converting a 2way lsd to 1.5way

[r-b-x]

i have a kaaz 2way lsd that i'm looking into converting it into a 1.5way, if that's even possible. the model number SAN2655 applies to both their 2way and 1.5way. plus the manual i got for it has references to a 1.5way setup, confusing me a bit and possibly hinting that it's possible?

has anybody tried or looked into it before? on kaaz ones or in general?

[GSXRJJordan]

Short story: I don't think so. Talk to Kaaz, they might work out an exchange though. I believe it involves switching a few internal parts (the cams inside that force the clutch plates together), but taking apart an LSD is ugly.

Talk to Kaaz.

[karl wasabi]

Yeah, do that...and why would you want to do that? Just curious.

[GSXRJJordan]

Lots of people decide to road-race their S-chassis cars/track them/"grip" them, and you hit a wall traction wise coming in to corners with a 2 way. The 1.5way is what all the road racers want.

[scir16v]

You'll have to rebuild either way. Once you open it up you'll see if it can be setup as a 1.5 way.

[Phlip]

Personally, I wouldn't think it worth the hassle, compared to simply selling 2-way and acquiring the desired 1.5-way.

[g6civcx]

you Lots of people decide to road-race their S-chassis cars/track them/"grip" them, and you hit a wall traction wise coming in to corners with a 2 way. The 1.5way is what all the road racers want.

Do you mean that trail-braking is unstable with a 2-way?

If so, this argument is really just an excuse for poor driving techniques. The substantial part of braking should be done in the braking zone, and trailing should only be used to transfer weight and NOT to scrub off speed.

If a driver finds himself trail-braking to scrub off speed, this means that the driver either completely missed the brake markers, or the driver misjudged the corner speed, at which point you should run off and hammer the brakes instead of trying to both turn and brake. This is only an option on corners with a good runoff area.


I personally prefer a 2-way because the 2-way rewards good drivers who can anticipate the corner speed and brake early. Trail-braking with a 1.5 way is also not as responsive as a 2-way.

The only disadvantage with a 2-way over a 1.5-way is you lose the ability to brake deeper into the corner entry.


I think people don't understand and appreciate how trail-braking should be done. Only slight pressure is need to transfer weight to the front end. Braking force should be minimal. The majority of the tyre's traction should be directed towards cornering. If you demand excessive braking while turning, you risk exceeding the tyre's traction budget, and should not be done regardless if you have open, 1 way, 1.5 way, 2 way, or whatever.

I know only of really good drivers who can use cornering forces alone to scrub off speed. Naturally, the car will lose speed while turning due to friction, but the speed scrubbed off would be minimal. Better to brake straight than to drive in too quickly.

The 1.5 way functions almost same as a 2 way but provides less lock when decelerating. The 1.5 way can provide more forgiving balance when braking than a full 2 way setup, although it is less effective for true racing applications, it provides easier operation for beginners in throttle off conditions


BTW, who are these roadracers you speak of?

[IStop4NoMan]

i think it could be done by switching the outer casing of the LSD.
1.5 and 2.0 work very similar.

[r-b-x]

kaaz says:

"the two way can be converted to 1.5 way by replacing the cams (pressure rings) inside.
The price of the cam set is $185.00 and we do have them in stock."

...so gonna have to consider my options. don't think i can trust myself to do the swap. can't think of anybody local i'd trust to do so either.

i'm looking into a 1.5 way since the 2way is more prone to understeer. and since my car is used for autox and its super tight corners, that's not desirable.

[luftrofl]

The only disadvantage with a 2-way over a 1.5-way is you lose the ability to brake deeper into the corner entry.



I think that's partly why. It seems to me that the 1.5-way, which doesn't lock as hard on turn in, would make turn in better than with the 2-way, which would lock harder and induce understeer. :confused:

[g6civcx]

i'm looking into a 1.5 way since the 2way is more prone to understeer. and since my car is used for autox and its super tight corners, that's not desirable.

I disagree. For your application, I would use a 2-way + lift throttle = instant rotation.

