Auto-LPG Conversion Thread

[ghosthunter]

1. is it correct to say that a well-tuned venturi/emulator conversion will be able to maintain the FC and power of the car at low rpms (up to 4k)?

No. Venturi systems can get close but not equal the FC of gasoline. Expect a loss of fuel mileage of 5% to 10% depending on tuning. Running lean, it is possible to match or exceed the gasoline FC figures but performance suffers as possibility of engine damage in the long term.

2. is it correct to say that the FC and power loss inevitable with a venturi/emulator conversion will be found only at higher rpms (5k and above?) ?

Yes. Also air filter condition can affect FC figures as well.

3. is it correct to say that the advantage of a closed loop system versus the open loop system is that the settings for tuning it will be provided by the ECU, but on-the-fly performance will be the same as a well-tuned open loop system?

SGI systems still have an advantage of potentially better air-fuel mixtures at ALL rpm range. Even a well tuned venturi system has one major drawback, the venturi itself. This constricts the air-flow which increases the intake manifold vacuum pressure at higher RPMs. SGI systems don't restrict the air flow, hence better high RPM performance.

[glennjv]

Thanks Xoom and GH.
Sana nga may 60L toroidal sila but I'm guessing walang available.
So if its a 40L tank, the useable amount would roughly be just 30L.
My FC on gasoline is 10.5km/L (last fill up ko).
So on LPG on my Mazda 3 lets say 8km/L lang siya.
My range would be 240km per fill up. Hmm that'll last maybe 3 to 4 days tops.
Called them up and I told lorna kung pwede sa kin nalang yung 55L toroidal na dadating=) pumayag naman. (increases my range to 330km)

I hope the conversion of my car goes well.

Here's an experience I had driving the Camry my dad converted to LPG yesterday. (Coding kasi car ko) On my way to the office at around 930am all was fine and it could even reach 100kph like gasoline.
Upon entering the parking ramp and getting the ticket from stop. The car had a hard time rev'ing up but I was able to park. So I thought... that was weird.
Ok on my way home at around 730pm it was raining really hard. So I thought hey this is good, LPG supposedly runs better in colder conditions.
So from Pioneer upto Buendia, all was fine then there was heavy traffic approaching the underpass of edsa cor ayala. It was crawling. So ok lang. Then after a few mins from STOP the car was losing power again, having a hard time rev'ing up. A few meters forward STOP ulit then Go ulit, the car was having a hard time rev'ing up when its on Drive and Stopped for a while. On my 4th attempt, it was really having a hard time to Rev up..... the car stalled. Turned off everything after less than 5 secs I started the car on Gas.. Vroom... No problem...

Approaching the incline of Magallanes the car automatically switched to LPG...toink! I was able to climb Magallanes but I definitely do not have the power, so parang Diesel siya umakyat...hehe bagal.
Traffic was moving fast again and the LPG was fine again from Nichols all the way to Alabang. WEIRD.

I told my dad the camry still needs to be fined tuned it looks like it has problems when STOPPED and on Drive for a long time.


Here's my question regarding SGI kits...
For example on my Mazda 3 it has a O2 sensor. Does the A/F mixture "Adapt" / Change in real time based on how my engine is doing?
Does the ECU do this thing?
I'm thinking sana my Mazda 3 conversion has less problems kasi its a newer model that's more compatible with the SGI kit.

In the case of my dad's camry the A/F mixture is like Pre Defined so it doesn't know to change the A/F mixture when needed?
Does it act like a SGI kit? or like a Open Loop lang? (na Fuel Injected)

[niky]

On stock tuning, the LPG injectors will mirror exactly what the gasoline injectors are supposed to do, with a slight correction factor put in so that your stock O2 sensors will be happy... but it's your stock ECU that controls closed-loop tuning and the preset ECU maps that control fuel... the SGI computer just translates those instructions for the LPG injectors.

Thus, it's really important that your LPG AFRs (air-fuel ratio) closely mirror your gasoline AFRs in closed-loop (typically 0-3000 rpm on a modern engine) so as not to cause weird running due to your stock ECU trying to adapt to the LPG.

But the cold running issues can be due to tuning and/or vaporizer/coil mismatch issues. We're still discussion ways to figure out how to regulate fuel pressure when it's cold... apparently, changing the fuel pressure setting on the LPG vaporizer helps for some people... we're looking at the problem.

