Direct Injection - the end of LPG?

[N_Willmott]

Gents,

I've always bought / converted large engined, high power cars.

I'm looking at new high power motors out there for conversion and most of the latest these days that I can see are all direct injection and from what I have read, DI kits are motor-specific and I don't recall seeing any for the kind of cars I am looking it - high power Mercs, BMWs etc.

A quick search leads to up to about 2005/6 from when a lot of German manufacturers have gone DI... so am I limited to motors before this tranisition?

Cheers.

Nige.

[Tubbs]

I would say as things stand at the moment yes, its limited. 4 cylinder cars etc. But thats not to say its always going to be that way. I would say the LPG manufacturers are concentrating on that end of the market at present. Its just a numbers game at the end of the day. There are more 4 cylinder cars on the road than anything else. But once covered I'm sure they would be moving on to other things. Saying that the mitsubishi gdi shogun thats been about since 2000 still doesn't have a system.....so i would doubt you will ever see a system for and AMG merc v8. Not enough to make it in any way worthwhile.

[N_Willmott]

Pretty disappointing as the newer DI engines are much more economical anyway and therefore in terms of a cost/benefit not sure it would be worth converting any longer.. the only 'case' I can think of is the high power stuff (as you say, Merc AMGs as well as BMWs and Audis etc)

I wonder if we could put together a list of models for the above 3 manufacturers that are not DI or if there are any specific dates that the switchover to DI happened? Would help consumers and installers alike?

Cheers.

Nige

[LPGC]

Agreed with Tubbs.

Just adding a few thoughts..

For the purpose of this post, DI means direct petrol injection - nothing to do with diesel engines (that's a different subject).

Where a vehicle manufacturer has developed DI technology, a reasonable assumption might be they'll use similar DI technology across their vehicle range. If true, then where a car manufacturer makes a 4 cylinder DI car and then makes an 8 cylinder DI car, it should be possible to convert the 8 cylinder using 2 x 4 cylinder LPG kits that were designed for the manufacturer's 4 cylinder car (and load the LPG ECU's with firmware designed for the 4 cylinder car).

Contrary to the above thought, it's necessary to check engine numbers on (example) 4 cylinder Vauxhalls, to see if an LPG kit is made for that engine number. I'm starting to put a scope on DI vehicles (when I have the opportunity) to check injector pulse widths, voltages, etc, in the hope of gaining more insight but will take time because it's not often I get the opportunity.

Would work out expensive to do the above though!

Have converted several direct injection vehicles with AEB3000's, would be good to be able to convert any DI vehicle, even if expensive to do so.

Some vehicles will always be more difficult to convert than others. Example, some engines have both direct and port injection on the same engine, so there might be options for the customer such as 'for price x we can convert it to drive on LPG and you'll use very little petrol but for y extra we can make it tickover on LPG too'. For y, at the moment read the price of another ECU and set of injectors... Unless an LPG system manufacturer makes a very special ECU that can interpret the fuelling signals from both the direct and normal petrol injectors at the same time - not likely because of the limited market.

Simon
http://www.Lpgc.co.uk

[rossko]

http://www.prinsautogas.com/articles/en ... urkey.html

[Tubbs]

http://www.prinsautogas.com/articles/en ... urkey.html

Finally !

[Gilbertd]

Didn't the LPG fuelled BTCC car use a Prins DI system back in 2010 (before they changed the rules to outlaw it)? I suspect that may have been a testbed for the system,

[N_Willmott]

http://www.prinsautogas.com/articles/en ... urkey.html

That's going back to 2008 though - where are the 'real life' examples of V8 (or any other high power) direct injection vehicles?

[Tubbs]

There isnt any im afraid. But a show one is a good start eh !

[Dualtechuk]

Just to add, Emer, a kit that I know Tubbs is very familiar with have sucsessfully been running a V8 direct injection in Australia. This 8cyl kit was avaialble from AEB (Emer) for a very short time but a problem with 'red tape' is stopping it being sold at the moment. But its encouraging to know it works and will hopefully be avaiable to all soon. Also the direct injection kits that have been fitted are only running about 5% less efficent than a non direct (due to the small amount of petrol used) so still well worth converting considering that the direct injection engines are already more efficent

[Tubbs]

There you go see, something else i didnt know, its all very encouraging really. Not as far away as it would appear then, my dads in aus at the moment. Maybe i could get him to bring a kit back

[N_Willmott]

There isnt any im afraid. But a show one is a good start eh !

So what happens next? Can I walk into my local Prins installer and get one fiitted?

[woody]

Didn't the LPG fuelled BTCC car use a Prins DI system back in 2010 (before they changed the rules to outlaw it)? I suspect that may have been a testbed for the system,

They certainly did , and i now possess the whole kit from both cars which will be fitted to our BMW E30 track cars,full story will be posted as and when we get going............the tanks are a little bit special !!

[woody]

http://www.prinsautogas.com/articles/en ... urkey.html

That's going back to 2008 though - where are the 'real life' examples of V8 (or any other high power) direct injection vehicles?

