Sequential Setup?

[Peter Wales]

The tests were run on an engine dyno. The procedure was to run the test at a
given rpm, measure the power and then change from batch to sequential injection.
In each case the fuelling was optimised for peak power at that RPM. It made
no difference. However, the fuelling requirements, if different, always gave
better economy on sequential injection. We were only looking for power.




>The reason i ask this is because you CANNOT quantify any results without
>looking into mixture preparation, temperature's of the inlet valve, fuel


snip

I didn't quantify them, I simply said that you didn't get more power. I
wasn't really looking for economy, but being an inquisitive sort of
character (some people call me nosey) I wanted to find out what and why, so
I tried it and the results were not defineable enough. This is because all
testing was carried out at WOT and on the dyno we used, part throttle
positioning was not sufficiently repeatable so we didn't use it.

>Well i must say different.
>I carried out some (well alot of) research on this subject from a combustion
>point of view. I saw a reduction in harshness (uneven combustion) and
>INCREASE in Power (Torque) when you FINISHED or JUST FINISH injecting the
>fuel just before the inlet valve started to open. 

I didn't alter the injection timing, just the mode.

>
>I am also assuming that you did your tests at a steady state. Test done in
>steady state only sometimes give you an increase, but mostly show NO
>increase in power.

Thats what I found

>
>The only way to see the effects of the above is to be in constant TRANSIENTS
>which is were our engines spend 80% of their time.

Now I'm getting confused. Why try and define economy for a transient which
is not defined. On that dyno, we couldn't have reproduced a transient, never
mind measured the power developed during it. How do you define power during
a transient? HP is a function of torque and RPM and if the RPM is changing
what does the answer mean?

Despite your willingness to disagree with me Sian, I don't think we do. You
are measuring under one set of parameters and I under another. I still say
that it doesn't matter whether you use sequential of batch injection, the
power won't change. I'm talking about *power* ie 300HP at 6000RPM on WOT,
not what happens at 1800 RPM on 1/4 throttle. That ain't power, thats pussy
footing :)





Peter Wales
President Superchips Inc
Chairman Superchips Ltd        "Timing is everything"
Superchips home page with all the answers http://www.superchips.com