[ghosthunter]

I told my dad the camry still needs to be fined tuned it looks like it has problems when STOPPED and on Drive for a long time.

Sounds like the Camry needs more time to be tuned well.

Here's my question regarding SGI kits...
For example on my Mazda 3 it has a O2 sensor. Does the A/F mixture "Adapt" / Change in real time based on how my engine is doing?
Does the ECU do this thing?
I'm thinking sana my Mazda 3 conversion has less problems kasi its a newer model that's more compatible with the SGI kit.

Well, the factory ECU is still doing it's "thing". The SGI kit reads the signals and adjusts the lpg flow based on the factory ECU signals. The LPG ECU simply corrects the amount of fuel flow per cycle.

As for the Mazda3... the M3's ECU is uber sensitive. Even our Mazda3 1.6L still experiences occasional CEL (check engine light) at around once every month to once every two months. Other than that, the car runs pretty well although it experience initial problems like power loss and stalling until the LPG kit was tuned by SPEEDLAB.

In the case of my dad's camry the A/F mixture is like Pre Defined so it doesn't know to change the A/F mixture when needed?
Does it act like a SGI kit? or like a Open Loop lang? (na Fuel Injected)

I am assuming it's using the SGI kit so the LPG system is simply following the stock ECU's signals (which is what it is supposed to do). Just bring it back to the LPG installer for another round of tuning or bring it to SPEEDLAB if they have the software tuning kit for your SGI system.

[XOOMaster]

Thanks Xoom and GH.
Sana nga may 60L toroidal sila but I'm guessing walang available.
So if its a 40L tank, the useable amount would roughly be just 30L.
My FC on gasoline is 10.5km/L (last fill up ko).
So on LPG on my Mazda 3 lets say 8km/L lang siya.
My range would be 240km per fill up. Hmm that'll last maybe 3 to 4 days tops.
Called them up and I told lorna kung pwede sa kin nalang yung 55L toroidal na dadating=) pumayag naman. (increases my range to 330km)

I have tanks coming in by October for Internal 3 variants 40, 45 and 55. You can check which one suits you.

Here's an experience I had driving the Camry my dad converted to LPG yesterday. (Coding kasi car ko) On my way to the office at around 930am all was fine and it could even reach 100kph like gasoline.
Upon entering the parking ramp and getting the ticket from stop. The car had a hard time rev'ing up but I was able to park. So I thought... that was weird.
Ok on my way home at around 730pm it was raining really hard. So I thought hey this is good, LPG supposedly runs better in colder conditions.

Actually LPG runs better when heated well. Our cars water system is tapped to the vaporizer for it to heat up thus turning the liquid LPG coming from the tank to Vapor LPG. This is what goes into the cars engine.

Uphills should be no problem with SGI systems since it directly injects fuel into the manifold and into the engine. I think your running too rich that's why "parang lunod yung mixture ng air and gas" Ask them to tune it up to avoid stalls.

Here's my question regarding SGI kits...
For example on my Mazda 3 it has a O2 sensor. Does the A/F mixture "Adapt" / Change in real time based on how my engine is doing?
Does the ECU do this thing?
I'm thinking sana my Mazda 3 conversion has less problems kasi its a newer model that's more compatible with the SGI kit.

In the case of my dad's camry the A/F mixture is like Pre Defined so it doesn't know to change the A/F mixture when needed?
Does it act like a SGI kit? or like a Open Loop lang? (na Fuel Injected)

What type of kit was installed on the Camry? Well Lambda O2 sensor connections are optional. It does help though for the ECU to recognize the mixture needed so installing it would be a plus.

My car has been installed with an LPG system since December07 and I have no O2 connection but it runs fine with no problems. So i think it boils down to the proper ECU calibration.

[chinacrisis]

No. Venturi systems can get close but not equal the FC of gasoline. Expect a loss of fuel mileage of 5% to 10% depending on tuning. Running lean, it is possible to match or exceed the gasoline FC figures but performance suffers as possibility of engine damage in the long term.

Yes. Also air filter condition can affect FC figures as well.

Thank you for the quick reply sir GH, but medyo confused pa rin ako. I guess to clarify lang, is FC and power loss in a venturi system to be felt in all spectrums of RPM, whether high or low?

