I'm interested in this mod:
Who has done it and what were the results particularly long term? Is this for all Sprints or certain year/models?You can modify the pressure regulator. Take a look at the fuel panel pics. in our tech album. It's the thingy on the right.
Remove that and you can see that it has a flange and an indent in the top of what I call the hat. That's were the spring is. Get a large socket to support the unit on the outer flange and a smaller one to match the indent on the top of the hat.
This is where the rocket science and engineering come into play so pay attention :razz:
You put the regulator with sockets into a vise and squeeze a bit so the socket that's in the indent makes a deeper indent. How much? Using the the engineering term, TAR. (That's About Right)
This will make Dan'l freak and geek :razz:
This is why I am going to make some pics and using a depth mic. take some measurements of a stock one comparing to a modified one.
What you are doing is adding pre load to the spring underneath the hat changing the psi from the stock 40 to about 50 or 60 psi.
What this does is to enrichen the F/A ratio per injector shot across the board of the current map. In addition to a superior driveability and much crisper throttle response I have seen my MPG get more stable and even a bit better that before. It looks like the added pressure aids in the spray pattern from the injector. (Last little 200 mile trip loafing along I got 56.7 mpg.
I'd still advise getting another regulator to modify. They are easy to come by.
I see this as no different than changing the jetting on the carbed. twins to get a better running engine.
I've looked around and can't find the Sprint Tech Album. Does it still exist?Hi Martin and all. Just take a peep at the upper right of our panel here. You'll see Album. Just click on the clicky and it will take you to the Sprint Tech album.