Diesel & LPG.

Hope so. There's quite a few hauliers running LPG fleets.

You mean the way of extracting lots of power via LPG?

I dunno about the power ratings, but as I understood it, the amount of diesel being used is reduced (replaced by the LPG) resulting in much- reduced black smoke emissions. I was just wondering if these things were actually being used.

A lesson cometh...

An engine is an air pump. A diesel pump tries to match airflow to deisel so that in an ideal world the fuel is always matching the airflow at WOT condition. (Even though a deseasel has none!)

Add too much diesel at any point and instead of power you get smoke. Add too little diesel and you get no smoke and less power than the ideal amount. Since programming and diesel pumps as well as engines all vary in fuel/air flow depending on revs and air pressure and temp all this is a bit "near enough" or a little short of fuel (so no smoke or particulate emmissions) most of the time.

Now to fill in the "weak" spots in the WOT power curve (yes I know it has no throttle) we add propane up the intake.

Why? Because it ads extra fuel in the places where resonances and extra airflow can burn it. A richer setting on your deisel pump would also do the same thing though...

You cannot add deisel up the intake because it would detonate or fire when the piston was about 2/3rds way up the cylinder.

It fires as soon as its SIT (Self Ignition Temp) is reached under compression rather than being added at around top dead via the fuel injection system.

Propane (and petrol, methanol, etc) are all high octane. Meaning a VERY high self ignition temperature. So they dont ignite until the spark (or the injected diesel in this case) burn. So adding propane (LPG) to the intake is safe. Too much will still just produce black smoke though.

Unless you also add Nitrous (more oxygen) to the intake to clean up the smoke...

Burgerman.

Thank you for that lesson sir! What is WOT though? So, do many diesel LPG & nitrous kits get sold then? I have seen those nitroused Mercs on that youtube, they looked quick enough. WHat is the potential for wringing more power out of diesels with laughing gas compared to a similar sized petrol engine?

WOT= wide open throttle.

None due to significant extra cost, hassle, the (space for)the tanc and the factor of doubt/danger that hovers over every LPG-installation.

Dieseldrivers are not very into bi-fuel: if they want extra power, then there is a remap with some extra boost; if more economy is wanted, there is the veg oil-crowd.

Diesel-LPG-engineering is still (allready 20 years) a gadget in the R&D- departement. It pops up every now and then when a "performance" diesel is wanted for a demo.

NOx-kits? Only a scattered few hardcore drag racers.

NOx carries its own oxigen, so the power-potential on any engine in theory is unlimited. On street application its use is limited to a red light-race and then -if tires and transmission keep up-: bottle empty, fun gone.

Tom De Moor

There are a few conversions knocking about, nitrous and pain kits can give lots of extra power on a TDi, you could theoretically get the same power from bigger injectors, turbo but that has downsides like extra lag and it can get quite tricky to map large injectors at low RPM (opening time is too short). On a petrol you would most likely run a 2 staged injection with an extra set of injectors up the intake tract but as Burgerman said you can't do that in a DERV. So you fill in for the turbo with Nitrous and the Diesel with Propane.

Fabia running both TDI:

that car has 2 maps one for Performance running both and one for better MPG running just the Propane. And an Audi 2L: Must be quite common if I found 2 on a seat forum. ;)

Wide open throttle only they dont have one so foot on floor! FOF?

So, do many diesel

trev at highpower sells plenty diesel nitrous systems but generally uses deisel to enrich by tricking the injection system one way or another.

I have seen those nitroused Mercs on

Not as good due to the low revs. But much more than a chipped turbo.

>

Wide Open Throttle

cheers, clive

Exept deseasels dont actually have a throttle so its FOF.

Not in to that kind of thing...