LS1 Vapour injection conversion results

[sleepa]

Just had my VX LS1 wagon converted to a Vapour Injection system and wanted to post some results if anyone else was interested in doing similar.
For more details my car only has a 2.5inch catback at the moment, I will be installing an OTR CAI with maffless tune in the next couple of months so the results will change then as well.

It still needs to be retuned after 1000km to get the best economy/power.

The system has been in for 2 days so far, first impressions are.

It runs smoother then petrol
It feels like it has more torque off the line then petrol
Driveabilty around town is actually better then petrol.
On cruise it is the same as petrol.
Doesnt quite have as much punch as petrol in the upper rev range. Noticeable, but there is still PLENTY of power to overtake.
Oh, and the tank is in the spare wheel, i didn't have a spare so no loss of space.

The first tank of 38l used 250km, which works out at around 15.2 lper 100km mixed town/highway driving, also some gas was used to initially tune the engine on the dyno. So that figure is not accurate enough.

Second tank will get better results.

Overall I am pretty please with the results. I will update this thread when i get more results.

[Munz]

thats sweet - except for the spare wheel part, but keen to see the what kind of power it would make - more or less?

[HamaTime™]

Vapour injection is a decent LPG system. Did you do a complete conversion (i.e. straight gas) or is it still a dual fuel system? Straight gas would probably yield some better figures.

Anyway, JTG Liquid injection systems are fantastic as far as I have heard. I would half consider running straight JTG Liquid Injection on a new V8 if this issue over LPG prices gets sorted out. At the moment it's hardly a viable option for me so I run petrol these days ... :/ ridiculous prices.

[yxyx64]

... I will be installing an OTR CAI with maffless tune in the next couple of months so the results will change then as well.

interested in why you are getting a maffless tune

[one_and_only2004]

interested in why you are getting a maffless tune

Less restriction in the intake - pretty much why everyone else does it too.

[sleepa]

Vapour injection is a decent LPG system. Did you do a complete conversion (i.e. straight gas) or is it still a dual fuel system? Straight gas would probably yield some better figures.

Anyway, JTG Liquid injection systems are fantastic as far as I have heard. I would half consider running straight JTG Liquid Injection on a new V8 if this issue over LPG prices gets sorted out. At the moment it's hardly a viable option for me so I run petrol these days ... :/ ridiculous prices.

Still running petrol as well, it needs to warm up on petrol in the morning, LPG is a pain to start on. Although I am looking for ways to increase the power of lpg. Liquid injection is meant to be a fair bit better than vapor injection, only reason I didn't is because they haven't got the tunes entirely right in my area yet.

[sleepa]

thats sweet - except for the spare wheel part, but keen to see the what kind of power it would make - more or less?

They put in a bracket so I can still have a spare if I want.

I'm very interested in seeing if it makes more or less. Considering LPG is meant to be 100 octane, with some supporting mods it should in theory make as much power as pulp

[HamaTime™]

They put in a bracket so I can still have a spare if I want.

I'm very interested in seeing if it makes more or less. Considering LPG is meant to be 100 octane, with some supporting mods it should in theory make as much power as pulp

In theory yes, in reality no. Whilst LPG has a higher octane rating (usually 108 Octane) than say Premium 98 ULP, it does have a significantly lower energy per Mili joule content.

• PULP - 34.8 MJ/L
• 26.8 MJ/L

This means that your LPG usage will be higher than that of PULP due to the lower energy per MJ content. Throttle response and pickup up higher in the rev range also reflects this. However, this should be easily fixed via a tune.

Now despite Vapour Injection being an inferior technology to that of Liquid Injection, Vapour will still yield similar numbers to Petrol as it is direct injection. However, the car is still disadvantaged by running two fuel systems due to extra weight, a tune for each fuel. The engine will run far better when it is set up and tuned solely for one fuel. (Putting the cold start issues to the side).

[sleepa]

In theory yes, in reality no. Whilst LPG has a higher octane rating (usually 108 Octane) than say Premium 98 ULP, it does have a significantly lower energy per Mili joule content.

• PULP - 34.8 MJ/L
• 26.8 MJ/L

This means that your LPG usage will be higher than that of PULP due to the lower energy per MJ content. Throttle response and pickup up higher in the rev range also reflects this. However, this should be easily fixed via a tune.

Now despite Vapour Injection being an inferior technology to that of Liquid Injection, Vapour will still yield similar numbers to Petrol as it is direct injection. However, the car is still disadvantaged by running two fuel systems due to extra weight, a tune for each fuel. The engine will run far better when it is set up and tuned solely for one fuel. (Putting the cold start issues to the side).

