70MPG-goal
Veteran Member
Who has tried a propane injection in their intake? BullyDog has discontinued the kit for our TDI, and all of them for that matter. What are the experiences? Where can I get one? Used kits are OK.
most propane kits use the standard tanks that you buy at local stores.. but i think they discontinued them because they are so unpredictable when injected before the intake manifold..a lot of cars/trucks had backfire and damaged there engine.propane is a very sensitive topic in canada.....only 1 major company certifies the propane tanks,,,,which suck btw. any propane system other then "theirs" would be illegal.
propane is not just for fuel eco, Polish and Hungarian guys have it on their 300+ hp tdis....If you want 70MPG, import a 1.2TDI, swap it into a MK2 and be done with it.
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The legal/safety tank issues ARE the big issues.Other than the legal/safety tank issues, are there any drawbacks? I saw some german kits that had LPG tanks that fit in the spare tire compartement. Often our goverment outlaws things out of fear & ignorance and very little facts or data yet permit very deadly products if the Lobby group is paying them enough. Ex, Pirahnas are illegal in many states because of how they are portrayed in movies (I owned 6 giant Caribaye Pirahnas with out ever coming close to any biting) and in recent history the federal goverment allowed the use of LEAD and ABESTOS in several products dispite science proving their dangerous affects on health and the enviroment. Mainly because the lobby groups where so influential with $$$. The oil companies want us hooked on their fuel. If a LPG or CNG blend makes us use less of their stuff, they are pissed.
These tanks are perfectly safe and legal in Europe. They are so overbuilt that they can easily withstand a rear impact. They have all the connections and valves inside a gas-tight enclosure on the side of the tank which is vented to outside the vehicle so there is no chance of them leaking in to the passenger compartment.The legal/safety tank issues ARE the big issues.
Installing the tank in the spare tire compartment means the tank is inside the passenger compartment, which means a leak fills the interior with propane. That + lit cigarette, or pressing a switch that makes a tiny spark ... kaBOOM. And if the vehicle gets hit from behind in a collision ... ? ? ?
do not confuse Catalyst with the chemical type.Propane is a fuel, not a catalyst. If you don't need extra beyond easy pump/injector mods why bother?
LPG has a lower flash point, but higher autoignition. What this means is that propane can burn and continue to burn at lower temperatures than diesel, but ignites without a spark at higher temperatures than diesel. Now before you say this is proof that propane won't pre-detonate, wait just a minute. The autoignition temperature rating of propane is at atmospheric. Once inside the cylinder, it becomes pressurized. Because propane is in a gas state (and gasses compress), that autoignition temperature drops significantly when under pressure. Diesel is injected as a fine mist - meaning its not in gas form, but rather still a liquid. So now, you have a piston moving up, compressing the propane, and as it approaches TDC it reaches the pressure/temp point of autoignition. Here's the catch - if you are running larger amounts of propane for power gains, that autoignition point can be reached well BEFORE the diesel is injected..
Propane burns faster than diesel. Nearly as fast as gasoline. What this translates to in a diesel engine: a more uncontrolled and rapid explosion. This pre-ignition is hard on any engine, even diesels. If you were to graph PCP, you would see a faster rising, faster falling, and higher spiking curve when using propane. This is not good at all for diesel engine longevity. A more gradual rising and falling cylinder pressure (smooth curve) will produce lots of power at greater reliability..
From my experience, pound for pound, progressive N2O in an overfueled diesel that is tuned for it (reduced timing, SOI) works better than LPG. A PWM progressive controller also smooths the delivery, much easier on internals than just WOT activation
But there are downsides to N2O. It's very expensive to refill the bottle ($4 to $5/lb.). It's not really for FE because like LPG, you will run out of it fast. It requires special tuning. Compressed gas of any kind also adds unsprung weight to your car (look at CNG tanks lol). And don't forget the safety factor as previously mentioned. Something as simple as a bad solenoid or switch can ruin your day real fast..
Remember this?
http://www.youtube.com/watch?v=_nYXkKN1k7M
http://www.youtube.com/watch?v=6hxOoM0-NJI
In the right AIR/FUEL mix propane is like a 105-110 octane rating fuel that needs a compression ratio of 14:1. If the fuel/air mix it too lean, it will not self-ignite (detonate). The lean mixture will only burn after the onset of the diesel injection ignites, and it will help this diesel burn faster and completely as propane has a faster burn rate. It was and still is used in many Diesel Trucks with promising results, but needs to be monitored.The lean combustibility limit doesn't apply when the bulk temperature of the air/fuel mixture exceeds the self-ignition temperature. All the lean combustibility limit means is that at normal ambient temperature and pressure, there is not enough energy in a spark to cause ignition. If you raise the temperature, much less additional energy is required (smaller spark) to cause ignition. Raise it enough - beyond the ignition temperature - and the fuel is going to burn, lean or otherwise. I don't know if 19:1 compression is enough for propane and air to reach the self-ignition temperature, but at a minimum, it's going to be pretty far into a detonation regime once ignition (e.g. by diesel fuel) does occur.