Because speeds are low, super heavy braking is not necessary like on the road course. How often do you need to brake and downshift?

I personally would sacrifice braking stability for responsiveness to throttle input.

I think that's partly why. It seems to me that the 1.5-way, which doesn't lock as hard on turn in, would make turn in better than with the 2-way, which would lock harder and induce understeer. :confused:

No, the 2-way induces rotation under braking = inexperienced people say 2-way is unstable.

You realize that if you lift the throttle and turn the wheel, with a 2 way the car will rotate. With a 1.5 way the car will not rotate as much. Some would say this is understeer. This is even before braking.

If you lift, turn the wheel, and brake at the same time, the 2 way will oversteer and turn in. This is how a car should react in my opinion. With a 1.5 way, the car will understeer.

That's a really simplistic view.


If you're new to roadracing, I recommend open diff or VLSD, honestly. They're more forgiving and you can get away with sloppy throttle and brakes.

[hey808]

If you lift, turn the wheel, and brake at the same time, the 2 way will oversteer and turn in. This is how a car should react in my opinion. With a 1.5 way, the car will understeer.

That's a really simplistic view.


If you're new to roadracing, I recommend open diff or VLSD, honestly. They're more forgiving and you can get away with sloppy throttle and brakes.

I would disagree with that. If you were autocrossing and using the lift-and-rotate technique, then it would slow you down. You want to stay in traction on the tighter autocross courses. I've tried doing autocrosses with a 2-way and it was a handfull. Luckily for me the course layout was big, with high-speed, wide-radius turns so I was able to fast-drift the course and finish in the top 5 (Miata club outing). Roadracing you should be ok with a 2-way as long as your transitions from throttle to braking are smooth.

[S14SwimShark105]

Just shutup and drive g6civcx, stop acting like you know everything.

[MaD1337M3DRiV3r]

my car is daily drivin, i've had

-open
-vlsd
-nismo 1.5

In that order too, the 1.5 is the best out of all of them. I still consider myself to be a noob at road racing, so I went with the 1.5 instead of the 2way.

Like g6civicx said if you have the skills a 2way is supposed to be the best.

[g6civcx]

I would disagree with that. If you were autocrossing and using the lift-and-rotate technique, then it would slow you down. You want to stay in traction on the tighter autocross courses. I've tried doing autocrosses with a 2-way and it was a handfull. Luckily for me the course layout was big, with high-speed, wide-radius turns so I was able to fast-drift the course and finish in the top 5 (Miata club outing).

It's all driver's preference. Again, like I said above, it's a very simplistic view holding all else equal.

Remember that with lower speeds like you see with most otterx, it's harder to reduce rotation because you're riding lower on the traction curve on at least some of the tyres. Most likely you're only exceeding traction on 1 or 2 tyres at most, unlike roadracing where you're trying to manage the traction budget for all 4. Look at pix of tripods.

You want to induce a little bit of a slip angle and then reduce the slip angle once you're almost pointed the right way. Remember that with lower speeds, inertial forces are not as high so you could get away with a larger slip angle for a longer amount of time. It's like you almost want to induce oversteer.

When you pick up speed, it's easier to induce rotation by slipping the tyres momentarily, then regaining control afterwards.

On a roadcourse you need the opposite (less aggressive turn-in so you don't spin) because speeds are much higher. Imagine what would happen if you tripod'ed at 100mph. I think this is why people say they prefer 1.5 because it keeps the car under the traction limit. Remember that for a given slip angle, as speed increases, it becomes harder to control the car because inertial forces are greater and you have less time to react.

Do what works for you. I prefer a 2-way because it's more predictable and responsive, but do what makes you comfortable.

Roadracing you should be ok with a 2-way as long as your transitions from throttle to braking are smooth.

This is right on. Transitions should be smooth everywhere :2f2f:

Just shutup and drive g6civcx, stop acting like you know everything.

I'm sorry you feel that way. I haven't said that I know everything ever. I don't know everything, but I know what I know well, and I know what I don't know. I just don't want to spread bad information.

my car is daily drivin, i've had

-open
-vlsd
-nismo 1.5

In that order too, the 1.5 is the best out of all of them. I still consider myself to be a noob at road racing, so I went with the 1.5 instead of the 2way.

