I have good news, I have reached my achieved goal of averaging 27 miles per gallon on 1981 Toyota Corolla and all I needed was a fuel pressure regulator. I was facing a life changing but necessary decision in my life, attempt to better the consumption of fuel on my DD or trade it in for a more fuel efficient vehicle. Who would have thought that all I needed to do was change the spark plugs and install an adjustable fuel pressure regulator. Before installing my regulator I was getting roughly 17 miles per gallon and so now I wont have to get rid my Corolla.
It's good to point out that I am running a Weber 32/36 carb and I have set the fuel pressure regulator to 3.5 psi.
Those carbs don't need a lot of pressure. When I went to an electric pump on my Capri the first I got was a Carter with something like 6 psi averaged pressure, and it would force the needle off the seat and flood things out. I replaced it with one that was supposed to supply an average of 3.5 & things worked excellently. The car would pull 35 mpg on the highway if I kept speeds below 70 mph (above that the lack of overdrive would start to bring things down pretty quickly).
The only purpose of fuel pressure on a carb'd car is enough to deliver the fuel to the carb.
deveous9 wrote:
It's good to point out that I am running a Weber 32/36 carb and I have set the fuel pressure regulator to 3.5 psi.
I'm glad you posted that...I'll keep it in mind when I put the 3TC and weber into my '83 Corolla.
Thanks,
Clem
Webers are really touchy! I converted my CJ7 over to a 34/34 and it ran awfull, I actually am running about 2.5 psi and changed the jets out using the "high altitude" kit...Runs like a dream now and gets close to 16mpg!
There are great carbs but needs some tinkering.
I am actually considering switching over to a Rochester 2 barrel carb for track use but dont know yet. I have also heard good things about the Weber 38 carb but I'll see what I can get my hands on first.
I am actually considering switching over to a Rochester 2 barrel carb for track use but dont know yet. I have also heard good things about the Weber 38 carb but I'll see what I can get my hands on first.
I think I would stick with the 32/36, it's probably as much carb as you really need and, in my experience at least, gives good throttle response. They're more complex if you want to tune on the thing but there's also a lot more that can be done to try and get precisely what you want. Might be time for some dyno time and a box of jets, emulsion tubes, etc etc.
pres589 wrote:
I think I would stick with the 32/36, it's probably as much carb as you really need and, in my experience at least, gives good throttle response. They're more complex if you want to tune on the thing but there's also a lot more that can be done to try and get precisely what you want. Might be time for some dyno time and a box of jets, emulsion tubes, etc etc.
emulsion tubes? what is that? and as far as jetting is concerned, which ones do you recommend?
Emulsion tube
Part of a fixed jet Carburetor, in which air is introduced into the mixture through holes to help atomize it and correct excessive richness at higher engine speeds. A perforated tube which extends from an air bleed in the top of the air horn down into the main well. Admits air from the air bleed into the main well to emulsify the fuel in the main well. Improves idle response and stability when the engine is hot and prevents fuel percolation and general hot-starting problems. Also improves response in the main metering circuit during part throttle conditions. Also called Main-well tube.
If you really want to use the Weber I'd get a book about them, I have no suggestion on what to recommend here, and I have no getting recommendations. You would need to have the carb in good condition then use a rolling road dyno or similar testing methods and go from there. I think the Weber is a good carb and I was happy with it in my factory application and after doing some major upgrades to the engine in my Capri, but I'm not a good voice to look to for help. Maybe someone else on this thing could step up but I wouldn't be able to give the information you really need.
responding via my psp go Thanks for the info, I am actually reading an online spread sheet on how to tune a weber carb and its so complicated my brain is going to explode.
deveous9 wrote:
its so complicated my brain is going to explode.
Make sure you're standing over Linoleum. It's much easier to clean head sauce off of.
deveous9 wrote:
responding via my psp go Thanks for the info, I am actually reading an online spread sheet on how to tune a weber carb and its so complicated my brain is going to explode.
At least there's no rat's nest of wires to sort out.
I like my carburetors.
Webers are pretty easy once you wrap your head around them. I found that the stock emulsion tubes were pretty close in most cases. Main jets and air correctors are where the majority of your tuning will be done. Emulsion tube changes will get you the last 10%.
Rochester 2GC's are awesome carbs for how simple they are. I've got them on a few of my cars and they work very well.
Shawn
