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Fuel mileage sucks! Please help!

Scottfunk
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Dieselfuture

Dieselfuture

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2 hours ago, Scottfunk said:

If you ever spend a bunch of time just staring at the rims of the cars around you almost all of them have 5 spokes to the wheels. I think this is done to minimize out of balance issues but I could be wrong.

Tire tread is kind of designed that way, none of the knobs are identical but they look the same. Has something to do with harmonics.

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pepsi71ocean

pepsi71ocean

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7 hours ago, Marcus2000monster said:

@pepsi71ocean I cant make up my mind on what injectors to get. Im thinking about a setr of genuine Bosch RV275s flow matched adnd popped to my specs. What would you have a set of RVs set at? 

Being that they are so close to stock fuel flow I would say 310-315bar. What do you think @Mopar1973Man?

It seems to me that the gain in raising pop pressure is proportional to the side of the fuel injected. the larger the injector the more you can raise the pop pressure.

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Scottfunk

Scottfunk

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On 1/7/2019 at 3:24 PM, Dieselfuture said:

:wow: your kidding

Also make sure your check back side of compressor housing for Boost leaks with soap water,  I ended up selling mine with light coat off rtv

What's the easiest way to get that stupid ring back in there. I think rtv is a great idea but the last time I had it apart it took nearly an hour just to get the ring back in. Finally had to ask my wife for help...that wasn't embarrassing.:duh:

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pepsi71ocean

pepsi71ocean

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36 minutes ago, Scottfunk said:

What's the easiest way to get that stupid ring back in there. I think rtv is a great idea but the last time I had it apart it took nearly an hour just to get the ring back in. Finally had to ask my wife for help...that wasn't embarrassing.:duh:

 

The silencer ring?

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Mopar1973Man

Mopar1973Man

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I know this doesn't exactly fit here but...

 

On my 1996 Dodge Ram I pulled the Mopar Performance PCM and pit a stock PCM back on I'm now at 19 MPG on the little truck. What I'm pointing out is the wrong tune can pull MPG down by overadvancing timing. Where the stock PCM is more retarded and now doing better than my Cummins. Price of gas is lower, I can now run 87 octane again. Bonus both ways.

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Scottfunk

Scottfunk

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So I'm still working through this. My egt's are still higher than I'd like and I've done everything I can think of. This weekend I replaced the intake plate gasket and RTV'd the hell out of it, as well as the compressor cover on my hx35. While I was putting the fuel system back together I got to thinking about the fuel inlet. Since I was doing a conversion I had the opportunity to build the whole fuel system from scratch. I replaced the banjo fitting going into the injection pump with a 3/8" elbow. The reason I'm mentioning this is I'm wondering if I'm producing more fuel at any given throttle than the hx35 can keep up with. Any chance a 35/40 hybrid would help keep up with the fuel  I'm supplying to the engine? 

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Mopar1973Man

Mopar1973Man

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20 minutes ago, Scottfunk said:

I replaced the intake plate gasket and RTV'd the hell out of it

 

Bad idea. No RTV or sealant should be used on that gasket. 

 

20 minutes ago, Scottfunk said:

I replaced the banjo fitting going into the injection pump with a 3/8" elbow.

 

 

Should be all 1/2" fuel lines from the fuel tank to the VP44.

 

20 minutes ago, Scottfunk said:

Any chance a 35/40 hybrid would help keep up with the fuel  I'm supplying to the engine? 

 

HX35/40 Hybrid is basically same as HE351 turbo on the 3rd Gens. The only different my exhaust housing is 12cm2 vs 9cm2 .

Edited by Mopar1973Man
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Scottfunk

Scottfunk

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24 minutes ago, Mopar1973Man said:

Should be all 1/2" fuel lines from the fuel tank to the VP44

If I recall this banjo had a 5/16" line going into it. Those two puny little holes don't hold a candle to a 3/8" swept elbow. In any event I'm getting too much fuel. What would you suggest? My turbo is not the he351 so would I be gaining by doing the 35/40 hybrid or would it be better to pick up a 351? I'm planning on going VGT at some point this year so I don't want to sink too much into it but would like to increase my efficiency some in the meantime.

