LPG

OK so my new 3.8 litre two ton van is on the boat sailing from the US as we speak.

How much, how accurately do they fuel (given it takes the OEM manufacturers about 6 months of dyno/road testing) and where to organise it as close to Grimsby as poss!

Its a Dodge but its the same as a Chrysler Grand Voyager to look at. The dodge is US specific in that we dont get a 3.8 petrol option here just the

3.3 and the awful deseasels.
Reply to
Burgerman
Loading thread data ...

formatting link
has a list of approved installers.

Reply to
Conor

Well arent they mapped to run on 89/91 octane?

I wouldnt be surprised if the CR is abit poor, so little to be gained by a remap, other than abit better response ??

A supercharger would be the way to go for most grunt per £. I spect there's several US tuning companys offering a s/c for the 3.3 / 3.8

Tim.

Reply to
Tim..

As usual the Americans thought they'd measure octane a different way. Their

91 octane fuel is more or less the same as our 95.
Reply to
Homer

Its not about a remap but a map!

They use 6 new injectors and a extra computer that has to be mapped. The existing one just gets switched off. So they either use a known trusted one (Ie for the 3.3 motor) or they think they can remap it by driving around and a quick trip to the rollers! You can, to a degree, but it takes a lot of science and testing to get it completely correct!

Reply to
Burgerman

It looks like there's a conversion already available in the US.

formatting link

Reply to
Homer

Mmmm So I have to send it back!

Reply to
Burgerman

They will put their best guess fuel map on it. You could always get the right cable and software and adjust it yourself, I managed to find the Tartarini ETAgas software for download before, although it was all in Italian...

Reply to
Tom Robinson

Just write "Retune to sender!" on it in big letters and pop it in the local post box.

Reply to
Depresion

So now I have to learn italian...

I suppose shouting and sticking an I or an O on the end of everything wont work...

Reply to
Burgerman

Groan

Reply to
Burgerman

In news:ASwoh.25651$ snipped-for-privacy@newsfe6-win.ntli.net, Burgerman wittered on forthwith;

The LPGA approval is helpful, if not exactly well policed, so you'll pay around £1200 for a decent multipoint LPG conversion - you'll probably need underfloor tank / tanks to save space, you get 80 litres or so of gas in a

100 litre tank. Decent multipoint conversions fuel at least as well as factory petrol injection systems as the best LPG ones use the cars brain for initial maps then adjust accordingly and accurately for LPG. With a decent LPG setup you'll lose no noticeable performance, but the power does improve higher up the rev range. I've noticed with my LPG Rangies that you get more low down torque on petrol but more top end on gas.

To be honest, most of the large engined recent Yank stuff I've driven has been pretty good on fuel considering. Lincoln Towncars will do 28 mpg (just) at 75 (22 if stretched). On LPG you're paying less than half for the fuel, so that's equivalent to 35 mpg and you're environmentally friendlier than half the fuckwits who complain about 4x4s and MPVs being bad for the environment - whilst they're driving knackered old Polos.

Can't lose with a big engine and LPG. My Scirocco averages 37 mpg and costs me more to fuel than my old 3.9 Rangie did..

Reply to
Pete M

For the most part it's a fixed ratio. say "x".

If petrol injector opens n msec then gas one has to open x * n msec.

Then they calibrate to stop the petrol ecu making fuel trim adjustments in closed loop - else the petrol mixture would be off on change over back to petrol as petrol ecu is still running it's just the injectors are off. What you don't want is the ratio "x" to be greater than 1, that means they fitted too small gas injectors. It can max out with an injector open time longer than 2 revs which makes it kick back to petrol.

Many installers are quite happy to fit systems that run on petrol at high rpm high load when the small gas injectors can't cope and may not tell you that is does switch back until you find it's still using petrol and go ask WHY? Their solution? Stop using the upper part of the power band - you had it converted for ECONOMY didn't you? Well you don't get economy using all the power.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Reply to
Peter Hill

"Pete M" wrote in message news:enupig$rf6$ snipped-for-privacy@registered.motzarella.org...

Useful info thanks.

Reply to
Burgerman

Err I am an ex drag racing turbo bike owning nitrous system designing (and using0) hooligan. I even got banned in my tow car at 127 on the M1 going to spondon engineering in Derby! (to get my drag bikes swing arm lengthened more)

And you are telling me that a gas conversion will default to liquid cash if I nail it! Whats the point then... Is there systems that can cope? Otherwise its a bit pointless! This is interesting information of the sort I was looing for!.

I always USE everything any vehicles got and I have driven a few within the first few yards of driving it. And have a bad habit of repeat performances! And I really cant help myself.

