› Forums › Reference › Tuning & upgrades › VR6 or Rallye tranny? Which is the strongest one?
The Haldex convertion is made by dutchdubs.com but their site is down. Have been in contact with them, but I prefer to upgrade the Syncro system if it is possible. The price will be approxamatly the same if I go with Quaife syncromesh, peloquin diffs front and rear, and do an upgrade of the VC.
A Swiss company does the VC upgrade, do anyone on this forum know who it is?
The parts you refer to are not the weak point in the syncro system. The main weak points are the angle drive, the rear diff bevel gears, and the rear diff spragg clutch(freewheel clutch). These are the parts that most commonly fail with high HP. Installing Front And Rear Peloquin LSD diffs will only increase the stress on the above mentioned parts, causing more frequent breakage.
I found some interesting reading on VWVortex. I’m posting the links here as a reference for future use.
Dis-assembling a syncro rear diff:
http://forums.vwvortex.com/zerothread?id=2733750
&
http://forums.vwvortex.com/zerothread?id=2645727
Broken Syncro rear diff Spragg Clutch:
http://forums.vwvortex.com/zeropost?cmd=tshow&id=3122615
VW Motorsports Modded rear diff info:
http://forums.vwvortex.com/zerothread?id=2742541
A discussion about bad Haldex rear diffs.
http://forums.vwvortex.com/zerothread?id=3094467
I got a mail from a VC specialist. He writes:
I have some factory OEM stiffer brand new VCs here.
But I think they make them stiffer by changing the amount of air, not
by using stiffer fluid.
It is not generally very successful to refill your own VC for the
reasons I point out.
There is no place to buy the fluid that I know of.
See also some of the links below.
Derek Drew Washington, DC
derekdrew@derekmail.com (NEW 4/2006) Phone 202-966-7907
(derekdrew@derekmail.com is old and should be changed to the above)
Email me for viscous coupling s (Cell 703-408-1532)
’90 Syncro Westfalia…
…seen off-road at
http://users.rcn.com/derekdrew/Syncro_Madness_Area.htm
…seen with 30.5″ tall tires at
http://users.rcn.com/derekdrew/vanagon/images/dereks245_75_16.jpg
Note: most valuable Vanagon sites on the planet (for owners) are:
http://gerry.vanagon.com/cgi-bin/wa.exe?S1=vanagon
http://gerry.vanagon.com/files/
http://groups.yahoo.com/group/Syncro
http://www.vanagon.com
http://www.syncro.org
Many of my Syncro list postings consolidated
http://groups.yahoo.com/group/Syncro/messagesearch?query=212-580-6486
http://groups.yahoo.com/group/Syncro/messagesearch?query=202-966-7907
My refrigerator article:
http://www.vanagon.com/info/articles/Refrigerator/Reefer_Madness.htm
All About 16″ Wheels And The CV-900.htm
http://users.rcn.com/derekdrew/vanagon/All_About_16-Wheels_And_The_CV_900.htm
All About Viscous Couplings
http://users.rcn.com/derekdrew/vanagon/viscous_couplings_vanagon_syncro.htm
Grab rates vs rpm of VCs
http://autos.groups.yahoo.com/group/Syncro/message/17172
Notes on off-roading and decouplers
http://autos.groups.yahoo.com/group/Syncro/message/24615
How To Live With Heavy List Volume–Mail Filters
http://groups.yahoo.com/group/Syncro/message/7403
My tutorial on how to strengthen your skid plates for off-road driving
http://www.syncro.photosite.com/ and after clicking on that click
on the image that says Skid Plates / Reinforcements and work your way
through the 10 photos. BE SURE to notice the text that is
below some of the
pictures, as it clarifies what the point of some of the pictures is.
