Fed up with filling cost

[adaxo]

Cool. I'm now look at buying a leggy and gassing it. Been running my cars on LPG for years now. Used to work for a garage that did kits a well so confident with them.

What size tank did you get in there?

Thinking of using the omvl dream xxin kit. Which one did you use?

Are you going to install a valve saver kit?

Hi, I completed my bits from various companies, ECU is Stag 300 plus, vaporiser is Prins/Lima, injectors are HANA2000, and tank is from Stako 650x270 70l.
Valve savers is IMO just a marketing thingy like plugs/oils 'designed' for LPG

[adaxo]

Well done Adam, that looks very tidy! Good man for doing this yourself! I wouldnt have the guts or know how to even begin!

Thanks

[Davezj]

turned out nice again!

you have finished up really well adam, really neat install.

[disco-ian]

650 diameter wow. I only thought a 600 would fit but 80% of a 70 litre tanks works out nice.

Yer I've never bothered with valve saver before wasn't sure if the valve seats were soft on the vr4 engine therefor might need some lubrication to cool them down.

Your conversion looks really neat. Really nice job. Any idea on mpg yet.

[adaxo]

turned out nice again!

you have finished up really well adam, really neat install.

Thanks, you can see that in the flesh on sat.

650 diameter wow. I only thought a 600 would fit but 80% of a 70 litre tanks works out nice.

Yer I've never bothered with valve saver before wasn't sure if the valve seats were soft on the vr4 engine therefor might need some lubrication to cool them down.

Your conversion looks really neat. Really nice job. Any idea on mpg yet.

No MPG figures yet, still in tune mode

[MarkSanne]

That looks very neat! And a 70L tank in the spare wheel well sounds just about ideal! I wish I'd have the guts to do such an install myself. That said: I'd like to know if there are LPG installations compatible with what you've got there... Most LPG installs over here (I think) are for more 'regular' cars, not 280hp turbo-ed ones...

I'll follow this thread with great interest regarding milage on LPG and other stuff that would be good to know/learn!

[adaxo]

Mark, you can get a ready made kit (especially become from Netherlands) from Prins , there are AFAIK top of the range and if money was no object I will happy fit that on to my vr4, problem is that, the front kit (without tank/shut off valves ect.) cost around 1000£ here, I see few more demanding cars (Cayenne, Navigator, Hummer) run on Prins systems with great success.

[pezza]

Yep well done Adam, looks very good... Hardly any traces of your hard work from looking under there.

I am not sure what software Krzysztof used on mine as it was in Polish but it displayed AFRs MAP pressure, gas and petrol injector timings, lag etc...

It's tuned to run on GAS to the red line and power wise feels exactly the same and even improvements on idle than with petrol.I tried a couple of Gtech sprints just to see and best I got was 5.1 0-60 on Gas AFRs at around 11 to 11.5 or so... with VTA BOV. Slightly higher with recirc valve. Only power mods I have would be boost controller downpipes (big difference) and 2.5 decatted powerflow. It took a couple tune up sessions but AFRs are spot on 15.5 cruising and about 15.5 to 16 on idle. We did a lot of foot to floor uphill runs to setup under maximum load.

Boost controller is normally off with gas but if not, set to max out at 12psi or so.


MPG wise getting a couple of mpg less than petrol maybe 19 to 22 depending on driving but at 37quid to fill up my 65litre tank its much less than unleaded or super.... from empty I tend to be filling up 52 litres max before it cuts out.


Spark plug wise I did try BKR7IEXs but now on NGK BKR8IEX after checking the state of the 7s. I also fitted and oil temp gauge just to monitor oil temps as with the gas people have stated that the engine can run up to 10% temp increase. Mine seems to hovver around 95 degrees to at max 110 which is the same as petrol.

Once every couple weeks also I will run the car on petrol for a couple of days or so too.

[adaxo]

That what's my aims are Derek, run on LPG only in all conditions (even on track). You got pretty much the same setup as mine, and as you mentioned it is require a few pedal to metal runs which is hard to do on my own with laptop on passenger seat (where is Dave when you need him) .
I fill up 60ltr of LPG last time for a whole 48£ and after 200 miles is still not empty

[Davezj]

i would be more than happy to bob round to do a bit of driving for you while you tweek the fueling.
give me a shout.

[disco-ian]

Getting good results then Adam. Don't forget on most lpg systems you can add petrol in with LPG at different load sites if needed to play on higher boost settings etc.

We're are the valves on the 70 litre tank you used. Inside the doughnut. Or is it a full toroidal with the valves on the side.

Did you have to cut the spare wheel well around at all to get it in.

[adaxo]

It is toroidal tank for 30 degree multi valve fitted in the middle, I know that you can set to switch back on petrol on high load BUT what is the point of fitting LPG and run on petrol??. I didn't cut anything, just remove that plastic pointless 'shelf'.

[disco-ian]

I agree it would be pointless switching back to petrol completely at higher RPMs :-) Was just think if the LPG injectors do reach max duty cycle the ECU's I have fitted in the past for LPG have the ability to run both petrol and LPG together at higher RPMs. Have never needed the function either, just nice to know its there incase you do start to run lean under boost.

Just a though....
But with the later Leggy ECU's have the ability to flash them and switch between maps could we write a specific fuel map in the petrol ECU with Lambda being 15.6 to 15.8:1 for LPG rather than running the richer 14.7:1. Also this would give us the ability to run the correct ignition timing for LPG as well as LPG burns slightly slower than petrol you can get another 6 - 8 degrees of ignition timing. (This is the main reason for power / economy loss on LPG because ignition systems are left for petrol)

Like I said just a thought. Something I might look into when I convert my'n but then saying that got to many projects on the go the whole time and I know once the leggy is on LPG and a start saving I probably will just leave it at that lol

[adaxo]

I agree it would be pointless switching back to petrol completely at higher RPMs :-) Was just think if the LPG injectors do reach max duty cycle the ECU's I have fitted in the past for LPG have the ability to run both petrol and LPG together at higher RPMs. Have never needed the function either, just nice to know its there incase you do start to run lean under boost.

