Re: UNDERSTANDING THE QUADRAJET CARBURETOR 2, Pt.1
OK, we are now up to 18.79mpg which is a good improvement over last week. But still, admitedly, not where i feel it should be because again, i had an 85 SS which got 19.8 AND the thing had a 305 not a 231 so i would think that a 231 should be able to get 23-24 ish.
Changes from last week:
The new plugs and air filter seemed to help (the engine sounded better). But also i had replaced a front tyre; Ruth(previous owner) had installed some off brand maypops which is ok because she really didn't do that much driving (car only has 66K) These tyres were not even round AND they were underinflated; i did not want to inflate them to the proper pressure because i only wanted to make one change at a time.
So not only did i change one of the fronts to michelin "rainforce" (which i think is actually a discontinued model), i inflated all the tires to 35psi. The rears are uniroyal nailguards. (these were also laying in my garage.) i feel the type and brand of tyre make all the difference in the world and can mean up to 1mpg improvment.
Even though i have decided (somewhat reluctantly) to sell the car now, as is, other ideas for further MPG improvement might include:
1) installation of a duct system to connect the the airhorn on the aircleaner housing routed to the front of the car so as do allow the carb to pick up colder, denser air vs. hot, "dirty" air underhood. This might account for a 1%-2% increase in mpg.
2) Jacobs electronics has a spark optimizer sort of device that allows for more complete combustion of the gas. They're claiming 15% improvement in mpg. The idea does sound good.
3) Switch to electric fan from pulley driven clutch-type fan. We might pickup 1%-2% here.
4) Chopping the top and/or lowering the car. Probably not cost-effective. Although we could see upto a 15% increase in mpg due to the drastic reduction in wind drag.
4.5) Exhaust/headers. This is a big one. And increases of up to 10% are probably very realistic.
5) Switch to EFI. i know holley sells complete bolt on kits for v-8s for $1000 (kit+plus you pretty much have to use one of their manifolds---i don't think a quadrajet manifold will work). The problem is i don't know if it would work on a six cylinder. I think we could see a 10% increase with this system.
Also, we have to factor in if it will be cost-effective. I feel that if you drive 600 or more miles per week, this system will pay for itself and start saving you money very quickly.
As it is now, i only commute about 100 miles per week, so something like this would probably not be cost-effective.
Do you have any other ideas to increase mpg.
So, anyways i did learn that you should take care of the basic maintenance stuff first, then try to diagnoise the more complex stuff later.