Well in my GTU I have LSD, from what I read only GTU's and Turbo's have LSD. When I do burnouts, Its always two solid marks, so I belive I have LSD so how can I tell wich rear end I have?

GXLs as well

Chances are 100:1 that it's a 4.10 ring gear.

you can mark the pinion and spin it. the driveshaft on the 4.1 wil spin 4.1 times to the wheels 1. chances are you dont have lsd either. you can check it in the air



mike

how can I check lsd in the air?

use two jack stands like mine is currently on. I have an 88 TII with lsd. https://www.nopistons.com/forums/pub...DIR#>/wink.png

i kno that but what do i do just rotate a wheel and one shouldnt spin the opposite direction?

correct, provided the car is in neutral. ... with enough resistance on the pinion the other side will turn in the opposite direction, it also depends on the condition of the diff (clutch wear, fluid etc)



the LSD's have a tag on the filler hole plug that says LSD fluid only, unless it's been removed.

ok, well when i turn one only one turns foward. the other just sits there, and if i turn the drive shaft and hold one wheel the wheel that is being held kida kicks.



But can a car that doenst have lsd do a two wheel burn out?

if the other just sits there with the car in neutral, when you turn one, you likely have a standard differential, because this would require differential action for it to happen, the pinion and side you are turning are rotating, and the other wheels side of the differential is staying still, which means... no clutches are introducing significant friction between the two sides of the differential (or they are seriously worn), it's most likley you do not have LSD.





and yes, you can get both wheels spinning with a car that does not have LSD if they both have similar levels of traction and you dump the clutch.

That just doesn't sound right. My truck for example is what we call a "one wheel wonder". U just simply can't get both to spin. Not if it's wet. Not in mud. Not in the air. Not even while turning. (differential effect) I'm definitely not an expert on this, but I've always thought that if it wasn't LSD, only 1 will spin. (with the exception of a "true posi-traction" unit)



I also heard that all FC's were LSD's. The only differences were the ratios. (4.1 vs. 4.3) I have a base model SE that I would think is LSD. Both wheels spin together very easily. I am 3rd owner & I know pevious owners didn't change the diff. I have never had it to spin only 1 wheel @ a launch, whether soft or hard.



Aight, just so I didn't feel stupid by posting this, I found something to back me up. If U have a Haynes, turn to page 27. (this book covers all FC's...i.e. S4's, S5's, turbos, etc.) Under diff. lubricant, it says LSD(all). Correct me if I'm wrong, but doesn't "all" include S4 & S5 SE's, TII's, verts, GXL's, GTU's, GTUs's, and whatever the hell else I may have left out?

1: not all FC's have LSD

2: I've been in cars with open diffs that would light em both up, I've also been in cars that would not, this depends on a great number of variables... tire differences, IRS or not, weight distribution... these are all variables a LSD has more immunity to regarding getting torque to both wheels, where a standard differential will generally end up putting all the torque to the side easiest to turn.



My coworkers truck, a piece of **** ford splash, can get them both spinning if there is a passenger in the car of similar weight to him, and no offset load in the back (or if it is offset, preferably on the passenger side).



when you have no LSD or other torque sensing/directing device, it is more difficult, but certainly not impossible to get both spinning.



I've done burnouts and donuts in my FC with the open diff, it just takes a bit more effort to do. I had LSD initially but broke it doing 2nd gear donuts, then picked up a open diff from a S5 GXL in the junk yard (LSD is an option on this model) and ran that for the rest of the summer. Now another 4.1 LSD is going back into the car, it certainly is annoying to only spin one wheel in most WOT turns.



LSD is certainly better though https://www.nopistons.com/forums/pub...#>/biggrin.png



BTW I've also ordered diffs from mazda dismantling and every time requested an LSD, most of the time they shipped a open diff and had to send another out, sometimes multiple attempts required before they managed to get an LSD to me. It seems like the open diffs are far more common.

ok, where can I bet a GTUs rear end? or just the 4.30gear and diff?

Racingbeat.com

Mazdatrix.com

Rx7.com

They all sell the 4.30 final drive ratios. They are around $400 - $500 for the ring and pinion gear ONLY. I'm sure you can expact at least another $300 to have it installed. Not worth the money, IMO.

