@SplitSsss if this discussion about ftb and pmd is going to far off point, I whole heartedly apologize and would request a mod do some chopping and moving of posts to keep your thread on track- if you feel it has been muddied too much.
I feel you should have both points of view and make your own decisions, hence continued counterpoint.
@royunion just want to make sure not microagressing you, and all points I make are informative intended, no negative feelings here, for the most part. But I am gonna pick on ya a little. Diesel love! I Still wanna be friends and play in the sandbox together.
So...FTB mod. You seem to be under the impression that when the guy on this forum created the name and modified his factory ffm, he was the first and only to decide a 5/16 fuel line was too small and he and everyone else all only ever used the factory p.o.s. pump. Also that no one else took jr high science class learning boyles law. No, exponentially.
I was already doing these and much more before hearing the term feed the beast. I had already run the 6.5 on nitropropane, twin turbos, twin injection pumps, and yes even blew up several trying to use nitromethane.
You never tried and never will. Ok, I say that in discussions with friends. One guy is bisexual. He swears the pleasure of his male partner is better than from his female partner. I never have, and never will know for sure. I have to concede that his experience is more advanced than my theory. So I won’t force you to try it yourself and see. However I will point out you could try without as many negative ramifications.
You say it is not worth the time and $. I never bought a FTB kit from anyone. I did my own, and the parts were under the $20 range. For convience, the added cost of a kit might be worth it. You repair your own burned up pmd- kudos. I would never spend my time doing that. Hell- you designed, built installed then later removed a fuel tank just to cool the pmd- dual infact! Wow, that sounds liks a lot of time spent. Maybe a couple bucks too. When I worked for the fuel company and had the best tig for my use welding up fuel tanker trucks, so of corse the materials as well in the scrap bin- I never would have spent that time. We just tried pmd in the cab, near the drivers, so they could move the plug over without getting out of the seat- multi million dollar lawsuits will do that to a company- make it literally as safty first as possible and still get paid their millions as testers for GM.
You mentioned the 75-100 gpm pump- please share. Many of us cant get pressure regulation accurate enough at these low numbers.
What is max on db2- 2 min, with 5 desired, and 7-8 max depending which papers and class I have been in. But at 6 we know timing advance issues begin. And that is why they set the pressure at 5. Now, i also did 1 class at stanandyne on the ds4. One of the three engineers that designed the pump taught the class. He said they stuck with 5 because their was no reason to redesign the supply feed of the test unit. But pointed out our company’s pump builder in the class and said doing custom builds, get base line testing done at 5, then tune it at your desired pressure. For example we used one of my db2 which was for the nitropropane engine that was running north of 30 psi. We showed results at 5 psi, then 10,15,20,25,30. Astonishing differences, as some of the serious hotrodding db2 guys here could attest. And for rookies- NO dont just run high pressure and think that helps- the pump is special built for it.
You mentioned the pressure changes through the years but missed the governor rpm limit changes- kinda related... also applications very it too.
So, keeping pressure from 5-14 psi in a ds4. And keeping in mind more problems occur at 15 psi than 4. Teach how. Have video showing psi at the pump from idle to 65 mph while towing max weight up hill. Then show the LP, water separator, and filter(s). No doubt GM screwed the pooch on things. Fuel system especially. But if you have a great solution, please share- you can rename it FTBB feed the beast better or ftb2.0.
You mentioned inlet fuel pressure being low causing wear of ip. I say something similar frequently, but not exactly the same. The lift pump fuel pressure does not stopor slow friction. Presence of lubricant does. When there is not enough fuel in the ip, the primary causes a vacuum inside the housing to occur. This vacuum draws the fuel out of areas normally soaked in fuel that has wear points. I always say less than 1 psi measured at the inlet, because when it falls below that the fuel gets drawn out of those points. This was demonstrated with the clear housing ip they used to teach in class just for demonstration of this point. The GM training video of the class in progress- thats me saying “holy macaroni!” when he shows it, and yes I have since cut my hair. haha.
