620TI on gas!

alexf2828 · Post by **alexf2828** » Sat Nov 27, 2004 11:29 pm

Just had 620TI converted to LPG ,bit lumpy at low speeds but on motorway/open road runs superb,system is tartarini fitted by autogas 2000 at thirsk n.yorks,31.2p per litre here I come!

Craig · Post by **Craig** » Sat Nov 27, 2004 11:36 pm

hehehe ... you great tree hugging fairy!

:wink:

Only joking. You may well be the first person on here to have a T16 turbo converted to run on LPG. It will be interesting to hear how it goes over the next few weeks.

alexf2828 · Post by **alexf2828** » Sat Nov 27, 2004 11:46 pm

Its different to petrol,bit more "savage" as the gas installer described it,but they said I have more power on gas than petrol on rolling road because petrol system was below par,it basically goes like fook on gas on motorway but throttle is a little jerky at low speeds.System is good for 300bhp and can be transferred onto next car

Craig · Post by **Craig** » Sat Nov 27, 2004 11:48 pm

Sounds good.

Do you mind disclosing how much the conversion set you back?

plasticmunky · Post by **plasticmunky** » Sat Nov 27, 2004 11:50 pm

my uncle has it on his beemer, smells slightly of gas when driving inside the car! :puking:

, also how long would it take to get your money back you paid for it by the cost of gas!??

Tom.

alexf2828 · Post by **alexf2828** » Sat Nov 27, 2004 11:57 pm

conversion set me back Â£1475,managed to get it VAT free! (being cheeky works wonders) worked out it could save that amount in as little as 15000 miles,have started really driving and enjoying the car now because Im not worried about fuel bills,will soon clock up the payback mileage

alexf2828 · Post by **alexf2828** » Sat Nov 27, 2004 11:57 pm

does not smell of gas at all BTW

dreaddan · Post by **dreaddan** » Sun Nov 28, 2004 12:37 am

I'm supprised that they expect it to8 do more power on the rollers as the general rule is that you loose a little power and mpg.

Though would be nice to know that it's posable to convert and get a power gain would be good

Dan

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 12:43 am

Its not really a power gain,the only reason it has more power is because my petrol system has some fault,on a car that was working 100% on petrol u would lose power on LPG,but not much

Post by **MarkCoupe** » Sun Nov 28, 2004 12:55 am

dreaddan wrote:I'm supprised that they expect it to8 do more power on the rollers as the general rule is that you loose a little power and mpg.

Dan

Yep, look at that civic touring car on lpg!

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 1:07 am

It is possible to get more power out of lpg than petrol with the right engine/compression ratio/timing because of its super high octane rating.

Si · Post by Si » Sun Nov 28, 2004 5:08 am

alexf2828 wrote:It is possible to get more power out of lpg than petrol with the right engine/compression ratio/timing because of its super high octane rating.

Octane rating is very different to specific energy of a fuel. Octane rating is basically how resistant the fuel is to detonation.

The specific energy of unleaded is something like 43 MJ/kg.
Lpg will probably be less than 40 as a guess, I know doesn't contain the same energy as petrol.

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 12:14 pm

yes it has a lower calorific value than petrol,but can take much more compression/advanced timing

daz500 · Post by **daz500** » Sun Nov 28, 2004 12:31 pm

have you any pictures of your installation?
how much boot space has been lost?
what sort of range do you get?

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 1:24 pm

spare wheel well is taken up with tank,tank takes about 45litres of LPG with 20% space left for gas expansion,range probably 200-250 miles depending on type of driving(not confirmed this yet),will get some photos done,the installation looks very professional with two banks of injectors bolted to top of inlet manifold,injectors sound a bit like tappets when they kick in but u cant hear em inside car

wez_p · Post by **wez_p** » Sun Nov 28, 2004 3:37 pm

did they say whether the lumpy on low revs was to be expected/normal? i had thought about this a while back but more for a bit of an experiment rather than fuel economy since i do prob less than 4k miles per year!

the idea was to get a company to do it for free, but in return i would provide them advertising at track days etc, showing that a performance car could do mods etc still with lpg on the car

sound like an idea or just doggies?!

marko · Post by **marko** » Sun Nov 28, 2004 5:00 pm

Shouldn't be at all lumpy or jerky at low rpms - the installation/tuning leaves a lot to be desired by the sounds of it.

Can make more power than on U/L because:

>100 octane
>If liquid-phase injection you've lot LOTS of intake charge cooling (like nitrous)
>No boost cut at 1bar

They're diffiult to tune correctly and cost a fair bit more to convert than a nat asp motor.

<plug> I've still got an LPG kit (single point injection, big 80l cylinder tank) for sale </plug> if anybody wants: (bottom of page)
http://www.cosic.org.uk/forsale.htm

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 6:47 pm

they did actually describe it saying that gas can be a bit "savage",the idle is good its just when u feather the accelerator in traffic/low speeds that the power comes in with a bit of a jerk(no big deal really),apart from that the power is very good when u floor it,will let the system bed in properly for a few weeks and see how it goes

WayneH · Post by **WayneH** » Sun Nov 28, 2004 7:55 pm

Sounds interesting...

Marko - why is there no boost cut at 1 bar with LPG

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 8:06 pm

probably because LPG uses its own ECU hence no boost cut

daz500 · Post by **daz500** » Sun Nov 28, 2004 8:38 pm

alexf2828 wrote:probably because LPG uses its own ECU hence no boost cut

that was my next question ... what happens to the ECU?

alexf2828 · Post by **alexf2828** » Sun Nov 28, 2004 8:47 pm

basically u have an emulator that fools the petrol ecu into thinking the injectors are connected when they've been disconnected,the gas ecu only needs battery and rpm signal to work,has its own MAP sensor etc,it then has to be mapped with all its own settings etc,so its basically a completely separate fuelling system

WayneH · Post by **WayneH** » Sun Nov 28, 2004 9:00 pm

alexf2828 wrote:basically u have an emulator that fools the petrol ecu into thinking the injectors are connected when they've been disconnected,the gas ecu only needs battery and rpm signal to work,has its own MAP sensor etc,it then has to be mapped with all its own settings etc,so its basically a completely separate fuelling system

Ahh, makes sense