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Discussion Starter · #1 ·
Yep, purchased 6 months ago, and just got it installed this week,
Mind you, the only benchmark I have is the GTI with regards to LSDs on a front driver.
But I can tell you that a mechanical LSD is much different than the VW implementation. For starters, the GTI implementation is smooth. You don't even know it has something going on in the front end until you compare the PP (Performance Pack GTI) against the base GTI (which does not have the e-LSD). But those test drives are what convinced me before I ever brought the FoST home, that I would be installing a diff in my car.

Now that it is in, I can say that it changes the dynamics of the car in 1st and 2nd gear just driving around town. Torque steer seems to be gone, but that could be due to my tracking the car and having grown so accustomed to it that I don't even notice it anymore. But around town driving, you notice a big difference pulling out onto the street in 1st or second gear. The wheel tugs a lot while getting on the gas, whereas before the inside wanted to spin, or the car just would not accelerate hard as traction control would (as it feels from the seat of the pants) reduce your rate of acceleration.
With the LSD, you get to accelerate into traffic for instance whereas before you might have trouble getting the power down.

Where is really is noticeable is in HOW it interacts. I have not heard anyone mention this, but my car bounces more when acceleration through or from a turn. It is like I am hitting bumps, and may be largely attributed to my coilovers...I will hopefully find out how the stock suspension reacts to the LSD, as I am thinking of pulling the coilovers for the winter (my laziness will ultimately determine this). But the power seems to cycle from inside to outside many times per second, and results in what sounds like the engine cutting, but I assume it is the sudden loading and unloading of the outside wheel.

I really can't wait to get the car on track to see how my brakes fare. I strongly suspect that TV that can't be defeated is seriously affecting my brakes, making full 20 minutes sessions difficult on track due to brake fade, or even brake loss altogether. There is T2 at Laguna Seca where I can never seem to get full power down until my steering wheel is basically straightened out all the way. Add T11 into the mix as with TC off, you have to feather the throttle to avoid inside wheel peel.

The true test will come next spring...I was hoping my last track day 2 weeks ago would have been with the LSD, but timing did not work out in my favor.
 

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Sounds like a great upgrade, I'm basically full bolt-on now, and if I do anything else to my car it will be a LSD.

What you are experiencing while turning under acceleration sounds correct to me. Since you are accelerating the diff is locking up, and the inside wheel and outside wheel are going the same speed but different distances, causing that feeling you are getting.

Same thing happens with RWD vehicles with a spool, if you turn sharp at a low speed you hear 'cherp cherp cherp' as one tire skips.
 

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Sounds like a great upgrade, I'm basically full bolt-on now, and if I do anything else to my car it will be a LSD.

What you are experiencing while turning under acceleration sounds correct to me. Since you are accelerating the diff is locking up, and the inside wheel and outside wheel are going the same speed but different distances, causing that feeling you are getting.

Same thing happens with RWD vehicles with a spool, if you turn sharp at a low speed you hear 'cherp cherp cherp' as one tire skips.
Helical diffs don’t lock up. They do allow a bit of difference in wheel speed and tend to send the torque to the outside wheel. It’s more like 60:40.
 

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Thanks a lot for this review - I've got the MFactory LSD on my shortlist and was wondering how it affected handling.

The wheel tugs a lot while getting on the gas
What do you mean by this? Does it tug in one particular direction, a'la torque steer?

Would you say it's been worth it overall, or would you spend the money elsewhere in hindsight?
 

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hmm, so it's negatively effecting handling in the turns?? that would be a big deal breaker for me as that is what is most fun about this car is taking it to the back roads and canyon carving heck it's almost as fun as my sportbike in the twisties.. while it would be great to have some straight line traction on this car, I would not want to sacrifice the performance handling characteristics in the turns to get it.
 

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Discussion Starter · #6 ·
I am still getting familiar with the LSD, and as i mentioned, my only reference was the GTI PP vs the GTI standard. The GTI-PP uses an eLSD which operates using clutches, so the engagement is transparent, up until you drive a standard GTI, and then you know something is missing.