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Scottfunk

Scottfunk

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25 minutes ago, pepsi71ocean said:

I disagree with Mike, I'm running 3/8" from my fass95 to the vp44 and I have no issues with fuel supply.

 

My next question is Joe is your drive train? Anything dragging? How's the VB and transmission?

I agree. I don't know exactly what size the holes in the banjo are but I still have the fitting at home...I'll check it when I get home from work. I definitely don't remember them being any bigger that 1/8" so basically it doesn't matter if you run a fire hose up to this fitting, if that's the point of restriction you'll never flow any more than that banjo allows.

 

I don't believe I have excessive drag...other than the 35" mudders I put on last week, hehe. Everything in the trans is brand new and all the clutch clearances were exactly middle of the specs so I don't think that's the problem. I put the truck on jack stands and the rear wheels spin freely, as do the fronts. Stopped, and in gear, if you let your foot of the brake the truck feels like it gets moving on its own without excessive resistance. I really think this is an internal thing. I'm going to make a new boost test boot (I blew the last one up) and I'll check for leaks again. I'm new to this whole positive pressure intake situation and it's kind of blowing my mind.

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Mopar1973Man

Mopar1973Man

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Clue. More boost you see going down the road means typically your burning more fuel. I've got to ask what is your engine load and boost pressure like at highway speeds?

 

Boost you should be below 5 PSI for 65 MPH. Engine load should be around 20% or lower if possible. 

 

Injectors what are you running? What was the pop pressure at? How many miles on the injectors?

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pepsi71ocean

pepsi71ocean

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30 minutes ago, Mopar1973Man said:

The only reason for 1/2" lines is pressure stability. 3/8" lines work OK for stockish trucks. When you start to see wild pressure swings its time to go up in size. I just opted for large lines in the beginning and just not worry about it.

 

I hear you, but ever since I moved to 1/2" from tank to fass, and changed my spring to a spring out of a fass150 I've never had an issue, even with my 100's smarty and boost elbow pushing 35+ lbs of boost she barely moves the needle. 

25 minutes ago, Scottfunk said:

I agree. I don't know exactly what size the holes in the banjo are but I still have the fitting at home...I'll check it when I get home from work. I definitely don't remember them being any bigger that 1/8" so basically it doesn't matter if you run a fire hose up to this fitting, if that's the point of restriction you'll never flow any more than that banjo allows.

 

I don't believe I have excessive drag...other than the 35" mudders I put on last week, hehe. Everything in the trans is brand new and all the clutch clearances were exactly middle of the specs so I don't think that's the problem. I put the truck on jack stands and the rear wheels spin freely, as do the fronts. Stopped, and in gear, if you let your foot of the brake the truck feels like it gets moving on its own without excessive resistance. I really think this is an internal thing. I'm going to make a new boost test boot (I blew the last one up) and I'll check for leaks again. I'm new to this whole positive pressure intake situation and it's kind of blowing my mind.

 

 

This begs me the question of what rear do you have on this truck?  35's are fairly big, and no matter what if you have a 3.55 rear your gonna be  struggling with the load. 

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Hawkez

Hawkez

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29 minutes ago, Scottfunk said:

I agree. I don't know exactly what size the holes in the banjo are but I still have the fitting at home...I'll check it when I get home from work. I definitely don't remember them being any bigger that 1/8" so basically it doesn't matter if you run a fire hose up to this fitting, if that's the point of restriction you'll never flow any more than that banjo allows.

The idea is to get rid of the banjo fittings all together.  You are right, those banjo bolts are restrictive.  I've replaced my banjo bolts with larger fittings altogether.

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