I bought some LSD for the ST...

"nafsucof" (galinskiomatic)
02/19/2015 at 09:57 • Filed to: lsd, FoST, Autocross

Just got a great deal on an LSD from MFactory for my FoST. I payed $599 shipped because of an introductory pricing deal they had on a few remaining units, before their production facility is moved. Normal pricing will be $999 i believe.

The differential is a Torsen torque sensing type which I have alot of experience driving on a FWD. I installed one on my SVT maybe 7 years ago and it's still kicking ass and taking names. I think I'm going to stay with the stock clutch and flywheel as I only have 27k and don't plan on raising power too much more nor do I drag race. I figure in the future if I have any issues with power handling I can upgrade then. I need to decide whether I slip a spec clutch in while I do this job.

Anyways, I'm very excited to autocross with it this year, as I think this will be as good or better than tires considering my eagle F1s have atleast this summer left in them. I run the stx class and this will keep me there. So far other things I have done are a Randy FSWerks tune, FSWerks Intake and CXRacing intercooler core. I'll be doing a rear motor mount to control the added traction and I have recently started buying up brake parts. There are some parts to upgrade the size of the rear rotors utilizing mazda 5 caliper brackets with the stock calipers and bigger rotors from volvo that I'm looking into. I'm positive the factory brakes are fine once you control the overspin the car exhibits. I may do a track day or two this year also...

DISCUSSION (33)

Coty > nafsucof
02/19/2015 at 10:02

Oh my. Do want.

DrScientist > nafsucof
02/19/2015 at 10:06

road TRIP ?

misinterpreted your title at first.

actually, a road trip with timothy leary anywhere would likely be an amazing experience.

Milky > nafsucof
02/19/2015 at 10:09

Why don't just all performance cars come LSDs? There is no downside to having one.

SidewaysOnDirt still misses Bowie > nafsucof
02/19/2015 at 10:10

Nice! Will you be able to disable the brake-based torque vectoring now?

nafsucof > Milky
02/19/2015 at 10:12

I agree, but even cars like mclaren mp12-c has open diff. eLSD is the wave of the future because brakes are less expensive to fix...

uofime > nafsucof
02/19/2015 at 10:19

how does the mechanical lsd play with the electronic lsd program? are people deactivating the elsd or just letting them fight it out for which one will control slip?

nafsucof > SidewaysOnDirt still misses Bowie
02/19/2015 at 10:21

nope, but it will be reduced considerably. That is a non defeatable function, that I actually like. It only ramps up when the car detects serious understeer and lsds like this one make turn in faster and pull you toward the apex so the car won't be as prone to understeer. The system works great in the snow...turning into slippery street and the car grabs the inside brake and voila car is rotated without ebrake into street. It's great for most situations except high speed on tracks where a little understeer at high speeds has that one brake trying to turn the car. Now the lsd will pull it right in. Of course this is all theory until it's installed, but my SVT went from power on understeer out of turns to yanking out of turns with huge amounts of point and squirt grip...we'll see I suppose!!

nafsucof > uofime
02/19/2015 at 10:26

Well a helical diff doesn't slip since its gear driven so the car will have a much higher threshold before the nannys kick in. That's why for now I'm staying at this power level...I can turn everything off except the torque vectoring which I don't hate. Right now I can pull out into traffic and easily light the tires to 60 mph...but that will all change ;)

Milky > nafsucof
02/19/2015 at 10:33

In all honesty I still don't even understand how that eLSD shit works. If I'm just sitting in snow how would applying the brakes to the spinning wheel get the other wheel to spin?

Coty > nafsucof
02/19/2015 at 10:36

When you swap in the LSD, what do you do about the eLSD? That's always been my question about these.

E. Julius > Milky
02/19/2015 at 10:37

I think it works something like this: in an open diff, the power split is based on wheel traction. That's why if you get a car with one in an extreme low traction situation (e.g. ice) all of the power will be sent to the wheel with no traction and it will spin without going anywhere. Braking the slipping wheel means that some of that power will go to the other wheel instead.

nafsucof > Milky
02/19/2015 at 10:38

differentials work by smoothly sending power to the path of least resistance. If you provide resistance to the path ie braking the spinning wheel, it is easier to transfer the power to the other wheel that isn't spinning via the differential. So when the car sees excessive wheel spin, adding more traction to that side by braking makes the diff spin the other tire. The car now will actively brake both sides to try and keep less than 100% of power from going to one wheel.

nafsucof > Milky
02/19/2015 at 10:39

it's just fancy better performing traction control...and by better I mean more modern.

jebusmoses > E. Julius
02/19/2015 at 10:42

Still the best explanation I've gotten on diffs, personally.

