David, Yes, And where are you going to get the shims and what size how are you going to get and how are the test results with out the equipment and when do you know when its to much or how much. Then what are you going to do about fuel going back to the tank now that you have increased fuel flow. The FV is going to get rid of it because there is more. So the purpose is defeated via the FV / Lambda system. The injectors are fine as they are it's the FD that has to be modified to gain the results that are needed. John Hervey www.specialtauto.com -----Original Message----- From: dmcnews@xxxxxxxxxxxxxxx [mailto:dmcnews@xxxxxxxxxxxxxxx] On Behalf Of David Teitelbaum Sent: Tuesday, March 27, 2007 7:51 AM To: dmcnews@xxxxxxxxxxxxxxx Subject: [DML] Re: Performace fuel system 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 [long quote trimmed by moderator] 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/