Smart injection

[Kapt. Q]

Hi Richard, that's excellent news, very exciting. It seems like such a good candidate for injection. Really impressed by your tailoring things special for the micro motor. I will get as much before and after data from the tuner as possible.

I know of a Scandinavian who has raised the compression in one of these engines (took .5mm out of a possible 2mm off block with no valve interference) in order to experiment with E85 and the economy aspects of it. He had problems with the spark, this has also been problematic with some brave/foolish(?) enough to venture in to NOS (never heard of it working for long in a Smart, lol).

No hurry on the shipping, still got to get a tank, methanol, etc, and we are snowed under too!

Cheers again!

[Richard L]

I must admit this is by far the more challenging customisation I have done over the years. making the system more flow twice as much is much easier. I am looking forward to see how well the system performs.

There are two things that affects the sparks. High cylinder pressure and flash point of the fuel. In cold weather, E85 could be a real pain especially the compression ratio is raised.

It is less of a problem in your case as you only need to introduce spray when the engine is under load and cylinder temperature is quite hot. Can you adjust your spark gap? If so, you can run higher wmi ratio, allowing more cooling for power increase.

[Dust]

How low are you thinking here Richard on flow? Would dropping pump pressure be easier?

[Richard L]

Dropping pressure will reduce flow for sure.

My problem is detecting the low flow with the same turbine designed for detecting flow in excess of 2 litres per minute.

Turbine mass (inertia) and bearing friction will affect linearity at low flow. We do have other turbines with different geometries for low flow applications.

[Dust]

You obviously know why I am subscribing, hoping to see what you come up with.

[Richard L]

If there is greater demand for low flow injection systems, we will scale down the flow sensor components. Problem is, low flow system may not require flow sensor based failsafe.

I have not forgotten the diesel systems.

[Dust]

I agree, and I don't really have a way to really use it for the setup I am looking at.

[Richard L]

The smart project car gives me an opportunity to evaluate the performance of the system under the low-flow conditions.

At the same time, it is interesting to know much water is required for this this highly stressed engine. I have learnt how fast the oil temperature rise under medium load.

[Kapt. Q]

How does size effect efficiency generally if at all?

Are smaller engines more or less efficient?

I made a motorway journey yesterday, the Ambient temp was 0C, I travelled in 6th gear at 3500rpm, boost .8-9bar (1.5 possible), for several miles. MAT was a constant 38C even with this medium load and an intercooler scoop picking up 0C air at speed.


The car still performs so much better right now than in the summer when it is completely overwhelmed even with our low summer temps!

Cheers!

[Richard L]

If you can push up more power per litre, you will be on a winning path but you are limited by fuel octane. Higher octane will enable you to run higher compression ratio hence higher incylinder temperature and pressure.

Water/methanol injection will enable you to cross that octane barrier. Water reduces incylinder temperature during evaporation as well as regulating the frame speed, reducing the chance of knock. Superheated steam will also raise the cylinder pressure resulting in significant torque increase. Addition of methanol aids inlet cooling as well as lifting the octane of pump fuel.

Your highly stressed engine is well suited for this, hence I am taking a special interest on this.