Quaife question

J

Joe Craven

New member
I recently drove my friends VW GTI in a local 25 hour enduro race and wonder if it really has a quaife. We removed the front sway bar from his car, rear has really stiff bar and we still experienced inside front wheel spin.

Is there an easy way to determine if a Quaife is actually installed. For example, with the wheels off the ground, should one be able to turn one of the wheels if the other is held tight?
 
Even with a Quaife you will get wheelspin. Especially if you unload the inside wheel while cornering hard. It happens in my ITC scirocco in turn six at Summit Point.
I bought the scirocco already built, my other cars have a welded spidergear diff which I like much better.
Try softening up the suspension more(lighter springs)that should help.
cheers
dave parker
wdcr ITC#97
 
Joe, that's why the suspension setup is totally different if you run a locker or a LSD.

With a LSD, with the front of the car off of the ground, you should be able to rotate one wheel, and have the other wheel rotate the same direction. If it goes the other way, then you have an open diff. (I think)

With a locker, they both spin the same direction. I have a quaife in the Scirocco, but haven't yet driven it, or tested out your theory. Want to buy it?



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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit
http://linerud.myvnc.com/racing/index.html
 
Yes, if you have a Quaife and jack up one front wheel you can turn it (if the car is in neutral) with the other wheel on the ground.

Many people misunderstand how a Quaife works. It locks up under drive torque, up to a point. The diff splits the drive torque according to how much traction each wheel has. As a wheel unloads, the quaife will split the torque so that the unloaded wheel gets less torque. However, if you unloaded one wheel completely (i.e. no weight on it) then it will spin. The Quaife has what is known as a "bias ratio" which is the maximum torque split it can handle. A typical Quaife has about a 3:1 bias ratio, or about 75%/25%. If you unload an inner wheel completely, it will still get about 25% of the drive torque. What most people don't realize is that the outer wheel is still getting 75% of the torque. This is unlike an open diff in which the outside wheel gets 0% and the inside wheel get 100%!

So a Quaife is still much better than an open diff in this respect, but it will still permit a wheel to spin if it is unloaded.

How do you keep the inside front wheel from unloading on a FWD car? It can be done, but if I told you I'd have to kill you...

biggrin.gif


I've raced at Summit Point several times in my Quaife equipped GP Scirocco, which has 140hp, and have NEVER experienced wheel spin in the carousel or anywhere else on the track. It has to do with rebound damping, roll couple distribution, shock droop travel, roll centers, etc.

A FWD car setup properly with a Quaife will almost always be faster than a car with a welded diff. My ITC VW with a VW Motorsports limited slip diff was faster than the same car with a Quaife. This was probably due to the VWMS limited slip being a LOT lighter than the Quaife, equivalent to having a lighter flywheel.

Hope this helps,

MC

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Mark Coffin
#14 GP BSI Racing/Airborn Coatings/Krispy Kreme/Tristram's Garage VW Scirocco
http://pages.prodigy.net/Scirocco14gp

[This message has been edited by racer14itc (edited December 14, 2004).]
 
Mark, yes, a LSD diff takes less "friction" than a locker, but you do gain "traction" with a locker.

I went with a welded diff simply because of economics.

I had the box welded and rebuilt for around $600. That was in 1993. I've not had to do anything to it in over 10 years.

With normal CV, hub, bearing replacements, I've only had 1 inner CV break in 5-7 years of running a locker. I do change the CV's and hub/bearings every year. That's standard maint on a VW.

It was just cheaper to go with locker. I do have a quaife in the Scirocco, but don't to change the entire suspension setup just yet.




------------------
Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit
http://linerud.myvnc.com/racing/index.html
 
Mark,

I had the same problem w/ my old ITB Rabbit GTI. I've got pics of the car w/ the p/s fron t wheel off the ground at the 2nd apex (6B) of the carousel. Sure felt like a lot more than 25% torque split. I always figured that it was because I had too much rebound dampening on the shocks (Bilstein Grp 1), and it was not letting the spring (650#) push the front wheel down fast enough.

------------------
MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Originally posted by Bill Miller:
Mark,

I had the same problem w/ my old ITB Rabbit GTI. I've got pics of the car w/ the p/s fron t wheel off the ground at the 2nd apex (6B) of the carousel. Sure felt like a lot more than 25% torque split. I always figured that it was because I had too much rebound dampening on the shocks (Bilstein Grp 1), and it was not letting the spring (650#) push the front wheel down fast enough.
Click to expand...

Yes, the rebound damping can pull the inside wheel off the ground or not let the spring keep the wheel in contact with the road. On an IT car, the front roll center can easily go below the ground, making the roll axis tilt downward. This makes the car pitch onto the outside front tire and lift the inside front tire as soon as all the rear weight transfer is done (the rear tire comes off the ground). Any more weight transfer will occur onto the outside front and off the inside front (can't come off the inside rear, it's already off the ground!). Since you can't change the geometry on an IT car, the only real solution is to raise the car and use long shocks/springs to keep from pulling the inside wheel off the ground. Most folks have springs that are too short and rattle around at full rebound.

On a prod car, we can fix the roll center problem. The car actually almost prefers to pitch on the outside rear in roll (weird feeling until you get used to it!).

As far as how much torque is going up in smoke with a Quaife, that's hard to pinpoint exactly, but there has to be some torque split going on or else no one would buy a Quaife because they'd be just as slow as when using an open diff. The fact that cars are usually much faster with a Quaife than with an open diff is the proof in the pudding.