Yea, well when I get more power and need a Diff I might consider it well untill then I am cool, well right now at wot in corners i dont burn up the inside wheel, even on hair pins like turn 11 at sears point raceway.

That happens to be the same truck I have. Well, not a Splash, but the same thing. (all 2WD's had 7.5 rears) I can nail the throttle on my truck and the passenger wheel will sit there and spin. I don't even have to power brake it. (needless to say, it is modded out the watusi) No matter how the weight is distrubuted, the driver's side WILL NOT SPIN. It sounds to me like your coworker INDEED HAS a 7.5 LSD. Ask him and see. If he doesn't, that 2nd wheel isn't lightin' up. This is my 3rd Ranger and my brother has 1 as well. 1 of mine was LSD, the other 2 were not. The LSD (8.8 4X4 BTW) was the only 1 that would spin both. It's not IRS. The tires are the same. There are no other factors. It just won't spin.



Back when I considered a V-8 swap in this car, I visited Grannys Speed Shop, who are notoriously involved with the RX-7 swap. They told me all 2nd Gens. were LSD. Aight, if my SE isn't LSD then why do both spin together so easily? If it don't have to be LSD to spin, then what would be the difference in an open differential and an LSD?

I believe there is a difference in how it affects handling, in the corning power etc. Not just power distribution from a dead stop.

its because your truck has a solid axle. the engine torque tries to lift the passenger side of the diff, since on your truck the wheel is connected to the diff it can lift the right wheel and push the left one on the ground. thats why a solid rear will always spin one tire if it doesnt have an lsd.

the fc on the other hand, does not have the diff conected to the wheel. so it cannot pick up on wheel. thats is why they both spin on an fc, no matter what.



mike

my 89 GTU did left two strips but i was dropping the clutch at 8k rpm https://www.nopistons.com/forums/pub...#>/biggrin.png

And i thought i abused my vert. Hardest ive went is 6k. If i went any harder than that i'd break something.

you have no idea how much i abused that GTU. it is still going strong! a friend saw it at the drag strip in PA https://www.nopistons.com/forums/pub...#>/biggrin.png



my old TII is gonna be running again too. i have owned too many rx7's https://www.nopistons.com/forums/pub...1047683785.gif

he doesnt have LSD, I know the truck pretty well... we were friends before we were coworkers.



do you need me to get pictures and/or movies ?



my other coworker has a turbo volvo wagon with a solid axle, he's volunteering to do a burnout with both one wheel and both wheels for your viewing pleasure.



he also has a grand prix gtp which does brunouts with both wheels, I can go to the parking lot and get some pictures. if you think there are no other factors, you should get a clue.

Well the guy at my shop looked at my diff and said either the clutch in the diff is loose or its a torsen, either of thoes two factors can make only one wheel spin when you turn it.

thats true, the best way to spot an lsd is to take it apart, but they only put lsd's in the gtus and turbo in 89 so unless they built it wrong (very very rare) or its been swapped at some point its open



mike

actually, I just remembered I already have pictures of the volvo from the splash doing a crazy burnout at a busy intersection:

http://pengaru.com/~swivel/volvoburnout/



thats both wheels, yes sir. https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

I wasn't lookin' for an arguement here. I guess I was just applying what I seen my truck do to the car as well. Mikes explanation helps. I didn't know all that "connected to the diff." stuff. Still though, with his explanation, I don't see how your old friend's truck spins both (without LSD). He said a solid differential will spin only 1 tire if it's not an LSD.



I'm not sayin' he can't get both to spin. I'm just sayin' that if he can, he has an LSD unit. (or a barnyard locker....very dangerous)

impossible to do a two wheel burnout without LSD?



what ever happened to where theres a wheel theres a way?

Don't a lot of burnouts use LSD? https://www.nopistons.com/forums/pub..._DIR#>/dry.png

Say again....

well it certainly is easier to get a burnout going with the help of LSD...



but if you have a open diff, it will make it easier if you back the drivers side tire over some water before you start https://www.nopistons.com/forums/pub...IR#>/smile.png (or antifreeze) and getting a passenger in the car...