GTR conversion to LPG

[psybic]

It is producing approx 175KW @14 psi and gets about 10km/L. Drivability is basically the same as petrol except that the power delivery is smoother and the gas gives more bottom end torque. I/we are willing to help anyone who wants to run LPG especially turbo owners.

<{POST_SNAPBACK}>

You kidding? THats awesome! I had a GT4 engine in a celica. Ended up with about same power on same boost, if you are talking at the engine, not at wheels. That was tuned with Microtech LT8, by RX Engineering, who know microtech better than most. Fuel consumption was worse!!! much worse.

So on same boost, same power, better consumption and cheaper fuel!

Sounds ok to me.

[bradkazz]

Hi Steve

We are using Keihin LPG injectors - they are supposed to last about 200,000 ks. I have been running injection on the laser for about 20,000 ks so far with no problems.

The catch is we are based in Perth and at this stage we are trying to keep all of our installs local until we have done more testing. We only want to supply parts to the most eager eastern states tuners at the moment.

Our Profire ECU is a complete replacement for the factory ECU this means if you run straight LPG most states will allow you to remove the airflow meter (we use a map sensor) and the catalytic convertor.

The secret with the milage is in the tuning my car runs an optimised ignition curve, and even though LPG has less energy the slow, even and more complete burn means more of the energy is converted into kinetic energy.

From my research I am getting better milage than most other BPT powered lasers.

[bradkazz]

I forgot to mention pricing you would be looking at about $2500 in hardware and about $1000 labour. LPG injection is basically 1K more than a standard conversion

[thedriver]

The catch is we are based in Perth and at this stage we are trying to keep all of our installs local until we have done more testing. We only want to supply parts to the most eager eastern states tuners at the moment.

<{POST_SNAPBACK}>

Cost isn't an issue for me... but geography is! I'm in Canberra but, am happy to see anyone as far as Sydney or maybe even a little further for my gas needs.

Any ideas on who can help me out?

Cheers!

[bradkazz]

Cost isn't an issue for me... but geography is! I'm in Canberra but, am happy to see anyone as far as Sydney or maybe even a little further for my gas needs.

Any ideas on who can help me out?

Cheers!

<{POST_SNAPBACK}>

[bradkazz]

sorry don't know what happened with my last post

I don't have any contacts over east at the moment. In the future we intend to have distributors in your area. Most gas installers should be able to setup our system - you could contact some local people and ask them to contact us, via our website. We can provide all the information they would require.

Some of our competetors also have gas injection systems, but I am not sure if they can do turbos, it may be worth making a few calls.

[thedriver]

Some of our competetors also have gas injection systems, but I am not sure if they can do turbos, it may be worth making a few calls.

<{POST_SNAPBACK}>

I know you might not be inclined to answer this, but any that you can specifically recommend???

They're probably not really direct competitors anyway given the expanse between customer bases.

Cheers bradkazz

[bradkazz]

How do I answer this one..... Sprint gas, Bohemo, Appolo gas, etc all have gas injection systems but they are not aimed at the performace market. I have seen some of them and they work very well on standard cars. They do not have ignition control so the mileage would not be as good as it could be and like I said previously I don't think they will work with forced induction but it is worth asking them.

I have basically just described the design brief for our system. I/We have been running lpg on many different cars for many years and have seen all of the benifits but it has never run exactly right. For example the gas research throttle body is a great idea and produces very good power but usually runs rich so emmissions and economy are not the best. A standard gas mixing ring gives good economy but at the expense of power. So thinking that it would be an easy project we set out to design a system that could do everything, 3 years, several board revisions and 15,000 lines of code has finally provided what we were after.

[thedriver]

How do I answer this one..... Sprint gas, Bohemo, Appolo gas, etc all have gas injection systems but they are not aimed at the performace market. I have seen some of them and they work very well on standard cars. They do not have ignition control so the mileage would not be as good as it could be and like I said previously I don't think they will work with forced induction but it is worth asking them.

<{POST_SNAPBACK}>

Thanks bradkazz!

I haven't had any luck so far and would be very keen to give your system a shot. Is this your website: http://members.iinet.net.au/~mikejh/ ???

I'll see if I can find an installer to install your system for me over here.

Cheers,

Tee

[bradkazz]

the actual address is profire.com.au but either one will get you there

[ADM]

Some interesting reading on the gas injector front......

http://zymo.homemail.com.au/bmw2.htm

[KamikazeR33]

on the topic of alternate fuels, mazda japan put an rx8 on hydrogen and pulled 2/3 of the power it originally had without tuning it for hydrogen

im pretty sure no one is aus is trying this yet but oh well

[thedriver]

I also found this interesting read, which would almost make anyone cringe at the thought of wanting to do an injected LPG conversion:

Basic Propane (LPG) facts.

There have been several posts recently (summer 2005) about using LPG, mostly by persons with no engineering background who appear to be hobbyists. Most of the posters do not appear to have a basic understanding of LPG properties, so I thought I would throw a few items on the table:

Propane is a hydrocarbon fuel, chemical description C3H8.

