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band1t
02-25-2011, 07:55 PM
ok this may not be the form for this but
can you make a 10 bolt rear just as good as a 12?

would love to put a vette independit rear end under the car but dont think they make a kit for a F Body YET!!!!!

the project is a 1979 TA

formula
02-25-2011, 10:14 PM
well, no, that's why people build 12 bolts. but you can make them a lot stouter. what are your plans for the car? especially hp and tq plans

BonzoHansen
02-25-2011, 10:30 PM
you can make a 8.5" ring 10 bolt plenty strong. weld the tubes, upgrade to 30-spline axles & posi

robsquezn
02-25-2011, 11:07 PM
well id say u can i dont know as mutch about the protouring stuff but we built a 8.5 10 bolt becuse someone told us it could not be dune it was in a g-body small tire race car the car ran 8.50s @157mph a hole lot off times & after 3 years is still in the car & it has not been touched i have a 12 bolt in my 66 impala that has also been in the car for o 10 + years that has well over 300 passes on the street & track so id say eather one can do the job in my eyes.

MonzaRacer
02-26-2011, 04:21 AM
OK so some say a 12 bolt cant be as strong as a 9 in Ford, or a 10 bolt cant be as strong as a 12 bolt but with proper setup and quality parts even a 7.5 10 bolt and 7.625 10 bolt can take a considerable amount of abuse, then addition of upgrade axles make any rear end usefull in power produced application.
If Corvette applications couldnt handle power would Lingenfelter (sp) be able to put down as much power as they do?
My buddy has had a 12 bolt in his Super Pro/Pro Gas class car for nearly 20 years, yes its been in the build/race stage since 91 or 92, not always racing but he has put some serious power to it and it hits hard with a transbrake, He first started with a good 12 bolt center, dome tubing tuned down and pressed in to tube holes, welded all around, aftermarket axle flanges and Strange axles(not my first choice but now running Moser). We install a set of Competition engineering billet carrier caps, and I believe now he has a preload cover on it too. since he run Pro Gears it has had a few different ratios and suchas he switched tire diameters also.
similar upgrades can be done to Corvette diffs. Big thing is the IRS or axles wont take as much as the center section will.
But the ring gears and center section can handle several hundred horsepower.
I remember Bob Joyseys Camaro would rune like 9s or 10s in quarter mile, stnad on back bumper nearly as well as figuratively in the 10" or 10.5" street racing classes, NMCA I believe. These were some of the big guys who used leafs and pinion angle to dial in track bite. Not sure which traction device they used but it worked, I still have a mag with a pic of that, blue I believe, Camaro nose high.
But an 8,5 10 bolt is said to be as 90% to 95% strong with appropriate parts as a 12 bolt.

Nothingface5384
02-26-2011, 02:34 PM
my 10 bold has 30 spline moser axles that are boltin(71-72 buick skylark/oldscutlass only) 3' axle tubes with 3/16th retaining plates..it'll take w3hatever i'll throw at it and then some with my future build, also have a ta diff girdle

clips will be a lil weaker for drag and i would imagine g-body/s10 versions would be too due to the 2 5/8? axle tubes

you can get bigger spline axles for a 10 bolt but youre limited to spools/mini spools unless you can figure out how to put a 35spline wavetrack for a 12bolt into a 10bolt housing haha..

as for the 12bolt or even 8.5 c-clip moser sells housing ends to put a torino bearing ends to use a bolt in axleshafts..
can go up to 35spline for posi for 12bolt..probably same for locker...and sure larger with a spool/mini spool

Nothingface5384
02-26-2011, 02:37 PM
ps i know guys with stock 28spline 71/72 bolt-in axle housings in the 10s and 11s(tubes are welded on majority and new bearing kits though)

newmexicosaint
03-17-2011, 04:12 AM
keep in mind that on a 8.5 10 bolt rear end that the pinion gear is exactly the same size as a 12 bolt and the ring gear is what is different. the ring gear in a 8.5 is only .375 or 3/8" smaller in diameter which is virtually insignificant if you use quality gears. Second thing is that typically the axles are the weak link at 28 splines. The axle upgrade is enough to handle what 90% of us are going to throw at it. The "weak" persona a 10 bolt has is largely a myth. If you have a 8.5 10 bolt and are on a budget spend your budgeted dollars on upgrading your 10 bolt and save some money.

sam 74
03-17-2011, 05:11 PM
in my 74 Cutlass i used the 8.5 10 bolt for a while, i did all the usual mods welded tubes support cover with braces new bearings carrier and gears, it lasted about 5 years with 650 lb ft. of tq, and nitrous, with slicks at the drag strip. when i finally upgraded to a 9 inch i found out that the axle splines twisted into the carrier and i couldn't remove the axles.

newmexicosaint
03-17-2011, 06:08 PM
Wow! interesting and impressive in a wierd sort of way. That gives a whole new meaning to 'bend but not break'

sam 74
03-20-2011, 08:19 PM
yeah it was interesting, we had to use a sledge hammer and a wrist pin to hammer out the axles, definately one experience i'll never forget, hitting on my car with a slegde.

Rod
03-20-2011, 08:30 PM
yeah it was interesting, we had to use a sledge hammer and a wrist pin to hammer out the axles, definately one experience i'll never forget, hitting on my car with a slegde.

ha ha ha h a ja ha a sledge is a great clearance tool, trans tunnel, wheel wells, you haven't truly enjoyed your car till you have had to wack a panel outta the way to keep racing!