Completely agree with you. I know with liquid injection you can get more power then petrol with a tune. (from what I have heard 10rwk on LS1s).
And I know vapour injection will use a bit more fuel to get similar numbers as petrol.

My aim is to use LPG as the sole fuel, (with a few litres of petrol for starting) and change the tune,plugs and perhaps cam to get more performance out of LPG at the expense of petrol which i wouldn't use anyway.

[yxyx64]

interested in why you are getting a maffless tune

OP, still interested in why you are getting a maffless tune.

(BTW: energy is measured in joules with a Mj being a million of the suckers)

[sleepa]

OP, still interested in why you are getting a maffless tune.

(BTW: energy is measured in joules with a Mj being a million of the suckers)

To remove that maf that's sitting after the filter. Less restriction, a good basis for a tune. The LPG ecu runs off the engines ecu so a decent tune should unleash some more power on both fuels.

[rathy1406]

Does your car switch back to petrol in the higher part of the rev range?

[yxyx64]

To remove that maf that's sitting after the filter. Less restriction, a good basis for a tune. The LPG ecu runs off the engines ecu so a decent tune should unleash some more power on both fuels.

you seem keen to spend all this money you are now saving so another option is to open it up now for CR (and cam) to really kick the gas (and use 98). this will provide a much better base for your returns from tune rather than throwing big $$ now to table fiddle to get a couple of hp at usual drive revs. you cant get around cr with advance.

[HamaTime™]

Does your car switch back to petrol in the higher part of the rev range?

I doubt it would, that's HSV's LPI system. Most if not all aftermarket systems only start on petrol and kick over to gas once the primary ignition has finished.

you seem keen to spend all this money you are now saving so another option is to open it up now for CR (and cam) to really kick the gas (and use 98). this will provide a much better base for your returns from tune rather than throwing big $$ now to table fiddle to get a couple of hp at usual drive revs. you cant get around cr with advance.

If the price of gas get's sorted out (through the government and consumer affairs, which is where I believe it is currently) then the savings of gas will come in time. At least for the OP he has gone and gone a semi decent system which will perform on par to petrol. At half the price? Thing is with gas, is since it has more octane you can advance the timing and get more HP out of it.

What the OP has done by switching to Vapour LPG (even though I still hold that straight gas is the only option) is similar to setting a car up completely for E85...I mean changing fuel source/type is irrelevant, a MAFless tune on LPG is still going to yield similar results to a PULP run car. True, difference being a $4k bill for changing fuel type.

LPG is a viable fuel source, but not at current prices. The government needs to wake up to itself, remove the taxes and promote it as an eco friendly fuel and push it more mainstream with more modern, advanced gas systems like Vapour/Liquid.

[sleepa]

Does your car switch back to petrol in the higher part of the rev range?

It hasn't so far, I have heard that some systems do, due to out performing the LPG injectors but that is only above or so, so when I get to that bridge I'll find out.

[sleepa]

you seem keen to spend all this money you are now saving so another option is to open it up now for CR (and cam) to really kick the gas (and use 98). this will provide a much better base for your returns from tune rather than throwing big $$ now to table fiddle to get a couple of hp at usual drive revs. you cant get around cr with advance.

Very keen
Considering I drive 7 to 800kms a week I am already saving heaps, so why not try and get more power. It will be possible, i am already considering a cam so..maybe

[yxyx64]

Very keen
Considering I drive 7 to 800kms a week I am already saving heaps, so why not try and get more power. It will be possible, i am already considering a cam so..maybe

Good stuff. Advance does get a little power but depending on the $$ you are going to spend there are better ways. I can only try to say to you again that you end up wasting money trying to get around a poor choice in cr. Open it up if you are going to spend money.

[sleepa]

I use to play around with high compression jap motors but forgot about compression ratios recently. I once had a little high comp 4 running an LPG mixer which was pretty fun. So upping the compression is quite a possibility. Also my installer has now got software to tune the petrol side, not sure what it is yet, but will find out next time I talk to him, should make it easier to get it all sorted and make more power.

Btw my last tank of 40l got me 300km of mixed driving, 80% highway. That's about 13.7L per 100km.

[sleepa]

Refilled again yesterday. 296km off 37L 90% highway, works out at 12.5L per 100km, that's better considering on that drive I usually get 10.5 to 11 on petrol.

