"single point injection" on turbo engine
Turbo Mini Forums

Has anyone ever tried a single point injection on a turbo engine?
(Of course not the Rover stuff; I am thinking about Emerald or Haltech ECUs)

I mean having one (or a stagged second) fuel injector placed before the inlet manifold didvides into the two inlet runners. To place the injectors there should eliminate the charge robbing problems that the twin point injectors run into.
(Similar to the carb setup - but only controlled and programable by an ECU)

I think all the Mini 5 port Emerald ECU users may have thought about this - what could the problems be with this setup?

Cheers
Harry

Bimmer Twinky headed and turboed A-Series:
http://www.minifreunde.at/harry/projects.htm

Good Call Harry.
EFI spi is almost as hard to sort out as Mpi, simply because you can't get the fuel to be injected at the right time. The inection start/end point still moves wrt RPM, hence you still end up with charge stealing on most propietry aftermarket ECU's.
If an ECU was developed that allowed you to configure the two injection point 'boundaries' per 360 crank degrees, and then had a 'second' correction map to shift both these points acording to RPM, the problem would be solved.

Now the challenge is to find someone to do this!

Ever thought of fitting 4 injectors (2injectors per port runner) that are controlled to inject fuel eg. 50? before the appropiate inlet valve opens? This would cure the "right time" problem. The amount of fuel would be controlled in the usual way by the length of injector opening. Of course this would mean, that there would be an overlap of spraying per port. (Because of this "very well designed" charge robbing layout. )
Do you think this could work? Or would there still be unequal fuel distribution?

Bimmer Twinky headed and turboed A-Series:
http://www.minifreunde.at/harry/projects.htm

For me, two high impedance 'modern' injectors per inlet tract is the only way to do it...
You still need to be able to set the injection point, and may run into problems at higher rpm with charge stealing (unless you are able to shift the injection point).
Definately the right way to go though...

That's the only way to get a half decent result.

Jean

http://www.jbperf.com/

look out for some awesome results (relative gains) on spi minis with single point injection - coming soon to a mag near you.


JK

If Carling made Mini engines
it would probably be like this one!

It will be very interesting to see the difference between inner and outer cylinder AFRs.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I think they borrowed one:

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=263627

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

wrong guess folks - patience!

JK

If Carling made Mini engines
it would probably be like this one!