Big change is fuel economy
Before the FiTech unit my old 350 truck with a stock GM TBI system installed was getting around 12 to the gallon. After Fitech it's getting between 9 and 10. I simple installed the unit and did the initial engine settings and haven't played with anything else think the self learning would do the job. The truck is a little more responsive but no noticeable increase in performance. The truck is used as a daily driver and I'm not looking from a drop-dead increase in performance. I'm in it for the dependability and was hoping to not have a 20% decrease in fuel economy.
Details: 350SBC w/ RV cam, 700R4, stock GM HEI distributor w/ vacuum advance. Go EFI 600 (30001)...I originally tried the Go Street 400 (30003) but because the unit the send me was faulty, FiTech "upgraded" me to the 30001 to compensate me for my trouble, so I never got to see what the 400hp unit would do for me.
Any suggestions?
First of all, both units would do the same thing. They are virtually identical.
Fuel mileage takes a little user input. Primarily in the AFR targets. This is done at your own risk.
For an example, my 67 c10 has the same unit, with a 700r4 and 3.08 gears. 275/60r15 tires. I have achieved 14 mpg driving 60-65mph on e85 fuel. If you figure a 20%loss for the ethanol, it would be somewhere around 18-20mpg. When I had 3.70 gears it was about 2mpg lower. I have worked for awhile dialing in the AFR targets and the timing. Without dyno tuning, it is a trial and error procedure.
With that said, you should be able to make some big gains right away. I will assume you have a good tune up and drive conservatively.
Start with your idle AFR target. To start watch your vacuum, lean out your idle AFR couple tenths. Your vacuum will most likely increase. Repeat until vacuum quits increasing and then richen 2 tenths. You may recognize this is very similar to idle mixture screw adjustment on a carb.
Now read your plugs. If you are happy with the plug reading, you should have a good starting point for your AFR targets. Here is where the trial and error comes in. Be careful not to get too lean and listen for spark knock.
Because the units are designed to work on a broad range of engine combinations, the unit can only tune to the settings and sensor data it receives. Also the default settings are set in a safe manner for liability reasons. Most of the time the default settings will get an engine going and run fairly well. User input on the AFR and timing can greatly improve the performance and mpg.
Thanks for the 411, Austin. My truck is a '65 C20 with 3.53 gears and I do drive conservatively - 99% of the time! I was glad to learn that the 400 and the 600 were virtually the same. I was worried that I was getting more than I needed and it was costing in MPG. I will play with my AFR settings and return and report.
Thanks again,
Van
Quote from Austin DeHaas on December 19, 2018, 7:02 pmFirst of all, both units would do the same thing. They are virtually identical.
Fuel mileage takes a little user input. Primarily in the AFR targets. This is done at your own risk.
For an example, my 67 c10 has the same unit, with a 700r4 and 3.08 gears. 275/60r15 tires. I have achieved 14 mpg driving 60-65mph on e85 fuel. If you figure a 20%loss for the ethanol, it would be somewhere around 18-20mpg. When I had 3.70 gears it was about 2mpg lower. ....Clip.....
I have a 65 C10. A somewhat lopey 283.
I also have a Goodwrench 350 I may use.
Both low mileage engines.
I have a Th350 with 26.5 tall tires, and 3.73 rear gears.
What engine do you have, and do you prefer the 3.08 over the 3.70 rear gears?
Quote from Deleted user on December 19, 2018, 7:02 pmFirst of all, both units would do the same thing. They are virtually identical.
Fuel mileage takes a little user input. Primarily in the AFR targets. This is done at your own risk.
For an example, my 67 c10 has the same unit, with a 700r4 and 3.08 gears. 275/60r15 tires. I have achieved 14 mpg driving 60-65mph on e85 fuel. If you figure a 20%loss for the ethanol, it would be somewhere around 18-20mpg. When I had 3.70 gears it was about 2mpg lower. I have worked for awhile dialing in the AFR targets and the timing. Without dyno tuning, it is a trial and error procedure.
With that said, you should be able to make some big gains right away. I will assume you have a good tune up and drive conservatively.
Start with your idle AFR target. To start watch your vacuum, lean out your idle AFR couple tenths. Your vacuum will most likely increase. Repeat until vacuum quits increasing and then richen 2 tenths. You may recognize this is very similar to idle mixture screw adjustment on a carb.
Now read your plugs. If you are happy with the plug reading, you should have a good starting point for your AFR targets. Here is where the trial and error comes in. Be careful not to get too lean and listen for spark knock.
Because the units are designed to work on a broad range of engine combinations, the unit can only tune to the settings and sensor data it receives. Also the default settings are set in a safe manner for liability reasons. Most of the time the default settings will get an engine going and run fairly well. User input on the AFR and timing can greatly improve the performance and mpg.
Did you do the 30% larger CID in order to run e85? Anything else?