73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: eventhorizon66 on July 08, 2007, 06:32:13 pm
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I am about to swap the POS 305 out for a Goodwrench 350 in my 85 C10. I shooting for max fuel economy and have a little extra dough to play with EFI. I have already decided against TBI due to the poor cost to benefit ratio (a well tuned Q-Jet will get about the same mileage as TBI). I was wondering if anyone has tried an Edelbrock Pro Flo system? I am looking at the 3503 system.
Also does anyone think a short bed with 700R4, 3.08s, 29" tire, free exhaust, no emmissions, and a light foot can touch 20mpg? No...stop laughing...I have an uncle who gets that in a heavier late model extended-cab Chevy (he doesn't even drive like grandpa moses).
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The TBI can get 20mpg, my truck has gotten almost 23mpg (22.8) on all the trips I go on. I drive it everday also. I can recheck, but last time I figured the mileage (I do alot of short driving) it was getting about 18mpg.
For the money, the TBI is a better option as the Pro-Flo is going to have a poor cost to benefit ratio unless you are talking about anything other than stock.
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Thanks for the reply, I will have to investigate TBI further. So far the only turn key TBI systems I know of are from Turbo City. Do you know of any others?
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http://www.customefis.com/
http://www.affordable-fuel-injection.com/chevy-system.htm
http://www.affordable-fuel-injection.com/tbi-kit.htm
http://www.howellefi.com/shop/customer/product.php?productid=16220&cat=252&page=1
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i think you can get at least 20mpg. I also have the crate 350 and i think that's what i'm getting; I will officially measure it soon.
I also agree that EFI is not cost effective unless you're doing alot of driving. I.e., 600+miles per week. But i do not nessesarily feel a Q-jet will equal EFI in fuel efficiency. I think EFI can get up to 10% improvement in MPG, not to mention the other benefits of more power and better driveablilty.
I feel the following contribute greatly to fuel economy (more than 2%):
Engine size----CID matches vehicle?
a)compression; higher is better for mpg
b)camshaft; conservative low end torque is better for mpg
Induction----carb vs. EFI
Tires
Aerodynamics
Weight
Gearing ,including overdrives and lockup converters.
Exhaust---big time
How you drive----makes the biggest difference.
I feel the following contribute to a smaller extent (2% or less)
electric fan(s)
Is the duct to the air filter hooked up?----so the engine gets cold air instead of hot.
Type of oil----synthetic vs. regular. Also the weight makes a difference.
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Thanks for all the help. Leaning towards TBI now, even though it doesn't have the cool factor that the Edelbrock system has. dang boring practicality!!!
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a)compression; higher is better for mpg
Type of oil----synthetic vs. regular. Also the weight makes a difference.
High compression is not a good idea if you are wanting good gas mileage, it will force you to use higher octane = more money per gallon.
You also wouldn't want to pair hight compression with an RV cam
Oil type won't have even a 2% impact on gas mileage.
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1)Good point about the higher compression. Premium is anywhere from .30 to .40 cents higher than regular around here, and that probably wouldn't be cost-effective. If gas prices were lower, maybe higher compression would be a good avenue to take.
2)Why won't an RV cam work w/ high compression?
3)i would like expand a little with the aerodyamics point above; I feel that lowering and chopping the top would produce substantial gains (possibly up to 10%) improvement in MPG. But i'm not sure i want to do that to my truck. At least not now.
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Most RV cams are designed with a max of about 9.5:1 compression, generally it is 8-9.5:1 range
Chopping the top off a truck with a flat front end isn't going to give any advantages that will be noticable.
If you want to make a big impact, do like GM did and drop the curb weight.
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Chevy trucks were built for hauling not speed. They have the aerodynamics of a BRICK ! (heavy & Square) If your looking for Aerodynamics and gas mileage, you might try looking for a ricer. It will be a quicker process.
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Nice point, toolmaster. :D
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Chevy trucks were built for hauling not speed. They have the aerodynamics of a BRICK ! (heavy & Square) If your looking for Aerodynamics and gas mileage, you might try looking for a ricer. It will be a quicker process.
I dare you to say that to my trucks face ;)
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Have you considered propane? It is cheaper and cleaner burning. You could even do a dual fuel system that would allow you to run on either propane or gasoline. With propane having a boiling point -45 degrees you wouldn't have any issues with having cool air fuel mixture either.
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Tell me more about propane.
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http://www.autopropane.com/
http://wps.com/LPG/
http://wps.com/LPG/LPG-book-final.html
http://science.howstuffworks.com/lpg5.htm
http://www.oldengine.org/unfaq/leadfoot/lpg.htm
http://www.axisauto.com/
http://cng-lpg-conversion.com/
http://www.propanecarbs.com/
http://www.propanetruck.us/ ( I know, its a Ford, but...)
This was popular around here a long time ago from what I remmber. Problem was it requires a large storage tank to store the LPG.
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I always felt that propane is more of a pain than its worth. But then again some people swear by them (mostly diesel guys).