Open front Diff to LSD...

[LowGripMaxFun]

I was wondering for people who either upgrade or got an STI, what the difference is like from going from an open diff in the front to an LSD. Do your driving techniques or strategies change at all? Does it make the car more enjoyable to drive? Also, are there any downsides to having one?

[UP2MTNS]

from what I've been told, an LSD up front increases understeer (but to what degree, I don't know).

of course, you have the benefit of having both front wheels being driven, even if one is up in the air.

I guess its good for backing yourself out of a ditch on stages ;)

[BlackParis]

ON a fwd car... it GREATLY increases CHANCE of snap oversteer on throttle off (corner entry).... But increased Understeer on throttle (mid to late corner) ;)


Not sure about Awd... But I would predict something similar....

[strat]

i would tend to believe understeer as well.

when you turn, your inner wheel travels a shorter distance than your outer wheel. with an closed diff, the inner wheel is going to try to travel the same distance as the outer wheel (being that the lsd will sense different wheel speeds which it will see as slippage and lock the diff)

[subie88]

i have a 99 2.5rs and went from a open to a ppg helical front diff and you can feel it pull you out of turns better. it wont let the inside front tire go up in smoke like it used to. the only thing different driving wise is i had to hang on the steering wheel better. it likes to return to going straight very quickly. it almost has a little bit of torque steer now.

[LowGripMaxFun]

i have a 99 2.5rs and went from a open to a ppg helical front diff and you can feel it pull you out of turns better. it wont let the inside front tire go up in smoke like it used to. the only thing different driving wise is i had to hang on the steering wheel better. it likes to return to going straight very quickly. it almost has a little bit of torque steer now.


So your saying that the front LSD would help get rid of understeer, especially when getting out of a corner on throttle. This is more along the lines of what I have heard as well.

[subie88]

it did a little but it would still understeer. i just put an anti lift kit on and that made a bigger difference. with the alk you can really feel the front lsd pull you out of the corner. it will understeer a little going into the corner but once you get on the throttle it pulls you right out of the corner.

[nization]

Driving my 1997 Outback Sport Wagon for two rallycross events, then Drako's WRX Sedan was an experience. Granted, I have a few variables involved, but also, I feel there are some misconceptions in the LSD=added understeer belief.

The first run in the WRX, I did experience more understeer, but I think it was due to the ease of over-driving the car. Between it having considerable greater power, and weight over my car. But in general, I think the LSD makes one think they can over drive the car. Once I got used to it, as I have gotten used to the LSD in the back of my MX-5, I found it had much more control to offer.

What I think I'm getting at here is that you simply have to modulate the Throttle differently, and not expect the car to slide as much. That is what the LSD is meant to do, prevent your car from sliding after all.

Of course, I'm willing to admit that all my theories presented here could simply just be my own opinions.

[pigpen]

it will be different from an STi b/c of the center diff being biased towards the rear instead of the front, and that has almost certainly made a bigger difference in my driving style. i would think it would affect a front-biased car more.

[UP2MTNS]

Driving my 1997 Outback Sport Wagon for two rallycross events, then Drako's WRX Sedan was an experience. Granted, I have a few variables involved, but also, I feel there are some misconceptions in the LSD=added understeer belief.

The first run in the WRX, I did experience more understeer, but I think it was due to the ease of over-driving the car. Between it having considerable greater power, and weight over my car. But in general, I think the LSD makes one think they can over drive the car. Once I got used to it, as I have gotten used to the LSD in the back of my MX-5, I found it had much more control to offer.



not sure what you're saying....WRX's don't have LSD's in the front, just in the rear. which is why its easy to get the tail to come out in a WRX with the throttle.

up front, it induces more understeer via what STRAT said.....

I'd agree with BlackParis' two comments too, especially if you're running rally tires (re: snap steering)

[BlackParis]

Part of learning to drive with a FRONT LSD, is to learn to slow down more, and take a straighter line, and have more exit speed... Cause you know initial turn-in isn't going to be as good, and Corner exit is going to go wider.... But if you get good @ this, your times will be greatly improved...

Also, should you start understeering, it is MUCH harder to get out of it with the front LSD, than if you had an open... Sometimes I pray for an act of god to make the car turn the rest of the way (LFB!).... Again only going from FWD experience... I put a Quaife LSD in my Escort, back in the days, so I got to see what was Different about it (same car/same suspension)...

I would say it is hard to compare A WRX with open diff, to an STi with LSD, because the whole car is sooo much different (increased caster, better trq distribution, reduced unsprung weights, etc....) All those things, HELP cover up the understeer from the Front LSD... If I had the moeny to burn.. I would fix all those first.... THEN the LSD...

[wr-ecks]

i went from a 04 wagon to an 05 sti and to be honest the wagon understeered more off road. im kinda hard on the throttle all the time and the stis are rear biased like previously mentioned and im sure that has a lot to do with it but when your car is sliding and you floor it to straighten it out i think the more tires trying to get traction the better.
on a side note if im driving slow around a long bend and its raining and i give it gas the front end def. wants to push out more so then my wrx.


I would say it is hard to compare A WRX with open diff, to an STi with LSD, because the whole car is sooo much different (increased caster, better trq distribution, reduced unsprung weights, etc....) All those things, HELP cover up the understeer from the Front LSD... If I had the moeny to burn.. I would fix all those first.... THEN the LSD...


x2

[Subie Gal]

I have an STi plated front diff in my rally car

under steer? ummmmmmm no.... not so much

why?

because I have a 20kgf Sti center diff and OE LSD rear diff as well

you cant just toss in a front diff and call it good

gotta go with the whole package on an AWD car and think it through

what are your goals? what do you want the car to do???



Hardest thing about the diffs?
learning to trust them

brake less
set the car up and hammer the throttle.


Now...
that being said
I had a welded front diff on my FWD Impreza
no... not quite the same but very similar

car will go where you aim it
again, point... gas and go.....


Jamie http://www.subiegal.com/subiegal-smilie.png (http://www.subiegal.com/)

[Allwheelsdriven.net]

Word. Good advice on the diffs Jamie. Much more to it than just installing it. You need to adjust your driving style accordingly, or you'll wind up in th trees..;) Even a strong center diff can have that same effect.

Rally On!
Barrett-
www.allwheelsdriven.net (http://www.allwheelsdriven.net)

[nization]

Word. Good advice on the diffs Jamie. Much more to it than just installing it. You need to adjust your driving style accordingly, or you'll wind up in th trees..;) Even a strong center diff can have that same effect.

I guess that's mostly what I really wanted to say.

Turns out that I was mistaken about the WRX I got to drive and was corrected in person the other day. So I also wasn't quite sure what I was saying ;)