Syncro 4&4 Discussion and Q&A last answered over 2 years ago.
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max and caddy wrote:Did some quick calculations earlier and found out that a 5.43 with a 0.70 (albins)4th gear fitted has the same road speed at 3200 rpm as a 4.86 with a standard .78....this surprised me and changing the cwp s is a much more effective method in my veiw.....
This is similar to what I had Aidan do when I got my box and diff refurbed. I had Aidan fit a petrol 4.86 CWP to a 5.83 diesel box. I wanted it done this way as it would be using VW standard parts. I get a nice 100 kph @ 3000 rpm running 225/70/15. The only downside is that while you loose the big gap you get running a 0.70 Albins 4th gear, you now get a bigger gap between all the gears but a decent AAZ / 1Z etc hides it ok.
£350 per pair..not per cog...I'm actually fairly keen to fit a stronger 4th gear as the fine tooth vw 3 and 4 look weak to me...if I can keep a standard 3rd and improve ( drop ) the revs a smidge in 4th so 70 can be hit at 3000 I think that will do....also keep the gap between 3 and 4 somewhere near normal..
max and caddy wrote:Did some quick calculations earlier and found out that a 5.43 with a 0.70 (albins)4th gear fitted has the same road speed at 3200 rpm as a 4.86 with a standard .78....this surprised me and changing the cwp s is a much more effective method in my veiw.....
This is similar to what I had Aidan do when I got my box and diff refurbed. I had Aidan fit a petrol 4.86 CWP to a 5.83 diesel box. I wanted it done this way as it would be using VW standard parts. I get a nice 100 kph @ 3000 rpm running 225/70/15. The only downside is that while you loose the big gap you get running a 0.70 Albins 4th gear, you now get a bigger gap between all the gears but a decent AAZ / 1Z etc hides it ok.
Cool beans...the 4.86 is what I have lined up...from an AVN petrol . 225 70 15 must be close to 215 75 15s...but with a vw .78 4th I work it out at 65.3 mph at 3000....to hit 70 needs a different ratio 4th...
Every gear is a pair...like the crowns whe'll and pinion...7 teeth on the pinion...44 on the ring for example...
It's a "gear set" for £350...one spur gear...one shift gear with replaceable syncro cone..nice!...all cut in strong tractor profile rather than the vw fine tooth offering.
I love the fact that so far no one has a definative answer brcause everyone is running different TDI setups, different CWP, Different 3rd and 4th gears and different weight vehicles.
The ultimate for me would be 225 70 16 with 4:57 with .77 4th and the equivalent of 5:83 G gear.
True..all different...no options on G gear though...or first...only 2 on 2nd...and 3 und 4 has many possibilitys....getting reasonable motorway rpm is my main objective....G gear will just have to deal with it...can always fit 14s for the 2 off road days a year when I get there!
jed the spread wrote:...the van got very very hot, the heaters had to be turned on full, I had to use the manual rad fan over ride switch and it was still very very hot.
If the coolant temp is up, and using the "manual over-ride switch" does anything at all, then you've simply proven that your automatic fan switch isn't working - nothing more or less.
If the rad fan, on high speed, can't keep the coolant temperature under control, then you need to be upgrading - or simply repairing - either the rad or the fan or both.
jed the spread wrote:...the van got very very hot, the heaters had to be turned on full, I had to use the manual rad fan over ride switch and it was still very very hot.
If the coolant temp is up, and using the "manual over-ride switch" does anything at all, then you've simply proven that your automatic fan switch isn't working - nothing more or less.
If the rad fan, on high speed, can't keep the coolant temperature under control, then you need to be upgrading - or simply repairing - either the rad or the fan or both.
I see where your coming from and in theory your spot on if I was putting the manual over-ride switch on manually when it was hot and it should have (and it does) come on automatically, but I wasn't. I found with the AAZ as soon as the turbo starts giving it some up steep hills the temperature would rise quite quickly. They run quite hot at the best of times so when you see for example the road up a mountain pass that goes up thousands of feet I would put on the highest speed on the two stage fan straight away, this would start to cool the van down straight away and buy me a valuable couple of minutes as I reached the top of a few areas allot higher than anything in the UK. I found this technique worked well most of the time in mountain areas.
Like you say, If the fan is on high speed and cant keep the engine under control you need an upgrade and my point from the beginning. The AAZ is a good engine for the UK or roads like we get in the UK.
Its good to get a comparison from theory driving and practical driving though but I can only tell you what happens to me as an owner of an AAZ and TDI and Syncro.
max and caddy wrote:I have never heard mine come even with the AAZ! It's running to cold now in fact with the 80c stat fitted...
Never heard mine either.
Infact, only time I've ever heard one on the second stage was when it was dieing, last time on my own van was when my mTDI died on the M56 while racing on a standard 3H box