My article that shows how to deal with insurance companies:
http://gerry.vanagon.com/files/auto-insurance-madness.html
To read some material about how to add a front differential lock to your syncro
http://groups.yahoo.com/group/Syncro/message/13105
To view Wolfgang’s incredibly informative wheel article
http://users.rcn.com/derekdrew/fitbigtiresonvanagon.htm
To view Tim Smith’s incredibly useful gearing calculator
http://users.rcn.com/derekdrew/syncrotireandgearratios.xls
To view two articles about how to think about improving your gears at
transmission rebuild time
http://groups.yahoo.com/group/Syncro/message/7207
http://groups.yahoo.com/group/Syncro/message/7221
To view an overview article about choices in larger sized tires see
http://groups.yahoo.com/group/Syncro/message/11535
To view some 16″ Trailing Arms that enable much larger tires see
http://groups.yahoo.com/group/syncrolist/files/Wheels%2C%20Tires%20%26%20Gearing/Wheel%20%26%20Tire%20Photos/16_Inch_Trailing_Arm.jpg
My article about belt protectors and CV joint protectors
http://groups.yahoo.com/group/Syncro/message/6112
SYNCRO OWNERS WHO DRIVE OFF THE ROAD:
You only get to change your ring and pinions once every 10 years because that’s how long the average syncro transmission goes before its next rebuild. If you want bigger tires and more ground clearance start planning your higher number ring and pinion sets right now so you can take advantage of your next trans rebuild.
Vanagon Vendors For Parts To Consider At Problem Time
http://www.van-cafe.com (parts and repairs too)
http://www.busdepot.com
http://www.vanagain.com
http://www.2weddle.com (drivetrain and transmission parts)
http://www.aatransaxle.com (transmission repair)
So what is the best possible upgrade of the entire Syncro system if money is not an issue? And how much Hp and torque will it be able to handle?
Speak up, experts!
replace the entire drivetrain with a custom made one to your required spec
That’s exactly what I aked you guys for spec suggestion for.
Any suggestions?
quote:
Originally posted by dannypreplace the entire drivetrain with a custom made one to your required spec
Probably Haldex as it will handle lots of both, or there is a French V8 in line (not transverse) conversion using (I think) Audi Quattro parts that has to be the ultimate
quote:
Originally posted by Chris SProbably Haldex as it will handle lots of both, or there is a French V8 in line (not transverse) conversion using (I think) Audi Quattro parts that has to be the ultimate
I’m trying to optimize the Syncro system. What is possible to get out of it?
Well we don’t know how strong haldex is yet, there were rumors that it could take 800 bhp but nothing said about torque, and there are so few cars running it so there haven’t been meany breakages yet, and its still unknown, but it’s probably likely to be around the 500 mark.
As for what the syncro system can handle and to what extent it can be upgraded entirely depends on what the car is doing. high speed cross contry or road races will break gears, Audi a2 turbo gears are stronger but they are very good till 300 but after that keeping the power on while airborn is a big no no, especially in 3rd, for drag racing the back diff and angel drive get it, there is suposed to a skoda setup thats tougher but how tough is anyones guess.
quote:
Originally posted by Vegard
I’m trying to optimize the Syncro system. What is possible to get out of it?
[/quote]
To run relatively safely without to many breakages, I would suggest not more than 140 BHP for the standard Syncro 020 rod change box, or 175 BHP for an 16v uprated Syncro conversion box fitted with a diff bolt kit.
For the standard 02C cablechange box a maximum of 220 BHP, or with an early Rallye ASU code box fitted with a a cast iron transfer box & diff bolt kit 275 BHP.
Other later gearboxes will withstand more power & abuse!
I realise that these figures are on the conservative side considering what power people have put through these boxes and they only express a personal opinion of what I would be happy to run with and are not absolute figures,
but as a general rule of thumb the formula is more power = more breakages, well actually its more torque = more breakages and once you get over 250 BHP you will also start to encounter problems with the rear diff,
Driving style also has a lot to do with how long the drivetrain will last,
Thank you for constructive answers!
And now to the Syncro upgrade part, what is possible to uprade?
Who can do it?
Where can I buy parts?
How strong will it be?
Have anyone done this before?
And at last another tread about the same issue:
http://forums.fourtitude.com/zerothread?id=2714614&postid=30736879
As said Audi a2 gears are tougher than stock ones, after that it’s aftermarket and custom ones, any good gearbox builder should be able to point you in the right direction.
It all depends how much of the syncro system you want to retain and how unlimited the unlimited funds are, it may be worth looking at the gearbox Ford are using in there Fiesta rally car as that has a viscous 4wd system that it may be possible to transplant.
I think Haldex will be the cheapest option mainly due to the drivetrain being so availible and for very little money, also in theory my ecu should be able to control it.