The feeling is similar to torque steer, but it is not torque steer. It is the outside wheel pulling the car around, where previously you would basically spin the inside wheel, or engage traction control. Now the TC light doesn't even flash at all (at least not yet).
Where you really notice it, or at least where I really notice it, is leaving work where I turn onto a 45mph street from a stop. Over time, I have been conditioned to accelerate slowly to avoid wheel spin, at least until I am pointed in the right direction. This is so ingrained that my foot instinctively knows exactly the point where the TC or TV (or both) intervenes. That point is no longer there. I can pull out much more quickly than ever before, and it has been raining here in the CA. Just last night while driving home from the gym, I was on a wet onramp, and I put my foot into it at the 3/4 point of the onramp and since it was wet, I was expecting the inside wheel to just spin up (I was in 3rd), but the car just hunkered down and boogied as if it was dry out. Even in 3rd, and in the dry, I can get the TC light to flash on this onramp, and it did not light up last night.
Again, subtle differences...and I truly cannot wait to get this thing back on a track. I suspect that I will be impressed, and I am becoming more convinced that my brake problems will improve. I say this because it sure seems that my brakes are no longer retarding my acceleration when the steering wheel is turned, like it used to do. But I will admit that I will not know for sure until I get it back on track.

For those that have LSD experience, I realize that this is not a locker type diff as described above. But the dynamics that I feel while accelerating with the front wheels turned is similar to overrevving a motorcycle. I assume that this is the power transferring from a slipping wheel to a wheel that is not slipping, and suddenly loading the engine -resulting in the sound of the engine fluctuating multiple times (5 to 10) per second. It is not the rev limiter, this is happening in the torque curve (3000-4000RPMs). It makes sense to me if this is what is happening. It sounds like the engine being cut, but it happens so quickly and I am still accelerating harder than the car used to be capable of under the same conditions...It is just an observation, and my only benchmark was an eDiff on a FWD car.

I did not answer the question as to whether the LSD is worth it. In my mind, yes. But I was so convinced by my GTI test drives that it was already a foregone conclusion. My only hesitancy was with the torque vectoring that cannot be defeated, but reading this forum for anything and everything LSD related, I decided to take the plunge. The ONLY reason that I have not given 100% endorsement is that I have yet to get it to the track. That will be the true test, as number do not lie.
I ran 1:56:80 on my car 100% stock (except RS brembos) at Laguna Seca
I ran 1:54:80 at the same track with coilovers and a passenger, and RE760S tires (tires should be slower than F1s)
I believe that my laptimes with the LSD will be easy to compare as my car will be the same as my second excursion. But the next outing is in March, so it will be all street driving, mostly around town from now until then, though I will try to jump in on another event prior to that, as I am not afraid of a little water like most of my RWD friends.

So, while I hope to see better laptimes, I really hope to see my brakes last the entire 20 session deep into the day. I strongly believe that my brake woes are not from my braking, but the TV braking on corner exits. I was always pretty hard on brakes with my motorcycles, more so on streetbikes than MX or Supermoto, but the focus is in a different league when it comes to brake problems, and I am listening and learning from others on how to address this. But the overarching opinion is that we do what we can to cool the brakes because we cannot defeat the TV, so the hope is that we reduce the load on TV with a lighter foot, or with something like the LSD.
 

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hmm, so it's negatively effecting handling in the turns?? that would be a big deal breaker for me as that is what is most fun about this car is taking it to the back roads and canyon carving heck it's almost as fun as my sportbike in the twisties.. while it would be great to have some straight line traction on this car, I would not want to sacrifice the performance handling characteristics in the turns to get it.
. By no means. You can give much more gas through the turn and get on power much earlier. It sends more power to the outside and overdrives the outside wheel which will pull the nose in on cornering. When you are braking it prevents lock up by keeping the wheels connected. Best mod I’ve done. And it’s a must once you are tracking and big turbo. Oh also since it limits wheel speed variances in corners it keeps tvc less active and doesn’t add as much heat to the brakes.
 

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^^^^^good to know, it's back on my mod list!!
 

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My only problem with the mFactory LSD is putting down too much power coming out of a turn, or accelerating into a turn (Which you shouldnt be doing on a track anyways). It wants to pull into the turn tighter, making you correct real quick. But no "cutting," out as you've described.

As for brakes, you are turning off traction control right? Holding down the button for 5sec or so, to disable things. It doesn't remove TV completely, but it does affect brake life on the track, dramatically. Even just sport mode is not enough, and you can burn through your brakes quick.
 

