LSD swap?

[Grandprix1]

So I've been told these cars 02 Grand Prix GT have open diffs. How ever when the car is on and lift and you spin the front wheels with your hand it acts as an LSD (wheels spin opposite of each other). When you spin the tires something seems to click and both spin (which is something an LSD would do) can anyone confirm this? If it truly is open then would it be cost efficient or even possible to do an LSD. Has it ever been done? How hard is it to do?

Grandprix1

 

 

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[digitaloutsider]

You don't have an LSD.  What you're describing with one wheel turning backwards when the other goes forwards is how a differential works. 

 

Unless you're really serious about autocross/dragstrip performance, I'm not sure what you'd be gaining from the cost of an LSD.

 

There have been different vendors peddling LSDs on-and-off over the years, but the only ones that are worth a shit are the Torsens (GMPP #88958682) and Quaifes (QDF18B), however both of them are long out of production. Quaife appears to be willing to build them again, but last I heard they wanted 30 firm orders to put them into production once more.  If companies like ZZP and INTENSE aren't willing to pony up the cash for 30 orders, I doubt you'd find 30 people willing to drop $1000 on one, either.

 

Your best bet is to wait around and see if anyone throws a used one up for sale, but expect to pay at least $1200-1500.

[RobertISaar]

You don't have an LSD.  What you're describing with one wheel turning backwards when the other goes forwards is how a differential works. 

 

 

to be more specific, that's how an open differential works. if it were limited-slip, they would both turn the same direction.

[vipmiller803]

A non-preloaded gear based LSD (torsen) would also rotate the tires in the opposite direction. A clutch based lsd or a pre-loaded gear based lsd would rotate the tires in the same direction if you're in neutral, or not at all if you're in park (assuming you do not have the strength to overcome the preload).

 

Either way, remember that the price mentioned above is for the unit alone. You gotta go into the tranny to get to it as well.

Edited February 27, 2017 by vipmiller803

[Grandprix1]

Ok I didn't think they were that expensive maybe 3-400 tops. I've heard they are a bit better then open diffs in the sense that if one wheel starts loosing traction power gets diverted to the other wheel that has more traction unless both wheels don't have traction and then your screwed. I think what I've read about open diffs is that if one wheel starts loosing traction most of the power is then diverted to that same wheel. Correct me if I'm wrong. Car just turned 44k miles gotta do something for it.

 

 

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[GabsOlds]

.....Car just turned 44k miles gotta do something for it.

 

 

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Take it for a detailing.

[Grandprix1]

Why spend money on that when I detail myself lol. I bought a rear strut bar to go along with the front so that will do it some good.

 

 

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[digitaloutsider]

Spend money on good sticky tires, new sway bars, better springs, etc before you throw down money on an LSD if you're worried about traction that much.

[redgrandprix]

 

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[GabsOlds]

If you have money to waste, waste it on a car wash.  An expensive one. 

[Nas Escobar]

I'd just get a steak somewhere

[redgrandprix]

That lsd is going into a turbo gxp with sheetmetal intake and a 4t65e counting around 8k in parts on the trans

 

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[jimmyfloyd]

 

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That lsd is going into a turbo gxp with sheetmetal intake and a 4t65e counting around 8k in parts on the trans

 

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You are talking about the picture you posted? That looks like a piece that just locks the axles in an open diff together? If so, that's NOT a LSD, that's more akin to a welded Diff. An LSD will allow both wheels to put power to the ground, but does have some ability to let them turn separately. A welded diff has the axles connected all the time, 24/7/365, moving at the same speed. You'll be able to spin the front tires, but in a FWD application, when the tires steer the car, and therefore may go at different speeds, you'll just chew up tires faster and may make steering worse. 

[vipmiller803]

That looks like a piece that just locks the axles in an open diff together

It isn't. That's an lsd.

 

Also, rear tires drive different distances during turns just like fronts. Has nothing to do with whether it is a steering axle or not.

Edited March 2, 2017 by vipmiller803

[digitaloutsider]

There is zero chance one of those would find their way into my transmission. "Traction Concepts" seems to just be the new name for Phantom Grip.  Look up Phantom Grip reviews on Google and check out all the satisfied customers.

 

Edit:  Good explanation of why it's junk: http://mycomputerninja.com/?p=440

[redgrandprix]

I would say its a typical enternet item. Those who hate it, those who swear by it. For a daily this probably isn't the best idea. For a car that will see track time and be maintained properly could be fine. The owner of the gxp thats being used on runs his own performance trans shop. Several people on here have used similar products some issues some not. Theres just variables

 

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[RobertISaar]

phantom slip?

 

I believe the Engineered Performance limited slip unit is somewhat similar, but I've heard far less gripes about it.

[digitaloutsider]

Jeff's LSDs are clutch-type I believe. He seems to make good stuff.

[RobertISaar]

i guess they are... I must have been thinking of a different unit, I was talking with someone about how it had a brass or bronze sacrificial surface,  supposedly working really well.

[Turbocharged3800]

You are talking about the picture you posted? That looks like a piece that just locks the axles in an open diff together? If so, that's NOT a LSD, that's more akin to a welded Diff. An LSD will allow both wheels to put power to the ground, but does have some ability to let them turn separately. A welded diff has the axles connected all the time, 24/7/365, moving at the same speed. You'll be able to spin the front tires, but in a FWD application, when the tires steer the car, and therefore may go at different speeds, you'll just chew up tires faster and may make steering worse. 

most of those are metal on metal sprung plates, yes easy quick LSD, metal on metal is the friction  material which works fairly well with the powdered metal gears but still wears.

a front engine/rwd is way easier to let the tires skip/chirp on corners with locked axles....less weight on the tires.

 

we have most of the weight on the tires and they are turning at a far greater rate of differential travel at the inboard/outboard wheel.

 

we welded a 4t80e diff for the Riv and it sheared the splines off the shaft at the wheel CV while making a right turn. sure it might have lasted longer with some hard slippery 225/60 16s but whats the point of a welded diff if you cant use the 295/50 16 MT's

 

good news is that you can still drive home after lol

 

on a fiero it'd be less of a side to side travel differential but with the weight it might still be a toothpick snapper

 

Jeff's LSDs are clutch-type I believe. He seems to make good stuff.

 jeff has/had recesses for clutch discs in the spring block to provide the friction....iirc he was also putting them between the gears and case too like the old C-ya racing diffs made by Mike Dye