LSD?????

[468cibu]

O.K. I want to swap out my spool for a lsd. I would leave the spool in before going to a locker. I asked moser, they said truetrac. I asked jegs, they said auburn pro series. I asked summit, they said a locker (because of my power level). My car has a big block making in the neighborhood of 575 hp. In the future I may use nitrous so when asking , I was looking for something that would live behind 700 hp. I have a moser 9" rearend with 31 spline axles. When researching these lsd units I was not comfortable with either options. Was hoping that asking tech dept. to be given an answer that would strip away any doubts I had, but it did not. I guess I just want to know the opinions of people running lsd's at this power level. What would you recommend and why? My car will be street driven (to cruises,not a D.D.) and go to 1 or 2 track rentals (quarter mile) a year.

 

[big gear head]

If you want something that is going to work well then a Detroit Locker or Grizly Locker would be my first choice. The Truetrac would probably hold up well and be smooth, but might not lock up well at the drag strip. There are some pretty good clutch type differentials available for the 9 inch now, but I don't know if they will handle 700 HP. I've got a Duragrip in mine right now and I'm checking it to see if I can break it. So far it's holding up well. I can tell you that there is no way I would use an Auburn. If you are not willing to use a locker then you are in a bit of a hard situation, because I think that is what would work best. I'm not sure how well the 31 spline axles are going to hold up to 700 HP.

 

[468cibu]

Thanks for the insight, I just picked this car up and it was set up with this rear in it. I would have gone with a 35 spline set up if I was starting from scratch. I'm a little nervous that a locker will not have much better street manners than a spool. I do take the car on an occasional trip down the Taconic Pkwy to go to cruises and shows in Westchester. That Pkwy is like driving on a downhill slalom course.

 

[big gear head]

A locker will work better on the street than the spool. I have a locker in my work truck and I've put over 140,000 miles on it. Other than a few pops and jerks from time to time it works great. I had a Detroit Locker from a '69 Mach 1 in my Camaro for many years before testing the Duragrip and it worked fine too. Just a few pops and jerks sometimes. The Grizly Locker is suppose to be an improved version of the Detroit Locker. It's suppose to have some of the weak parts fixed. They have a $2000 warranty with it from time to time. The Duragrip is a beefed up Traction Lock. It's got a much stronger case and in most cases you have to grind a little clearance in the diff case for clearance.

 

[abigda]

I've had good Luck with my trutrac, I purchased my 9" from Qp setup with 31 spline moser axles and the trutrac for up to 750hp according to them... No issues to date even with the 4 speed

 

[78purplebu]

got a mini-spool in my bu. the only time really bothers me in town. or tight parking

 

[468cibu]

I like the concept of the true trac, but Jegs and Summit led me to believe it wouldn't hold up or launch straight every time. If they would have said truetrac like Moser, it would already be in the car. Now I'm starting to lean toward the yukon grizzly locker, I just don't want to spend all this money and wind up unhappy, or finding myself doing this all over again mid summer. Waiting to hear back from strange.

 

[468cibu]

well, strange just got back to me, they recommend truetrac. abigda, what power range are you at? What rpm are you launching at? Ever have a problem spinning one wheel? How long have you been running that rear? Don't mean to be a P.I.A. Just want to get it right the first time.

 

[355_79bu]

I have the trutrac and like it alot. My car is around 500+ hp at the flywheel (400 on motor+100 shot). It always launches straight spraying out of the hole. And I can also tell you 1 wheel never spins always both. The guy who set up my rear has a fox body with a stroked 351 making over 650 hp and a top loader 4 speed running drag radials. He runs the trutrac in it and beats the snot out of it every time he's in it. He has had absolutely no troubles with it. He switched from the Detroit locker to the trutrac for a little more street manners.

I'd say as long as you are in the 750 hp or under range with an auto trans you'll be fine.

 

[468cibu]

thanks guys, knowing the car will launch straight and have good street manners, I'm gonna go with the true trac. I want to enjoy driving this car on the street, since that's where it is 95% of the time. It'll still be a blast in the quarter, as often as I go.