Club 80-90 Forums

silverbullet wrote: Is the Polo supposed to pass at higher or lower pressure than the 719/12? I honestly can't remember the figures for either...

I can't remember either. I read it on here somewhere though - I'm sure it was one of your posts

scottbott wrote:stuck my head under the van today and I can put my fingers between the exhaust and the end of the pushrod cover easily

That's quite a difference then. Was the gap that big all the way along? On mine there's a kink in the J-pipe approximately mid-way along the pushrod cover, which means I can get my fingers in the gap at the pulley end, but it tapers down to 1 or 2mm at the flywheel end.

CJH wrote:

silverbullet wrote: Is the Polo supposed to pass at higher or lower pressure than the 719/12? I honestly can't remember the figures for either...

I can't remember either. I read it on here somewhere though - I'm sure it was one of your posts

According to the Mann catalogue website, the T25's original W719/12 has a bypass pressure of 1.00 Bar. The Polo's W712/52 has a bypass pressure of 2.5 Bar. So I guess that's better in that it's less likely to be bypassed, but combined with the smaller surface area I suppose there's a greater chance of the paper element ripping. Still, it must have been designed to stand at least the 2.5 Bar bypass pressure.

Interestingly that catalogue page has a useful search facility, which allows you to look for a filter according to dimensions, bypass pressure, thread size etc, and there seems to be another one that matches the spec of the original W719/12 a bit more closely. The W713/19 is identical in every respect, but is only 23mm shorter (rather than the ~43mm of the Polo's, after the removal nut is taken into account).

There are also a couple of others with the same dimensions as this one, but with a slightly higher bypass pressure (1.50 Bar), if this is deemed a good thing. The W712/2 has 2 anti-drain valves, and the W718/2 has one, like the original filter.

Now that IS useful! Well done Chris

Thinking about the bypass pressure a bit more, by specifying a 1 bar valve pressure I reckon VW's engineers decided that it was better to allow a bit of unfiltered oil into the system than to let the filter drop more than 14.5 psi. So by fitting the Polo's 2.5 bar filter, the filter can potentially rob the oil of up to 36 psi in extreme conditions. As you say Ian, it's probably only in extreme conditions that this could happen, but on balance I think I'll stick with VW's decision and go for the W713/19 with the 1 bar valve. It's also better than cutting the spigot and making the original filter fit I think, since the end of the filter will be a lot further from the hot exhaust.

Just for completeness, as far as I can tell from Googling, the standard interwarmer is 55mm deep, which is about 20mm more than the Mocal sandwich plate I'm using, so the W713/19 may not fit if using that interwarmer. If that's the case, then the Lupo filter W712/54 looks like it may be a better choice than the Polo one normally used. It's the same overall length as the Polo one, but without the removal nut on the end so the filter area is probably bigger, and it has the same 1.00 bar relief valve pressure as the original T25 filter.

A visual comparison:

The correct T25 filter is on the left, the Polo filter that's often used with the Speedshop exhaust is on the right, and in the middle is the biggest one I can find that will fit my setup, with the same 1 bar bypass valve pressure as the original.

I can't tell if it would fit a setup that has the original DJ oil cooler. It's only 7mm longer than the Polo filter, so to anyone that has the original DJ oil cooler you should be able to judge whether it would fit in place of the Polo filter. One thing to remember is that it doesn't just have to fit in the gap, but you have to be able to get it square on to the spigot, so the length of the spigot protruding through the cooler could be the constraint. If the W713/19 won't fit then as already noted the Lupo's W712/54 is the same overall length as the Polo's, so ought to, but I suppose it's still possible you won't be able to get it onto the spigot - it doesn't have the removal nut on the end and it may foul the exhaust.

713/19 looks like a very good compromise.

has this been wiki? as this was very handy for when i had my exhaust fitted

Superal wrote:has this been wiki? as this was very handy for when i had my exhaust fitted

What combination did you go for? I'm guessing you've got the standard 2.1 oil cooler and went with the 713/19. Did it go on the spigot easily enough with the Speedshop exhaust in place?

Roydini wrote:I also chose to replace the engine mounts - I received mixed advice on here about whether or not to bother doing this but decided to go ahead anyway as the early vans don't have the 'cradle' to support the silencer and I wanted to reduce the engine vibrations as far as possible. Again, this might have been overkill, time will tell

I am about to install a speedshop exhaust on my 1.9 engine and am not convinced about it having no supports other than the muffler being strapped to the manifold so the full weight of the system just hangs off the exhaust studs. I am considering installing the 2.1 engine mounting bracket to allow the exhaust to be mounted to this somehow but can't work out how this would be done.

The speedshop exhaust has a short muffler which looks like it completely misses the left hand exhaust mount on the 2.1 engine mount and looks like it only just make the right hand exhaust mount. But the speedshop muffler is an oval shape and the manifold sits behind it so I am not sure how you would mount it even if it did line up with the right hand mount.

Any ideas or photos on how to mount this in the 1.9 would be appreciated. Or is this overkill and there are no issues with the speedshop exhaust cracking without additional mounts?

my speedshop exhaust has been on for about 3-4 years no problems at all,on a 1.9 DG motor

The very early systems suffered with cracking at the support, which was welded into the silencer. This has been addressed by redesign, using a stainless strap around the silencer. It seems to work. I've not heard of any problems with any of the many systems I've fitted. I now keep them on the shelf, as everyone seems to want one and Speedshop often run out of stock.

Andrew is bang on the money here, as always. The early systems had issues but the one you'll buy could run without the rear tail box strap, it's that strong. It'll bounce though so suggest using the strap Speedshop provide, bit ugly mind.

...and this is why the forum is a useful repository of information