craigoscott

cool, nice to hear that it is going well

Westwood2006

iTrader: (1)

There's going to be an open day open to both trade and public at MintLPG - (Autogas Worldwide, Newport) on Sunday 5th June.

They are promoting a new diesel kit that is more performance orientated than economy.... and if you are into this kind of thing a new sequential injection ECU, new tanks and the launch of the mintLPG Network.

I'm going to pop down for a couple of hours. Many of the LPG conversions are on larger engined cars.... Might be a couple of interesting cars there.

I'm considering selling this WRX to release funds for another project. If you are interested let me know and I'll meet you at the LPG open day on Sunday.

Westwood2006

iTrader: (1)

Definitely decided to sell it !!

If anyone is interested I placed the ad here:

https://www.scoobynet.com/subaru-444...x-ppp-lpg.html

Westwood2006

iTrader: (1)

Changed over the multi-valve today.

For some reason the float only floated when the LPG tank was cold (i.e. in the morning) but when it was warm (i.e. in the afternoon) it would sink again showing empty on the gauge! It also sank during filling so the 80% auto cut off feature didn't work.

This hasn't happened before (allegedly) and they usually float or not!

We don't know why it behaved like this but one theory is that LPG is denser when cold hence making the float more buoyant.

Please send your answers in on a post card.

Anyway, it is all fixed now.



Here are a couple of pictures of the multi-valve that I took before install during the conversion. It does several things:

- Excess Flow Valve - shuts off if the flow to the front of the vehicle is too high, eg. outlet pipe damaged
- Inlet Check Valve - only allows flow into the tank
- 80% cut off Valve - prevents over filling
- Electronic Level Sensor - shows level
- Pressure Relief Valve(s) - keeps pressures in check by blowing off!
- Shut-off Solenoid Valve - only allows LPG to flow when engine running and ready to switch over

Here you can see the inlet, outlet and manual valve.



Here you can see the solenoid (in blue) and the round cut-out where the level sender / gauge sits. The float arm moves the sender using magnets!



Shot from the "inside" of the tank. The spring is part of one of the safety relief valves in case pressures get too high in the tank.



Whole multi-valve assembly from "inside" the tank showing the non floating float. It is made from a synthetic cork like material covered in hard black plastic. The pipe you see sits near the bottom of the tank so that liquid propane is delivered to the front of the car.



Close up showing one side of the lead plug. If the tank finds itself engulfed in flame then the lead holding this plug will melt allowing the LPG to escape "in a controlled manner". No doubt this would be impressive to watch but not as impressive as if the tank exploded. That really would be impressive!

At the factory they actually test these by filling a tank and putting in into a bon-fire!!! I need a new job!!!



Another view of the same valve. Here you can actually see the lead.

Westwood2006

iTrader: (1)

Quick update.

She's been running really well except for a slight hesitation around 2500 rpm which I sorted by tweaking the LPG mixture. Took me a few attempts to get it right. I got it OK solo but it still hesitated when loaded so in the end I had to get some mates to sit in it while I fooked around.

I also found that it switched over to LPG too early some times; before the temperature gauge had moved off the stop. So it held back for a while. It felt a little like a carburettor car needing a little more choke. It was set for 30 seconds / when the water temperature reached 30 degrees. I changed it to change over to LPG only after 50 degrees. This seems to have done the trick.

Happy now.

I also tweaked the change over settings so that it switches over to petrol completely after 5000 rpm. This gives me better peace of mind when making progress but more importantly it uses less petrol on the daily commute.

Previously it was set up to introduce petrol after 4500rpm / 15ms and so it used about 1/8 tank of petrol every 300 miles or so. It took me a while to cotton on to this!

Since replacing the multi-valve I can only fill the tank to 80% (which is how it it supposed to work)!!! So the range has come down slightly. Still 300 miles though for about 46 quid. So I'm saving approx 30 quid per week which equates to about £1,500 per year at my current mileage.

Also been messing with the LPG fuel gauge settings. The sender gives out digital signals (0 for full > 255 for empty)... but because the tank is cylindrical the level gauge shoots down quickly at first, then spends ages about 1/2 full, then reports "reserve" and runs out almost immediately.

After unsuccessfully guessing what the numbers should be I drove around with my laptop in the car and stopped every 60 miles to set the next level light. So when the reserve light comes on I know I have 60 miles to go. So 4 green LED's and a red "reserve" LED representing 60 miles each.

