DW400 to DW440?

[COYOTTMach1]

Currently i have the DW400 in tank pump and 1050x injectors. Lund says fuel system is safely maxed at 950 whp with small margin of safety. So dont really wanna go a huge fuel system just yet so was thinking is it worth it to take out the DW400 and drop in a DW440? What about dual DW400s i have been hearing the the fore systems are frying fuel pumps quite often and id like to avoid that. Love the DW400 but would like to have a have a bigger safety margin

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[COYOTTMach1]

Saw this setup and looks pretty good https://www.americanmuscle.com/deat...nzUibOPmqxQWs-xLisoaAkHMEALw_wcB&gclsrc=aw.ds

 

[LOL WUT]

DW400 seems to be the most reliable setup. So if the draw in amperage isn’t too much and the fuel heating isn’t too much (shouldn’t be). I’d probably recommend dual DW400s.

 

[Angrey]

Don't think the 440 flows all that much more. But it is brushless so much more robust and durable, especially if you boost it.

I'm running dual 440's with no siphon system and unboosted we ran out of pumps at 1130 or so. So with a syphon, probably 1050-1100, maybe a little higher on a bigger feed line (I have an 8AN feed but the real restriction is the 6AN whipple rails). The 440's can handle constant boosting to 18V with no sweat. So if I ever wanted to bump it, I have the DW booster waiting.

The real advantage of the 440 isn't necessarily the flow (although it is when boosted) it's the durability and the lower draw at low levels.

 

[engineermike]

Yes if you compare the charts the 440 is a very small improvement over the 400. If you want more I would recommend a 22 volt bap and upgrade the power wire.

 

[Angrey]

Yes if you compare the charts the 440 is a very small improvement over the 400. If you want more I would recommend a 22 volt bap and upgrade the power wire.

DW rates the 440 at 18V constant and 22 intermittent. I'm sure it could probably handle 22V constant, but if you boost that high I'd recommend only at full rip or selective conditions.

I'm still internally struggling with wrapping my head around variable control, current and voltage, pulse width and how that all works with a booster. I suppose boosting to 22V constant would work as long as the pulse widths are reduced at low draw levels. Not sure how it modulates though.

 

[engineermike]

Does the dw440 have a built in check valve?

 

[Angrey]

Does the dw440 have a built in check valve?

Yes. And apparently, they've upped the rating on the intermittent boosting. The old tech sheet (2019) shows max of 22V but the new tech sheet is 18V constant, 26V intermittent/max.

 

[engineermike]

If you compare the flow at 13.5 volts of the dw400 vs 440, it’s only 5% difference at 70 psi. It’s unclear how the check valves might affect this.

As for pwm, the fpdm essentially cuts down the electrical power supplied to the pump. My electrical engineer buddy told me that the variable baps are actually also using pwm to cut their output when not needed. So I said…so why not run a 22v bap constant all the time and let the stock fpdm cut it down to what is needed. His response was yep, you can do that and the end result would be the same but with simpler execution. The caveat is that the fpdm control would need to be tuned in the logic and most tuners won’t touch that.

 

[Angrey]

If you compare the flow at 13.5 volts of the dw400 vs 440, it’s only 5% difference at 70 psi. It’s unclear how the check valves might affect this.

As for pwm, the fpdm essentially cuts down the electrical power supplied to the pump. My electrical engineer buddy told me that the variable baps are actually also using pwm to cut their output when not needed. So I said…so why not run a 22v bap constant all the time and let the stock fpdm cut it down to what is needed. His response was yep, you can do that and the end result would be the same but with simpler execution. The caveat is that the fpdm control would need to be tuned in the logic and most tuners won’t touch that.

So help me/us understand, does the PWM use constant voltage and just vary the pulse width (current) to modulate power? I know others have said it varies voltage, but generally I thought in order to vary voltage it would need some sort of transformer assembly (which is generally tell-tale because it's larger and requires a heat sink/fins). I'm having a hard time believing that either the factory FPDM or the DW controllers have the physical infrastructure to vary voltage, so the only thing they must be using to vary total power is the current and varying the on/off (ground) length.

 

[Angrey]

And I think you misunderstand, pretty sure my DW440's have internal check valve. I tried to confirm using the literature, but all I could find was an excerpt from a 3rd party indicating DW tests for check valve performance in their quality checks. I'm pretty sure I didn't incorporate an in line check valve and my system maintains pressure. Or are you saying the 400 doesn't have them? I thought they did, or did they change and all of them no longer have it now?

 

[COYOTTMach1]

So talked to Lund the original tuners of the car with this exact combo on the dyno where it hit 945whp with cutouts open and 13psi. They said that the fuel system was maxed out an it would need more fuel to make more, totally cool with that. Then email them talking bout the dw400 and the tuner Devin says they dont advise the use of the dw400 and that those numbers are over inflated. An they wouldnt tune for that combo and i said but you did tune the combo and sent them the link of it. Even he had said he found the original tune from the previous owner who i bought it from in a previous email. So confused, car is wicked quick ..... not the fastest thing out there but it sure does good. But its beating cars that have dynoed higher on differing dynos. I explained i wouldnt mind a nice fore system if it werent for the quality control issues the walbros are having lately. Heres a link to 2 videos the dyno tuning day and heres a roll race day its not a slow car just want to find the right setup so i can buy it and install and not worry bout it.

 

[Angrey]

So talked to Lund the original tuners of the car with this exact combo on the dyno where it hit 945whp with cutouts open and 13psi. They said that the fuel system was maxed out an it would need more fuel to make more, totally cool with that. Then email them talking bout the dw400 and the tuner Devin says they dont advise the use of the dw400 and that those numbers are over inflated. An they wouldnt tune for that combo and i said but you did tune the combo and sent them the link of it. Even he had said he found the original tune from the previous owner who i bought it from in a previous email. So confused, car is wicked quick ..... not the fastest thing out there but it sure does good. But its beating cars that have dynoed higher on differing dynos. I explained i wouldnt mind a nice fore system if it werent for the quality control issues the walbros are having lately. Heres a link to 2 videos the dyno tuning day and heres a roll race day its not a slow car just want to find the right setup so i can buy it and install and not worry bout it.

I had Lund when I was N/A. They wouldn't tune my car if I went with a custom brushless setup. So we parted ways. I'm grateful for it. They're a pain in the ass if you want to do anything custom or outside of their comfort zone.

I also suspect that they get free stuff and kickbacks for pushing certain components. Seems like the previous owner "sneaked" one by them.

Find a tuner who's less restrictive to what YOU want to do with YOUR car using YOUR money.

 

[COYOTTMach1]

Would love a recommendation i was told lund was the best so never questioned it haha. But im hearing more and more people say same thing.

 

[engineermike]

And I think you misunderstand, pretty sure my DW440's have internal check valve. I tried to confirm using the literature, but all I could find was an excerpt from a 3rd party indicating DW tests for check valve performance in their quality checks. I'm pretty sure I didn't incorporate an in line check valve and my system maintains pressure. Or are you saying the 400 doesn't have them? I thought they did, or did they change and all of them no longer have it now?

The DW440 literature isn't super clear regarding the check valves, and the DW400 spec sheets show the same curve with and without the check valve which isn't possible. I'm just saying it's 5% difference on the given flow curves, but that could be more of less depending on the check valve.

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