Heres a question for you guys and gals who know your rear-ends (and drag racing): My goal for my 62 Buick Special street/strip project car is to eventually achieve10.0s in the -mile. The 3,000# car is equipped with a 600+ HP/TQ Buick 464, so it should be OK in the power department. Im concerned about the Mopar 9 & -inch limited-slip (Sure-Grip) rear-end, though. That is, I keep thinking that one or two careless burnouts (where one wheel has significantly more traction than the other) could pretty much smoke the friction clutches or cone. Also, I would think leaving straight would be tougher to do with a limited-slip rear-end than, say, a locker-type. So, wouldnt an amateur drag racer like me be better off with a locker-type set-up? I would prefer to avoid use of a spool since I dont want to turn this car into a trailer-only car. Of course, I would also prefer to avoid running my brand new car into a wall at the drag-strip. Your opinions, advice, etc. will be greatly appreciated. Thanks.
Dan-I used a locker in old orange since 91. That car weighed 4000 lbs or so and the locker worked ok, but it did behave like a spool most of the time, ie: on wet roads, car was always slipping around, you had to really concentrate on holding it straight; it would only occasionally "release" on tight turns and then the car would bang loudly and shudder as though someone just rear ended you. That is just the nature of the beast. it also caused the rear wheels to kind of "push" the fronts on a quick decel, lifting off at 70 or so on the freeway. OTOH-in 19 years of street driving and drag racing required exactly ZERO maintenance and it is as tight today as when I installed it. My point in trotting all this locker behavior out is to point out it was pretty much the same as having a spool. on my current Ford project, the finished weight goal is 3200 lbs, not much different than your 3000. the lighter the car, the less the locker will "work" or release and behave like a posi or limited slip. I am going to just skip the expense and install a steel spool in the Ford, in the lighter car it will behave the same as the more expensive locker. From my experience, it IS an either-or kinda deal-posi or locker. I have seen an air locker advertised which seems slick, but requires an on board air bottle or compressor and air link to the rear axle housing, etc-too much aggravation for me.
Thanks for your response, Scott. I'm surprised at your description of how "cranky" the locker rear end of yours can be... Especially since I didn't feel or hear anything out of the ordinary when we took that short demo ride in old orange. I have heard that they are noisy, though. So, anyone, why shouldn't I just keep the limited slip system I have now in place? Can they be set up to work just as well as a locker during drag strip launches? Or does even the strongest, best set-up, etc. units still allow a certain amount of torque bias to one wheel or another (which can translate into lost time during launch)? Anyone?
The original Detroit Lockers from the 60's 9" Fords are clunky.The newer ones are not as severe,but still have their sounds.If you want an out-of the box unit,I would go with a Detroit Locker.Most posi units need to be set-up a little more aggressively with their clutches to make them last at the track.
Scott, If your locker (power trax? unit ) is banging in the corners it is either broke or installed wrong. Detriot lockers I am not as familiar with so if it is that then maybe but I doubt it is suppose to have that much clunk as the locker units tend to work and stay tighter upon acceleration then in slow turning cruising. Now since you have a 9 1/4 I would assume you have the stock trac lock unit? no preload spring just preload spring loaded clutch plates that keep the preload on the clutch pack??? Yes or do you have a aftermarket Auburn? etc. Or did they use factory Auburns in the 9 1/4 car rears. There are not really a whole lot of good choices for the 9 1/4 rear out there...They do not even sell a full spool for the rear. I think the reason is the main bearing caps for the carrier are thin and weak for racing application. Plus 8 3/4 and Dana really over shadow that rear. For what your doing it will hold a good long time I am sure. You have a detroit locker as a choice or true trac or power trax and no slip which I think are probably your best and cost effect way to get the job done. You much assemble the richmond power trax and no slips in the tolerances given in the instructions or the unit will be doomed to eat itself. This is how most of the products on the market get a bad name. MIS INSTALLATION... Just like ring gear spacer with stock bolts doomed to fail. If you use the right parts and good install technique you most likely will come out on top most every time. Jim
Thanks for the thorough and informative response, Jim. I'm doing a lot of this long distance, so I'll have to contact the car builder/previous owner for specific details. I'll get back to you when I get the info. After all, the more I learn, the more questions I have.
Jim-I think you and possibly others might have the impression I was unhappy with the Detroit locker in the Buick---not at all. When i chose it (1990) the current crop of tru trax and eatons and everything else were still on the drawing board-none of them had been introduced for any rear back then. It is also in a FORD 9 inch rear-the choices were the 9 inch posi units, know to be undependable in high hp or heavy car applications-Ken Duttweiler advised me the ford posi units were not holding up in 400 hp 3500 lb GNs he was building, go straight for the locker or spool, which I did. In 19 years/80k street driving and at least 300 drag strip passes, the Detroit locker equipped, moser axles ford 9 inch rear was the most dependable, bullet proof drivetrain item I have ever had. The "detroit locker" was designed for heavy truck/tow applications, where a lot of weight makes them behave reasonably when turning corners. even at 4000 lbs, the rear axle of my Buick did not carry that much "weight" load, and when it would release occasionally on tight turns, it was a pretty harsh snap. Just a reminder it was back there, working as designed. On my current build, a muich lighter car, I am going to use a spool because it si cheap, light, strong and won't see enough street use to cause an issue. I know Dan fairly well and he is pretty particular, so my original post was to try and inform him how a true "detroit locker" carrier might behave in his 3000 lb car. He had ridden in and driven my Orange car, and had not experienced the locker releasing on a tight turn, as he mentioned, becuase it rarely did it-usually it would just drag the inside tire around on its tread. In my opinion, the only thing beefier than a detroit locker is a spool, mine was that good-and still going strong. But I knew going in how it would behave, so it never really troubled me.
"Particular"??? Why, Scott, that's the nicest term I ever heard from someone describing my "condition" (Especially compared to what my "ex" comes up with).