Prins have done the Cayenne twin turbo [from memory] using liquid not vapour.
Speak to Will @ prins autogas uk he will be able to tell you whats what.

woody

[LPGC]

Just to add, Emer, a kit that I know Tubbs is very familiar with have sucsessfully been running a V8 direct injection in Australia. This 8cyl kit was avaialble from AEB (Emer) for a very short time but a problem with 'red tape' is stopping it being sold at the moment. But its encouraging to know it works and will hopefully be avaiable to all soon. Also the direct injection kits that have been fitted are only running about 5% less efficent than a non direct (due to the small amount of petrol used) so still well worth converting considering that the direct injection engines are already more efficent

The Emer systems for DI's are all similar, you update the firmware to suit the vehicle. We don't know which Audi V8 was converted but it's likely possible to look up settings in the 8 cylinder firmware and adapt 4 cylinder Emer ECU firmware to run the same settings. Then convert the same Audi V8 using 2 x 4 cylinder ECU's (that are available now) instead of the 8 cylinder ECU (that isn't available), this would be kind of like what I said in my earlier post but in reverse.

Incidentally, the AEB DI systems I've fitted were/are Emer.

[Tubbs]

Hmmm...i see your thinking, but you are fully taking a punt on wether it will work properly really. I would rather just wait for the proper system. Afterall if you cause some long term damage to a customers car its Emer's look out and not yours
I would rather fit a fully tested, approved di system than a work around.

[LPGC]

Hmmm...i see your thinking, but you are fully taking a punt on wether it will work properly really. I would rather just wait for the proper system. Afterall if you cause some long term damage to a customers car its Emer's look out and not yours
I would rather fit a fully tested, approved di system than a work around.

Agreed Tubbs, a dedicated 'designed for specific vehicle' would be the best way. Though if we did cause damage by fitting an Emer system to a vehicle for which it was designed I doubt it would be easy to prove the system caused the problem and get Emer to pay up! Interesting point there - Never tried to claim from a manufacturer, has anyone else?

We all usually fit generic systems that are not designed specifically for the vehicle / engine models that we install them on. Most of the time of course, this is fine, because nearly all port injected vehicles have similar electrical specs for injectors and the injectors are pulsed for similar durations.

The above isn't the case with DI vehicles and DI LPG systems, and DI vehicles might be damaged by fitting even the correct DI system with the wrong firmware (at least with Emer), the firmware sets/controls the emulation.

There are three things that make a certain DI LPG ECU compatible with a certain DI engine: Emulation of the vehicle's petrol injectors, Interpretation of the DI pulse times, Appropriate petrol addition to protect the DI injectors.

The only aspect that will damage an engine quickly (before the installer attempts to calibrate etc) is the electrical / emulation aspect (ok you could burn out some DI injectors quickly with no petrol addition, damage cats, burn valves etc but I'm talking during initial running on LPG.
By interpretation, I mean we're used to installing systems that measure a single injection pulse (ok some vehicles have short extra pulses, K series for example) for every induction stroke with pulse lengths typically between 2ms and 16ms (ok some keep injectors open constant at full load, some low revving big block V8's go up to 25+ms, full group engines might go to 8ms). DI engines have multiple pulses which are shorter. Depending on the design of the DI system there might be (just examples) several pulses of between 0.5ms and 2ms, or fewer pulses of up to 4ms, or a high number of 0.5ms... All these examples might inject the same amount of petrol but the DI LPG ECU needs to know how to interpret them to arrive at suitable LPG injector pulse times (we are stuck with a single long duration pulse with LPG injectors) or calibration would be impossible.
The petrol addition point is obvious - protecting petrol DI injectors from damage due to overheating etc.

Was just suggesting that if we have two vehicles from the same manufacturer (no reason why it shouldn't apply to vehicles from different manufacturers really but would want to try it on same manufacturer first ideally), Vehicle 1 a 2 litre DI 4cyl and vehicle 2 a 4 litre DI V8. Then we physically examine components and they look the same, then we check resistances of injectors and they're the same, then we check voltages to injectors and they're the same, then we check pulse times and they're the same, then there's no reason why 2 x systems designed for vehicle 1 shouldn't be just as appropriate for vehicle 2, including the petrol addition specs.

The 4 cylinder Emer ECUs are the same size as the usual 8 cylinder AEB ECU's, so I hope they manage a reasonable size box for 8 cylinder DI ECU's - maybe that's another reason they're not on the market. Not had one to pieces yet to see what's inside, doing so would be interesting.

Simon

[N_Willmott]

I can understand 2 x 6 cyl ECUs to do a V12 which aren't all that common but there are many more V8s at the moment so 2 x 4 cyl ECUs wouldn't really be acceptable.

I'm just surprised no manufacturer is really pushing DI LPG systems as I also have loads of buddies who want a later (DI) car and would pay to have it converted if the option was there. Maybe the technology isn't mature enough yet.. who knows.

[Gilbertd]

Might be of interest, might not http://www.ebay.co.uk/itm/LPG-Conversio ... 4d08b7c12e

[Tubbs]

The technology is reasonably new, and as i say it does seem emer are concentrating on the VAG group first for whatever reason. Be it good links, free test cars for development or whatever it may be. It could also be to do with the recent buy out by westport. Now they are a big player in the LPG market, so they bought emer who also own valtek and Omvl recently so probarbly well over half the Italian automotive LPG market in one foul swoop.
So who knows what 'pressure from above' the Di development department are facing. They did seem to be rolling out cars a lot quicker when they where emer, and it seems to have slowed down a bit since they have been owned by westport. Maybe westport require more stringent testing and type approval ?
Maybe thats not a bad thing ? But i have to say all the Emer stuff does seem to work impeccibly.
Now from what i have seen, you buy a di kit. It comes with an installation manual telling you how and where to drill holes, mount injectors with piccies and everything. And you have to folliw these instructions to the letter. Technically no longer making it a 'generic' system but far mor vehicle specific with a box of components. Now that takes it all into a completely different spectrum as far as culpability is concerned.