I know I'm on borrowed time. I've heard of people breaking the spider gears in their 12bolts and I didn't want to go through the hassle of fixing it when they break.

I wanted to know how hard it is to put in a 9" into a 3rdgen. And if anyone has broke one. ring and pinion or spider gears.

Thanks in advance.

551RWTQ?

What does that equate to... 675 at the crank?:sillylol: Not on those mods bud. Maybe with supercharger cranking 15lbs boost. Are you sure that wasn't 351RWTQ? That would put you around 430 at the crank - which is a little more realistic.

Anyway. Putting in a 9" is just like a 12 bolt. No different - several aftermarket companies offer both choices - bolt right in.

HAHAHAHAHAHA
Thanks for the reply and the bs flag. Your fookin hilarious.

It was on a dynojet last summer in midland virginia. She pulled 267/356 on motor and 361/551 AT THE WHEELS on a 100 shot. Don't be skerd.

I think you have the dyno numbers backwards, the numbers are always less at the wheels than at the crank due to parasitic drag from the tranny/rear end.

Actually Redbird, You read it wrong, the lower numbers were on motor alone, and the larger numbers were with a 100 shot. Both measurements taken at the rear wheels on the dynojet.

I'm not going to agree or say BS. Anything is possible. I know a guy that ran a 13.00 in the 1/4 on a stock ZZ4.

And his first set of numbers I would say is correct. His setup is similar to mine, and I dyno'd at: 271 HP and 349 Ft/lbs TQ My 1/4 mile time and MPH is very close to his as well. (13.5 @ 103)

Sounds like I need to get a 100 shot....

It's the launches that kill them!!! If you have total traction off the line w/ drugs, your causing the case to twist which causes the pinion & ring gear to seperate. Sooner or later it's going to pop, and I'll put money it will pop off the line.

They make re-enforced covers with weld on axle brackets to keep the twisting to a minimal...
A good aftermarket posi will have larger, and hardened spider gears. I think the Auburn's comes with spider gears that are 30% larger than stock.

Out side of that, get ready to shell out around 2 grand for a 9", 12 bolt, or the 10 bolt 8.5" that is preped to drop right into a thrid gen.
I like the 8.5" personaly...You can beat the **** out them, and replacment part are cheap & easy to find...

Ron

ronterry, where can you get the 8.5? I haven't looked into that yet.

Would it help if I posted my dyno sheet, or would you guys just say it was someone elses? A shot of n20 will give you HP. But you see the most improvement from the TQ. Have you ever seen the power curve on a dyno sheet for a sprayed car? You will get almost 2x the amount of tq then what HP jets your running. Like me, I'm jetted for a 100 shot. I get that and an additional 200 TQ. Ask some of the guys in the power adders forum.

I'm not going into the 551RWT, But with that much torque and the Nitto's whats your 60ft time 2.5, at @90mph, due to MASSIVE tire spin. With 8.50 /1/8th mile times, you probably don't have to worry much. Now get a set of sticky tires and its sure to grenade. I have made about 15 passes low 8's to high7's in the 1/8th, and my 7.5 26 spline axles are doing OK, I can't say good because I haven't checked them. They haven't let loose though.

John

Here's you go http://www.amazingmechanical.com/rearend.htm ...

No, I believe you on the N2O. Looking at the numbers your lacking higher RPM torque? Since your HP number are much lower, I would go with a cam with more duration, which will move the peak torque upward of 4500 or so. That will give you much more HP. Of course it will need to breath up to 6000grand, or even 6500 for some killer HP.

If you had 551 @ 4500, your HP at 4500 would be 472!!! And of course that will be even higher @ Red line(peak HP)


Just crunching number I bet your current set up has a peak torque around 3441 rpms or so, and drops off like mad???

Ron

<b>12.45@109 w/o the cam or tuning</b>
is that before a ZZ4 cam or what cam?

Your sig mentions you have stock TPI. I didnt know Stock TPI could be pushed so far?

just curious.

about rear ends, our 10-bolt is fine as long as you never hook. start doing 1.8 60' or better and it gets dicey.

I can beleive your #'s with those times, but only if you insist you have tire spin till 90+ MPH. I have the same problems, and the same times, with much higher HP numbers even.

I run 12.5-12.8 @ 117-119 MPH with a 2.2 60' time. No juice, just 9 PSI of boost.

Thanks for the link.

King,
The TPI is stock plenum w/ the egr wall removed, stock runner, stock base. Its amazing what a 100 shot will do.
My peak tq is as soon as I hit the button at 3,1XX rpm. It hooks pretty good at the track. 1.85 60' I can spray in 1st at the track, but it takes a while before I can go WOT and it engauges. I can spray in 2nd on the street. (good weight transfer)

The cam is a CC306 (lt1) 230/244* and .544/.576 w/ 1.6 rockers
I can't complain to much about how the car is running.

