4l80e swap - combatting MPG loss with gearing
05-30-2012, 06:42 PM
#21
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05-30-2012, 06:53 PM
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05-30-2012, 07:27 PM
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It all depends on your goals.
I personally like the 3.42s for what i do. The 3.73s will be just fine.
I could get better mileage if i drove it easier. But for normal driving it stayed up around 2k.
I average roughly 17 on my daily commute and 24ish on longer hauls.
When i was livin in town i went from the 60 to 80 and i still had the turbo so there was some fun driving in there and several sets of back tires.
In the week after Hurricane katrina i drove as smooth as i could cause we had a limited gas supply and that tank averaged 20mpg around the house and town. Havent drove like that since haha. It was hard.
I personally like the 3.42s for what i do. The 3.73s will be just fine.
I could get better mileage if i drove it easier. But for normal driving it stayed up around 2k.
I average roughly 17 on my daily commute and 24ish on longer hauls.
When i was livin in town i went from the 60 to 80 and i still had the turbo so there was some fun driving in there and several sets of back tires.
In the week after Hurricane katrina i drove as smooth as i could cause we had a limited gas supply and that tank averaged 20mpg around the house and town. Havent drove like that since haha. It was hard.
05-30-2012, 08:04 PM
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It all depends on your goals.
I personally like the 3.42s for what i do. The 3.73s will be just fine.
I could get better mileage if i drove it easier. But for normal driving it stayed up around 2k.
I average roughly 17 on my daily commute and 24ish on longer hauls.
When i was livin in town i went from the 60 to 80 and i still had the turbo so there was some fun driving in there and several sets of back tires.
In the week after Hurricane katrina i drove as smooth as i could cause we had a limited gas supply and that tank averaged 20mpg around the house and town. Havent drove like that since haha. It was hard.
I personally like the 3.42s for what i do. The 3.73s will be just fine.
I could get better mileage if i drove it easier. But for normal driving it stayed up around 2k.
I average roughly 17 on my daily commute and 24ish on longer hauls.
When i was livin in town i went from the 60 to 80 and i still had the turbo so there was some fun driving in there and several sets of back tires.
In the week after Hurricane katrina i drove as smooth as i could cause we had a limited gas supply and that tank averaged 20mpg around the house and town. Havent drove like that since haha. It was hard.
05-30-2012, 08:56 PM
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Not really any HP goals. The only goal would be to avoid burning up 9 60e's before switching to an 80e like a lot of people do. The truck will have the following withthin the next 6 months:
TBSS Manifold
Random intake or homemade one
92mm Fast TB
Isky 212 cam
Custom 70mm turbo
Cutout
Tune
I will run around with 6psi most of the time, maybe have a tune for 12psi. And if I feel like it 19psi on race gas. I don't think a 60e would hold up to any of the above for very long in a 5000 lb truck. Considering the tranny is already going out, I was thinking that this is the perfect time to just drop in an 80e and be done with it and move on to the next mod.
TBSS Manifold
Random intake or homemade one
92mm Fast TB
Isky 212 cam
Custom 70mm turbo
Cutout
Tune
I will run around with 6psi most of the time, maybe have a tune for 12psi. And if I feel like it 19psi on race gas. I don't think a 60e would hold up to any of the above for very long in a 5000 lb truck. Considering the tranny is already going out, I was thinking that this is the perfect time to just drop in an 80e and be done with it and move on to the next mod.
05-30-2012, 08:58 PM
#28
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Yea I know but there is always a sacrafice somewhere in the powerband. If I do 4.11's or 4.56's I'll get great mileage around town, but have to drive like 60mph on the freeway to get any decent mileage. I think just leaving the gears alone will net me the best overall gearing/mpg. And considering that I'll be going turbo, I'll want the longer gears anyway.
05-30-2012, 09:08 PM
#29
Excuse me, I read the beginning posts of the thread and skimmed over the middle. I guess you decided to stay where you are with the 3.73s?
What I mean is the cost of buying and installing new gears is expensive...money that could otherwise be used on buying gas. For instance, lets say it costs $700 to change gears. If you truck current gets 18mpg and you drive 10k miles a year (pretty typical) and gas costs $3.20. That is 10,000/18 = 555.55 gallons @ $3.20 thats $1778 per year on gas. So you gear change would basically buy you 4 and a half months worth of gas.
If you change gears to say 3.42s and you now get 20mpg, everything else being equal, you will spend $1600 a year on gas. At that rate it will take you 700/(1778-1600) = 3.933 years just to break even on the costs of the new gears.
This whole scenario may be purely academic, but it helps to crunch numbers on something like a gear swap to see if it will actually help in the end.
What I mean is the cost of buying and installing new gears is expensive...money that could otherwise be used on buying gas. For instance, lets say it costs $700 to change gears. If you truck current gets 18mpg and you drive 10k miles a year (pretty typical) and gas costs $3.20. That is 10,000/18 = 555.55 gallons @ $3.20 thats $1778 per year on gas. So you gear change would basically buy you 4 and a half months worth of gas.
If you change gears to say 3.42s and you now get 20mpg, everything else being equal, you will spend $1600 a year on gas. At that rate it will take you 700/(1778-1600) = 3.933 years just to break even on the costs of the new gears.
This whole scenario may be purely academic, but it helps to crunch numbers on something like a gear swap to see if it will actually help in the end.
05-30-2012, 10:17 PM
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Yea i agree with atomic. Alot of people will spend over a grand just to get a couple more mpg and never think bout how long it actually takes to pay for itself.
Ive looked at numbers for gettin a beater car to drove to work.
Factor in a 1000$ car. Plus the extra insurance, maintance, gas. It would have to be a stupid cheap car or get wicked mpg!
Ive looked at numbers for gettin a beater car to drove to work.
Factor in a 1000$ car. Plus the extra insurance, maintance, gas. It would have to be a stupid cheap car or get wicked mpg!