Hi

I had been thinking that maybe easiest and cheapiest way to get extra "fuel" to Common rail engine is just adding CNG to input air stream.
Installation should be like:
- One Gas nozle near each intake port
- Small CNG 7kg cylinder (tank)
- CNG regulator
- Adjuster ECU

Usually these mods are done for getting Diesel engine to run 90% with CNG but for our case we add much ass possible GNG for getting extra "fuel" for high RPM. CNG is self ignition after 650-700 degree so knocking is not problem like LPG. So basically there is not limit how much you can add CNG to cylinder, if there is enough air to burn all of it.

I had found few projects from internet but this is not so common way aproach "not enough" fuel problem.

Most people is now thinking, why not upgrde commonrail pump, nozles, lift pump, .... like other are doing. Maybe i should, but at least this option need to study before we go to normal way on "road" to get 250hp+ from 2.0L engine :)

Think about this way: on engine speed 5500rpm you spend huge amount of power to achieve 1800Bar and 120mm3 IQ. In case of CNG you can do even more power just using 1500bar, 80mm3 if you get extra fuel from CNG.


For me this sound more than Ultimate way to solve "enough fuel with out late EOI problems", but this sound too good for being true :)

Maybe you guys can point what challenges or problems i am missing :)

It seems that maybe there will be autoignition possible to happen. Maybe WMI could solve this issue ?

https://www.google.fi/url?sa=t&rct=j&q= ... Gs&cad=rja

More Crazy ideas come to mind :)
Have you ever been jellous for Guys with Gasoline engines because they have easy option for adding some No2 and extra fuel for getting extra power ?
With CNG and N02 we can get same thing. No2 will also make sure that there is enough oxygen for burn all fuel(diesel and CNG)
Also No2 will decrease mixture temperature so auto ignition for CNG not be a problem.

Maybe we will have old HDI what old EGR valve is upgraded for other purposes :) Maybe over sizing it and acting like waste gate durin CNG+ No2 SHOT :)

IMHO you had a nice idea. I explain:
CNG has a high number of octane and it gets on well on Diesel engine with high compression ratio.
Theoretically it can be injected simultaneously with diesel fuel.

One thing what is bother me alot.
Why not this is not tested yet ?
At least short google session didn't bring any direct hit.

CNG is used in diesels, for fuel saving and for performance tuning.
NOS is used for power upgrade.
But CNG+NOS not yet :(

Think about setup what can be inject 190hp with decent EOI. Setup has turbo what can push easily that 1,5-1.6 boost with decent EMP. Then we add NOS+CNG and extra wastegate. We adjust that we are getting nice fueling(diesel+cng) for rpm 5500 and enough NOS burn everything.