[Diy_efi] Donegan ECU

Steven P. Donegan donegan
Thu Jan 4 20:03:45 UTC 2007


I have not yet added OBDII to my project - it appears that I have to if
it is going to be plug compatable for my Z28 so that will likely
happen. 
My intent for this project is a universal EFI/ECM/PCM/MSD box -
something useful on any engine up to 8 cylinders. If it lacks any inputs
or outputs tell me and I'll add them :-) 

On Thu, 2007-01-04 at 11:53 -0700, Tom Visel wrote:
> Those OEMs that moved the regulator to the fuel tank did it for 
> evaporative emissions control reasons - less heat in the tank means 
> fewer vapors to deal with.  This is the same batch of deep thinkers that 
> brought us oxygen sensors after the catalytic converter(s) for measuring 
> catalyst efficiency.  If the "Donegan ECU" isn't going to be OBD-II 
> compliant (or did I miss something) why bother to have the extra two 
> oxygen sensor inputs?  The poor OEMs only have them so they can 
> guarantee to the EPA that they have a way of measuring catalyst 
> degradation since all emissions systems have to be monitored.
> TomV
> 
> Steven P. Donegan wrote:
> 
> >Well - for track days I simply put dry ice in my fuel cold-can thing -
> >that solves most vapor-lock style problems and lasts for a couple of
> >hours. Simple low-tech solution to that problem. Given the lack of
> >response to my original posting I believe providing PWM fuel pump
> >control and support for a fuel pressure sensor is useful. 
> >
> >Given that I normally run at Willow Springs or Buttonwillow during the
> >winter months temps are not normally a factor anyway.
> >
> >On Thu, 2007-01-04 at 12:23 -0600, cobraman at insightbb.com wrote:
> >  
> >
> >>My "Edelbrick" ProFlow has fuel pressure controlled with engine vacuum. On track sessions on very hot days, the fuel in the rails will boil under hard braking - accelerator closed (low fuel pressure). When you finally step on it (52 psi), nothing happens until the vapor "recirculates" or is expelled.  Usually takes a second or so.  I don't think dead heading would do any better - probably just need to keep a constant fuel pressure. 
> >>IMHO, hot fuel should give better economy - easier to vaporize - for those green members.  TomS
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>ld
> >>    
> >>
> >>>consume the gas in the rails well before it got warm :-) However this
> >>>does raise a point - perhaps my ECM/PCM/EFI computer needs a way 
> >>>to open
> >>>a fuel return line and to sense fuel temp in the rails? Any 
> >>>ideas on how
> >>>useful that would be in the 'real world' anyone?
> >>>
> >>>On Thu, 2007-01-04 at 14:56 +0800, Mike wrote:
> >>>      
> >>>
> >>>>Isnt one of the main needs for fuel return the fact the fuel 
> >>>>        
> >>>>
> >>>is heated quite a
> >>>      
> >>>
> >>>>bit in the fuel rail whilst its waiting for injection ?
> >>>>
> >>>>Of course there is a commercial factor as fuel returns used to 
> >>>>        
> >>>>
> >>>be so
> >>>      
> >>>
> >>>>much cheaper than any electronics but getting around the fuel 
> >>>>        
> >>>>
> >>>heating etc
> >>>      
> >>>
> >>>>Also the issue of control feedback is an issue to avoid 
> >>>>        
> >>>>
> >>>vapourisation> during hot start, the good thing about return is 
> >>>this can be flushed out,
> >>>      
> >>>
> >>>>and esp for a turbo as a pressure hold tank can "remember" the last
> >>>>max pressure and temporarily raise the fuel rail pressure to 
> >>>>        
> >>>>
> >>>this during
> >>>      
> >>>
> >>>>start to avoid vapour issues... etc
> >>>>
> >>>>Regards
> >>>>
> >>>>Mike
> >>>>
> >>>>
> >>>>
> >>>>At 07:23 AM 1/4/07, you wrote:
> >>>>
> >>>>        
> >>>>
> >>>>>This sounds cool...is closed loop control of fuel pressure an 
> >>>>>          
> >>>>>
> >>>oem feature for any new vehicles? Or just something you are 
> >>>trying out? Are you going to use a PI controller? I am guessing 
> >>>when you snap the throttle open the PI controller should know 
> >>>about this quite quickly...not wait to see a drop in fuel 
> >>>pressure? 
> >>>      
> >>>
> >>>>>>To add something somewhat useful to the list in this reply 
> >>>>>>            
> >>>>>>
> >>>I'll say the
> >>>      
> >>>
> >>>>>>Donegan ECM is coming along nicely :-) The input board is 
> >>>>>>            
> >>>>>>
> >>>going to fab
> >>>      
> >>>
> >>>>>>out at about 3.0 inches by 2.2 inches (exactly matching the 
> >>>>>>            
> >>>>>>
> >>>CPU board -
> >>>      
> >>>
> >>>>>>ARM based Steve). Inputs designed in are MAP, MAT, 
> >>>>>>            
> >>>>>>
> >>>Barometric, Coolant,
> >>>      
> >>>
> >>>>>>Throttle, Oil pressure/temp, 4 ea O2 sensors, Crank and Cam 
> >>>>>>            
> >>>>>>
> >>>position, 2
> >>>      
> >>>
> >>>>>>ea EGT sensors - well pretty much everything everyone told 
> >>>>>>            
> >>>>>>
> >>>me should be
> >>>      
> >>>
> >>>>>>sensor inputs. Fuel pressure input I'll put on the 'relay' 
> >>>>>>            
> >>>>>>
> >>>control board
> >>>      
> >>>
> >>>>>>- that will do PWM control of the fuel pump eliminating the 
> >>>>>>            
> >>>>>>
> >>>need for a
> >>>      
> >>>
> >>>>>>regulator or return line.
> >>>>>>
> >>>>>>Happy New Year :-)
> >>>>>>            
> >>>>>>
> >>>>>_______________________________________________
> >>>>>Diy_efi mailing list
> >>>>>Diy_efi at diy-efi.org
> >>>>>Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>>>>Main WWW page:  http://www.diy-efi.org/diy_efi
> >>>>>          
> >>>>>
> >>>>_______________________________________________
> >>>>Diy_efi mailing list
> >>>>Diy_efi at diy-efi.org
> >>>>Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>>>Main WWW page:  http://www.diy-efi.org/diy_efi
> >>>>        
> >>>>
> >>>_______________________________________________
> >>>Diy_efi mailing list
> >>>Diy_efi at diy-efi.org
> >>>Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>>Main WWW page:  http://www.diy-efi.org/diy_efi
> >>>
> >>>      
> >>>
> >>_______________________________________________
> >>Diy_efi mailing list
> >>Diy_efi at diy-efi.org
> >>Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>Main WWW page:  http://www.diy-efi.org/diy_efi
> >>    
> >>
> >
> >_______________________________________________
> >Diy_efi mailing list
> >Diy_efi at diy-efi.org
> >Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >Main WWW page:  http://www.diy-efi.org/diy_efi
> >
> >
> >  
> >
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/diy_efi
> Main WWW page:  http://www.diy-efi.org/diy_efi





More information about the Diy_efi mailing list