Siamese Code Trial - With Boost
Turbo Mini Forums

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."

That explains it, I wasn't sure what was vacuum & what was boost.

Edited by Rob H on 8th Aug, 2009.

Very good, I think we knew it would all come together in the end.... Thanks to Jean...

Only points of interest to me...

You seem to have a hard top limit on your widebands of about 22. TechEdge has a similar limit (can't remember the exact value) but the way your plot shows it is very precise, ie confidence in the readings.

However, there does seem to be a bit of noise on the outer reading (ocassional spikes both up and down)

Not quite sure what you mean about "limit of the injectors" at 12mS....

Assuming you are running the new single pulse mode, at 6K RPM, 12mS would equate to over 50% duty (over both cylinders), ie, beyond valve open/close times, so I wouldn't expect to be able to change the relative AFRs at that point...

Or I may have got the maths wrong (it's happened before....)

As a matter of interest, how many cc do you inted to put on the Miglia ???

I'm looking at staged 1680 or 2000 per port and from my maths that should still keep me away from a duty cycle that excedes valve timing.

Schrödinger's cat - so which one am I ???

The LM-1 on the outer cylinders is very spikey. I'm tempted to get another LC-1 and compare the results.

Yes, at 960 cc/min per port, I'm running at over 50% duty cycle and don't seem to be able to get any more fuel in the outers.

However, I've got an idea I might try to improve it and will report back.

I'm tempted to go to the RWYB at the Pod tomorrow and do a bit more testing. It's starting to get a bit dangerous now that we are spinning tyres and starting to feel a bit of torque steer.

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."

excelent.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

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."

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."

Presumably with 1 only for the first stage and the other 2 for the second stage ???

Have you done the mod on your second daughterboard for the staged injection yet - I've just got my second one and it looks like I'll need an even stronger pair of reading glasses than I already use for PCB work to do it safely, Mr Magoo type.....

Schrödinger's cat - so which one am I ???

Could you not use 2 injectors a small one for the first stage & bigger one for the second stage or have I missed the plot?

i think overall demand is requiring bigger inj than are common for 2 rob ,.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

It's a matter of individual size and total capacity for staged injection.

Hence why I'm interested in Paul's choice.

Ideally, yes, a small one for the first stage and a bigger one for the second stage.

The trouble is there are a limited number of "large" ones available because the average engine needs nowhere near the capacity we need.

A "one port per cylinder" engine will run at 80% or more duty cycle, we are limited to a lot less to work the siamese code.

Schrödinger's cat - so which one am I ???

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."

reading glasses??

loosing my closup vision is not somthing i'm looking forward too as i get older,

at the moment i'm the guuy peple come to if they wan somthing like this changed....

You have got me thinking (again).....

The inlet manifold I'm currently building does have potential issues with the injectors pointing in different directions so potentially favouring inner/outer cylinders.

If I do it again but with three bosses per runner, the centre boss could be stage 1 and have no preference (like my current manifold) and the outers could be stage 2 and cancel out any preferences.

It will physically fit (I've just measured) but then I have a new issue with low z... The TIP 122s on the P&H drive are only rated at 5A, injector peak current is 4A so I may need 6 P&H drives..... need to do some maths on the average current and power dissipation (or PM Jean !!!! ...)

Schrödinger's cat - so which one am I ???

On 9th Aug, 2009 mini13 said:
reading glasses??

loosing my closup vision is not somthing i'm looking forward too as i get older,

at the moment i'm the guuy peple come to if they wan somthing like this changed....

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."

Edited by Paul S on 9th Aug, 2009.

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."

can do Paul,

is there a link or some info on what mods are needed?

Joe,

Picture is about halfway down here
http://jbperf.com/sequential/index.html

I've done worse but my eyes used to be a LOT better....

Schrödinger's cat - so which one am I ???

no problem,

if anyone wants this done i'll do it for nowt.

Paul,

If you want to stay with high impedance injectors then your choice is quite limited. But if you're willing to go to low impedance injectors, you can get up to 5000cc/min injectors (at a price).

Jean

http://www.jbperf.com/

http://www.jbperf.com/

I've just done a quick calc to check the fuel flow and hp relate.

Based on a BSFC of 0.5 lb/hp/hr (5.25 cc/hp/min)
Density of the fuel of 720 kg/m3
12mS gives 60% duty cycle at 6000rpm
60% of 960cc/min is 576 cc/min

Power would be 110 hp at 6000rpm.

Looks about right.

I might just increase the fueling by adjusting the VE to check, but I should find that all the extra fuel goes to the inner cylinders.

Edited by Paul S on 9th Aug, 2009.

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."

If you have an adjustable fuel pressure regulator, you could increase the pressure to make some more tests.

I'm quite surprised that you can get up to 60% duty cycle. That shows that the single pulse is definitely the way to go to optimise the available injection window. Nice work.

Jean

http://www.jbperf.com/

Schrödinger's cat - so which one am I ???