I think I broke a tq arm mount yesterday though. It's making some really good banging noises now. Its not the tranny mount, it feels a lot different. I'm going to check it out tonight.

I love how quick people are to call BS on a combo they don't know anything about.


500+ ft/lbs of tq on a 100 wet shot isn't too uncommon.


Average rwtq gains for a NX wet kit is the advertised hp * 2, ... I've seen everywhere from 280-310 rwtq added from a 150 wet shot (NX)

I dunno if you're still considering the 8.5, but generally people say it won't work.

It doesn't have provisions for the torque arm. Neither do 12 bolts or 9"-s, but the difference is that you can get either one of these setups with the bracket pre-welded on from companies like Strange and Moser.
If you're going to go through the trouble of converting a 8.5" 10-bolt for a third gen, you could as easily convert a junkyard 12/9" which would stand up to the power better.

BTW, I totally believe the torque #'s. As 12 sec GTA said, N20 add tons of trq.

I dont know where all the 12 bolt problems came from I havent seen many. My truck has over 300,000 miles on the rear end (Not BS) and the engine is a 406hp/425tq at the rear wheels, solid camed 355 and it hasent given me any sign of fatigue. fNord 9's are just as prone to failure but fixing them or poping a new gear sets in is sooooooo easy thats why racers use them no other reason. H&ll If you want a bullet proof rear end nothing beats a 14 bolt, thats what I got planned when I swap in the BB 402, 4.56 ratio 14 bolt, N20 feed 402 and still a 3 speed on the tree.

Free Bird I say you settle this at the track on motor with Dyno Slip in hand

We could do it at the new spot shoot it would be right in the middle of both you two

The "BS" flag was raised because there was no mention of a 100 shot in the orginal post.

I can't believe that everyone here is ignoring the fact that this guy is running a 230/244 cam with a stock TPI. That is the worst match of a cam to intake I have seen in a long time. TPI = lowend torque with no high RPM power. The CC306 was made for upper end power. You would definitely get better numbers with a smaller cam. The TPI ran out of breath 1000rpms before that cam begins to shine. I know - I'm running a 230/245 cam with a MiniRam

Tim

Yeap, It's like a 2 barrel on a blown 502????????

Ron

This is true, but when the cam was installed there was supposed to be an LT1 intake to go along with it. Unfortunately there were some complications (I'll let Free Bird chime in with some answers) with the intake and it never made it onto the car.

IIRC, there is a Stealth Ram very near in the future

Ahhhhhhhhhh - that makes perfect sense now It will be interesting to see how the CC306 works with the StealthRam.

Tim

It's apparent that you'll be thrashing your car through the quarter mile so my suggestion to you is to DEFINITELY get your self a stronger rear. I myself went thru this already 3 new ring and pinion setups and auburn unit isn't cheap might as well save your money and get a bullet proof rear. But one thing that I can say is that my last rondevous on my 7.5 fitted with Auburn posi unit and richmond 4.10's held up to regular beatings at the track to the tune of 1.5x 60'ers. But recently well a few months ago she gave up the ghost and it wasn't the ring gear which it usually was for me but to my surprise it was the spider gears.......So I am in the process also of getting a bullit proof rear myself.....So do yourself a favor and start saving!

Thanks for backing me up Jeremy (Poorboy). I'd be more than happy to make a trip to the new spot and bring my dyno sheet. But there will be a little money on the line. Gass ain't free.

I do plan on a HSR in the very near future. I really want to order a TQ arm soon but that won't give me another 50 hp. Its very tempting. The doesn't run all that bad considering it is one of the worst miss matches in the history. Then just save up for the heads.

I was originally planning on running an LT1 intake but that didn't work out as stated earlier. I'm hopin to make a pretty good pass on the juice w/ some tuning. Anyone want to take a stab at a 1/4 mile time.

If you can hook it at the track then I would think somewhere around 11.7. Just my guestimate. The torque is very impressive but you still have only 360rwhp.

Tim

I think with the TPI on it and as it is running right now you are looking at a 11.9 - 12.1 ETs.

I definately think you should be looking into a rear. A nine incher would be nice and so would a 12bolt. I think either way its going to stay together a lot better than the ol' 10bolt.

On the other hand, i dont know a lot about rears

Thanks for the replies. I hope I can hit a low 12 as is. I can't complain about that. When you figure its a stock l98 motor w/ a cam and a shot.

Poorboy - I'd like to come up and make a pass or two on a 150 shot to see if the pump will hold up. I'm still burning rich as all hell too. My eyes can't take it anymore at stop lights.

Marc - you up for a run? What r u doing this weekend?