hahah reading this thread is like watching a monkey **** a football...just weird and awkward....I think some of you guys are on LSD....

LSD is Limited Slip Differential as mentioned. Both wheels are NOT locked together, this is what a "Locker" does but not LSD.

LSD is clutch operated. In a nutshell if one wheel is spinning faster then the other it will screw 2 clutchs together making the opposing wheel spin. These clutches are connected to the axles. It requires a bit of spinning for both to engage, this is why you cant feel it while you are turning since if both wheels were locked together the outter wheel will bark as it slides on the asphault around a turn, a locker will cause this. But if you peel out that is more then enough to engage the LSD.

The clutches can actually wear out but not usually under normal coniditions. Failing LSD's become open diff's. This happens alot with Jeeps with the factory LSD and then the owner takes it rock climbing alot. The clutches will burn and eventually where out. Happened to me and it was replaced with a air-locker.

Thats all there is to it. Its nothing magical. My car has one in the rear. The only time you should need it is when launching. If you a on a road course you shouldnt need it that much the tires shouldnt be sliding around that much. Oh, it helps in the snow alot too obviously...

 

What he said, except not all LSDs are clutch "driven".

 

There are no clutch plates! It is gear driven! You don't even know what the hell you are talking about and your critizing other users on the thread???

This will settle all the BS floating on this thread!

Source: http://www.quaifeamerica.com/differentials/diffs.htm

 

Or maybe if everyone just read my posts.

 

true true, but when you're running very close to 21 pounds of boost and 296whp in a car that weighs 2900 pounds.... its really worth the extra changed if you like sparing tires....

 

I'm confused...you posted a link on now a Quaife unit works. Does the G85 come with a Quaife unit? Because that is NOT LSD. Although it does the same job.

I explained how an LSD works. Soucre http://en.wikipedia.org/wiki/Limited_slip_differential

So your telling me the G85 is made by Quaife? BTW I do know what I'm talking about I explained how LSD works. I never specified what car. So if the G85 = Quaife then my post didnt apply...

EDIT: The SS does come with a Quaife unit. Leave it to GM to rename their parts, they successful call all their forms of differential traction control LSD's now. mi6 is right its not a stardard clutch driven LSD. Follow his link on how it works.

Side note: The Quaife "LSD" is a pretty nice unit. Generally stronger then LSD's with clutch packs and dont wear out. It used to to only come in high end cars. Then stardard in the SRT-4 in 04 I believe. I thought dodge called it a Quaife unit rather then LSD but I could be wrong...

 

This is how I look at it. I could have gotten a g85 ss/sc but for the 1500 I saved in not getting the g85, I bought stage 2, exhaust, pulley, etc.

I wish I had it just to say I do, but i know ill never be driving my car hard enough to need it.

Get it if you want it, but dont worry if you can't.

 

1st) G85 is a GM RPO code, nothing more.

2nd) LSD = Limited Slip Differential. There are many different makes and types of LSD.

3rd) The "G85" package includes a Quafie LSD. The LSD is built by Quafie and installed by GM in your transmission when you order your G85 car.

 

Well i traded in my first cobalt with 700 miles for me new one now just to get the g85 package i ate almost 5000 dollars and it was worth every penny

get it you will love it and the great thing is there is no torque steer.

 

I have a non G85 car and got a ride in Screamin's G85..... the difference in coming out of corners is HUGE!!!!
I Auto-X / track days and kick myself in the butt daily for not getting the G85.

even better.... NO SC should be produced w/o G85!!!!

snow gonna be challenging w/o G85

 

Since starting this thread , i have purchased a COBALT with the G85 package and i'm very pleased. Everyone told me that it is worth getting for the recaros alone and they were definitely right, they are awesome. As for the LSD is is very predictable while launching and very linear without a lot of pull to one side or the other. I can definitely say it is easier to get a better lauch out of a g85 car than a non g85 car, after driving both. It is worth the money but if you are looking to save on the price of the car you are still getting an excellent, underated car if you get the non g85.

 

bottom line- Quaife=good
no Quaife=OK

It really depends what you want- a pretty much stock car that runs a 13 or 14? then the quaife don't really matter much. If you plan on pushing the car into the 11 or 12's then a Quaife is a must(so are custom made axles from the Driveshaft shop).
Cost of a Quaife for my Dodge is about $1,200 and most others are about the same price. Figure if you take it to a trans shop to be installed it will be about $1,000 for the whole job- take then just the trans and you should be able to get it done for $750. You can do it yourself but you need a few special tools and some knowledge- if you can set up gears it's actually pretty easy to install a Quaife.

 

while i dont know a huge amount about this..... i see a slight discrepency in the logic posted....

"The Quaife Differential powers both drive wheels under nearly all conditions, instead of just one. With an ordinary open differential, standard on most cars, a lot of precious power is wasted during wheelspin under acceleration. This happens because the open differential shifts power to the wheel with less grip (along the path of least resistance)."

If this is true that would mean that the second you break loose in a NON lsd car, 1 wheel will spin and continue to spin. because it would always have the least resistance.

So why is it that NON lsd Cobalts seem to be able to burn both wheels without to much issue?

 

Back in 2005, I had to serach my ass off to find one with G85, and finally I did. Salesmen usually don't know anything about the car, so don't listen to them.

 

this is a continuing arguement on this site that I keep coming across. for some reason, it ends up being opinionated. lsd does not help in a straight line. you guys make me laugh so hard.

 

In my Dodge with over 400WHP it helps incredibly on the 60' times. Without it my 60's were all over the place and I would be anywhere from 1.85- to 2.0. But with the quaife the norm is 1.81-1.86. If this unit is doing nothing for my 1/4 mile times I would like to know how my average 60' time has dropped a tenth and all of a sudden I am consistant? On the street I can finally get on it a little bit- before Quaife it would break the right front tire loose in the first three gears and sit there but with the quaife it will spin both tires and move out at the same time.

 

Are you serious? It doesn't help in a straight line? Wow.

 

is the lsd an addition to the ecu, or is it a tangible mechanism in the tranny ( example of tangible mechanism being something that is metal, aluminum, whatever, not something uploaded into an ecu)

 

It is a mechanical piece, yes. It is made by Quaife, similar to these units.

 

IMO LSD is very important. I would not say I'm the best driver but I pulled off the second best stock time on this site. I honestly think it had alot to do with the LSD.

 

idk i really dont c in buying the g85 i didnt i hate the recaros i rather my red inserts but thats IMO, but ive done burnouts with both tires spinning.

 

I feel the same way. Only for that "rarity" factor.

 

I would rather have something like the eaton looking differential than a LSD. It is a cheap option on 2wd pickups. I wish they would make a unit for us.

 

An Eaton on the front would be annoying as all hell. The Qaife unit we have is about perfect for the car. It is an LSD with no clutches to wear out.

 

i dont have the g/85 cobalt and have alot of problems with my launch, would it be better to get lsd or a traction bar and springs?