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Discussion Starter · #10 ·
. By no means. You can give much more gas through the turn and get on power much earlier. It sends more power to the outside and overdrives the outside wheel which will pull the nose in on cornering. When you are braking it prevents lock up by keeping the wheels connected. Best mod I’ve done. And it’s a must once you are tracking and big turbo. Oh also since it limits wheel speed variances in corners it keeps tvc less active and doesn’t add as much heat to the brakes.
What he said... I did not mean to indicate that there was or is any sacrifice in handling... In fact, it is the opposite. Now you can get on it much earlier.
All I'm trying to do is describe the sensations that having the diff adds to driving...

CrashMW
 

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I've had the MFactory LSD on mine for over a year now. The sensation you're getting coming out of turns is normal for a helical LSD. Since your inside wheel tends to lose traction in a turn, the LSD will direct more torque to the outside wheel which is the one with more traction. The feeling you get is like it's "helping" you through the turn. Keep in mind that in a BT car with an LSD, you can still end up spinning both wheels coming out of a turn resulting in terminal understeer.

Regarding TVS, I've noticed that brake pad wear (and brake temps in general) has reduced considerably on the track. Probably because the LSD reduces speed differences between left and right wheels to a minimum so the TVS ends up working less.
 

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Discussion Starter · #12 ·
I've had the MFactory LSD on mine for over a year now. The sensation you're getting coming out of turns is normal for a helical LSD. Since your inside wheel tends to lose traction in a turn, the LSD will direct more torque to the outside wheel which is the one with more traction. The feeling you get is like it's "helping" you through the turn. Keep in mind that in a BT car with an LSD, you can still end up spinning both wheels coming out of a turn resulting in terminal understeer.

Regarding TVS, I've noticed that brake pad wear (and brake temps in general) has reduced considerably on the track. Probably because the LSD reduces speed differences between left and right wheels to a minimum so the TVS ends up working less.
Awesome. Thanks.
I failed to mention that yes, in the wet, I can spin up both fronts and basically have limited steering control....

CrashMW
 

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I've had the MFactory LSD on mine for over a year now. The sensation you're getting coming out of turns is normal for a helical LSD. Since your inside wheel tends to lose traction in a turn, the LSD will direct more torque to the outside wheel which is the one with more traction. The feeling you get is like it's "helping" you through the turn. Keep in mind that in a BT car with an LSD, you can still end up spinning both wheels coming out of a turn resulting in terminal understeer.

Regarding TVS, I've noticed that brake pad wear (and brake temps in general) has reduced considerably on the track. Probably because the LSD reduces speed differences between left and right wheels to a minimum so the TVS ends up working less.
Awesome. Thanks.
I failed to mention that yes, in the wet, I can spin up both fronts and basically have limited steering control....

CrashMW
Yeah, I am known for lighting up both my 255 MPSS with my Mfactory.

Terminal is the correct term, either let off or wreck pretty much. I front end drift entirely too much. Nothing against the LSD, it's a great mod, I just built a burnout monster for some reason, lol.

Still stock turbo pump gas, putting down 370 plus torque to the wheels. Going wider tires when I install the body kit that's collecting dust.
 

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Yeah, I am known for lighting up both my 255 MPSS with my Mfactory.

Terminal is the correct term, either let off or wreck pretty much. I front end drift entirely too much. Nothing against the LSD, it's a great mod, I just built a burnout monster for some reason, lol.

Still stock turbo pump gas, putting down 370 plus torque to the wheels. Going wider tires when I install the body kit that's collecting dust.
I'm running 245s on mine which has a EFR7163 with WMI. Not done tuning it yet and it already blows away the tires. LoL!

Body kit plus ridiculously wide tires? Need to post that up when you're done! :D
 

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I'm running 245s on mine which has a EFR7163 with WMI. Not done tuning it yet and it already blows away the tires. LoL!

Body kit plus ridiculously wide tires? Need to post that up when you're done! :D
Probably in the spring time. Right now im just working on my winter beater. Of course I will post it. It should be interesting one way or another, lmao

Thinking 265 or 275 MPSS, on some 9.5 rims with a subtle offset, unlike the +33 I am running now.
 

