Thread: Diesel with LPG kit??

Originally Posted by DiscoDB

And as the original question was around fitting to a 2.7 engine, has anyone actually fitted an EGT gauge and knows what actual temps the TDV6 actually hits? Given the increased power and torque over the slightly smaller TD5, I am guessing it is pretty high to start with but have seen no data to support this suspicion. An upgraded intercooler would probably be a good idea if doing anything to increase the power on the TDV6.

the TDv6 seems to get to higher egts quicker then holds it there, they seem to hover around 600 all the time. i suspect this is due to the EGR valve. not only the heat that provides but it also produced a richer burn and thus higher egt values.

my thoughts are, based partly on what i have been told about some of the issues with modern diesels and LPG fumigation. it all seems to be based around the EGR valve and what it is supposed to do. this also efects the inter-cooler, or the fitting of a larger one.

the realy modern diesels do not want to run lower EGT at any load. this is to cut the production of bad emissions gas and well as a more complete burn.
the EGR valve lets exorst gas into the inlet manifold to displace oxygen in the combustion chamber. thus producing a richer burn. it also add heat into the combustion chamber, to produce a hotter burn.

while this works well with diesel along it is not advantage when adding lpg fumigation. the LPG drops the EGT, the cars ECU then trys to compensate by opening the EGR valve and letting in more hot exorst gass or in some cases reducing boost. the same scenario is applicable to a larger inter-cooler.

this is my logic based on a post 2007 TDv6. IE if the 10 digit of your vin is a 6 or lower. my above statement is not applicable.

so in addition to fumigation and modified map would be needed. one that shuts off the EGR valve, then you would receve the full advantage of a larger intercooler and only after that could you look at a smart lpg fumigation system

Originally Posted by 85 county

turn on the lpg at any fuel setting drops EGTs and the vehicle accelerates.

a 300 tdi loaded with a camper trailer, in 4rd gear hammer down at 70klms blowing smoke and just holding its own, egts at 720 and climbing. turn on the LPG the rig accelerates to the govanor EGTs drop to 685, and of course further when you hit the govanor and back of the hammer

yes and that is a function of the governor cutting diesel. Now try it with a couple of tons more up the freeway and see if the egts drop.

Originally Posted by bee utey

yes and that is a function of the governor cutting diesel. Now try it with a couple of tons more up the freeway and see if the egts drop.

yes the governor cuts the fuel so the egt drops but not at 70klm the governor is at 110 klm. so full fuel at 70klm tun on the LPG and egts drop. hit the governor and there is an additional drop but this second drop is due to fuel being reduced. only the first drop is due to LPG fumigation

Originally Posted by 85 county

yes the governor cuts the fuel so the egt drops but not at 70klm the governor is at 110 klm. so full fuel at 70klm tun on the LPG and egts drop. hit the governor and there is an additional drop but this second drop is due to fuel being reduced. only the first drop is due to LPG fumigation

Well that's the opposite what I've observed across a large number of fumigation installs I've done with electronic EGT gauges. We must have different kinds of eyes. Not that it matters to the OP in any case.

I drive down to Mandurah for Uni each week and sitting on 110 with straight diesel my Tdi sits on 460-480 degree's,using LPG it sits on 400-430 with a 3rd less throttle.I have just fitted a 2 psi switch gas switch from the original 6 psi one to get the gas on earlier and the turbo lag is almost gone,not TDCi gone but going around a run-a-bout doing 15kms/hr in third and it pulls away smoothly. Pat

Originally Posted by bee utey

Well that's the opposite what I've observed across a large number of fumigation installs I've done with electronic EGT gauges. We must have different kinds of eyes. Not that it matters to the OP in any case.

ok interesting, 3 of them are your installs and on the same bit of road

85 County, a few posts ago you said "I am more than happy to take on the technical ability of our certified practising engineer"

I'm no engineer but I do know you are wrong about EGR's. Exhaust gases are introduced to reduce combustion temperatures to keep NOX down, it's an emission control measure.

If you are recycling "facts" of forums it's best to make sure they are actualy correct.

Originally Posted by lambrover

85 County, a few posts ago you said "I am more than happy to take on the technical ability of our certified practising engineer"

I'm no engineer but I do know you are wrong about EGR's. Exhaust gases are introduced to reduce combustion temperatures to keep NOX down, it's an emission control measure.

If you are recycling "facts" of forums it's best to make sure they are actualy correct.

Hay guess what i did at uni that was after doing my trade.

Exhaust Gases are introduced into the combustion chamber to displace air/ oxygen, under lighter load conditions.

and since we are talking diesel and not petrol motors. lean burn is colder rich burn is hotter.

by displacing oxygen for the same fuel given we are creating a richer burn, IE a hotter burn. Plus the actual heat from the Exhaust gas itself which i think we can agree is a bit hotter than ambient air even compressed air ( turbo)

ok coverd that, NOX or nitrogen dioxide or NO2, we are told that this is an emissions nasty, not going to argue with that, so where is it coming from. not from diesel, that's a hydrocarbon, hydrogen and carbon. nope it comes from air, air being mainly nitrogen Oxygen and carbon.

so basic, make air hot and under pressure it swaps atoms about. IE the oxygen not burnt by the combustion is now hot enough to bond with the nitrogen thus making NOX.

simple solution, reduce the amount of oxygen and nitrogen in the combustion chamber when there is not enough fuel to burn up all the oxygen. so fit an egr valve.

and EGR valve will not reduce combustion chamber temperatures, it makes it hotter, considering that the egr valve is only open on light loads its not that hot anyway. as i have said its job is to reduce the amount of oxygen in the combustion chamber. IE richen up the burn

the opposite is also true, more air colder burn, ask the tubo guys or have a look at the izusu threads. or any diesel turbo tuning stuff