The propane tank shown above - obviously professionally designed for the application! - looks interesting. If it has passed the certification tests, that's good. I'm quite sure that in the OEM application, this is meant for use with a spark-ignition engine, not as a supplement to a diesel engine ... but the tank is the same. The OEM's don't build dual-fuel systems for diesel engines.
Really? I just became a member so I wouldn't know of past trends. Just hoping of finding someone that did the test befor I do. As for the Snake oil comment, let it be known that propane does add power for real.What is with this every few months? Someone posts another thread on this topic that has been discussed ad-nauseum and refuted over and over.
Do they think we will buy their product just because they keep posting on here?
This subject needs to be banned just like other snake oil postings on this board.
Folks, this is why bully dog has pulled this product from their line.What is with this every few months? Someone posts another thread on this topic that has been discussed ad-nauseum and refuted over and over.
Do they think we will buy their product just because they keep posting on here?
This subject needs to be banned just like other snake oil postings on this board.
need we say more....if I had gone through with out as I was planning
See, they made this really useful tool for people who are new members, it is right here: http://forums.tdiclub.com/search.phpReally? I just became a member so I wouldn't know of past trends.
So are you saying LPG isn't a FUEL when injected in a diesel application?do not confuse Catalyst with the chemical type.Think of it as the Promoter type.
(def.Wikipedia: Catalyst that SPEEDS up the reaction is a positive Catalyst. (reaction for our engine is the ignition, burning speeded up by propane).
Substance that increase the activity of the catalyst is called a promoter.)
Catalytic reactions have a lower rate-limiting of free energy of activation than corresponing uncatalysed reaction, resulting higher reaction rate at the same temperature.
Thats means a propane/diesel mix will give a more powerful push on the down stroke of the piston compared to diesel alone, meaning an extra push without raising EGTs.
The CATALYTIC reaction NEEDS the compression of air in the combustion chamber mixed with fuel for a reaction to occur (IGNITION).
The Propane will PROMOTE the ignition of diesel/air mix under high compression and provide a CLEANER and COMPLETE combustion (combustion=reaction... of fuel/air mix under pressure).
Take any one out (compression, fuel or air)of the equation, and there will be no reaction (combustion).
So we are all on the same page, view propane as a PROMOTER to our reaction of combusting.
Not trying to offened anyone, just trying to clarify the use of the word CATALYST. A fuel can BEHAVE like a catalyst.
True. Gf drives the tdi now, she didnt like the idea of driving around with a propane tank in the back.need we say more....
Never said it's not a fuel, but ACTS like a CATALYST by PROMOTING (the same way a catalyst does) the effect of the DIESEL FUEL. If any fuel is too LEAN in any AIR/FUEL mix there will be no COMBUSTION (Reaction)! So in an extro lean PropaneFuel/Air Mix there will be no combustion at any compression ratio as the LEAN mix PREVENTS COMBUSTION. Problem occur when a rich amount of propane is used and cause preignition. Just like NOX the wrong blend will destroy any engine. If someone wishes to run only propane (like a forklift) then a 14:1 compression ratio is best. Ever wonder why those american FLEX FUEL cars run so poorly on E85? Because E85 needs a 13:1 C/R but this would make it impossible to even run RON rating of 93octane. To make it run 87 octane it has low C/R under 10:1, but whenever on E85 (that's like racing alcohol fuel) it run on a rich blend (more fuel) to burn.So are you saying LPG isn't a FUEL when injected in a diesel application?
If it's not a fuel, then it wouldn't negatively impact EGTs
Wouldn't the increased unsprung weight of LPG tanks AND the necessity to run extremely low CR (avoiding detonation) yield efficiency LOSS in a diesel application??
Why bother with LPG unless you need extra fuel beyond available delivery mods?
FWIW, this is the POWER section...and for that purpose, N2O > LPG![]()
Here's someone who understands how to use propane on a TDI!What gen tdi are we talking about? A lot of people jump to conclusions when talking about injecting propane into tdis. I had the bullydog on my mkvi and if i had went through with the build i was plannign it would have neen sick but i shortly removed it. My attention was drawn to my new gli. What was posted before was correct about the compression ratio. But thos preignition concerns can be delt with with running the lpg extreamly lean and with that, if your planning on installing propane on an engine with 18:1 cr then you can potentally run more lpg than say and old 1.6 idi. Diesel engines run lean naturally so theres a bunch of unutalized oxygen in the engine. Using that o2 with lpg allows the potential for more power but also greater efficency. As the rate of burn is faster with lpg it allows the diesel itself to burn more efficently and if you lean it our proparly the lpg will only ignite after the diesel has combusted.
Things to remember:
Never run on a cold engine.
Its better to inject closer to the engine, not preturbo.
Have an auto shut off but always run the engine a little without lpg before shut down.
If your installing inside a vehicle make sue the propane tanks pressure release valve has a pathway outside your vehicle.
The basics.
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