napa 600

so as i understand it the edge ez is the only pressure box thats causing problems? anybody know what pressure it runs the rail to? my truck runs so much better with the ez up all the way but i don't want to pop the relief valve or screw the injectors up. should i get rid of this thing and jump to a TS mp-8 or should i feel comfortable running the ez?

abc4yew

Napa600, Do some searches on fueling boxes or posts by Doug, here's one. ks
doug
Senior Member Join Date: Jul 2002
Location: Boise ID
Posts: 1,319

Member's Photo Gallery

Member's Classified Ads

thought I'd chime in here with a couple of thoughts.

Pressure concerns: Basically it has to do with approaching the limits of the safety pop-off valve. The rail itself is durable but thats not the issue. Testing at DD/Edge showed that once the pop-off goes from high pressure, the valve never seats again like new and must be replaced. Edge decided that ~70 HP to the rear wheels was all they would do (to keep rail pressure down). Early models of the EZ could go higher but they don't sell those any more...

The TST is certainly the king of power, and does not raise fuel pressure at all. they are exploiting what appears to be the fact that the HPCR has a lot to give in duration and that mondo power can be had with zero pressure increase. the drawback is that lengthening duration has an EGT penalty. Guys are finding out that an EZ box on level 3 (approximately 50 HP) stacked with the TST gives great results. Not necessarily for an increase in power (although there is some) but for an EGT advantage. I expect that any of the simple pressure boxes run in the 50HP setting (Quadzilla, Bullydog, EZ, ) would work well.

The penalty of long duration is that as RPM increases, there is a narrowing time-window of opportunity to squirt fuel into the cylinder so that the expansion of the burned fuel pushes on the piston near the top of its stroke.

Another advantage of stacking a pressure box with the TST (especially an in-cab adjustable pressure box, i.e. quadzilla or bullydog) is that you can dial in timing only (on the TST) and then choose a small amount of pressure. Thats arguably the most economical way to run. Or dial up a wee bit of duration to sweeten things up a hair. Or go wild and burn your turbocharger up. you literally have mild and economical to wild and destructive.

on using 2003-2004 pressure boxes on the 600: I worry about any mfg recommending this. fortunately I don't know of any! The ones that are succesful have written new fueling maps for the 600. For example, the Ramifier is the most customizable box out there, and if memory serves was easily configured to run with the 600. Edge is soon to release the EZ box for the 600 but made it clear very early on that the original EZ was not approved for the 500. I think Quadzilla is (or has) out with a 600 version of their box. Point is that the fueling curves ARE different (305 vs 600) and the boxes DO need to be different.