LPG Injector Sizing / Power Rating

LPG Injector Sizing / Power Rating

Author
Discussion

V8RX7

Original Poster:

26,903 posts

264 months

Wednesday 15th October 2014
quotequote all
Hi I'm hoping someone might be able to help.

I had a 215bhp Forester which had a BRC LPG kit fitted before I bought it, it was slightly less powerful on LPG than petrol but ok.

I've now had it remapped and Dyno'd at 270bhp and the LPG can't keep up and is running lean.

My issue is that the current Orange injector are rated as 48bhp/cylinder (192bhp) I was advised by an LPG installer to change these to the largest (BRC) size which are Yellow and rated at 54bhp (216bhp)

I can't seem to find out how these ratings are calculated - I'm wondering if they are at say 80% duty and the installers run them closer to 100% or do they run them at higher pressures ?

It seems a bit pointless paying £300 for injectors that are only rated 6 / 24 bhp higher.

V8RX7

Original Poster:

26,903 posts

264 months

Thursday 16th October 2014
quotequote all
I'll try giving Tinley a call but I pulled the Inj sizes from his site.

My regulator is rated to 268bhp - which seems close enough.

V8RX7

Original Poster:

26,903 posts

264 months

Friday 17th October 2014
quotequote all
Oh.

I thought it would be more like construction where a 2 ton rated beam can hold in excess of 4 ton.

The local LPG guy said he's run 300bhp through my type of regulator.

V8RX7

Original Poster:

26,903 posts

264 months

Saturday 18th October 2014
quotequote all
stevieturbo said:
You cannot extend injection period longer than 100% duty

nor would you want to run it that high
Agreed

Why ? I've heard this many times yet I've run petrol injectors at 100% duty on my supercharged MX5 for thousands of miles including track days without an issue.

V8RX7

Original Poster:

26,903 posts

264 months

Sunday 2nd November 2014
quotequote all
Update:

I called Tinley Tech to ask whether I could fit the Hana A+ injectors are they are cheap and good and are the largest available - apparently they are a copy of the Keihin used by Prins - they said yes as the impedance was the same.

Unfortunately they were wrong - the basic Hanas are 1.9ohm but the larger A+ are 1.3ohm (as are the Keihin)

However I went to a recommended LPG installer in Stoke (a 60 mile drive) and he found that:

A Bristol LPG "specialist" had electronically disconnected the MAP sensor and removed the replaceable element BRC filter and fitted a cheap one.

He reconnected the MAP and raised the gas pressure from 1500 to 1800 and then "tuned it" which seems very basic and relies upon the fact that LPG has a far higher octane rating than petrol - however it seems to have worked as it now runs as well on gas as LPG - although I will be monitoring the fuel trim and installing an AFR gauge