AusFatty
05-06-2011, 03:37 AM
This is great news! Previously I was told a 10 bolt can only handle as much as 350 to 400 HP max... so I was looking at 3 to 4 thousand bucks for a new rear. I just got a price for a posi, gears and axles at $1600. I'd call that a saving...

BonzoHansen
05-06-2011, 05:10 AM
By 10 bolt we are talking 8.5" ring gears found in 2nd gen Camaros, Novas and others. Not the 8.2" ring gears found in 1st gens. I'm not sure I'd put $$ into an 8.2".


12 bolt has better resale cache as well. Having the likes of speed tv hosts unfairly slagging 10-bolts on the B-J auctions does not help. That is the only reason I am considering one for my 67 - damn housing will cost nearly as much as an 8.5" build.

moreHP
05-06-2011, 09:20 AM
When you are talking about spending the money to put aftermarket parts in the rear diff you need to realize that the prices may not be all the different from a 10 to 12 bolt. Axles usually cost "X" amount and it doesnt matter what spline or length until you get into the big aftermarket carriers. For a factory style set-up you will pay just about the same for a good posi, axles, bearings, hardware and the labor to assemble whether its a 10 or 12 bolt. The 12 bolt will indeed be stronger than the 8.5 10 bolt but if you have the 10 bolt housing that fits the car then use it unless you have access to a 12 bolt housing to use. From what it sounds like, you are not going to be doing anything all that wild with the car forcing you to go "big".

BonzoHansen
05-06-2011, 10:18 AM
right, the cost difference is essentially the housing - for a 2nd gen add a 1 or more to the front of the cost of a bare housing. I'm sure 1st gen ones are nearly as high despite being more common. point is if you already have an 8.5 it'll take a beating.

Nothingface5384
05-07-2011, 05:07 PM
mines very stoute with 3/16th thick retaing plates, moser bolt-in 30 spline axles shafts, ta aluminum girdle cover and ofcourse a posi..trutrac

mines a 4link version and will be platny strong for the 10s and 9s..

since youres is leaf spring, just for the big bearing torino ends for youre 8.5 throgh summit, get bolt in axles(better ten clip with elimintors) a girdle to help with r&p deflection and you'll be golden..

Only way i'd consider to upgrading to a 12bolt is if my current setup breaks..which i doubt it will at any point down the future..or if my project car had a ****ty 7.5 or 8.2 rear

ps..onlything i live about the 12bolt is the option for a wavetrack diff.
But I hear they're considering on making a unit for the 8.5s now.
I emailed them to atleast make it for 30 spline and hopefully for 33spline :-D

Nothingface5384
05-07-2011, 05:10 PM
oh and look up jdrace.com monzaz/jim is a great guy and most likely can beat anyprice

Nothingface5384
05-07-2011, 05:13 PM
This is great news! Previously I was told a 10 bolt can only handle as much as 350 to 400 HP max... so I was looking at 3 to 4 thousand bucks for a new rear. I just got a price for a posi, gears and axles at $1600. I'd call that a saving...

not exactly sure what the common c-clip chevy 8.5 can handle but alot of 71-72 buickskylark/olds cutlass boilin 8.5 handle 10s pretty easy with just welded tubes.

but adding moser torino style bearing ends with moser custom bolt in axles and youl'll be at the same strengh..probably better since thre torino ends are bigger? then the buik/olds

chicane67
05-09-2011, 08:15 PM
Whom ever says that you cannot make an 8.5" as strong as a 12 bolt (within measurable debate)... is mis-informed. Greatly, mis-informed.

What exactly what are we saying the argument actually is ?? The whole premise behind the idea of the 12 bolt being stronger is the diameter of the inner pinion shaft and the size of the inner pinion bearing itself. The 3/8" in ring gear diameter is somewhat trivial in this debate, so I wont even get into that argument. The thing is, the 8.5" and the 12 bolt both have the same pinion shaft diameter and utilize the same inner pinion bearing. So therefore, for sake in this argument, the strength is nearly the same... within some infinitesimal amount.

The weakness in the 8.5" however... is the carrier journal diameter. When you get into larger axle diameters, say the difference between the 28 and the 30 spline, this is about where you max out the ability of the 8.5" verses the 12 bolt. But up to that point, they are nearly identical.

For some other supporting evidence... just look up Ken Duttweiler and what he used to throw at Buick Grand Nationals back in the 80's and early 90's. 7 to 800 hp, on pump gas (even long before there were such thing's as "blower" or "turbo" pistons), on the street... and 1500+ hp on good petrol, that would run in the 9's all day long... and that was back in the very late 80's / early 90's. That would be equivalent to a 7 second street car now-a-days.

So to say that an 8.5" isn't strong or isn't as strong as a 12 bolt... is somewhat a mis-informed opinion. At best.

As previously stated, welding the tubes to the housing... changing the housing ends and axles out to a press on style axle bearing... utilizing studs on the main caps or even stepping up to 4340 main caps... and proper set up, you can built an 8.5" to withstand an amount of abuse unthinkable.

Just stay away from Moser axles... or their entire product line all together. Just my opinion, but what the hell do I know ?