Drawstraw Users - How low can you go?

[Mopar1973Man]

2 minutes ago, Dieselfuture said:

How is that heater controlled, is it always on or iat does it? 

 

Internally in the heater there is a temp switch. There is no external control. There is a power relay in the PDC. All done inside the fuel filter housing. 

Edited February 4, 2021 by Mopar1973Man

[LorenS]

 

16 hours ago, Mopar1973Man said:

I can say safely the fuel temp of 140*F and below is no cause for alarm at all.

I know we want to keep the PSG cool, but to a certain degree cold fuel doesn't burn as efficiently.  To heat 30 gallons (over 210 pounds) of diesel from 0 degrees to 50 or 70 degree would take a while. And in the mean time that cold fuel isn't burning as good as it could.  For reasons you described very well, I wouldn't run the diesel over 140F on a regular basis - this is something I hope to address in the spring - but just like IAT temp, fuel temp has effects on combustion.  Seems like 70-80 to the pump (and higher leaving to the injector as it picks up heat) would be a reasonable starting point.  I do agree it may be more trouble than it's worth, it's more of a theoretical.

[Mopar1973Man]

1 minute ago, LorenS said:

but just like IAT temp

The only thing that IAT does... Temperature below +80*F is going to add +3 to +4 degrees of extra timing. Warmer air does burn better and easier. I make up for that in my Quadzilla tunes so I don't really care about the IAT temps because I can adjust for my weather as needed. I can just watch the engine load vs. temperatures (coolant, oil and IAT) I make adjustments to handle the changes in weather. 

 

4 minutes ago, LorenS said:

fuel temp has effects on combustion

Again even this I can adjust my tune for. You can advance timing more and give more pre-heat time for cold fuels. Just adding a few degree give that much longer in the cylinder to heat the fuel, turn to vapor and go BANG on time. Why re-invent the wheel but actually take a stab at tuning properly and over come all the weakness. Yeah super cold fuel doesn't burn well in a cold cylinder with cold air running in. Again since I kept my fuel filter housing and fuel heater its a mere few minutes of warm up rolling down the highway and the IAT and Fuel temp running side by side. This why I'm not even worried about fuel temps being low because the stock fuel filter housing absorbs heat from the cooant passage in the head hence why my IAT and fuel temp are typically the same. Now for those that deleted the fuel filter housing now those people have issues with cold fuel because they delete there fuel heater and being able to absorb heat from the manifold. That 1/2" pipe plug near the IAT is a Coolant passage. 

[Doubletrouble]

 Novice question here:

 Does coolant pass through the filter housing in some way or does the housing absorb heat through metal to metal contact? Might be a dumb question but I have never removed the housing from the side of the block so I don't know. Thanks.

[Dieselfuture]

8 minutes ago, Mopar1973Man said:

Now for those that deleted the fuel filter housing now those people have issues with cold fuel because they delete there fuel heater and being able to absorb heat from the manifold.

To my defense all my fuel is returned to the basket, so in the winter it stays warm and in the summer it's not crazy hot unless I'm running on empty tank. If I keep half a tank or more it stays cool 140 or in that range, if I'm running empty I have seen it close to 170. Either way should be fine as long as it works, I would think we would see more failures or associated problems with how things are plumbed, if one way or another it didn't work as good. 

[Mopar1973Man]

2 minutes ago, Doubletrouble said:

Does coolant pass through the filter housing in some way or does the housing absorb heat through metal to metal contact?

 

Contact with the head it will absorb the heat. 

 

3 minutes ago, Doubletrouble said:

Might be a dumb question but I have never removed the housing from the side of the block so I don't know. Thanks.

Lots of people have delete there stock filters and just running the FASS 150. Majority of these local are having gelling and freeze up issues. Thew ones that follow my suggestion and kept the stock filter basket and did the big line kit. Reduces the gelling issues. Then getting the filter and pump assembly moved out of the damage path of the front tires and not hang down in the cold wind now the fuel temps will rise. 

 

Remember mine has been hanging behind my transfer case for YEARS and to this day 428k miles later I've never had one gell up or freeze up of fuel even while operating at -30*F to -40*F winter. 

 

Since 2006 this AirDog 150 has been hanging in this position till today and never had one issue with cold fuels. Ever! - Never had fuel gel or freeze up. 

[Doubletrouble]

And that's behind the T-case on the inside of the frame rails correct?

 Looks like an easy install and easy to get to for filter changes.

[Mopar1973Man]

3 minutes ago, Doubletrouble said:

And that's behind the T-case on the inside of the frame rails correct?

 Looks like an easy install and easy to get to for filter changes.

 

Yes it is...

 

Skid plate needs to be loosen and hang to change the filters. The skid plate is guarding the filter. I can still reach behind the AirDog 150 and check the fluid level in the transfer case. There is much less cold wind blowing on the filters fuel stay warmer. Then I've upgrade since that photo and ran all my fuel line inside the frame to keep the fuel lines shielded from extreme heat and extreme cold. 

Edited February 4, 2021 by Mopar1973Man

[LorenS]

You may be able to tune around not having a thermostat, too, but isn't it better to just run one?

[Mopar1973Man]

Take a pick? I've got an 180F, 190F and 200F thermostats. Why try tune around cold that much I can just jump to the 200F thermostat. Gain the heat for both fuel and coolant that way.

[Dieselfuture]

2 hours ago, Mopar1973Man said:

There is much less cold wind blowing on the filters fuel stay warmer.