I'm still pretty chuffed with the way this project has gone.

Stuck it on eBay tonight. Would like to move it on.

Westwood2006

iTrader: (1)

Finally got round to tidying up the under bonnet wiring today:



I have been getting the run around from DVLA about updating the V5 to show LPG / Petrol.

Is it me or have DVLA seriously gone down hill recently? What a fu cking shower of tw ats they are at the moment.

I got into a kind of Mexican stand off with them (having returned my V5 without the updates) telling me over the phone to tax it again and apply for a refund for the current tax disk.

After 25 minutes of arguing with the retard I was speaking to it turns out I can just present to a DVLA office with a V70 "Application to exchange a vehicle tax disk" form. I'll then get a refund cheque. It has taken me WEEKS to get to this stage!!!!

I made one more change to the settings.... I brought the vaporiser change over temp down to 40 degrees and I have finished messing with the settings now. Very, very happy with the way she runs... 99.9999% like factory.

On another completely unrelated note. I just found a country MOT station in the middle of nowhere that sells LPG at 71p per litre!! Bonus.

Rob Day

iTrader: (78)

Thats a great thread mate, nice read up with good photos
The Mrs wasnt to happy about me reading during breakfast with the laptop on the table though lol

Rob

Westwood2006

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Glad to be of service

flyingflatfour

Hi! Congratulations with your conversion.

I had a similar setup on my '97 GF8 turbo. Initially had problems with the mixture and contaminated gas (filters clogged), eventually all sorted, then was quite happy with it, but I had one problem that could never be solved: the lube system.

The vaccum systems basically means that it will only suck out lube if your inlet manifold's pressure is below atmospheric pressure, hence below approx 1 bar absolute.

Which means that when the turbo starts to build up pressure above 1 bar absolute, there is no lube coming out anymore, quite the opposite: the lube reservoir gets pressurized and not only are the valves not protected anymore but I had lube leaking out of the reservoir through the filler cap screw, onto the turbo, having it burn into smoke

Is your system similar or does it manage to send out lube even under boost?


Another important thing: I had to have the valves' clearance sorted every 18000 miles, that wasn't exactly cheap. The valve seats were getting worn out a little.

Other then that I covered about 55000 miles with the system before I got it removed because my car was turning into a track-only special.

Interesting to note is that the gas tank helps a lot to cancel most of the understeer at corner entry. It was very noticeable when I had it taken out, actually made the car slower! Just a proof that weight reduction doesn't work always as you'd expect - weight distribution is certainly as important.

Westwood2006

iTrader: (1)

It is interesting to hear other peoples experiences with LPG. I hoped this project would stimulate some discussion. There isn't enough quality info out there.

The flash lube seems to be working fine. I have no blow back like you describe. We installed a dedicated nipple right in the middle of the inlet manifold. Before I installed the kit I messed around and found that I couldn't blow into the bottle.

If you think about it in a normally aspirated car the flash lube will only work on idle, over run or during gear changes when the vacuum is at its highest. As soon as you open the throttle the vacuum is not enough to suck flash lube in. Same for turbo cars (except they also go positive on boost). It seems to be getting through it OK.

I was paranoid about any potential valve problems so I started with a brand new engine and went to great lengths to make sure the valves stay good. Here are a couple of pictures taken of the heads after they had been reconditioned at API.





I have it set up so it uses 10% petrol over 15ms injector demand and it changes over to 100% petrol after 5000 rpm. So depending on how it is driven plenty of petrol lubricates the valves.

In reality 15ms seems to approximate to about 1/3 throttle. If you push on past that then you aren't worried about economy! You can easily drive it quickly without using any petrol.

I kept everything well away from the turbo. Especially the flash lube kit!!! That's just asking for trouble.

This particular system only has a filter in the feed from the tank (combined with the solenoid just before the vaporiser). The injectors are a new design that do not need vapour filters.

Of course. Time will tell how well this set up works.

flyingflatfour

I can tell that you have thought your installation in and out before proceeding, and it's great to see that you are running trouble-free!

About the flash lube: you are right, setting it above the turbo wasn't the cleaverest thing my installer did How did you figure out you couldn't blow into the bottle? Is there a non-return valve in the line. We also used a dedicated nipple IIRC.