I have also just reached the 1000km for it's first service, but that won't happen for another week as easter has gotten in the way.
At idle the gas feels rougher than it used to and it feels like it has lost a bit of power. I suppose that is why you need the first tune at 1000km.

Also I have noticed that the idle on LPG is slightly higher then petrol, prob around 700 as opposed to 600.

[sleepa]

Ok, it's been 3 weeks since the install and I am pretty happy.
The last few weeks Litres per 100km figures from a variety of driving are as follows.
14.96,
14.41,
16.24,
12.10, (highway)
14.17,
12.5, (highway)
12.5, (highway)
14.29

Not too bad, but it was using a bit more LPG than when it was first installed.
Had the 1000km service done today, even though it was up to 3000km. I couldn't get it done with easter in the way.
Replaced the air filter and tuned it up on the dyno.
Runs heaps smoother, and leaned it out a fair bit to make more power.

And to get a benchmark, on a Mainline Dyno the peak power is 178.7RWKW/239.7HP on LPG which I am very happy with considering the operator stated that similar LS1s on unleaded are getting around 10kw less on that dyno.

Will post economy/power/driveability results in a few days.
And it appears the price of LPG has come down 5 cents where I am, it's not heaps, but it's a start.

[s_ikari2015]

*scratches his head*
ummm... I don't like those dyno figures. Does anybody else think they're way too low for an LS1 considering stock FW is 260KW? (roughly 200 RWKW by most conversions).

"The LS1 was rated at 350 hp (260 kW) and 365 lbf·ft (495 N·m) since 2001 (LS6 Intake)"

Although, given that all dyno KW/HP figures are entirely mathematical as it can't actually be measured, they use formulaes based on the torque measured to come up with a number. The stock numbers used 495Nm at 5000rpm to get 260KW at the flywheel.

So allowing for around 30% loss through the drivetrain (as commonly suggested) the dyno torque should be reading around 380Nm at 5000rpm.


Anyway, looking forward to reading more fuel usage numbers now that you've had the retune. I'm seriously considering a liquid LPG system when costs of both installs and LPG return to more reasonable levels.



EDIT: actually, considering earlier LS1's were rated at 240 odd KW at the flywheel I guess 180rwkw is reasonably close to "stock".... MAFless will boost that sucker though lol

[sleepa]

*scratches his head*
ummm... I don't like those dyno figures. Does anybody else think they're way too low for an LS1 considering stock FW is 260KW? (roughly 200 RWKW by most conversions).

"The LS1 was rated at 350 hp (260 kW) and 365 lbf·ft (495 N·m) since 2001 (LS6 Intake)"

Although, given that all dyno KW/HP figures are entirely mathematical as it can't actually be measured, they use formulaes based on the torque measured to come up with a number. The stock numbers used 495Nm at 5000rpm to get 260KW at the flywheel.

So allowing for around 30% loss through the drivetrain (as commonly suggested) the dyno torque should be reading around 380Nm at 5000rpm.


Anyway, looking forward to reading more fuel usage numbers now that you've had the retune. I'm seriously considering a liquid LPG system when costs of both installs and LPG return to more reasonable levels.



EDIT: actually, considering earlier LS1's were rated at 240 odd KW at the flywheel I guess 180rwkw is reasonably close to "stock".... MAFless will boost that sucker though lol

Your not really wrong with the power figures. Although my LS1 is the first version, 225kw at engine. So 180rwkw is about right.

Since the tune I have been getting consistently low 13 L per 100kms

[s_ikari2015]

13L/100kms on gas? That's comparable to ULP. Sounds good.

[sleepa]

That is mostly highway driving with a little town. Power is better too, feels the same as ulp.
Uses only a little more then petrol, 1 to 2 l/100 more, which is pretty awesome, had a bloke in a 4L falcon on LPG ask what I get to a tank, was amazed I get 300kms out of 40L, he gets the same Kay's out of 85L.

[Galixia]

I have a VT SS with a LS2 in it and im running duel fuel. my lpg setup is a KME Gold LPG Vapour Direct Injection System with a 90L tank in the boot above the rear axle so still have my spare as well. My current setup is for fuel economy so on LPG last dyno i only got 276rwkw (can obviously re tune the gas to get way more out of it) but got 294rwkw on petrol. i recently drove from Toowoomba to Melb and it cost me about $130. its setup so it always starts and warms up on petrol then switches over to lpg when engine has reached 65 degrees. i have two ecus running as well one for each fuel system.