Synch or Alternate Firing

maztah · Post by **maztah** » Thu May 11, 2006 6:27 am

which of the setup will give a better acceleration? The one that can give the right amount of AE at the shortest time

My setup is TBI 2 injectors currently alternate firing, fires every ignition event, injectors is rated at 14.2lb/hr each

Bernard Fife · Post by **Bernard Fife** » Thu May 11, 2006 9:04 am

which of the setup will give a better acceleration?

maztah,

Either will work if they are tuned properly. Generally more squirts work better on TBI (up to the number of cylinders), alternating tend to reduce any fuel pressure fluctuations. However, too many squirts reduces the range of the injectors (due to the extra opening times). On my V8 with an open intake plenum, I used 4 squirts alternating and this worked well.

Lance.

maztah · Post by **maztah** » Thu May 11, 2006 10:10 am

oh i see.. thanks

though I am quite limited right now to two injectors making them work longer. That is why I am guessing that there might be a fluctuation in fuel pressure cause of high req fuel of 29.3ms. And also the AE values tends to be larger than the req fuel extending the open period of an injector. Will my AE still work with this length of PW?

Bernard Fife · Post by **Bernard Fife** » Thu May 11, 2006 11:39 am

maztah,

You have to be careful to keep in mind the maximum pulse width (25 milliseconds in MS-I, 32 milliseconds in MS-II).

Commanding pulse widths larger than the limit has no effect on fuel, soit can make tuning confusing.

So if this were mine, I'd increase the number of squirts to make sure the 'lower' req_fuel (the one that is adjusted for the number of squirts and alt/sim, etc.) is less than 20 (but more than 6).

Lance.

maztah · Post by **maztah** » Thu May 11, 2006 8:22 pm

does the limit mean that it is not recommendable to go beyond that req fuel?

and for my last question, is the PW divided among the injectors for a simultaneous firing on an open plenum setup?