Edelbrock TBI Conversion

[jweir at att.net]

Ok, thats why I asked.  I was under the impression that 
with a batch fired system, it fired half the injectors 
and them fired the corresponding cylinders which on a 6 
cylinder would be 3 ignition events before it fired the 
other half of the injectors..

So are you saying that with every ignition pulse (at the 
coil) there is an injector event.. ? 

Maybe I need a basic course in how a TPI batch system 
works...

I understand that I need to keep the injector sizes/fuel 
pressure and such relative so I am still getting the same 
ammount of fuel vs. the TBI

Jason

--
88 Wrangler - 155K miles and counting
258 I6, 4.0 head, Cherokee header, 2 1/2 exhaust with 
high flow cat & Flowmaster
GM TBI, Crane 260H Cam
TJ Fender Flares
http://home.att.net/~jweir
CNC 4X4 Member - http://cnc.4x4.org/
			
			
> Jason Weir wrote:
> 
> > 
> > TBI
> > 
> > 1 injector fires for every cylinder firing.
> > 8 cylinders firing means 8 injector events, alternating 4 per injector
> > 
> > Edelbrock 7747 TPI Setup
> > 
> > 1 injector fires for every 4 cylinders firing
> 
> Huh???
> 
> > 8 cylinders firing means 2 injector events. 2 groups of 4 alternating
> 
> 4 injectors fire for every ignition pulse
> 
> > 
> > So my question did Edelbrock just put a divide by 2 after each original
> > TBI driver and use that to trigger a secondary driver that fed the
> > injector groups?  This is the only way that I can see how they might
> > have made it work?  Any other ideas..
> > 
> > This brings up my application question.  When we are dealing with a V8
> > things are easy its a divide by 2.. But what if I wanted to do the same
> > thing on a 6 cylinder?  Now I have 6 injector events that I need to turn
> > into 2.  Its not as easy to make a divide by 3.  Has anyone heard of a
> > chip that could do this.. Customizable to do a divide by x, with just
> > jumping pins or resistance to pins or whatever.
> 
> You're getting some strange numbers here.  Alternating batch systems
> fire 1/2 of the injectors per ignition event, when in synchronous
> mode.  The fuel pressure, injector size, and fuel map work together to
> prevent creating a rich condition.  To prevent large amounts of
> remappingin your case, the 3 port injectors together should flow as
> close to the same amount of fuel as one TBI injector as possible.   
> > 
> > Any ideas???
> Start looking up injector flow rates.
> Shannen
> > 
> > BTW I am running a TBI right now but I've got the Multi-Port manifold
> > just waiting till I can get the electronics figured out..  I know I
> > could just swap the ECM to a V6 TPI computer but thats the easy way and
> > them I have to learn a new ECM all over again, just when I almost have
> > my 7747 setup running great.
> > 
> > Jason
>