As soon as I get my hands on another VWMS close ratio gearset, I'm going to put my VWMS limited slip diff in a gearbox so I can do a back to back test vs. the Quaife in the prod car. I'd be curious to see how much of a difference it makes in a prod car. The VWMS limited slip diff was slightly faster than the Quaife everywhere I raced in the ITC Scirocco.

MC



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Mark Coffin
#14 GP BSI Racing/Airborn Coatings/Krispy Kreme/Tristram's Garage VW Scirocco
http://pages.prodigy.net/Scirocco14gp
 
Originally posted by racer14itc:

As soon as I get my hands on another VWMS close ratio gearset, I'm going to put my VWMS limited slip diff in a gearbox so I can do a back to back test vs. the Quaife in the prod car.
Click to expand...

Here is an e-mail address that can help you get the gear set if you are really looking. [email protected]
Unfortunately with the weak dollar to the GBP, it is a bit pricey. The LSD is 975GBP.

------------------
Ralf
ITB Golf GT
Parked till '06
frown.gif


[This message has been edited by Ralf (edited December 14, 2004).]
 
Interesting comment about the weight of a quaife.

I have one and noticed that it is a porker and thought it may have had some detrimental characteristics as a result. It sure works smoothly, however.

Because of welded diff braking and wet weather characteristics, that is not the way to proceed, but it sure is effective in the dry.
 
Braking with a welded diff? Joeg, what's the issue? You just brake in a straight line, turn in, mash the loud pedal, and hit your apex and exit marks.

What's so hard about that? You have to be on the gas in order for it to steer. Braking isn't an issue with a locker, IMHO.



------------------
Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit
http://linerud.myvnc.com/racing/index.html
 
Braking in the wet...that's my issue with a 220 Diff.

Maybe it's not a problem with others, Tim.

Cheers.
 
I've got some experience with a welded diff in the wet and actually didn't mind it as much as I was led to believe I would. I started to think of the car more as a hydroplane than a wheeled vehicle and, if I just let it have its head when it wanted to skip around, it always came back to me - as long as the power was on. It's not optmimal, probably but it's not deadly either.

I don't mind this conversation at all, by the way - thanks. Mark's input is great, particularly, since I'm getting ready do drop serious dime on the gearbox of the MkIII and I want to look at the problem holistically.

My first choice right now is the clutch-type diff that Bildon can get - it's by the people that make the Honda-application KAAZ units, as I understand it. I too really like the VWMS unit that we had in the rally car and am basing my choice on that experience...

My second favorite option is a spindle and I may go that route simply as an economy measure, depending how much final drive gears end up costing. Were I not going to do other stuff with the car, besides road racing, this would probably be my first choice but loose and unpredicable surfaces (rallycross, hillclimbs) argue for the compliance of a "real" diff.

K

PS - It looks like I will have a surplus 4.25 "small shaft" gearset (used, out of a Jetta TD), if anyone is interested.
 
Just curiosity...Does anyone run a welded diff. in a ITA GTI ? I have heard conflicting arguments about it causes to much damage from to much power.. I just seems to me its logical ,from a "putting the power to the road" sence, to run a welded diff. Wheel spin = loss of time ...right?

John
 
Yeah I was wondering about the front end damage/ wear on the CV's and hubs and bearings... Being a weak spot on the VWs. I know with regular maintenance, it shouldn't be a problem....right?

John
 
>As soon as I get my hands on another VWMS close ratio gearset

Still available...getting wery wery scarce.

List of Products
Part No. Description
ANZ001 02A 6-speed Straight Cut Dog Kit (VW Ratios)
ANZ002 02A 6-speed Straight Cut Dog Kit (SEAT Ratios)
ANA000 02A Final drive selection for ANZ001/ANZ002
DSAJ050 02A Limited Slip Differential for ANZ001/ANZ002
ANJ063 02A Limited Slip Differential (Big Diff.)
COZ000 02A VW '99 DTC Straight Cut gearkit
COA000 02A Final Drive selection for COZ000
DSAJ053 MQ350 Differential 25/45 30/60
ND71278 MQ350 Differential 60/60 70/60

List of Products
Part No. Description
AMZ000 MWAC 6-Speed Sequential transmission
BEZ000 AWFX 6-Speed Sequential transmission
GEARS Gear and Final Drive Selection chart for MWAC/AWFX

List of Products
ANZ009 02A 6 Speed Synchromesh kit
ANZ010 02A 6 speed Synchromesh kit 3rd to 6th gears only
ANZ011 02A 6 speed Synchromesh kit 5th to 6th gears only
ANA017 5th and 6th gear selection chart for ANZ009/ANZ010/ANZ011
02A FD 02A Final Drive list for use with 02A synchromesh gearkits
ANZ008 02A 5 Speed Synchromesh Kit
ND71080 02A 5 speed Synchromesh kit 3rd to 5th gears only
DSAJ051 02A Limited Slip Diff. Assembly (also DTC helical)
ND69882 02A LSD (also DTC helical) - VW Spec. (1-piece crosspin)
ALT000 020 6 Speed Synchromesh kit
ALT002 020 5 Speed Synchromesh kit (gears only)
020 FD 020 Final Drive list for use with 020 synchromesh gearkits
ALJ023 020 Limited Slip Diff. Assembly
ND69901 020 Limited Slip Diff. Assembly - VW Spec. (1-pc crosspin)
DDJ008 085 Polo Limited Slip Diff. Assembly

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Bill Sulouff - Bildon Motorsport
Volkswagen Racing Equipment

[This message has been edited by Bildon (edited January 14, 2005).]
 
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