So, the Honda/Acura factory equips some of their transmissions with LSD's. Other aftermarket manufacturers offer replacement/add-on LSD's.

-What's the difference between the aftermartket LSD's (clutch pack vs. gear vs. welded) and the Honda LSD?
-Is there a benefit to one over the other, besides wear on the clutch packs?
-How do they each react to, and transfer torque loads to the wheels?

John -- who's LSD'less for the time being


[Modified by johng, 2:05 PM 10/23/2002]

 

hybrid did their own summary of the differences, but i dont reall agree with the authors personal opinions. of course it depends on what youre doing i guess.
http://hybrid2.honda-perf.org/tech/lsdinfo.html

speaking of which, did ITR come with quaife LSD? evo (best euro sportcar mag) made a mention that it did and i wasnt sure if that was just a euro thing or they made a mistake.

also, i recommend picking up this months issue, they have a guy importing the factory built, track ready, non street legal, race integras (RSX) for like 11K pounds.


[Modified by Tyson, 2:28 PM 10/23/2002]

 

Head over to improvedtouring.com. Many of them swear by welded diffs.

 

Ah, the elusive LSD question... very few people know the difference.

I am seriously considering pulling my quaife this winter in favor of a clutch-type diff just to see what the difference is for myself. (and then sell the one I like the least). I've only run across a handful of people ever who have driven more than one type of LSD in the same car.

 

I have!! well almost....it was in two RWD cars...but not at all the same....ESP Solo Cobra and EP Road Race 84 RX-7....only problem is the diff in the cobra is shot...it's getting lot's o slip right now....but when it was new it was great!

 

On top of that, most of the people I've talked to that have used multiple kinds are drag racers so that doesn't tell you a whole lot.

 

I Drove my car with a quaife this past weekend and Chris(Rodney)'s car with an ATS... The difference was NIGHT and day. With his you could REALLY feel the inside wheel pull in a turn!!

 

i'd be happy to read about anything you'd have to post about the differences when you finally get around to it. i've only got experience with the quaife, and a torsen-type...

 

Thanks for all the quick replies. I guess I'm really trying to figure out if there's a significant advantage or difference between Honda's LSD and a Quaiffe. Any thoughts on that?

 

Lifetime warrenty on the Quaiffe including racing on it.


[Modified by Geratol, 3:32 PM 10/23/2002]

 

Can anyone comment on the performance difference of the honda LSD vs the Quaife?

 

The most important difference is what's referred to as the Bias Ratio - how many times the torque of the inside wheel that the outside wheel gets. This is done by friction locking up the axle pair - whatever the specific mechanism. Problem is that it's not a spec you can easily lay your hands on for all options.

Gear type LSD's like the ITR have modest bias - that's why some of us wear out the inside fronts surprisingly fast. Quaiffe's appear to have a higher bias ratio. These diffs are open under decel and turn in is unaffected.

Clutchpacks usually express this in terms of ramp or cam angle. The steeper the ramp the higher the bias (or lockup if you wish). Mugen LSD's have optional high angle ramp kits (which King Motorsports run in the Grand Am car). Cutchpacks have decel ramps too. If the decel ramp angle is the same as the accel ramp angle we call it a 2-way diff, if the decel ramp is softer / half (as it happens) we call it 1.5 way.

Welded diffs or spools have max bias obviously. But you pay for that in the turn-in zone with a tendency to push the front end. It also go's very badly for you if you break an axle or cv under power because the car will abruptly turn in the direction of the break. Alot of people have done very well on a solid diff however.

After 5 years good service from my ITR diff (including lots of curb hopping under full power), I'm planning on running the steep ramp 1.5 way Mugen setup next year. Scott Zellner told me that Bob Endicott likes the Mugen better than a Quaiffe, but that Pierre likes the Quaiffe better.

The lockup of the add-on / slip-in type accessories is widely considered to be inferior. Maybe with a really low power car on a really low budget they make sense.

John - you are gonna NEED an LSD as soon as you can fund it. If you can afford a good clutchpack or a Quaiffe, then fine. If you've got to keep cost low, try to find an ITR diff to tide you over for a while.

Scott, who thinks a good self funded regular guy privateer race car and driver development program takes about 10 years worth of time and money........maybe more...I'm working on it.....


[Modified by RR98ITR, 3:52 PM 10/23/2002]

 

Scott, a couple questions on the mugen piece:

- Am I reading correctly that the diff comes 2-way ($1200), then you buy whichever pressure ring set (45-20 or 58-200 ($300) to convert it to a 1.5-way?

- If you want a speedo, do you have to buy the mugen speedo gear or can you transfer stock?

- Are you comfortable that mugen will offer replacement parts long enough for you to be done with the diff? This is my only concern with the japanese-made clutch diffs. They're being made for a discontinued tranny, primarily for a market that will quit using them long before we will.