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I have a MFactory LSD as well, what I have noticed on the crappy Michigan roads are when the roads are uneven you can definitely feel it pulling one way or the other. I've also noticed the "sensation" of it swapping power back and forth to each side.

This may be amplified because I have all season tires and they lose traction easily.

I will say it helps a lot in the snow.
 

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Discussion Starter · #17 ·
I thought that I would add an update...
I have run my first track event with the LSD. Brake issues meant that I was unable to give much feedback that is backed by laptime.
Furthermore, I seemed to have issues all around.
First session, blew off my chargepipe, so not much in the way of laptimes, as the pipe blew off on my first open lap without traffic.
Second session, I lost brakes at about 11-12 minutes in.
Third session, about 10 minutes in before brakes went away.

So, while I think that the brake issues must have been from previous track outings, meaning that perhaps I cooked the seals -which I have since replaced, I cannot comment on whether the LSD helped with brake wear. In fact, my pads Carbotech XP10s are not very worn as I cant get enough laps to stress them.
So, my only assessment is seat of pants.
there are two locations on track that I felt that the car was not making power on corner exit before the LSD. Turn 11, where I would spin the inside wheel and not accelerate very hard, and on the exit of T2, I never noticed wheel spin, but I did notice a lack of acceleration as the car was trying to accelerate while still pulling cornering loads. It seemed that once the car would straighten out, i would get more power. This time around, I felt that the car was able to power out much earlier and stronger than before.

Next event I will have my cameras working better, a BBK, as well as Harry's laptimer working.
Then I should know more about whether or not the LSD results in better laptimes.
The only laptime estimate that I got was based off another car that said he had run a 1:53.6, and I was pulling on him a bit. Which would indicate that I had dropped at least a second from my previous best...
 

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I thought that I would add an update...
I have run my first track event with the LSD. Brake issues meant that I was unable to give much feedback that is backed by laptime.
Furthermore, I seemed to have issues all around.
First session, blew off my chargepipe, so not much in the way of laptimes, as the pipe blew off on my first open lap without traffic.
Second session, I lost brakes at about 11-12 minutes in.
Third session, about 10 minutes in before brakes went away.

So, while I think that the brake issues must have been from previous track outings, meaning that perhaps I cooked the seals -which I have since replaced, I cannot comment on whether the LSD helped with brake wear. In fact, my pads Carbotech XP10s are not very worn as I cant get enough laps to stress them.
So, my only assessment is seat of pants.
there are two locations on track that I felt that the car was not making power on corner exit before the LSD. Turn 11, where I would spin the inside wheel and not accelerate very hard, and on the exit of T2, I never noticed wheel spin, but I did notice a lack of acceleration as the car was trying to accelerate while still pulling cornering loads. It seemed that once the car would straighten out, i would get more power. This time around, I felt that the car was able to power out much earlier and stronger than before.

Next event I will have my cameras working better, a BBK, as well as Harry's laptimer working.
Then I should know more about whether or not the LSD results in better laptimes.
The only laptime estimate that I got was based off another car that said he had run a 1:53.6, and I was pulling on him a bit. Which would indicate that I had dropped at least a second from my previous best...
Thanks for the update! looking forward to more
 

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Second session, I lost brakes at about 11-12 minutes in.
Third session, about 10 minutes in before brakes went away.

So, while I think that the brake issues must have been from previous track outings, meaning that perhaps I cooked the seals -which I have since replaced, I cannot comment on whether the LSD helped with brake wear. In fact, my pads Carbotech XP10s are not very worn as I cant get enough laps to stress them.
My understanding of the brake vectoring system is that steering angle is the primary input while TC and SC use slip. It will activate on turn in even without throttle input. I don't think the LSD will completely prevent brake vectoring from happening, however, it should prevent SC from activating since the car will have an easier time keeping its intended line. I've tracked my car half a dozen times this year, and there has been another FoST with the Quaife LSD at the events. They definitely experience less brake fade than I do but its not completely gone.

Also, did you upgrade your synchros? Many people in my local ST group with the diffs have had synchro failure which they blame on the LSD. They also favor drag racing which obviously isn't nice on the transmission but I'm curious if their complaint holds water.
 

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@Crash, Are you using the stock brake set up less the OEM pads? Motorcraft brake fluid? What were the track temps?
 
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