Anyways- like 10psi oil pressure between the crank and rod bearings cant possibly over power the hundreds of psi from the power stoke after detonation, 14 psi of fuel is not going to withstand the pressures of the metals in contact in the pump. The presence of lubricant helps the wear. Do db pumps running at max 5psi wear faster than ds4 with double the psi? No. Infact they last longer.
You mentioned ford- yet failed to mention they use the db2 with 3/8” line. When having performance db2,4,0 built- they just use the ford part rather than drill and tap the gm housing. Do ford engineers not understand boyles law when they made it that way? Oh wait- the stanandyne engineers did both- silly me. So why did ford do 3/8 all the time and gm did not? You do know some gm db2 cane with 3/8 line inlet, right? They must have been protesting the microagressions caused by boyle that day and called for a suspension in his law. Or, maybe, THERE WERE OTHER REASONS GM USED A 5/16 LINE.
Far be it from me- the guy who GM sent engineers to work with, the guy GM gave hundreds of engines to test with, many of them destructive tests.
I have mentioned before that GM did a ton of stuff for profit alone knowing they make some things worse than they could. A cousin that is still a gm engineer has met a couple of people on this forum and explained his job is affordably redesigning great parts down to good parts at the expense of GM to the economic benifit of the dealerships. Although we are the end customers, the dealerships are the real customers and their $ needs addressing too. Ya think they dont know and didnt know then: bad lp makes truck no go vroom vromm and make ip go blamo sooner? C’mon man!!! Engineered designed failure points.
GM taught the first year, before the rigs were out mind you, that since no longer using the manual lift pump, to always first test: fuel quality, volume, and pressure from the newly incorporated electrical lift pump. WHAAAAT? It’s like they new in advance or something. Whoa! Ok did I stress that too much?
Emmisions: ok. Ds4 required only because epa mandate said desired and delivered fuel must be available at electronic reading port. Ever see the db5? Yeah 5. It it the one that looks like all other db pumps except has 2 big sensors on the rectangular box above the entire pump. It has fittings that tied to the in-n-out (dang now I want a double double) fuel lines. And the sensor on the side tied to the tps. Those sensors-well you get it. Ford was out of the picture. GM bumped his head and said it was too big. Yes, another case of GM telling the company they pay to change best design into something they want to fit or look different. So they came up with, a ds4. SMH.
You said the fuel inlet pressure of the ip wrecks the emmisions and went into electric injectors and such. We dont have Bulls here so :
really really really big dog crap!!!
That fuel company I worked at doing the testing of biofuel for unky sam- where we learned peanut make crap biofuel and ruined the Las Vegas transit system for almost a year... YEAH, we had smog machines for gas and diesel like any bobs smog hut can have- but ours was live dyno and also we had 2 engineers from the epa running them. You guys know how I always comment db2 is better emmisions capable than ds4? Yes- I got in a HUGE fight with the epa morons and prived to them on their own equipment with their engineers running it that the db2 was cleaner, and had better mpg to boot proving not just ppm gains but overall use benifits and that their law was making things worse on accident. They argued the better long term effects and big gubmint vs me- guess who won? Haha.
Dude. Go adjust you psi to your minimum spec and smog it on the rollers. Then adjust it up to max and donit again. Show the difference. Make a youtube video. I know the results, we did it. We tried to vary the outcome through experimentation. You are wrong. You cant compare direct injection with idi. Inlet fuel pressure being in the peak VOLUME and PRESSURE makes the best power & cleanest emmisions at the same time, period. It is an efficiency issue.
My bisexual friend, soon to burn in Hell unfortunately, keeps telling me to try it that it is worth it (and not with him btw- he only likes black men that way). I will continue to reject the offer. But having run db0,2,4 and ds4 engines with different lp supplying and in some cases no lp supplying... I am telling you: try it, it is worth it. The 3/8 line btw, not the backdoor test. Gotta clear that up. Cuz like he says who are you gonna believe someone who doesn’t REALLY know and only can guess by what they imagine, or buy someone who has done it and REALLY knows.
