Transients

[Espen Hilde]

Hi All!
I think transients is the weak link in EFI systems to day.
I dont know what the Indy or F1 guys are doing but the regular EFI system 
is more conserned about steady state emisions .
In a realy fast car you can allmost trow away every sensors exept TPS
witch gives input for acceleration mode.
The acceleration enrichments lasts longer than going from one gear to
another, in the lower gears offcurse.

For the efi controller to try to estimate how much air is trapped inside
the cyl with cam with lots of overlap is like trying to estimate the
lottery 
numbers.
Look at the 2 strokers they have great problems using efi, especialy with
expansion cambers. One cyl that is not ignited pours the unburnt mix into 
the expansion camber ,the expansion camber cools of and gives no socktion
wave.The result is to rich mixture next time around.
The new 2 stroke direct injected outboards is running very nice at idle
much like a 4 stroke......
The air trapped inside the cyl on a 4 stroke with much overlap is much
dependent on the pressure waves.If a syl is not ignited ,maybe the mix is
ignited into the exaust system, it will change the pulses and the
enviroment compleatly. All OEM manufacturers stay away from this "field" 
Relaying on TPS on this self EGR state is stabilacing tings .Maybe 
using sequential EFI you are stopping some fuel going out into exhaust 
and ruining the steady pulses.
I think the solution is to measure each cylinders air consume and maybe 
how much that is dumped out again , and inject the apropriate amount
of fuel .
Another way is to have variable cam system or control the air with
additional electronical valves that is capable of controlling the air flow
and 
not the high compression pressure.Maybe read valves in the inlet is the DIY
aproch.Then you have widend the dynamic range of the valve system 
so you dont get self EGR.

I think the enrichments should have different output from where in the map
you are acclerating from , acclerating from leanburn aria is different than

from a rich aria.Maybe a accleration map.....
This is whats called rambeling isnt it?........
Espen Hilde  (used to wearing the CSH , its not that ugly......)
Flame on!