Compucruise

[80cvcc]

Does anyone out there have any experience with a Zemco Compucruise? I recently picked one up (ZT-4), and can hardly wait to install it. For those who don't know - it's an old school version of the Scangauge, but only works on cars with carburetors. It consists of the "computer" which is fed by a fuel line transducer and a driveshaft sensor. Finally I will be able to answer the question - "shift high or shift low". I'm not real clear on the results of my vacuum gauge. It gives me a higher vacuum at higher rpms (better FE?), but what I've read here points to lower rpms giving better FE. Hopefully the Compucruise will answer these persistent questions. I'll update in a week or two.
PS - Is it "legal" to fill up, drive like a maniac for a day or two, then top it off without recording the results? Of course this would be used for comparison (not for fun) - purely scientific.

[SVOboy]

It's illegal!

I've heard a lot about them but no experience, good luck and let us know!

[Fourthbean]

I had the same problem with my vacumn gauge. And wanted to buy a Zemco but didn't want to spend 100 bucks on that just yet. How much did you end up paying for yours?

I was recently looking to find a meter for fuel that I could send to a serial port on a computer and calculate mileage there. But have not had any luck finding something affordable. Please let us know how that zt-4 works out and if you can find out any info/part numbers on how the thing measures fuel usage I would be much obliged!

[80cvcc]

I got the Compucruise for about $60 - nib. If there's any info on replacement parts I'll let you know. I also looked for other flow sensors, but all I could find were for industrial applications ($$$).

[Mentalic]

The flow element is likely similar to the ones used on boats, I'd think you will find its a very small turbine meter. When you look down the tube you will see a very tiny fan, very similar to the front of a jet engine. Little puff of air and you can see it spin.
Anyway I have a Navman 2100 on my boat that measures fuel flow in GPH. The Navman uses a turbine meter flow element. Theres a few brands out there, another one is Flowscan. Turbine meters deliver a pulse per unit volume factor so you could homebrew your own flow indicator/totalizer.

I have one on my boat for two reasons, one to calculate MPG while under way! Two would be to keep tabs on how much fuel I have burned since boat fuel tank level gauges are lousy due to all the different running angles of the boat.

[Fourthbean]

I did notice the market for flow sensors in boats was quite large, I just did the calculations and I think 1.5GPH lower limit accuracy(what most boat sensors go down to) would just work for me. At 1.5GPH that would give me accuracy up to 28MPG. And since I pulse and glide that accuracy would be better as my engine would be running only have the time making that an effective accuracy of 56MPG.

Found a sensor on Ebay, I will see if I can find a navman GPS for a good price and maybe I will spring for the two together.

[Mentalic]

Originally Posted by Fourthbean

I did notice the market for flow sensors in boats was quite large, I just did the calculations and I think 1.5GPH lower limit accuracy(what most boat sensors go down to) would just work for me. At 1.5GPH that would give me accuracy up to 28MPG. And since I pulse and glide that accuracy would be better as my engine would be running only have the time making that an effective accuracy of 56MPG.

Found a sensor on Ebay, I will see if I can find a navman GPS for a good price and maybe I will spring for the two together.

Lowrance makes a line of boat GPS that are built to take flow meter input and directly indicate MPG on the GPS.
I've seen my boat read in the few tenths of a gallon while idling. I'm sure you loose a tiny bit of accuracy at very low flows due to the way turbine meters work, still quite good enough. My boats Navman has always been within 3% of the gas pump.

[corvairman]

Originally Posted by 80cvcc

I got the Compucruise for about $60 - nib. If there's any info on replacement parts I'll let you know. I also looked for other flow sensors, but all I could find were for industrial applications ($$$).

where did you find this item for $60? do you know where i can find parts for one ? its a 1975

[corvairman]

where did you find this item of $60.? do you know where i can find parts for one? it,s a 1975 unit. thanks