LPG Discussion Forum

Am I right in thinking you cannot convert a car with a turbo? Should say that I am refering to Bentley.

No, numerous turbo and supercharged cars have been converted both with old school mixers and modern multipoint injection.

Thanks.

Must have been some misinformed person that told me that.
I am thinking of getting another Bentley or a RR. I already have an LPG kit for an injection engine but dont know it it is the same as one for a turbo.

Gremlin wrote:I already have an LPG kit for an injection engine but dont know it it is the same as one for a turbo.

I don't think anyone else could guess from that much info either. Some components in the kit will be limited to a max horsepower, that'll be your most likely obstacle.

Should have said that the kit is off an EFI Bentley engine of the same capacity.

Hasn't really moved us along. You have a mystery kit of some unknown capability (I would not just assume it could handle the bhp in its previous life, inadequate installs are shockingly common, best to work out what is really capable of) - and what you're going to ask of it is just as unknown so far.
I could guess the "target" is somewhere between 300 and 550bhp.

It also depends what sort of system it is. An EFi Bentley isn't exactly cutting edge technology so would work reasonably well with a single point mixer system. Equally, a multipoint could be fitted and work too. I take it we are talking Mulsanne Turbo here and not Continental GT so would require a single point as the turbo blows through a big 4 barrel carb.

An EFi Bentley isn't exactly cutting edge technology

That also applies to the rest of the car

If you expect an answer, it may be an idea to answer the questions. What kit have you got?

Gremlin wrote:Am I right in thinking you cannot convert a car with a turbo?

If it's a mixer system, then the reducer for a turbo installation has a pipe from the intake (just upstream of the mixer) to the rear of the diaphragm(s) instead of having them open to the atmosphere. That way, whatever boost is being applied, will also be applied the the "atmosphere" the reducer is regulating against - so the pressure as seen by the mixer doesn't change.

Injection systems already regulate against manifold pressure/vacuum. Because the injectors are downstream of the throttle, the reducer must regulate against manifold pressure - otherwise the injectors would see a pressure differential varying by anything up to 1 bar for a normally aspirated engine, more for a turbo.

The reducer for an injection system (that's the gas, not petrol) are different to those for a mixer system. For an injection system, the reducer supplies a positive pressure which pushes gas through the injectors. For a mixer system, the reducer just supplies gas at about atmospheric pressure (or intake tract pressure when the remote sensing pipe is connected as would be the case on a turbo), and the mixer sucks it through according to airflow.

As others have already said, there's a few questions you need to answer before anyone can even start to guess at what you have and whether it would be suitable for the car in question.