Installed DDP2, What else to adjust?

Charlie_Smith

Charlie_Smith

Puzzled
Joined
Feb 13, 2008
Messages
31
In my '96 2WD 3500, I have 16* timing, and a #5 fuel plate done by Enterprise Engine Performance. The '96 would get just over 23 MPG at a very steady 65 MPH, usually running an exhaust temp a hair under 600F.

I just installed DDP2 injectors in this truck, and have not really determined fuel mileage yet. But, I'm seeing EGT of 650F or a little more. I had to adjust the idle a little higher to prevent stalling. The DDP2s have .020" gaskets, and the 180s that came out had .060 gaskets.

My questions are, what else do I need to adjust to see the best mileage improvement? I assume that I need to get the cruise EGT back down, probably with another half degree or degree of timing? Should I have used the .060 gaskets? I know I need to play with the AFC to make it easier to roll off a start without making clouds of black smoke. Before this install, I could drive smoke free unless I really put my foot in it.

On the good side, hp/tq went from 264/780 to 355/970 :)
 
so the ddp 2's are pretty good, then cause i have a 96 2wd rc lb and im trying to reach 450hp with 25mpg's still. the starwheel back so u have less pre boost fueling should help with your mpg's idk what else will help im sure someone who knows a lot about p-pumps like smokem will chime in and tell you what u need.
 
Did you specify .020 gaskets? When I ordered my DDP4s I had to specify .020 gaskets and DDP wasnt to happy with it. They said they ship with .060s and that they run best with them.
 
sounds like pretty good milage for an auto truck to me. i dont see an intake or exhaust in your sig. that might help. there is someone here playing with a hydrogen generator and saying that its doing well. other than that maby a taneau cover
 
tony597fitter said:
Did you specify .020 gaskets? When I ordered my DDP4s I had to specify .020 gaskets and DDP wasnt to happy with it. They said they ship with .060s and that they run best with them.
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The DDP2's came with the .020" gaskets. They were installed by Enterprise Engine, and they had them in stock. I guess it's possible that the ones on the shelf had been ordered that way ... I'll call Dynomite Diesel and ask how they usually ship DDP2's.

I've read on these forums that having the injectors deeper into the combustion chamber causes slightly higher EGTs - is that true? If that's so, then slightly higher EGTs may not indicate more fuel being consumed.

I'll run for a couple thousand miles and see what mileage I get.
 
When I put DDP-1's in my motorhome, they came with .020 gaskets. I was wondering about if the injector would be too deep too. I measured the distances of the stock and DDP injectors from the gaskets(.060 stock) to the injection holes and it was the same. So don't worry about that!
sjholt.
 
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