Let the tinkering get serious!!....

[benough]

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.

[Greg Roles]

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!!

[Greg Roles]

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...

[gldgti]

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.

[Greg Roles]

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.

[gldgti]

hmm 2mm is more difficult.

If you're using stainless 1.6 is plenty, which is the standard from sandvik (and most places).

are you concerned about strenght at temperature?

[Greg Roles]

No mate, I want it to get HOT and stay hot to help regen the DPF, they need heat to burn off the soot even in partial flow. The more metal the more heat it will hold. Once it's done it's also getting a good coat of ceramic!

Looking forward to getting this finished, bloody close now.....

[gldgti]

If you want it to get hot fast, better to build it light and wrap it with some insulating glass cloth. The less thermal mass it has the more quickly it will get up to temp and keeping it at temp with insulation will be more effective than relying on the thermal mass. Because the core of the dpf is made of a ceramic material with a high heat capacity itself, anything you add there to heat up as far as the metal casing will just extend the time to reahc max temp.

anyway you're in the early stages yet and we're not talking huge differences but just have a think about it. I design furnace equipment for operation at about 1200C for a living so I've been dealing with this subject for quite a while now if you want any help.

[Greg Roles]

Had a bit of play time available over the weekend, so I re-glassed the airbox and other carbon bits with expoxy resin - the polyester based coat had browned somewhat - and I rebuilt my pre turbo intake with less joins and only one pipe between the airbox and MAF to keep the air as undisturbed as possible. I also deleted the bump style joiners and bellmouthed all the pipes, the insides are all as smooth as possible. I decided against beading the pipe ends, just causes unecessary turbulance, the intake isn't under any pressure. Also finally cut a slot for the MAF sensor over the round hole I had, made it as tiny as possible.

I have an intake heat sleeve on it's way from the states, so here's some poor quality phone pics of the current setup. Even though there's no performance difference really, I just felt my old setup had too many pieces and was over tinker-gineered. Still need to tweak it a bit to get it to sit right, but I'm happy with the few hours effort.

[gldgti]

great stuff mate - know where you're coming from. I re-did the pipework on my mk3 many times just trying to simplify and optimise, seems to take a few tries to get it right sometimes - but thats what it's all about!

Your intake pipe looks hot as now mate, and not in the temperature relative sense.

[Buller_Scott]

lookin good greg!

did you do the "dissolve moth balls in diesel" experiment yet?

im thinking about it myself... or should i stop being a pansy and just do it, given i've done other mild, very slightly tinkerish things to the car before?

[Greg Roles]

Yep they dissolve, it's a few pages back. I reckon you can give 3 in a tank a go, just for giggles, but make sure you get the pure napthelene ones, there are other formulas out there. They really shouldn't work in a diesel, but I have to say I miss them when I don't put them in!

[benough]

Now I want to try em!

[Buller_Scott]

Yep they dissolve, it's a few pages back. I reckon you can give 3 in a tank a go, just for giggles, but make sure you get the pure napthelene ones, there are other formulas out there. They really shouldn't work in a diesel, but I have to say I miss them when I don't put them in!

well then, looks like i'll be making my way to bunnings again soon... very soon.

i just pray to the powers that be that i dont start seeing bright shiny objects in other isles, given that it's the rockingest place to shop (as well as costco and 24hr kmart).

[Greg Roles]

Well another time gap between updates, this one obviously due to finalising Viezu, so a GOOD problem!

I put the first of many maps on my TDI tonight, Simon from Viezu HQ wants me to experience the varieties they can do, and who am I to argue??

I now have a DPF equipped performance map, and HOLY COW, the car is amazingly different. Bear in mind I still have a stock exhaust, but a full custom inlet. I also skipped mothballs and other crazy factors for my testing, no water injection, just the tune and car as is.

Only a short test drive tonight, but a decent drive tomorrow to Toowoomba to tune another surgeons Megane F1 track toy. See how it goes up the range!

Before it was very much a tractor at idle, and my intake made ludicrous amounts of intake noise even at idle. It had a huge torque spike at 1750 ( which I love by the way ) but the power was pretty much over by 3500, and I spent all my time short shifting between 2 and 3 k where the meat was. Beyond 4000, forget it, just sounded painful.

Now it is alarmingly quiet at idle, and the induction noise has halved! There is no real obvious hit at 1750, but between 1000-2000 where it used to be nothing, nothing, nothing, BOOST, now it feels much more lively and willing off boost, and dramatically smoother on cresting / coasting situations, a big downfall with a manual tractor.

Boost used to spike to 24psi and settle to about 21, now it only hits 21 but stays there till - wait for it - 5000rpm!

Before 4000rpm was just painful, and there was nothing beyond this. Now it feels amazingly petrol like and just keeps pulling, and a drag at the lights saw traction control absolutely struggling, and with it off, the tyres still complaining at 4000rpm!!

Astounding, can't wait to ditch the DPF and go to town and then put the meth over the top, it's deceptively faster now!

I love my new job!!!!