5.9 Fuel Economy Rebuild
#21
02-18-2016, 04:22 PM
Big Green 360 thanks for starting the thread and posting your progress, I am new here and stumbled upon it while hunting for some other info. It's cool to see there are more people in the world with the wherewithal to even draw up such an animal. I am considering a similar build later this year for my 3/4 ton and I'm wondering how things are going for you.
Back in the 90's after reading some of David Vizard's books I built an "experimental" Ford 351W with the same goals in mind...good low-end power so the motor is in it's "sweet spot" a cruising speed = better MPG (about 10.5:1 CR, roller rockers, flat-top pistons, edelbrock intake & carb, and the right cam) and dropped it in a '83 Crown Victoria. I also didn't want to run premium fuel (I ended up needing minimum 89 non-ethanol, was hoping for 87 but couldn't quite run it). That engine had really good power where it needed it. Peak HP was probably nothing to brag about, but who drives around at WOT-redline-the-tach anyway? It easily pulled over 20 MPG, anywhere from 55 MPH roads or running 85 MPH across South Dakota on I-90. That was an interesting project, and what I have since decided is having a diesel for occasional heavy towing is fun, but way overrated (and very expensive).
So my goal for a 3/4 ton 4wd pickup would be low-end towing power, and with the EFI and electronic timing I think 15 MPG should be "easy" to dial in.
Once again thanks for posting your build, keep the posts coming and let us know how it turns out!
Back in the 90's after reading some of David Vizard's books I built an "experimental" Ford 351W with the same goals in mind...good low-end power so the motor is in it's "sweet spot" a cruising speed = better MPG (about 10.5:1 CR, roller rockers, flat-top pistons, edelbrock intake & carb, and the right cam) and dropped it in a '83 Crown Victoria. I also didn't want to run premium fuel (I ended up needing minimum 89 non-ethanol, was hoping for 87 but couldn't quite run it). That engine had really good power where it needed it. Peak HP was probably nothing to brag about, but who drives around at WOT-redline-the-tach anyway? It easily pulled over 20 MPG, anywhere from 55 MPH roads or running 85 MPH across South Dakota on I-90. That was an interesting project, and what I have since decided is having a diesel for occasional heavy towing is fun, but way overrated (and very expensive).
So my goal for a 3/4 ton 4wd pickup would be low-end towing power, and with the EFI and electronic timing I think 15 MPG should be "easy" to dial in.
Once again thanks for posting your build, keep the posts coming and let us know how it turns out!
#22
02-18-2016, 06:18 PM
Grand Champion
I should be doing better than that now, but it'll be a while, maybe even a long while, before I see flat ground again, and even longer before I get down that low again. In order to get to that thicker air I have to go where the rabid badge monkeys are hunting for folks like me, so I'm not really keen on going there. I don't like those guys at all and don't care to meet them.
#23
02-19-2016, 12:32 PM
My build has again slowed down due to time constraints, but I'm almost done porting/polishing the heads and will post before and after pics. I think you guys will be impressed. After that it's just reassembly and tuning.
As far as smaller diameter long tubes. . . from the exhaust engineering I've read, the most important factor by far is diameter, with length a distant second. Diameter must be properly matched to the exhaust speed and volume exiting the heads. Too large and you lose velocity and thus efficiency. Too small and you lose volume handling ability. There is not a long tube on the market that is small enough diameter to properly match the flow characteristics of a relatively conservative street build. If you could get long tubes in 1.5" diameter, there is no doubt they would outperform the shorties as you are moving the first pipe junction farther away from the ports which helps with pressure reversion waves.
As far as smaller diameter long tubes. . . from the exhaust engineering I've read, the most important factor by far is diameter, with length a distant second. Diameter must be properly matched to the exhaust speed and volume exiting the heads. Too large and you lose velocity and thus efficiency. Too small and you lose volume handling ability. There is not a long tube on the market that is small enough diameter to properly match the flow characteristics of a relatively conservative street build. If you could get long tubes in 1.5" diameter, there is no doubt they would outperform the shorties as you are moving the first pipe junction farther away from the ports which helps with pressure reversion waves.
#24
02-21-2016, 09:25 PM
Grand Champion
Adding a potentially useful data point: My truck ran either side of 6,000 pounds before, depending upon how much fuel was in the tank, and I just added about 250 pounds of bumper. I just did a round trip to Steamboat Springs and got 15.09 MPG for the trip.
The headers and e-fans seem to have made a fine difference. I'm also using overdrive now where I couldn't before, so yay.
The headers and e-fans seem to have made a fine difference. I'm also using overdrive now where I couldn't before, so yay.
#25
02-23-2016, 01:38 PM
My build has again slowed down due to time constraints, but I'm almost done porting/polishing the heads and will post before and after pics. I think you guys will be impressed. After that it's just reassembly and tuning.