Its why I have been banned 5 times and had extra pages in my licence! And at one point 13 endorsements an rather a lot of points... The feds dont seem to get that safety has little to do with speed or attitude and everything to do with experience and ability. I can drive nicely/economically but its hard! If forced to behave would rather pick up a plastic cone (they are easy) and drive until it wears away under the car. Then pckup another... You can always pretend you didnt know... I know I dont fit the modern tree hugging safety nazi culture but I am old... And like to play.

So what happens when you run low on fuel. and ignore it because you switch to the LPG? presumably it runs weak or cuts out when you nail the throttle? Stupid! But it gives me another important question to ask. Thanks for the info.

Reply to
Burgerman

Ahh misunderstood...

Depending on the type / model of gas computer, they are self mapping, largely.

In learning mode, the GAS LPG firstly watches the petrol injectors duty cycle against speed and load. Second stage is it shuts off the petrol injectors and fires up the gas ones. It then swings the mixture about and watches the duty cycle as supplied by the petrol ECU in accordance with the lambda reading, and fine tunes itself.

Full load, very light load and idle still usually have to be fine tuned via a RR and laptop tho.

Other systems need a total RR / laptop set up, inwhich case I would think they would start with a 3.3 map as a base line.

FES autogas and go-lpg are both VERY good firms who know what they're doing. Both online.[1]

Tim. [1] no affinity to either.

Reply to
Tim..

No, a proper conversion will remain on gas at full power.

Tim..

Reply to
Tim..

Ahhh. for years I thought this group was useless and came here for its comedy value! Now I find several bits of useful info is several replies in one thread! This is amazing!

Reply to
Burgerman

The one I had piggy-backed onto the petrol ECU, and spoofed the petrol injectors when in LPG mode (i.e. as far as the main ECU knew, nothing was different). The only 'map' which needed to be set up was the petrol-injector signal to lpg-injector signal scaling, which is a trivial operation, and doesn't even have to be particularly accurate.

Reply to
Albert T Cone

:-)

You get to buy a new petrol pump, they don't take too well to runing dry. Supposed to keep about 1/4 tank of petrol to keep pump in liquid and running cool.

Burgerman:

Having looked at the wiki, 215bhp (knowing your history, it can't be one the 180bhp ones, can it?) from a V6 isn't going to cause any problems. 36bhp per injector is well within the injector sizes available, the limit's around 45bhp/injector and can be taken a bit above that by increasing the gas pressure. So you have scope for

270bhp (300bhp at a push).

Tim:

I wrote that knowing Burgerman's predilection and addiction to performance. (215bhp in a van that size, do you think he's getting old and slowing down?)

I couldn't find anyone that could source gas injectors to match my stock 370cc/min petrol injectors (60bhp/injector). Everyone I asked told me it would switch back to petrol around 5000rpm (redline 7200).

A recent disscusion on the LPG forum also covered topic of gas/petrol switching.

:LPG Discussion Forum: General Discussion: :OMVL DREAM software 4.67... F4 Gas/petrol :------------------------------------------------------------ :Posted by keith woods (Woody) on :Thursday, November 30, 2006 - 11:39 pm:

:Mark hi, this button is basically a get out of jail card. :If you have a vehicle with a problem that normal tuning wont get rid :of ,ie,hesitation when pulling away, stalling at idle, or change back :to petrol at higher rpm.You can set the system to run on petrol at the :rpm you programe it to,when it runs on petrol the switch light stays :green , gas mode.It gives the impression of running on gas when it is :actually running on petrol. :It is basically A cheat to hide the inability's of the system.

:Chears Keith :------------------------------------------------------------

You can't tell and unless you ask some won't tell, others may just forget or think you don't need to know.

:------------------------------------------------------------ :Posted by iain sherriff (Iain) on :Friday, December 01, 2006 - 2:42 pm:

:mark..... a bit cynical i think

:The user should be able to tell from the switch LED that change over :has happened. I have been asked by quiqte a few owners of "hot" cars :if they cna specifically have this feature for more "traffic light" :power :------------------------------------------------------------

:------------------------------------------------------------ :Posted by keith woods (Woody) on :Friday, December 01, 2006 - 9:21 pm:

:Iain,with this function enabled the switch stays in gas mode[green]you :cant tell which fuel you are on unless you connect you laptop up or :check the pulses on the injectors.

:I cant understand why the hot car owners would want this function , as :a really good system which is set up correctly will give like for like :performance.

:cheers Keith :------------------------------------------------------------

So if you run it dry of petrol you will stall - just when it's needed most, just as you go for a foot to the floor overtake.

:------------------------------------------------------------

:Posted by C S Autogas (Classicswede) on :Friday, December 01, 2006 - 11:46 pm:

:The feature is on all AEB based systems and finding its way :onto most others tbh. :------------------------------------------------------------

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Reply to
Peter Hill

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.