Let the tinkering get serious!!....

Partial flow mate, open ended, basically a big cat. Never blocks!

Greg - I'm kind of confused where this is going. Sorry to be a pedant -

You are basically looking at replacing the DPF with a high flow cat. Nothing wrong with that per-se, but its not really going to function as a dpf anymore since the majority of soot will go through it just like it does through a cat.
By having 2 cats you'll trap more of the soot than you would with no dpf and 1 cat, for sure, but not anywhere near what the stock dpf catches, which we all agree is pretty much everything.

I guess the only way to know for sure will be to give it a try - and its great that you are. But, in my opinion, you'de likely acheive more with tuning in terms of soot reduction. (you probably already know this too - which is why i'm a little confused....)

Am I missing something? Is this mainly for lagalities sake?

I'm going to give it a go, and see. Reality is always the bottom line.

It's not like a cat with chambers that are straight through, the "chambers are more hourglass like, but at a minimum the manufacturer claims 50% soot reduction, and it can be lengthened or a second one added to reduce even more - up to 70%. The stock closed cell DPF is supposed to remove 90% by comparison, and in reality the other 10% out of a stock DPF is too small to see.

So the net result worst case is 40% more soot out the back.

Add a decent tune, less soot, as you get the fuel rate more accurate. Tick.

Add extra cooling tinker efforts and you reduce the soot further. Tick.

Remove EGR, and soot is reduced quite a lot apparently. Tick.

Add water meth, providing even better burn and cooler charge - less soot. Tick.

I'm convinced in my case I can have a high flow DPF, produce next to no real visable particulates, still get all the NOX and SO reductions, and have power to boot. I would expect a bit on WOT acceleration, but hopefully it is like the 103 in that it is a very light haze at best.

It's a lot closer to legal, and depending on how it works will determine if I consider getting it approved - expensive and hard!!

In the least I will be able to get stock closed cell recores for the DPF's, so people can just retrofit a new one when the old one clogs, and I will have a hi-po oiler that doesn't belch black soot out the back, which personally I dislike.

Thanks, that does clear it up.

Hovex 99% Napthalene mothballs do indeed totally dissolve in Diesel fuel, tested it over the weekend in a glass jar.

Try at your own risk, but I love it, and 3 a tank is plenty for the effect, again more than 5 is apparently too much....

What's the basic chemistry of this Greg? Is it like a Cetane boost or you're making it a more volatile fuel.

It just sounds so dodgy but I'm torn b/c I know you're not a ****e meister. :)

Yeah it's a bit dodgy at first glance, but you inly have to have a look at the various "diesel performance" products on the Supercheap shelves, I found 3 containing napthalene. Napth has historically been used along with Toluene to raise octane, which is fine for petrol cars, makes the fuel less likely to detonate, and the later you can get it to go bang in a petrol engine, the better, as the piston is stil rising.

Diesels on the other hand donlt go bang till much later, and the fuel has to be injected and ignite due to the heat of compression. Cetane is the exact opposite of Octane, in that it is the rating of the volatility of the fuel to explode basically, and for an oiler you want the fuel to combust quickly, as with no plug it is the speed of the flame front that limits a diesel. Napthalene should therefore raise the "octane" of diesel, and lower the cetane - making it less likely to explode, but the reality is the Napth also helps combustion, and it is aiding the combustion process that I think it helps.

The downside is Napthalene easily forms carbon, so it may clog the DPf faster, and you have to be careful just how much you add, I'd asy no more than 3 per full tank, the recommended max is 5, but that's pushing the limits as apparently that sort of concentration can remove the oil film from the piston bore, and that's very bad obviously.

I wouldn't recommend anyone do it actually, as I am prepared, and able to rebuild the engine if I blow it up, and I never suggest anyone try half the crazy, unproven ideas I do!!

Been tinkering here and there, business been keeping me busy, but in a GOOD way. Getting close to finishing the custom DPF / 3" dump, 42DD are getting me some suitable bends. Getting the right DPF core out of China has been a nightmare, but I WILL get there....eventually...

http://www.vwwatercooled.com.au/foru...P1000732-1.jpg

http://www.vwwatercooled.com.au/foru...P1000733-1.jpg

http://www.vwwatercooled.com.au/foru...P1000727-1.jpg

http://www.vwwatercooled.com.au/foru...P1000734-1.jpg

Greg, might be worht a call to truckline or someone with regard to bends.... not sure if they have them but give it a shot.

I buy bends from Sandvik (work account) but I think if you call them up and ask really nicely they will do an over-the phone credit card sale if its more than $100. Anyway, also probably worth a phone call.

Thanks Aydan, thing is I want 2mm walls which are tricky to find, I'm sure truck places do them, but as I have 42DD shipments coming every few weeks anyway.....it's all to easy to get them to sort it. I havn't been pushing the issue as tinkering has taken a bit of a back seat, but hoping to weld this all up in the next few weeks.