6.8L V10 exhaust and intake...

[haywoodphotomaccom]

Bill, like to come take a look sometime soon. I am in the La Mesa area.

I think that will be my first upgrade when I get the van back from having the interior done.

Just drove up to the mountains last night and stopped for a pit stop and laser tempted the header area which read about 700. Always seems like a lot of heat coming up when I get out from driving which I don't have with my other V10 van. 700 in range? Outside air about 45.

Also noticed the floor under the pedals reads 80 or so while driving and 110 on the passenger side floor area.

[BillPa1]

I am in WA for a couple for weeks. I will let you know when I get back.
BillPa

[haywoodphotomaccom]

Great, standing by....

[ANZAC]

Originally Posted by BillPa1

I am in WA for a couple for weeks. I will let you know when I get back.
BillPa

Where in WA, would love to ogle your exhaust!

[BillPa1]

I am back from Whidbey Island WA. If you want to see my rig email me at:
harleyloverinlm@cox.net
and we can arrange a meet.
BillPa1

[NRL]

Originally Posted by BillPa1

I also just installed JBA Headers from JBA Performance Center in San Diego.
BillPa1

I was checking my exhaust manifold / header since the famous 460 big block manifold exhaust pipe stud nut heat cold fatigue snap happened too me.
I found remants of a stud nut on the ground 2 yrs ago but ignored it since it drove fine.
Everyone mentions losing the one on the end near the final leg of the manifold was common.

I think its time to get new headers.. Any recommendations? Tight fit where the headers are..
JBA may not have it for the 460 big block since those pics showed them thicker compared to stock, any opinions on the Banks RV headers? Pathetic stock ones just don't seem to be efficient and they are super heavy cast iron.

I might go stock new since it's such a tight fit, I don't know about the V10s, but the 460 big block has to take up more room.. That engine is enormous.
Or I could just get the exhaust manifold stud bolt nuts all replaced with a new kit.

No issues with my last 460 big block with EFI (last year and generation with the 460 big block) so far no complaints other then having the lowest mpg probably of all econolines and exhaust heat issue I took care of.. Exhaust pipe wrap and heat shield film along the sides and along the underside of the floor above the exhaust..

[Chance]

Originally Posted by j.whitbread

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Fact: When you allow more air into your engine, and get the air out more quickly, the computer will add more gas to keep the fuel mixture correct, thereby using more gas, lowering your mileage.

I figure this is mostly true only at wide open throttle, or near WOT. And then the engine would be making more power so it can't be compared directly. At low partial loads where we drive most often the throttle would close more to offset pressure drop reductions in intake and exhaust, so overall power is the same -- whatever the vehicle needs to maintain desired speed. Fuel economy gains at low power can not be much.

Yesterday I filled up during long trip and got 15.1 MPG out of my V10 with 130K on odometer. I was driving through Virginia, Maryland, and Delaware on smooth low-traffic roads at 55 MPH much of time. I figure 305 HP engine was working under 50 HP most of time. Intake and exhaust improvements under these conditions wouldn't get me much. Not enough to pay for upgrade, which is why my van is stock Ford.

[carringb]

Originally Posted by Chance

I figure this is mostly true only at wide open throttle, or near WOT

Another factor is the throttle position sensor, and this is one of the primary parameters the transmission uses to decide shift points. Less restrictive breathing allows more air in at a given throttle position, and hence more fuel and power. But because throttle position has not changed, the transmission will not make more power in the same gear, reducing the need for a downshift.

Prior to installing the AFE intake, my van would drop out of OD one started using more fuel than 8.2 MPG (an more accurate way to represent this would be gal/hr but I keep the scangauge on instant MPG). With the AFE, it will allow me to use more fuel, at a rate of 7.4 instant MPG and sill pull in OD! How does that help overall average MPG? Because once it drops out of OD, instant MPG will be in the 6s or less. Note this refers all to towing conditions. Not towing, the V10 will stay in OD anyways.

So yes, more power will allow a higher gear which will allow less fuel used more often. But, for me my average MPG never changed, because it also means I can also pull hills faster. I don't baby it in the mountains. Foot to the floor, 2nd gear, 5000 RPM and pulling hard in the left lane passing most of the cars. As mentioned above..... more HP = more fuel used. That is simple physics. In fact, my V10 needs so much more fuel due to my breathing and programming changes, its not getting enough above 5200 RPM. Still haven't done the testing to see of its the injectors or fuel pump causing it to lean out.

[Chance]

Originally Posted by carringb

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Not towing, the V10 will stay in OD anyways.

.....cut........

Exactly, which is my case almost 100 % of time. Between 45 and 75 MPH even up gradual hills.

Overdrive versus drive at same horsepower means lower RPM and hence higher torque. That leads to throttle being more open which reduces pumping losses. And that leads to more efficiency and thus higher MPG -- everything else being equal.

In my case where I'm in overdrive most of the time anyway, upgrades would not be very productive in my opinion.

[carringb]

Originally Posted by Chance

In my case where I'm in overdrive most of the time anyway, upgrades would not be very productive in my opinion.

I would agree with you. With the V10, it takes a big and heavy load before any power gains would be necessary to hold OD (but that also varies greatly based on gear ratio too) on rolling hills or moderate grades.