Your LPG/petrol mix setup is very interesting, we couldn't do that with our ECU and software (Easyjet was the brand), it would be interesting if for science you could have the compressions taken after about 18.000 miles to see if there is a need to take care of the valve clearances

For sure, the fact that I had it installed in a 80.000 mile old engine meant that LPG would clean the valve seats and valves of any combustion residues, leading to a insufficient tightness.

One more piece of information for the scepticals:

There is an urban legend about LPG installations blowing impreza engines. This was with older carburetted LPG installations that would basically fill up the whole intake system with LPG/air mix. In such circumstance, when valve clearance became too big due to seat wear, the mixture would ignite and blow up the intake... This will never happen with a multi-point injected system


Good luck!

Westwood2006

iTrader: (1)

It was a good training course. Highly recommended. I had plenty of time to decide where to put stuff. Of course it helps when it is your own car... you put more effort in!

The classroom was an Aladdins cave of broken this and broken that. Incorrectly installed injectors in old manifolds, exploded manifolds, photos of burned out cars and all sorts of interesting stuff. It really focused the mind!

Yes, I think it is safe to say LPG systems have come of age now. The Romano LPG ECU is fairly sophisticated when compared with the early fumigation type systems used on carburettors.

You can set it up to do almost anything. For fault finding you can run one cylinder at a time on LPG for example.

When it switches over it does so one injector at a time every 10 revolutions .... so you can't actually detect the change over even if you know when it is!

Clever stuff.

Westwood2006

iTrader: (1)

Added a couple of pictures above.

Gareth79

Thought I'd post here.... I've just bought this car from Ian, and have been very impressed.

I haven't owned an Impreza before, in fact no turbo or AWD cars so it is all very good fun! My previous vehicles have been: '94 1.3 Micra (owned 09-11), '92 Chevy Caprice (5.7 V8) (03-08), '85 Chevy Camaro IROC (5.7 V8, 03-06), '87 Chevy Camaro (2.8 V6 01-03, slow)

Anyway, the car drives great, Ian ironed out all the bugs and I haven't noticed any problems whatsoever. I've refilled it a couple of times and on the last tank it returned 24mpg, or a petrol equivalent of 44mpg taking into account the cost, not bad!

I'll try and remember to update any LPG relevant info here, for those interested.

Westwood2006

iTrader: (1)

Glad you are enjoying it. I put a lot of time into making it perform as normally as possible!

I have driven loads of Imprezas and I can tell you this is one of the better examples! Hopefully you'll just be here telling us how well it is going!!

Nice meeting you and good luck!

nevespereira

iTrader: (1)

Excellent thread, I from POrtugal and owned a 1999 WRX wagon, that runs on LPG and also a Toyota AE86 since year 2000 with LPG too.
My Scooby runs 70% on LPG, since 89000km as now 110000km and the AE86 since 116000km, now with 150000km, nothing so far.

Both, doesnt have special lub, only take some care when running on LPG try not to go more than 4000rpm.
Also each +-80km I run a little on gas to lub a litle the valve seats.
must try a compression tests...

The main reason were:
- Pollution (have 2 worderfull children and try to me part of the solution).
- price in POrtugal for LPG: from 0,65€/l or Kg and 0,80€.
- price for unleaded gas 95: 1,666€/l
- run 50% on city traffic

I dont notice any special change in the performance, only some hesitation, due I belive the sparks (iridium).
Note that gas are a litlle demanding for the sparks, are harder to explode with the mixture.
its a multiple LPG injector (Vapor)
because its a turbo engine, the lub dont work very well I belive, so why to add more pollution...
Also like its a turbo the «less performance», i can´t feel noting.
Perhaps the secret for the valves is running with the mixture a litle richer to prevent higth temperature and the formation of NOx and extra HC...

Its increble like in the 21st century we still use petrol, and even diesel...

Best regards from Portugal

Gareth79

Bump, I am now selling this car, full FS post in the sale section:
https://www.scoobynet.com/subaru-444...onversion.html

Put over 40,000 miles on it with no major issues.

Ap83

Hi guys I'm just about to buy a 2002-2005 wrx, preferably a wagon and would like to LPG it as I will have the car for 5 years or so. Could you advise which LPG fitter to use please? Or if you know of someone looking to sell please shout out. Many thanks. AP