As far as smaller diameter long tubes. . . from the exhaust engineering I've read, the most important factor by far is diameter, with length a distant second. Diameter must be properly matched to the exhaust speed and volume exiting the heads. Too large and you lose velocity and thus efficiency. Too small and you lose volume handling ability. There is not a long tube on the market that is small enough diameter to properly match the flow characteristics of a relatively conservative street build. If you could get long tubes in 1.5" diameter, there is no doubt they would outperform the shorties as you are moving the first pipe junction farther away from the ports which helps with pressure reversion waves.
As far as smaller diameter long tubes. . . from the exhaust engineering I've read, the most important factor by far is diameter, with length a distant second. Diameter must be properly matched to the exhaust speed and volume exiting the heads. Too large and you lose velocity and thus efficiency. Too small and you lose volume handling ability. There is not a long tube on the market that is small enough diameter to properly match the flow characteristics of a relatively conservative street build. If you could get long tubes in 1.5" diameter, there is no doubt they would outperform the shorties as you are moving the first pipe junction farther away from the ports which helps with pressure reversion waves.
#26
02-24-2016, 07:05 PM
A magnum needs to breath, the 1-3/4 Spintechs are the best you can get...Don't waste your time on 1.5" diameter pipes.
#27
02-25-2016, 09:55 AM
Depends on what you want. If you want the low-end grunt, then the 1.5" primaries are the way to go. If you want your power up top, then larger diameter is where ya wanna be. There just isn't a 'one size fits all' application here.
#28
02-25-2016, 10:55 AM
I tow my Dakota with my 5.9 gas Ram, where I need power is 3500+ rpm, like trying to get up to speed on an entrance ramp,
I think a bigger primary will suit most people so they are making more power in the mid range where you need it. Granted not everyone needs 2" primaries like I have on my Dakota, but 1.5" is a straw. why kill the mid to top end range for the small amount of time you're poking along needing power?
My Ram is getting 1-3/4 Pacesetter LTs, 1.7s and a M1 2bbl, for the reasons I stated above, towing. Installing 4.10s (which I won't because I tow at freeway speeds) will move the power band up so even more need for bigger primaries.
#29
02-25-2016, 12:34 PM
The low end grunt for what..Power at 1000 rpm? Who needs power at 1000-2000 RPM?
I tow my Dakota with my 5.9 gas Ram, where I need power is 3500+ rpm, like trying to get up to speed on an entrance ramp,
I think a bigger primary will suit most people so they are making more power in the mid range where you need it. Granted not everyone needs 2" primaries like I have on my Dakota, but 1.5" is a straw. why kill the mid to top end range for the small amount of time you're poking along needing power?
My Ram is getting 1-3/4 Pacesetter LTs, 1.7s and a M1 2bbl, for the reasons I stated above, towing. Installing 4.10s (which I won't because I tow at freeway speeds) will move the power band up so even more need for bigger primaries.
I tow my Dakota with my 5.9 gas Ram, where I need power is 3500+ rpm, like trying to get up to speed on an entrance ramp,
I think a bigger primary will suit most people so they are making more power in the mid range where you need it. Granted not everyone needs 2" primaries like I have on my Dakota, but 1.5" is a straw. why kill the mid to top end range for the small amount of time you're poking along needing power?
My Ram is getting 1-3/4 Pacesetter LTs, 1.7s and a M1 2bbl, for the reasons I stated above, towing. Installing 4.10s (which I won't because I tow at freeway speeds) will move the power band up so even more need for bigger primaries.
Just put 4.10s in it. Why bothering towing anything without them.
#30
02-25-2016, 01:28 PM
The low end grunt for what..Power at 1000 rpm? Who needs power at 1000-2000 RPM?
I tow my Dakota with my 5.9 gas Ram, where I need power is 3500+ rpm, like trying to get up to speed on an entrance ramp,
I think a bigger primary will suit most people so they are making more power in the mid range where you need it. Granted not everyone needs 2" primaries like I have on my Dakota, but 1.5" is a straw. why kill the mid to top end range for the small amount of time you're poking along needing power?
My Ram is getting 1-3/4 Pacesetter LTs, 1.7s and a M1 2bbl, for the reasons I stated above, towing. Installing 4.10s (which I won't because I tow at freeway speeds) will move the power band up so even more need for bigger primaries.
I tow my Dakota with my 5.9 gas Ram, where I need power is 3500+ rpm, like trying to get up to speed on an entrance ramp,
I think a bigger primary will suit most people so they are making more power in the mid range where you need it. Granted not everyone needs 2" primaries like I have on my Dakota, but 1.5" is a straw. why kill the mid to top end range for the small amount of time you're poking along needing power?
My Ram is getting 1-3/4 Pacesetter LTs, 1.7s and a M1 2bbl, for the reasons I stated above, towing. Installing 4.10s (which I won't because I tow at freeway speeds) will move the power band up so even more need for bigger primaries.
I have the 2bbl m1, 1.5" JBA shorties, and a 52mm tb and the powerband is strong throughout. Good down low and up high and everywhere in between.
Last edited by dapepper9; 02-25-2016 at 01:30 PM.