Different system for the same function. Make your choice.

 

2 way LSD is not really ideal for FWD cars. I dunno why the Mugen kit is 2way, then offer a separate kit to reconfigure it to 1.5.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wai &raquo;</TD></TR><TR><TD CLASS="quote">2 way LSD is not really ideal for FWD cars. I dunno why the Mugen kit is 2way, then offer a separate kit to reconfigure it to 1.5.</TD></TR></TABLE>

So you have to buy both

 

The Mugen kit can be ordered with 2way lockup but 1.5way is standard. There are also 2 different types of cam angle plates that control lockup for both setups.

If you don't need driver specific tuning, do not want to deal with overhauls or expensive LSD fluids the Quaife is your only choice!

1.5way is the best for fwd circuit racing and togues (mountain runs) and you can get away with using a 1way for straight line ONLY use. 2way LSD are reserved for extremely experienced drivers who like to late brake and have no problems dealing with the oversteer produced by a 2way LSD locking on decel.

Read this post for more LSD info.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dee &raquo;</TD></TR><TR><TD CLASS="quote">2way LSD are reserved for extremely experienced drivers who like to late brake and have no problems dealing with the oversteer produced by a 2way LSD locking on decel.</TD></TR></TABLE>

The above statement in bold is not true.
For FWD cars, 2-way LSD would induce understeer at turn in because during deceleration (foot off gas), the outside front wheel would spin faster than the inside one. So the LSD would restrict the motion of the outside wheel (as opposed to the inside wheel during *acceleration*) and cause understeer.

 

it sounded authoratative and impressive anyway....

 

Both Quaiffe and Clutchpack work like this in simplified terms:


* They "lock-up" the inside wheel to the outside wheel.
* They "lock-up" the wheel with less grip to the wheel with more grip.
* They "lock-up" the wheel going slower to the wheel going faster.

Where the amount of lock up is dependent on engine torque output or differential axle torque.

In corner entry under brakes or not, the outer wheel is running faster about a longer radius than the inside wheel. This differential in speed will rotate the cams about the pinion locking both wheels to the diff carrier and hence each other (less so in the case of the 1.5 way diff). It's most conventional to designate the wheel with the most traction as the Master, and the wheel with less as the Slave. Thus we say we "overspeed" the inside wheel, resulting in an understeering moment about the CG, rather than say "the LSD restricts the motion of the outside wheel", though it's correct to say both "accelerate the inside" and "decelerate the outside". The resultant moment about the CG is the same no matter how you parse it.

This suggests how interesting it would be to play with Ackerman on a FWD car, since you would be changing the moment arm length between the inside wheels thrust vector and the CG.

Scott, who finds the Mugen diff with 1.5 kit to be benign during corner entry. But I hear Pierre prefers the Quaiffe.

 

The biggest difference is clutch pack LSD's can be setup to lockup fast or late and the amount of torque needed to make the packs slip can also be adjusted.

Both setups are awesome and have their advantages.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">Thus we say we "overspeed" the inside wheel, resulting in an understeering moment about the CG, rather than say "the LSD restricts the motion of the outside wheel", though it's correct to say both "accelerate the inside" and "decelerate the outside". The resultant moment about the CG is the same no matter how you parse it.</TD></TR></TABLE>

Scott thanks for putting it into the correct terms. You know I'm not a good writer at all.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">]This suggests how interesting it would be to play with Ackerman on a FWD car, since you would be changing the moment arm length between the inside wheels thrust vector and the CG.</TD></TR></TABLE>

When you say "play with Ackerman", do you mean simply playing with the front toe setting? Or changing the actual suspension components?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wai &raquo;</TD></TR><TR><TD CLASS="quote">...When you say "play with Ackerman", do you mean simply playing with the front toe setting? Or changing the actual suspension components?</TD></TR></TABLE>

Ackerman is dynamic toe change as the steering wheel is turned. More Ackerman means more dynamic toe out. Static toe settings are "carried" thru into dynamic toe, but of course there's a limit to how much static you can use. IF an application could benefit from more toe out while turned, and you couldn't take any more static, you'd do it by adding Ackerman.

You control this with the angle of the steering arms on the upright, or the longitudinal position of the steering rack.

You can find numerous opinions on how much Ackerman (Positive or Negative) is appropriate for which application (Banked Oval, Road Race, etc) - it's extremely controversial, and most people arguing about it haven't actually tested it extensively, they're just parroting some line of dogma. In their defense, testing any of the finer points is extremely tedious and expensive, you can't blame them for simply throwing in with what makes sense to them.

It's not easily changed on most production cars. I'm planning on spending some time modeling the DC2 and maybe I can play with it a bit in 2005.

Scott, who may find no worthwhile benefit in that excercise...but after a point what can really compete with more power eh?

 

Ackerman = Voodoo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Ackerman = Voodoo </TD></TR></TABLE>

RJ, sometimes you're just SUCH AN ***! &lt;shakes head&gt;

 

Either way, a heavy improvement in both aftermarket setups over the stock units. I personally tend to drive alot of back roads and track time so the clutch packs quick lock-up agrees with my driving style heavily. I think if you were a "smoother" driver the quaife could be quite agreeable.

 

Scott can you recommend a fair priced decent laser alignment kit to determine Ackerman?

what do you use as your centerline reference BTW? (ie. frame rail reference for carpenter's square)

I know you spoke against altering the tie rod lengths in the past. Have you had a change of heart?

 

Tuan,

I think I was advising somebody not to fool around with bump steer correction using cheap hardware and crude methods.

I don't have any laser equipment recommendations. I played with some borrowed turn plates once but didn't do very well with them.

I'm still in the string age.

Scott, who doesn't have any centerline reference, just a squared box around the car...

 

analog works for me.

I think most of us are in the string age as well.

I was thinking you used a laser to determine Ackerman since it's the only recommended method amongst the paddock folks.