Fw: Fw: injector flow rates

[Peter Rueb]

> Peter,
> Many thanks for this list, fantastic. I shall try to track down this
> microfiche in the UK, I was not aware of its existence, even having
spoken
> to Bosch. Do you know how the dynamic test (ccm/1000cyc.) is defined - ie
> what is the 'ON' time for each cycle? Not even Bosch were able to explain
> this to me. Comparing the static flow and dynamic flow rates on this
list,
> there are some large differences between some injectors eg. 0 280 150
215:
> 0 280 150 744; both have the same static flow but very different dynamic
> figures - different pull-in time perhaps?

Sorry that i forgot to mention the pulse time. As far as i remember most of
them were 2.5ms or 2.2ms. But there were differences. It is also on the
microfiche mentioned as ti (time interval). All injectors beginning with 0
280 150 XXX are the same size and shape. There are some other injectors for
mono jetronic etc. that begin with 0 280 YYY where y is different. So if
you want to change your injectors for whatever reason stick to the same
numbers. The dynamic values are also important. They depend on the engine.
If you have a big engine with e.g 4 cylinders 2.0l and maximum rpm of 5.500
you have a relative small range you need to fit. Other example: Look at the
injectors of a small, but charged engine like fiat uno turbo with 1.4l and
maximum boost 0.7 bar, rpm up to 7000. Here you need a injector with a
relative wide range from 1.4l idle up to 2.4l effective at full boost and
rpm. So the static value is important for full load and rpm and the dynamic
value is important for part load and idle. If your dynamic value is to high
for the engine you get no smooth idle, very bad emissions or worst no idle
at all. So the injectors have different sizes inside, other weights of
needles, different angles of the needle heads, stronger coils inside and
other resistance values.
We had the same problem with our VW 1.8l G60 engine converted to 2.0l
16V/G60. The fuel ammount was to small and we now use a injector that is
around 20 percent bigger in static and dynamic value. This seems to work.
The knock table is the main problem now. So i think this method works as
long as you make minor changes to your engine. But if you plan to adapt a
turbo you need to calculate a bit more. Please correct me someone who
really knows if  i am wrong.

Good luck.
Peter