By shimming the spring on the Primary Pressure Regulator you can increase the pressure a little which would increase fuel flow. I know it isn't much but it IS one of the tweaks that can be done to increase fuel delivery. Other more radical mods would be to change the notches or the plunger inside the fuel distributer or even changing it to a model that flows more fuel. Changing the injectors could also help if necessary. The main problem is it is a mechanical system. To make tuning changes you have to either modify or replace actual parts. That is the most impressive feature of an EFI. You can adjust it all kinds of ways without even getting your hands dirty! David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "John Hervey" <john@...> wrote: > > David, How is he going to change the fuel pressure and why would he do it. > If he is going to maximize the engine capability then the lambda system will > have to be done away with and the fuel distributor changed to a non lambda. > Casey, the injectors are fine but there needs to be more fuel flow to them. > You can't adjust that or modify the distributor without the proper > equipment. That's what the builder does. Like I said, we do this to Porsche > all the time. > John Hervey > www.specialtauto.com > > > > -----Original Message----- > From: dmcnews@xxxxxxxxxxxxxxx [mailto:dmcnews@xxxxxxxxxxxxxxx] On Behalf Of > David Teitelbaum > Sent: Sunday, March 25, 2007 8:54 PM > To: dmcnews@xxxxxxxxxxxxxxx > Subject: [DML] Re: Performace fuel system > > As Joe K points out the modifications you mention should not affect > the fuel mixture too radicaly unless you also plan on using forced > induction along with the forged pistons. Even so the fuel distibuter, > fuel lines, fuel pump, etc should be able to keep up with maybe some > tweaking of the line pressure and the mixture screw. The thing to > watch for if you go lean is that you may have to find a higher flowing > fuel injector. The fuel curve of the fuel distributer is set by the > profile of the notches. Difficult to change. With this kind of > experimentation you have to consider an EFI which is infinately more > adjustable and does not have to be as linear as notches. It can better > match the torque and HP band of the motor and be even more effcient. > David Teitelbaum > vin 10757 > > > --- In dmcnews@xxxxxxxxxxxxxxx, "John Hervey" <john@> wrote: > > > > Casey, > > Unless you run out of fuel under acceleration the distributor would > have to > > be modified to keep from running to lean. If you think it's running > right or > > running ok you might be surprised with the distributor modification > we do > > for your type of engine and turbo engines. It's done for 930 Turbo's al > > > > To address comments privately to the moderating team, please address: > moderators@... > > For more info on the list, tech articles, cars for sale see www.dmcnews.com > > To search the archives or view files, log in at > http://groups.yahoo.com/group/dmcnews > Yahoo! Groups Links > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/