Like the bandwagoneer g6civicx said if you have the skills a 2way is supposed to be the best.

I'm not a noob but I'm not an expert either, but I'd venture to say that I have more experience than most people posting in the tech forum.

Like I already said above, do what feels the best for you. I prefer 2-way because it rewards good driving techniques with instant response and predictability. I've experienced all types, open, vsld, helical, 1-1.5-2, welded, etc.

My only concern with your post is that you did not say that you have had a 2-way. Why would you rule something out if you haven't experienced it?

Just remember. When you're new, adjust yourself to the car, but when you have more experience and developed your own style, adjust the car to you.

[MaD1337M3DRiV3r]

My only concern with your post is that you did not say that you have had a 2-way. Why would you rule something out if you haven't experienced it?




I actually agreed with you, the 2way is supposed to be much better. I am currently working on getting a quaife. I will probably never go 2-way for any of my street cars and my s13 is just a daily driver.

[g6civcx]

I actually agreed with you, the 2way is supposed to be much better. I am currently working on getting a quaife. I will probably never go 2-way for any of my street cars and my s13 is just a daily driver.

Why not 2-way on a street driven car? I daily my Tomei 2-way for 2+ years.

What is your concern, excessive wear?

[GSXRJJordan]

G6, you hit the nail on the head, eventually. The bottom line is, if a racer (not auto-x) could have anything, it'd be a 1.5way. Not saying 2 way's can't be tracked very successfully, but you never want that lockup and rotation from the rear on the track at speed, when you're on the edge of traction from cornering.

Anyhow, all good points, and I also daily my Tomei 2way. People, you really can't judge the whole '2way lsd' thing until you drive a car with one - they don't lock up unpredictably, they don't make noise, etc etc - it's essentially the perfect diff for having fun putzing around.

[luftrofl]

No, the 2-way induces rotation under braking = inexperienced people say 2-way is unstable.

You realize that if you lift the throttle and turn the wheel, with a 2 way the car will rotate. With a 1.5 way the car will not rotate as much. Some would say this is understeer. This is even before braking.

If you lift, turn the wheel, and brake at the same time, the 2 way will oversteer and turn in. This is how a car should react in my opinion. With a 1.5 way, the car will understeer.


I'm not 100% sure about what you're saying, so am I right in assuming the following is what's happening:
-The 1.5-way doesn't lock as much, which puts less strain on the tires on turn in and thus prevents oversteer.
-The 2-way locks more, which induces some oversteer on turn in due to the increased strain on the tires.

I'm confused, as I would think that the locking would cause understeer like a welded(locked) differential going around tight corners. :confused:

[GSXRJJordan]

2 way is not the same as welded.

The 2way doesn't lock unless you 'jolt' the drivetrain, and start one tire spinning much faster than the other. When cornering in, as long as you're not downshifting aggressively, the 2way will not be locked on turn in. That's what g6civcx is talking about when he shits on people who compain about 2way's turn in "unpredictability".

[g6civcx]

you never want that lockup and rotation from the rear on the track at speed, when you're on the edge of traction from cornering

I hear what you're saying, but this should never happen. What you're describing is only an issue when transitioning from straightline braking to turn-in. You should not be on the edge of traction from turning and excessive braking at the same time.


2 way is not the same as welded.

The 2way doesn't lock unless you 'jolt' the drivetrain, and start one tire spinning much faster than the other. When cornering in, as long as you're not downshifting aggressively, the 2way will not be locked on turn in

Nailed it.

That's what g6civcx is talking about when he shits on people who compain about 2way's turn in "unpredictability".

I wouldn't put it that way, but perhaps in terms you could better understand?


On your gixxer, you come down the straight, position your body, brake, downshift if necessary while you're braking, stop braking, set the lean angle and start applying throttle.

Do you set the lean angle while under braking, and if so, how much braking are you applying as the lean angle increases?

If you do, then perhaps there is something you could teach me? I've only seen pros who can do that (apply braking all the way to the apex).