I remember discussing this before. I can see how filters are protected from debris but I didn't think that wind has anything to do with temperature, it's not skin. If you're saying it's wormer there because of the tcase I can see that just not when you're going down hwy, I'd think the wind would get under everywhere on bottom side of the truck.   I suppose it could be like when you get behind a simi close enough it almost drags you with it, why they put wings on trailers now, so maybe filters are in sweet spot where there's no wind and warm air from tcase keeps them warm. 

[Mopar1973Man]

9 minutes ago, Dieselfuture said:

why they put wings on trailers now, so maybe filters are in sweet spot where there's no wind and warm air from tcase keeps them warm. 

Exactly... This is why I don't have the gelling issues like others, plus remember the fuel heater is in the circuit yet too so the fuel is warmed supplying and leaving the engine eventually it does warm the tank up.

 

Compared to the FASS 150 that left here with the filter hanging in front of the rear tire and in the damage path of slung snow and other road debris. 

[dieseldon]

On 1/26/2021 at 6:26 AM, Mopar1973Man said:

Most part yes. Mine was the supplied draw draw with my AirDog but I know the truth that Eric and Vulcan Performance produce it. So yeah that is like it but mine was a bit different fitting wise as you seen my photos. 

 

The big things...

• Cut the straw STRAIGHT. No angles!
• The straw must be with in the thickness of a single quarter coin (my design) or 2 quarter coins (FASS Design) between the straw and the bottom of a empty tank.
• You may notch the end of the straw but no more than like a 1/8 of a inch and no more.
• Make sure to measure with the tank EMPTY. A full tank will deflect the bottom by nearly 1/4" from full to empty.

The trick is do this all on the empty tank so as the fuel runs out the bottom of the tank will rise back up to the straw allowing everything to be draw up and used. Where cutting to much gap now create the 1/4 tank slosh problem.

 

I could have used this info a few months ago when I was installing my raptor 4g looking for advice, all I heard was pretty much crickets, l MIGHT have installed that way? All I know is that the airdog instructions made no sense and that guy that works for airdog was less than helpful to put it politely!

 I'll just suck fuel from the stock basket for now I guess.

Is there a good reason I'd want to go back and change it??

 

[Mopar1973Man]

1 hour ago, dieseldon said:

Is there a good reason I'd want to go back and change it??

Only if the fuel temperature is getting out of control. I would move out of the fuel basket...

[LorenS]

5 hours ago, Mopar1973Man said:

Why try tune around cold that much

That's my whole point, only with fuel.

[dripley]

7 hours ago, dieseldon said:

 

I could have used this info a few months ago when I was installing my raptor 4g looking for advice, all I heard was pretty much crickets, l MIGHT have installed that way? All I know is that the airdog instructions made no sense and that guy that works for airdog was less than helpful to put it politely!

 I'll just suck fuel from the stock basket for now I guess.

Is there a good reason I'd want to go back and change it??

 

My AD has been sucking fuel from the basket for 9 years with no issue and both my fuel returns go to the basket . I cannot check temps like others can but nothing odd has happened to me with this configuration. I can drain the tank dry. Not saying fuel temp can't be an issue but I have experienced none. I would not sweat it for now but if it concerns you do it when you have time.

Edited February 5, 2021 by dripley

[Mopar1973Man]

Like finding some members in the high 160's for fuel temp is kind of alarming. I can see why people have issues with VP44 and the PSG frying in southern states with it all be returned to the fuel basket. After being to Arizona in early summer and its starts at 78*F at 5am and the ramps up to over 120*F by midday it really hard to keep anything cool but it even worse for some returning hot fuel to the sender basket and re-pumping back to the VP44 and wonder why the VP44 is failing so often. 

 

I'm pretty sure the upper limit before tripping the P0168 code is 195*F. Only seen one member here ever post P0168 code...

 

Even the Quadzilla is set up to trip the fuel temp alarm at 160*F. But I've seen several members reporting 150 to 160F temps... Majority are running returns in the fuel basket. 

 

Just remember electronics do not like hot temperatures. No there is no way to put a heat sink on the PSG cover. It won't work being there is a air gap between the cover and module. Not to mention the PSG is heatsinked to the fuel side. So if the fuel is hot its going to heat up the PSG electronics. Of course this shortens the life too. Good return flow from the overflow valve helps but again if the fuel is already hot the return flow is meaningless being it supplied with 150 to 160 degree fuel. 

 

As you can see in my photo the circuit board is mounted to the fuel side. There is a air gap on top then the cover plate also has a air gap too. So yes fuel temp is important to cooling the PSG module.

 

Now that goes back to people trying to install fuel coolers and fans to cool the fuel before the VP44. Again separate your return and supply so you not pump back the hot fuel and the fuel temps go down. 

Edited February 5, 2021 by Mopar1973Man

[dieseldon]

I am kind of a slow learner, but I'm still having a hard time equating why using the fuel basket makes the fuel overheat?

[dripley]

4 hours ago, dieseldon said:

I am kind of a slow learner, but I'm still having a hard time equating why using the fuel basket makes the fuel overheat?

Its not the basket itself. It is what you put in the basket. The return fuel that is. Mine has the lift pump return and the engine return into the basket. They both heat the fuel up. And when you have a low tank it can get pretty warm. If you have a draw straw picking up fuel outside the basket the return fuel can mix with the rest of the tank and cool it down. If you are pulling fuel from the basket it can get pretty warm.

 

[crf450ish]

We'll be moving to Chandler, AZ in the near future and I never ever thought about fuel temps.