Its boiling point is -44°F (-42°C)

Its octane rating is 104

Latent heat of vaporization = 183 BTU’s / lb (426 kJ/kg)

91,500 BTU’s per gallon (25300 kJ/L)

Autoignition temperature 855°F (457°C)

Stoichiometric by weight = 15.5:1

Molecular weight = 44.09

Carbon % by weight = 89%

Hydrogen % by weight = 18%

Flammability limits = 2.1 – 9.6%

Viscosity at 68°F = 0.592 BTU/lb °F (2.48 KJ/Kg °K)

Expansion rate = 270:1 (expands in volume 270 times from liquid to ambient pressure vapor)

LPG is auto-refrigerating, when pressure is reduced, it boils by absorbing heat

Propane’s vapor pressure (the amount of pressure required to keep LPG liquid at ambient temperatures) is zero at -44°F (-42°C), about 120 psig at 70°F, about 250 psig at 125°F, and close to 400 psig at 160°F.

Questions arise where these temperatures may be reached, but simply said, anytime the engine is running, underhood temps can quickly reach 175°F, making LPG boil at any pressure under 450 psig.

For example:

Considering a liquid LPG injection engine:

If the ambient temperature is 100°F, the internal tank pressure will be about 175 psig. If LPG is taken directly out of the tank in liquid form and plumbed to a fuel injector, it would work just fine. Now, add in underhood temperatures and the relative pressure must be increased to at least the vapor pressure plus enough pressure to retain liquid state. This is usually about 3 BAR (about 50 psig) plus tank vapor pressure. The LPG in any proximity to the underhood temperatures will begin to percolate, causing a constantly varying mixed-property fuel at the injector, something that is impossible to meter or calculate.

To prevent this from happening, fuel is typically circulated through the fuel rail, at pressures 50 psig above vapor pressure. This flushes the vapor slurry and returns it to the fuel tank, where the added heat is absorbed by the tank and storage fuel. This allows the fuel to return to liquid state, but the side effect is that the fuel tank temperature is slowly increasing, causing the entire fuel system to increase in pressure. I have seen fuel injector pressures at 400 psig on a very hot day on a vehicle operating in mixed mode service.

Common gasoline injectors cannot withstand these pressures, nor can they meter LPG efficiently.

LPG has no lubricating qualities, so operating a gasoline injector on vapor LPG will quickly wear the internal components. Also, operating a gasoline fuel system is at a relatively constant pressure, whereas LPG may vary considerably.

Since LPG vapor is 270 times less dense than liquid LPG, a single fuel injector cannot meter both fuels. Vapor will require a large orifice with high volumes and good injector control. The weight of the internal injector components could be considerable, and moving these components quickly enough to properly meter fuel may be challenging.

In liquid mode, the injector must be precisely matched to the engine, with tiny orifices capable of opening at high pressures. This also requires internal injector components to be strong enough to pull against the higher pressures, plus the injector must be capable of response time 270 times more precise than vapor phase. Also, the injector programming tables must be able to operate much more precisely (reduced MS response time) than either gasoline or vapor phase.

On the fuel systems that use the gasoline PCM, the injectors are sized for liquid flow, frequently without any intercept modules, plus the fuel systems use staged flow recirculation for the fuel rails. I have not seen any vapor service systems using a straight gasoline PCM with no intercepts to change the injector profile.

[ADM]

Bradkazz,

Any chance you could respond in relation to the acticle above and explain what actually happens in practice.

[thedriver]

Bradkazz,

Any chance you could respond in relation to the acticle above and explain what actually happens in practice.

Some of the systems I have seen use water cooling around the supply lines to keep the LPG from boiling.

Wonder if you could plumb it through a small intercooler???

Edited October 18, 2005 by thedriver

[bradkazz]

It is true that LPG Liquid injection would be a very complicated system, which is why our system like all of the other current LPG injection systems is vapour injection, not liquid. The water pipes that you are talking about are actually used to heat the lpg to cause it to vaporise. The LPG is delivered to the engine via LPG injectors as a high pressure vapour. The injector flow is massive in comparison to a petrol injector.

[davey_b2001]

you will find alot of top racing teams in the U.S who dive deeply into the single digits actually run LPG

[bradkazz]

Hello All

Just thought I would provide an update, we have finally put a skyline engine on LPG, a baby one at least. We have fitted our ProFIRE system to an RB20 powered hilux, the latest issue of Perth Streetcar mag has an article on it. Runs well and was easy to tune, after we replaced the iridium plugs, they are not very compatible with LPG.

[ADM]

Can you update your website with the details please

[bradkazz]

We have added a couple of pics of the RB20 powered Hilux to our website, so far its made 241rwhp at the recent Motorvation dyno comp.

I have just purchased a 1993 R33 GTS, I will be fitting a toroidal tank tomorrow and will hopefully have it running on LPG within a couple of weeks. I intend to install 12 LPG injectors (staged) and 2 regulators.

I have also been looking at the horsepowerinabox.com RB25 turbo upgrade kit, has anyone got any first hand experience with these? http://horsepowerinabox.com/HPIAB2/category50_2.htm

Edited January 26, 2007 by bradkazz