[luftrofl]

Sorry if I made it sound like I was saying that locked & 2-way were the same.

I still don't see why 2-way induces rotation and the 1.5-way doesn't. :X

Oh, and most bike racers (on pavement) are on the brakes while turning in and often to the apex. Not sure how familiar you are with Laguna Seca, but here's a video of the brake/throttle hand of a MotoGP rider going around http://youtube.com/watch?v=kbpqe-wvcuU

[MaD1337M3DRiV3r]

that guy on the bike has skills

[GSXRJJordan]

^^^ Remember two things... that that's Nicky Hayden (the US champ in 2001 and 2002, and won that MotoGP race at Laguna Seca, where that video was taken - I have his replica jacket :)), and that bikes have separate controls for front and rear brakes, making drifting and train braking possible because you control the braking load (and power load as well to the rear) separately.

Anyway, traction is described as a finite amount - you only have so much traction on a tire before you lose it completely. When you brake, you're using some (rarely all in the case of a bike's front tire), and when you corner you're using some. Keeping the balance between braking + cornering and not using up all your front wheel traction is what makes great riders better than average trackday junkies.

So the same thing applies with the rear wheels of the car - coming in to the braking zone, you're unloading the weight from them, so they're going to have a tendency to rotate anyway. If, while you're turning (meaning right and left wheel are already rotating at different speeds, and the diff hasn't locked yet), you shock the driveline with an uneven downshift/etc, you'll lock the 2way where you wouldn't lock the 1.5way, and start a drift.

[luftrofl]

If, while you're turning (meaning right and left wheel are already rotating at different speeds, and the diff hasn't locked yet), you shock the driveline with an uneven downshift/etc, you'll lock the 2way where you wouldn't lock the 1.5way, and start a drift.

So the 2-way will cause a slide, while the 1.5-way won't? Wouldn't that make the 1.5-way better as you could throw the car harder into a corner without worrying about the rear end coming around? :bite:

[MaD1337M3DRiV3r]

So the 2-way will cause a slide, while the 1.5-way won't? Wouldn't that make the 1.5-way better as you could throw the car harder into a corner without worrying about the rear end coming around? :bite:

Not really, the 2-way is supreme... the 1.5 is more forgiving.

When you throw your car into a hard corner with the gas pushed down the 1.5 and the 2 way will do the same thing. Its only when you're off the gas does a 1.5 act more like a 1 way.

[g6civcx]

^^^ Remember two things... that that's Nicky Hayden (the US champ in 2001 and 2002, and won that MotoGP race at Laguna Seca, where that video was taken - I have his replica jacket :)), and that bikes have separate controls for front and rear brakes, making drifting and train braking possible because you control the braking load (and power load as well to the rear) separately.

Right on.

Keeping the balance between braking + cornering and not using up all your front wheel traction is what makes great riders better than average trackday junkies.

Keith Code has a slightly different take on the same concept, but he focuses more on rear wheel traction. The front wheel is really meant for stability. You want to transfer weight to the rear for traction, and not overload the front with too much weight and braking/turning.


If, while you're turning (meaning right and left wheel are already rotating at different speeds, and the diff hasn't locked yet), you shock the driveline with an uneven downshift/etc, you'll lock the 2way where you wouldn't lock the 1.5way, and start a drift.

I think this is the key point of this thread, which goes back to my original point.

1.5 way - forgiving if you don't heel-toe just right, and don't control throttle transitions that well

2-way - more responsive if you have good technique. At this level, I wouldn't call shockloading a mistake that needs to be tuned out, but instead, shockloading is a way for good drivers to induce rotation, like starting a drift, without having to resort other things.

You don't have this option on a 1.5-way. If you don't understand these techniques, then yes, go with a 1.5.

But if you've progressed far enough, a 2-way is more responsive. Don't want to induce a rear slip angle? Heel/toe. Want to slide out the rear end? Lift throttle or clutch drop. Your choice.


I personally prefer having more freedom to make the car react however I want, but as we all know, too much freedom isn't necessarily a good thing for some people.