SidewaysOnDirt still misses Bowie > nafsucof
02/19/2015 at 10:43

The 12C has a multi-plate limited slip diff. The load behaviors are controlled electronically and there is active braking on the inside rear corner, but it does have a proper diff.

Desu-San-Desu > nafsucof
02/19/2015 at 10:44

Nice! I'm looking at about $2,000 for a quality LSD for the Mini.

Milky > nafsucof
02/19/2015 at 10:45

Welp, that does make sense. Seems like you're losing some of the power then though just to heat up the wheels wells.

nafsucof > Coty
02/19/2015 at 10:47

nothing. There is a ton of new found traction and the computer doesn't have to compensate if there isn't wheel spin. On dry pavement launching my SVT from 5000 rpm on snow tires with the torsen there is virtually no wheel spin. I can literally launch with traction control on and it doesn't interfere. This *should* compliment the system only requiring it in extreme low traction situations. Hammering out of a turn or through a decreasing radius turn etc the tires will be way less likely to light up and throttle modulation will be reduced. It's wild, you can literally peg it out of turns and the front end just pulls you toward the inside instead of pushing wide.

Milky > E. Julius
02/19/2015 at 10:48

So its just making the other wheel become the easiest path, I see. Still think a traditional LSD would be better though, you wouldn't lose any available power.

Coty > nafsucof
02/19/2015 at 10:50

Kinja'd!!!

SidewaysOnDirt still misses Bowie > Coty
02/19/2015 at 10:50

eLSDs as being described aren't usually differentials at all. What most people are thinking about is brake vectoring. An electronically controlled diff is a different animal. That's a mechanical diff with electronic controls over the parameters such as the preload.

nafsucof > SidewaysOnDirt still misses Bowie
02/19/2015 at 10:51

I don't care for clutch plate style or viscous diffs. They only do 50:50 but for rear drive it's what you want fwd the torsen is the way to go.

Coty > SidewaysOnDirt still misses Bowie
02/19/2015 at 10:52

Well I knew that, I just was concerned about both of them trying to work at the same time and fighting each other.

Yes, I know now that that's stupid but damn it I'm sick I shouldn't have to think.

E. Julius > Milky
02/19/2015 at 10:52

I agree.

E. Julius > jebusmoses
02/19/2015 at 10:53

Classic, that's where I learned my stuff haha.

nafsucof > Desu-San-Desu
02/19/2015 at 10:53

I wonder since your mini(r53-r56) use the same getrag as the SVT focus if the splines on the axles where the same. The torsen or quaife unit for those is right around $600-1000...

SidewaysOnDirt still misses Bowie > nafsucof
02/19/2015 at 10:57

I've never really messed with FWD diffs before, so I don't know what the characteristics of them are. I like clutch packs because of how they're adjustable. My BRZ has a torsen one. I like that one too. Viscous diffs are barely limited and suck.

nafsucof > SidewaysOnDirt still misses Bowie
02/19/2015 at 10:59

The viscous relies on a series of clutches with a viscous fluid that needs to heat up once it heats up it expands and will lock the clutches together they wear out faster and don't seem to have as hard of a lock they are easy to live with and have a smooth transition between on and off my friend had one in his 92 Sentra SER and it worked but I didn't like it as much as the Torsen

thedevilinside > nafsucof
02/19/2015 at 10:59

No LSD is still my greatest complaint with my FoST. Are you planning on the install yourself? I think an LSD install would be beyond my comfort zone.

SidewaysOnDirt still misses Bowie > Coty
02/19/2015 at 11:00

I don't know if they'll necessarily be fighting each other. Doesn't the brake vectoring use the same sensors and computer as traction control and abs to decide when to kick in and how much brake to give? If so, it should be able to adapt without issues and probably just kick in higher since you're already cutting some understeer out.

nafsucof > thedevilinside
02/19/2015 at 11:02

yes I will do it myself but at my friends garage he has a lift in about $35,000 worth of Snap-On Tools. It is actually rather straightforward once the transmission is out it is all about taking your time being methodical and paying attention to exactly which bolts come from exactly which holes. BI did my focus SVT by myself in seven hours start to finish including taking the transmission out of the car and reinstalling it I'll be doing a new slave cylinder and axle seals while I'm at it. It's easily a $500-$1000 job if you're just paying someone out of pocket.

Coty > SidewaysOnDirt still misses Bowie
02/19/2015 at 11:03

Yeah it does. That's why it was teh dums.

Desu-San-Desu > nafsucof
02/19/2015 at 11:08

I've been looking at an OS Giken, though.