iTrader: (21)

[QUOTE=Shock Hawk]Ok, Please tell me if 4.10's break easier than 3.73's. QUOTE]


In my understanding they do the higher the number the weaker the gears are espeically in the 10 bolt.

Be nice if they was a bulletproof 10 bolt.

Shock Hawk

Why can't someone improve upon the design? I know it's a highly technical subject, but if someone comes up with one that's better, even just a little upgrade, it has a big market. If it was known to help, I'd buy it at the drop of a hat (or a T-Top).

coolformula

iTrader: (21)

Well you can upgarde the axles (moser) get your the rear end cover etc, but its still a weak design.

its like an house with a bad foundation, sure you can add a room, remodel, but the FOUDNATIOn or platform is still highly flawed for an high HP appilcation.

After you buy new axles,cover,and differential and gears yoru looking at about 1000 bucks I would imagine.

sapper_daddy

iTrader: (12)

man as far as 3.73 or a 4.10, that is a alot of work and money to go to a 3.73, I don't think you will feel it that much. My opinion go for the 4.10s, you are chaning it anyway, what the hell.

Shock Hawk

What brands would everyone recommend? Lets forget budget, but no parts over 1k.

Alex L.

iTrader: (16)

I don't know what your racing history is but my suggestion would be to learn to drive first and only then modify the car as you feel necessary. If you don't plan on winning any races unsprung weight should not really be of any concern to you. Also a trans am is too heavy for any REAL drifting. It would need to be lightened up quite a bit for that spectator sport, unless it's just for your own amusement Having said that you can never go wrong with Konis, they make the car a lot easier to handle in just about every situation. DA's are for people that plan to win races, SA's are for the rest of us IMHO

190 lbs - Moser 9" (3.250 bearing) w/35 spline axles, Strange nodular iron section, full spool, 3:70 gears, no oil
135 lbs - Stock 7.5 rear end w/3.73 gears and oil

Switching rear ends is a pain in the ***, I would stick with the 10 bolt till it blows. If you must do something with the rear end get the T2R zexel torsen I hear it does wonders but not really necessary if you don't plan to seriously compete

subtlez28

iTrader: (15)

I totally agree.
Except, I plan on (and have) won races...and I have S/As.
Plus Strano himself doesn't run D/As. Only so much adjustment is needed, D/As are over kill in most applications (like Alex was saying).

And thanks Alex for some actual weights, I was thinking the 25lb number (diff between 7.5 and 9") was off.

I've spent some time thinking about a rear upgrade, and weight was a big issue(increased ride hieght another). Ultimately I think its mainly drag launches that kill these things, so I will run it till it dies (the 7.5).

Still wondering though, how much weight diff is the aluminum 9" center section worth?

Shock Hawk

Fair enough, I'll just get Strano's combos and get some experience. My only hope is that I don't buy anything wrong if I do wanna compete locally. I know there's lots of rules out there. I wouldn't want to waste money on something like triangulated sbc's if they're not allowed in the race. I'm pretty sure though that most of my competition will be from the local club and not a real championship.

Say, how much do brake upgrades weigh? If I get a C5 conversion or something similar (13" rotors), how much more does it tend to weigh? Is it worth it to get slightly smaller rotors in back? I'm going for solid disks.

Alex L.

iTrader: (16)

Sam knows the rules for most if not all classes, if you are going to do more then just practice runs and actually compete, Sam will sell you parts that are legal for that class. But you have to call him