Duration Vs Rail Pressure Findings

Alright, many of you know that I have been fighting some smoke at my high altitude for a while now. I have a pretty laggy turbo for this altitude and 50 hp injectors. People have always said just lower pulsewidth. Well, that works at the cost of losing all my power. So I have started lower PW to the point where power and smoke drop off, then upping the rail pressure in these areas. This seems to be working well so far. In addition people also said, advance timing in smoky areas. This does not work as the turbo cannot spool up worth a crap. So I have retarded timing in these areas slightly as well. So far so good on these results. I know there has not been much said about lowering PW and raining RP so I thought I would mention my findings.

Lower pulse and higher pressure help...atomization is better...lower timing before boost come up too....i use these 3 method in my tune

I'd also assume most people who said "lower your PW" really meant you do it by raising rail pressure lol. I know they may not have made it seem that obvious. I view it like this, If you need X fuel to make X power like at idle or cruse well lowering fuel amount isn't doable because of the engine dying or not being able to actually cruise from power loss, so raising rail pressure is the only way to achieve your goal of same total fuel amount while having a shorter PW. BTW how many flashes do you guys have on a single ECU using HPT on your trucks? Any failed ones? or any bricked PCMs?

You can lower pulse without adding pressure...because for exemple if your engine need 800 us to do the work but the cell at thay rpm/mm3 is 1000us if you are on acceleration it will use the 1000us and will smoke...put the cell at 850us and will be able to do the work but with less smoke on acceleration

I would nee to count my revision/test but 100 for sure

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Originally Posted by JaegerWrenching

I'd also assume most people who said "lower your PW" really meant you do it by raising rail pressure lol. I know they may not have made it seem that obvious. I view it like this, If you need X fuel to make X power like at idle or cruse well lowering fuel amount isn't doable because of the engine dying or not being able to actually cruise from power loss, so raising rail pressure is the only way to achieve your goal of same total fuel amount while having a shorter PW. BTW how many flashes do you guys have on a single ECU using HPT on your trucks? Any failed ones? or any bricked PCMs?

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Easily over 100. I have had some failed tunes that get stuck in the middle ant its a bi*ch to get it back to working again. I think my failed tunes could be due to my batteries getting weak. It seems to be happy when I put a charge on them while I write the tune.

Noah i sent you a pvt message

I know this is a little old but what should i do on a 6.7 cummins to spool compounds the compounds are a gated s367 with a t6 s475/96/1.32?.

How's the waste gate for the s367 setup? Does it bypass the s367 and feed into the s475? or bypass both? I'm assuming it bypasses the s367 into the s475. Since you have a non VGT primary you can help it by staying slightly more positive around cruse area 3-5ish BTD with timing lowering towards 0 degrees BTD as you tip in towards spool up keeping it around 0 until it lights the s367. This helps keep the truck peppy until you get enough RPM to have enough flow to actually light the s367. Because your primary is a non VGT you need exhaust flow to get it moving, and that requires some engine speed no matter what. But don't waste potential power with low timing until you need to like with tip in trying to light the turbo. There is no one tune fits all or one style fits all, play with it and see what works best for you. You could start at 7* heading towards 3* BTDC each truck and fuel setup is different. Also try upping fuel pressure some as timing drops towards spool up to help with smoke.

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Originally Posted by cracummins

I know this is a little old but what should i do on a 6.7 cummins to spool compounds the compounds are a gated s367 with a t6 s475/96/1.32?.

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