Just a though....
But with the later Leggy ECU's have the ability to flash them and switch between maps could we write a specific fuel map in the petrol ECU with Lambda being 15.6 to 15.8:1 for LPG rather than running the richer 14.7:1. Also this would give us the ability to run the correct ignition timing for LPG as well as LPG burns slightly slower than petrol you can get another 6 - 8 degrees of ignition timing. (This is the main reason for power / economy loss on LPG because ignition systems are left for petrol)

Like I said just a thought. Something I might look into when I convert my'n but then saying that got to many projects on the go the whole time and I know once the leggy is on LPG and a start saving I probably will just leave it at that lol

Good thinking here

While LPG injectors reach they max duty (still 'open' while next 'open' signal arrive), which was mainly 'old' style 'injectors' (more like small electro-valves) issue, you risking damage of injectors and/or LPG ECU, is not happen on keihin type injectors (@ right cc chosen, obviously).

About maps, yes you absolutely right to say about create LPG map in petrol ECU as long as your LPG ECU not have that option build in it (most don't had ability to create 3D LPG maps), my LPG ECU had the option to create 3D LPG map which is IMO much easier to do than reflash petrol ECU, this is working 'on the fly' and changes are straight away
affect AFRs on each cell of the map.
What I will look to do is, as you mention, change ignition tables on petrol ECU just to chase that few more ponies but I need to go for session on dyno to set that properly.

BTW. what system/components are you chose to go for??

[disco-ian]

Im used to using the Romano RISN and OMVL Dream XXIN systems. These actually follow the petrol ECU injector timings, perform a calculation to it then send the signal to the LPG injector.

The 3D fuel map that you see on the LPG screen for these is not a map. its more an adjustment of the calculation that the LPG ecu is performing.

So the petrol ECU when running "closed loop" is aiming for lets say 14.7:1 and adjusts its fuel trims to get there. The LPG ECU simply follows this, so if the petrol ECU thinks its rich it shortens the injector time, therefor the LPG injector time gets shorter and the petrol ECU gets closer to its goal of 14.7:1.

So if you write a map for LPG you can change the wanted valve and therefor get better figures from the LPG.

Thats my understanding of it anyway and have had an in-depth conversation with the supplier / importer of OMVL kits about this. I guess really only time will tell an just hope I take the plug and get into flashing the ECU on my'n when I get it. Hope to pick it up Saturday if the previous wonder has fixed the misfire which he tells me he has fixed with a new set up plugs.

Can't wait till Saturday :-)

[adaxo]

Im used to using the Romano RISN and OMVL Dream XXIN systems. These actually follow the petrol ECU injector timings, perform a calculation to it then send the signal to the LPG injector.

The 3D fuel map that you see on the LPG screen for these is not a map. its more an adjustment of the calculation that the LPG ecu is performing.

So the petrol ECU when running "closed loop" is aiming for lets say 14.7:1 and adjusts its fuel trims to get there. The LPG ECU simply follows this, so if the petrol ECU thinks its rich it shortens the injector time, therefor the LPG injector time gets shorter and the petrol ECU gets closer to its goal of 14.7:1.

So if you write a map for LPG you can change the wanted valve and therefor get better figures from the LPG.

Thats my understanding of it anyway and have had an in-depth conversation with the supplier / importer of OMVL kits about this. I guess really only time will tell an just hope I take the plug and get into flashing the ECU on my'n when I get it. Hope to pick it up Saturday if the previous wonder has fixed the misfire which he tells me he has fixed with a new set up plugs.

Can't wait till Saturday :-)

That is my undestanding too, its just the fact that you put this in proper English


Where in UK are you live, if you don't mind me asking?, hope you pick your vr4 soon and then start play with your LPG conversion, looking forward to see how its going

[disco-ian]

I live in Norfolk. Just by snetterton race circuit. I checked your profile about 200 miles away from you. Would have been good to meet up really i think between us we could really get the best out of LPG on these engines.

Have you played with the flash software on the petrol side of things at all.

[adaxo]

I live in Norfolk. Just by snetterton race circuit. I checked your profile about 200 miles away from you. Would have been good to meet up really i think between us we could really get the best out of LPG on these engines.

Have you played with the flash software on the petrol side of things at all.

Will be nice to meet and share few tips/hints about LPG, IMO LPG as a fuel is the last chance to drive powerful cars this days at reasonable cost. You may consider japfest 2 ?, looks like it will be a good turnout of few interesting ppl and vr4s.

I think is another vr4 LPG converted in your area (white, ex-derv).

We (means Davezj) looking to get in to flashing game, Dave got all tools required, I just didn't do that yet due to fact that I wait to drive 1000 miles on LPG to let all settle and then start to play with ignition timings on dyno which we try to rent and organize RR day.

[disco-ian]

I have a V8 Discovery that I use off road and had it on LPG for the 6 - 7 years that I have owned it. I used to work for a company that specialised in Rover V8 engines and LPG so kind of got hooked on the LPG band wagon a long time ago. Seeing the new Supercharged 400bhp Range Rovers take well to a conversion kind of made me feel that a 280bhp v6 should be alright :-)

[disco-ian]

Japfest 2 is a little close for me to make it (this Sunday lol)

Will be going to Ten of the best though. Always get to that.