Turbocharging an LPG-equipped vehicle with OE ECU?

[Steve]

Hi everyone

I'm beginning a project and need a little advice. I will be fitting a turbo to my 94 Jeep Cherokee 4.0 which is fitted with a single-point LPG system(italian-make..not sure which)running closed-loop with lambda, I'd like to run it predomantly on gas whilst on boost and have been led to believe this might be possible without going to the extent of aftermarket ECU's and the like. Will not be running silly boost pressures(prob around 6-7psi)and will be using an intercooler if needed

Is this possible? If so, could someone point in the correct direction of which parts may be needed?

Cheers
Steve

[dodgerover]

Yes it can be done, you need the right old school gear to do it though, you would probably be best asking on the LPG discussion forum.

Dredging my memory when turboing there is an extra pipe (from the mixer i think?) which connects to the vapouriser to allow it to compensate for boost - this is going back years so could be way out

[squonk]

Check this out: www.go-lpg.co.uk/Turbo.html

Looks like the answer is yes but not with the system you have. Budget for another £1500 to get a decent sequential system fitted and set up properly.

[dodgerover]

Right, thought about this somemore last night and yes it was a pipe that allowed the diaphragm inside the vapouriser to work with boost pressure as the reference rather than just atmospheric. Its definately do able with 1st generation tech, after all turbos aren't exactly new, but i don't know if you can modify your existing vapouriser to work in this way or its just case of buying a new one.

Sequential injection nice though it is isn't the be all and end all. You'de have to be a real numpty IMO to use a turbo or supercharger in a situation where you were putting a LPG/ air mix through it as the go-lpg site suggests.

[ChasR]

Without trying to sound too nasty there is not much advice that I would trust from one of the above links (after the issues a friend of mien (and others have had with their cars) You can search for other people who are dissatisfied yourselves). Considering how much my friend has thrown at the car (a downright F**king fortune (possible more than what my retros are worth!)) I would put this in a nun killing kittens situation (You can use your imagination for the rest (leaking LPG (and petrols) connections are the tip of the iceberg ...).

Saying that I am sure other chaps on here will come up with a more plausible solution .

[froggy]

I looked at this when I converted my camper to petrol turbo power . From what I could gather if you have an oe turbo set up you could run a port injection system with the right sized vapouriser but getting one to flow enough gas to support over 200 hp gets expensive .
For the emulator system to work it needs signals to do its job and if your efi isn't setup for boost ie injector duty doesn't follow boost etc it won't be able to fuel properly .

With an oe turbo set up its do able at a price but you run the risk of very lean mixture without the proper info for the emulator to read

[CFmania]

A twin chamber / diaphram vapouriser will do the job on a turbo, it's just like a twin choke two stage carb.

[squonk]

Feb 24, 2014 9:56:19 GMT CFmania said:

A twin chamber / diaphram vapouriser will do the job on a turbo, it's just like a twin choke two stage carb.

But that will be basing its gas supply presssure on atmospheric pressure, not boost pressure. To overcome the increased pressure of the turbo the vapouriser needs to know the boost pressure so that it can compensate and produce sufficient pressure itself to flow the gas. Without it the gas pressure will be overwhelmed by the boost pressure. That doesn't really read very well, does it!!

[10mpg]

I've tried to do a couple of mixer ring lpg conversions over the years on turbo cars, despite using appropriate gear they never work right on boost. No problem with an injection kit though, (building one now as it happens) and as you already have the tank and piping, I'd just fit a sequential front end kit on it, new from 300 and second hand from 75.... Get rid of that grunt sapping mixer ring from the intake and make it run sweeter on both gas and petrol, no brainer imho, then youcan just adjust the map to cope with turbo as appropriate...

[dodgerover]

I've got a 6 cylinder LPG injection front end from a Grande Cherokee if you get stuck.

