Does a Quaife help?

[Joe Craven]

I've been running GTI Cup recently and we've been averaging about 6 car fields with very similar modifications. It's a spec class but we've been playing with the various specifications as a group to make our cars more fun (basically make them faster!)

Parts that are the same include
Rabbit or GTI chassis A1
Same engine prep 1.8 IT type
Same Transmission
Same shocks (Bilstein Sports)
Same spring rates (~500F/350R)
same sway bars etc. (I don't run a front bar)
Toyo RA1 tires

Some of us run a header and a couple of us have Quaifes.

The interesting thing is that the racing has been close and we are unable to notice a difference in handling or performance when comparing the open diff and Quaife cars. Headers don't seem to make much of a difference either as we race down the long TH straights. Here is a link to a pdf file showing lap times with Bailey and Suarez having Quaifes in their cars.
http://home.infostations.net/GTICup/GTI-Cu...mber%202005.pdf (http://home.infostations.net/GTICup/GTI-Cup%20Points%20Standings%20September%202005.pdf)

Driver ability is pretty close and Neville has recently stepped it up and competed GTI to GTI with his open diff which negates the theory that my car is the only fast open diff car.
One might conclude that Thunderhill doesn't require a limited slip but Infineon does. I don't know but we will have more data next event since it will be at Infineon.

BTW, the times are decent and compare reasonably well with competitive ITB cars, especially if one adjusts that GTI Cup is on Toyos rather than Hoosiers.

[Bill Miller]

Joe,

Those cars don't make tons of hp, so I'm guessing that you can probably set the car up to work fairly well w/o one. However, it will probably help you squeeze out some lower lap times, once you've got everything else optimized. Just make sure you get it shimmed pretty tight. Still won't stop wheel spin of an unloaded wheel. I was really surprised when I changed to a Quaife in my old ITB Rabbit GTI, and it wasn't 1-2 seconds a lap quicker, right out of the box, at Summit Point.

[Bildon]

Originally posted by Bill Miller@Sep 16 2005, 08:11 AM
Still won't stop wheel spin of an unloaded wheel.
60368


I concur...

Also you don't have to settle for a Quaife anymore. The clutch type diffs are once again available for our cars and relatively "cheap" too. :023: No more Gemini pricing!

My experience: Quaife, helps with traction to the point where you lift a wheel. And they are tremendous in the rain! Peloquin is a better deal and every bit as good on quality.

The clutch type is the way to go however. It's a no compromise racing diff. Our Corrado was burning the inside tire up in it's SSA configuration. Once we switched to the VWM type diff... all our traction problems went away. :happy204:

Clutch Diff (http://www.bildon.com/pub/Diff/)

http://www.bildon.com/catalog/Admin/photos/thumb/kaaz_DBV1810.jpg

[racer14itc]

Originally posted by Bildon@Sep 16 2005, 05:53 PM
I concur...

Also you don't have to settle for a Quaife anymore. The clutch type diffs are once again available for our cars and relatively "cheap" too. :023: No more Gemini pricing!

My experience: Quaife, helps with traction to the point where you lift a wheel. And they are tremendous in the rain! Peloquin is a better deal and every bit as good on quality.

The clutch type is the way to go however. It's a no compromise racing diff. Our Corrado was burning the inside tire up in it's SSA configuration. Once we switched to the VWM type diff... all our traction problems went away. :happy204:

Clutch Diff (http://www.bildon.com/pub/Diff/)

http://www.bildon.com/catalog/Admin/photos/thumb/kaaz_DBV1810.jpg

60397


I'll 2nd the recommendation of the clutch type diff. I have two of these (cam & pawl - Gemini? and the VWMS limited slip) and love them. The Quaife is a good compromise but I think the clutch types are indeed faster. :023:

MC

[Marcus Miller]

Joe,

Did you guys open up springs yet?

I bet some stiffer rear springs would make the thing rotate better, wouldn't it? Might help ward off any push the front diff provides...
I wonder what the IT guys are running for spring rates?
Marcus

[Joe Craven]

I don't think any limited slip or locked diff would have helped much that weekend because my car barely spun the inside front wheel even with my open diff GTI. I notice a bit of spin on real tight slow speed corners but not enough that forces me to lift off the gas. Add a few hp and speed and my comment might differ.

We have removed the spec springs and sway bar requirements but retained the Bilstein Sport shocks with stock damping. The stiffened spring rate of about 500/350 seems to be the primary improvement in reducing front wheel spin. The prior GTI springs seemed about 300/200 and the Quaife cars were noticeably faster in a couple of turns at TH with the softer springs, front and rear spec sway bars..

I would like to run stiffer rear springs but common opinion on this list is that the stock valving on Bilstein sports won't support it. I run the rear tires at 70psi hot which definitely helps the car rotate. Sometimes too much!

[Bildon]

Originally posted by Joe Craven@Sep 19 2005, 09:49 PM
stock valving on Bilstein sports won't support it.

60635


You could run the V36 and B46 race shocks. They can deal with 400+ without revalving.
Over that and you should really be getting the revalved. Heavier Golfs (A2/A3) can deal with 500# (un-revalved) on the similar VE3 / BE5 since the car is heavier and has a lower natural frequency than the bunnies.

[Marcus Miller]

Interesting. the trade off would then be to
stiffen the rear springs, stiffen the valving in the shocks, and pump down the tires.. a lot of money for litle gain, if the "well beyond manufacturers recommended spec air pressure" does a good job of creating rotation. :rolleyes:

Marcus, who will stick to his rally car like Pro7, and ITA/7.

[Bryan Addis]

Our Tranny went out during the 12 hour at Nelson. "Driving a VW Scirocco" The crew told me it would not hold in the corner cause the Quaife was gone. they told me this just as I was heading on to pit road...In the DARK mind you. I didn't notice any difference at all in traction. Good place to save a buck or two especially in endurance racing.

Just my opinion on that last part.