 

how come no one has made a mention of Kaaz? from what i had been hearing previously they were one of the better ones..do you guys not agree or?

 

Yup - you gotta spend $1500 to go with the 58-20. Scott says alot of people use them as they come (2-way) and like them, but I'm gonna go for what makes sense to me (and what Bob happens to prefer.)

I don't know nuthin bout the speedo issue.

I've thought about the parts issue. Scott says I can get several years troublefree service out of it. I'm considering buying a rebuild kit just to be safe. I think I trust the Japanese at least as much as I trust the British.

Scott, who may not have any money left for next years race entries and tires....

 

Damn Scott beat me to it...

I've autocrossed with no LSD, a stock ITR unit, Quaife, Mugen 2-way, and a Prelude SH which is a bit of its own animal.

I've also been to HPDE's with all of the above.

In autocross it's the Mugen 2-way hands down. There is benefit, IMHO, using a 2-way at autocross where moving the rear end quickly is key to getting through some turns. Second place was the quaife, but it is very close to the stock ITR.

On the track, depends on the track, I'm up in the air. Depending on your style and the track, a 2-way can get you in trouble with agressive off throttle action.

Gotta run to dinner. Just my $.02.

BTW - Bob Endicott ownz......

 

Thanks Scott. I've got a bead on some JDM factory LSD that'll fit my tranny. Price seems to be pretty reasonable (less than half the price of a Quaiffe). Just wondering if the Quaiffe is a better unit.

 

I thought that the ITR & Quaife were very similar.

John, they have lsd for the our trannies? I think if it will fit yours it should fit mine. You are running the D15 right? I have the D16.

Quaife have come down in price, so I have been told.

Scott, Do I really need a LSD? Damn. The money I just spent on a welder could have gone to that. I guess I should have put one in during the rebuild.

 

Yes, similar. But they have different bias ratios from what I gather.

Yeah - you need. Hmmm, welder huh? Well, ya could Weld up your diff......kinda scary....

Scott, who knows lots of people with welded diffs.....sometimes they fail.....but what doesn't occassionally...right? <cringes slightly>

 

not 1st hand info, but on other lists people who went from ITR LSD to Quaife said there's a notiable improvement. ITR LSD is pretty slow, inside front still spins a lot and I agree with Scott most of the inside front tire wear comes from the inside front tire spinning. having lot of negative camber also means inside front's traction is even worse, and spins even more.

 

Just get the ITR LSD and a JDM final drive for the same price as the Quaife and be much happier

 

I have the ITR LSD in my GSR and while it works fine, I'd like something more aggressive.
I have autocrossed a CRX (yes, I know it's a different car but bear with me) with the Mugen 2 way and the difference was incredible. At an autocross, even with the ITR diff, I have to be very gentle with the throttle or the inside wheel will spin and cause my car to push. With the Mugen diff, the torque transfer is so strong that it jerks the wheel in your hands (in a 100hp car no less) and the car actually tightens it's line as you add throttle. My first run I was smashing apex cones all over the course.
I've heard that the Kaaz 1.5 way performance is similar, but I have never driven one.

Whenever I need to go into my tranny again, I'll be upgrading the diff (if I have the budget at the time). Again, the feel of a FWD car tightening it's line as you add throttle puts a big assed grin on your face.
I highly recommend it.

 

Mike, our trannies are the same except for gear ratios. Apparently there's a Japanese D15??? with factory LSD. I'm looking into getting that and the Si/EX final drive (4.250). I'll know more in a few days. If it works out, the parts will ship Monday.

I was just trying to decide weather to jump on this deal, or save a few hundred more and get a Quaiffe. I think since I have a good deal on the table, I'll see it through.

 

It's the D15B. SOHC VTEC with an LSD. A guy in Ann Arbor has a del Sol VXi imported from Japan with that engine in it.

Also, I wanted to ask. I understand the different types of LSDs, but what exactly is a welded diff and how would one go about doing it?


[Modified by happycorepuppy, 6:45 AM 10/24/2002]

 

My only comment on clutchpacks other than the Mugen is that I don't know anyone who uses them successfully.

King Motorsports actually uses a Mugen and actually wins championships in US Pro endurance racing and actually has had excellent mechanical reliability and longevity.

That's a whole lot more credible testimonial than "My friend has a XXXXX and just loves it."

Kaaz differentiates their product on the basis of bigger diameter disks, but that's a useless difference if the Mugen works just fine with smaller disks.

I need a really good reason for something that important to go on my car. Saving a few hundred dollars doesn't qualify as that sort of reason in the absence of obvious demonstrated success.

The stock ITR diff, and the Quaiffe are well known quantities too - you know what you're getting with them.

Scott, who has learned the hard way (over and over) that doing it right the first time is actually cheaper.....