nkeehn

Ok, I know the last couple of propane threads have been basically just giant arguments, but has anyone actually tried propane yet, either as a auxillary fuel or as 100%?

ronbros3

YES! interesting subject, anybody??

bumpstart

https://www.rx7club.com/australia-new-zealand-forum-43/anz-rotor-pic-montage-put-up-your-rides-786585/
i have been doing straight LPG turbo for a while, under OEM and custom manifolds
works A1, cheap as chips to operate, smooth as silk , far better than shitty cheap EFI conversions

ima very experienced across many rx's with aftermarket EFI from the earliest d4s days till present day
( i do HEAPS of trouble shooting for rotors locally )
and i can categorically state, from sitting on both sides of the fence
the LPG from a impco mixer is less troublesome, and smoother than most EFI tunes
- and pretty much out of the box
poo poo all you like, i have done both, with more than just "user" experience
i have 20 yrs of daily owning and modding mazda rotaries ( not just for myself )
LPG / propane, even in simple mixer application, kicks **** for smoothness, ease, and practicality
with very minimal losses in power before boost, and NIL losses with boost
( propane/ LPG fuel only )

its disadvantage when compared to petrol = lack of latent cooling, and only 3/4 the calorific value
( and its ability to deny the inlet of 10% of its volume when it expands fully )
on the road, you wont know the difference until told your driving an LPG vehicle
- the only practical limit here is the shorter range for the same litres

compare that to the loses and advantages of E85 to petrol
- LPG whips E85 on EVERYTHING but latent cooling


when you want to get smart and control the inlet manifold temps for higher than normal boosts, then WI brings many boons

a propane/ H2O injected rotor will also take more boost and timing than a petrol/ H2O one !


PS
my operating costs nearly halved when swapped to LPG
( and here in OZ there is now federal and state government rebates that PAY you to fit it )

slo

iTrader: (1)

^^^Nice thread revival

I like the idea of using aux propane injection directly after the turbo

Typically its not possible to inject propane as a liquid because the injectors freeze, the state change cooling from liquid to gas is enormous, far greater than the liquid to aerosol state change of methanol.

But if injecting directly after the turbo only under load (and as an AUX system, not so much that the vehicle could be run entirely) I would guess that freezing wouldn't be an issue.

There would be no need for a pump and a standard fuel injector could be used with an aftermarket ECU controlling it.

Propane is a very stable fuel not prone to pre-ign with a high "octane", which is evident in the fact that port injection of propane (read conversion) can be done on compression ignition engines without changing the compression ratio.