[froggy]

Thinking about it you might be better off leaving the stock ecu and going with an emulator injection system that you can map if you aren't going for a lot of boost as lpg has a higher octane rating you will have some knock protection on boost as the stock ignition won't be altering the timing in boost . The only issue I can see is having big enough vapourisers to supply gas for over 250hp

[dodgerover]

Looking at doing this on my transit now as its going to be the easiest way to make more power from the low compression pinto, will report as and when, hoping to use the BLOS carb i've just bought.

[dubmeister]

I've got a vapourizer on my 5ltr v8 s class that will do up to 385 bhp so vapourizer shouldnt be a problem ,has anybody used a blos style carb on a turbo lpg car ?

[dodgerover]

Mar 17, 2014 13:16:33 GMT dubmeister said:

I've got a vapourizer on my 5ltr v8 s class that will do up to 385 bhp so vapourizer shouldnt be a problem ,has anybody used a blos style carb on a turbo lpg car ?

I asked the UK seller of the BLOS carbs and got the following reply

How do you get the turbo and gas in the mixer is from the inlet cone to the mixer must be a certain distance

otherwise it would not produce Aug. vacuum and sucked Bidz respectively regulator

this distance kombinujcie

different with Blos because his opchodzi how much air flows through the blos because this flap decides to open gas dose and in this situation the cone closest to BLOS is indicated

but if on mixerze to the corresponding dobrało distance from the cone to the mixer can adjust easily to the bottom of the dose and in the mountains with no problem adjusting only when driving with the probe in the exhaust pipe is not at a station control


I might add that the dose of gas should begin at the time of the turbo pump and the bottom would have to bypass on the reducer support dose to the idle screw

you could for example set up for this kompa eg bingo set me on the basis of the probe to regulate the dose of

but here you have a kumatego not gaziarza

as they wrote in spite of orchards gaziarza

you would then divide the dose to low and high loads on the basis of tp

would be even better because the stag has 3 ranges of low medium and high loads

hence three different gas dose corrected by the probe or blocked but roughly adjustable regulator

it would be much more powerful but you have to remember with it will be very economically with respect to the combustion

because it's such a combination will be less agility than injection because few sensors and electronics

not better to put 2 webery double and take advantage of the boost dynamic as perzcie 205 1.3 100 ponies

Which to be honest left me none the wiser, i'm guessing it was translated by google, I'm going to get one of my Polish speaking friends to email the guy who makes them directly when I get a minute and hopefully clarify things.

[dubmeister]

I had all kinds of problems with blos carbs going through my head and as you did sent a message and got a completely unintelligable reply
i was thinking the blos would put the right amount in if it was before the turbo but then thought of a highly explosive gas going through even the cool side of a turbo wasnt a great idea and also you are recompressing a gas which you just put through a vapouriser to expand ,i realise boost would probably be 20psi max but not sure how much difference it would make after the liquid in tank was compressed to 280x atmosphere
Blos carbs are only good to about 100bhp too i think so you might need a couple at getting on for £100 a pop
Speaking of pops a blow off valve would be good somewhere in the inlet would be good for backfires but would need to be stronger than what boost was set at
confused i am lol

[dodgerover]

Have seen single BLOS installs on rover v8's so they are probably good for more than 100 bhp, I've got a couple of LPG injection front ends but they are way too complex to be going onto an old pinto.

Its probably not that much different (on a potential for problems basis) putting a LPG/AIR mix through a turbo compared to putting petrol/ air - at least LPG is guaranteed to be a vapour not a liquid fuel at that point......still don't want to do it though

[dubmeister]

The 100bhp limit on the blos carb is just what they quote on ebay and could be down playing the power so you buy a couple when you don't really need to .
blos carb works just like a cv carb on a big motorbike a pretty much all you need to do when you turbo them is use the venting system to equalise the carb float bowl pressure and boost in the manifold so reckon as long as the vapourizer can keep up you should be ok on the fueling side and you can buy ignition boxes that alter the ignition when you fit lpg so ignition sid of things might be as simple as picking the right one of those (real steel used to do them for rovers and chevys but not so sure about pintos)
I figure if you can run a car on a blow through turbo system surely you can run it on lpg just the same as a car runs on petrol vapour really not liquid .