[ghosthunter]

Thank you for the quick reply sir GH, but medyo confused pa rin ako. I guess to clarify lang, is FC and power loss in a venturi system to be felt in all spectrums of RPM, whether high or low?

Power loss starting mid range RPM (or around 3500 and 4500). This is because you are trying to suck in more air through a small openning. At low RPM, the openning is adequate but at higher RPM, it becomes a constriction.

FC in well maintained system, keeping the engine running at lower RPMs can help maximize fuel mileage (as with any fuel).

Just imagine the difference in a carb and fuel injected engine. The analogy between venturi and SGI systems are pretty much alike. The efi systems are more efficient. Carb are easier to tune in DIY situations but are sensitive to any changes like airfilter condition and atmospheric pressure changes.

[XOOMaster]

Thank you for the quick reply sir GH, but medyo confused pa rin ako. I guess to clarify lang, is FC and power loss in a venturi system to be felt in all spectrums of RPM, whether high or low?

Power loss generally will be felt on high RPM's on this type of system. During Low RPM's its forgivable. On Fuel Consumption, there are still ways to tweak it to make it save more BUT point of caution if done to LEAN you run the risk of damaging your engine. Tune it just right and you'll still be able to save

[1997]

When I switch to Gas... Sobrang hirap yung makina... Kanini hindi ako makaakyat sa Parking... Will try to use Petrol tom... Do i need to tune my LPG system?

[ghosthunter]

When I switch to Gas... Sobrang hirap yung makina... Kanini hindi ako makaakyat sa Parking... Will try to use Petrol tom... Do i need to tune my LPG system?

1997 - 1996 Nissan B14 A/t (Venturi-mixer close loop - eroom)

You might want to check stuff like the air filter.

[vanleano]

dunno if this is OT..but am contemplating on coverting my accord to LPG..how much would it cost me kaya??and what's the best kit so far na bang for the buck????

[XOOMaster]

dunno if this is OT..but am contemplating on coverting my accord to LPG..how much would it cost me kaya??and what's the best kit so far na bang for the buck????

hi vanleano should range from 40-48k if its SGI. depending on the company you choose plus the tank etc. check out our link for the accord that we converted. so far we have done 2 - 99-2000 Accord and 1- 2003 Accord. xoomautogaz.multiply.com
Cheers!

[eikichi]

I noticed just this week when running around 70 kph that my car seems to have a difficult time at that speed. Parang nawala yung pick-up niya unlike the time when I was using gas. I was not able to notice this before because I seldom go higher than 80 kph in metro traffic conditions. Is this normal or there's something I need to check or need for retuning?

Also, do I need to use gas before and after using LPG? I try to run on gas for a few minutes on start up and switch to LPG. Before turning the engine off, I also try to run it on gas for a few minutes too. Am I doing this correctly or do I need to change the steps?

My kit's running condition is fine at low speeds and rpms. FC is also acceptable at around 9.5 km/li on LPG as compared to 11 km/li on gas. I think I will still need to get more samples of my FC to get a more accurate reading since I've had only a number of fill-ups. My kit is an emulator on a 98 Corolla GLi.

[ghosthunter]

dunno if this is OT..but am contemplating on coverting my accord to LPG..how much would it cost me kaya??and what's the best kit so far na bang for the buck????

GREENFUEL can convert your car to SGI-LPG for P42K with cylinder tank. P45K if with donut tank.

SGI kits give better over-all performance but costs more and you can't tinker with the settings.

Venturi kits are cheaper and simpler but more modern engines aren't compatible with these. Tuned well, these can perform nearly like SGI systems up to around 4000rpm. But keep the air filter clean.

[filchaser]

dunno if this is OT..but am contemplating on coverting my accord to LPG..how much would it cost me kaya??and what's the best kit so far na bang for the buck????

Go to Green Autogas in Minanao Avenue. I don't know the price now but I am sure you will be satisfied with the kit, installation and performance.

[1997]

1997 - 1996 Nissan B14 A/t (Venturi-mixer close loop - eroom)

You might want to check stuff like the air filter.

Bago naman Air filter ko... hehehe

[chinacrisis]

does anybody here have any experience with Thermoline as a LPG converter? They have conversion shops along Pasig Blvd. and E. Rodriguez. Their kits are priced lower than the rest. Feedbacks please. Pulido ba ang gawa? After sales service? TIA