Rochester FI Tuning

[Jim L.]

Re: Rochester FI Tuning

Good eye, Rich, yes that is the official Kent-Moore computing tool-J-4004 which used the then-state-of-the-art ultra miniature vacuum tube logic modules:



OK, all seriousness aside now....

I use equipment from Innovate Motorsports which comes with their Logworks software. Innovate hardware is designed with a serial port which allows daisy-chaining your choice of Innovate add-on modules and (optional) connecting to a computer for data logging. Logworks is their data logging software. Available add on modules run the gamut from additional wide-band sensor controllers, to thermocouple amplifiers, or general purpose sensor interfaces.

I can't say enough about the ability to record a test session for later, off-line review. There have been numerous times when there were transients I didn't notice from occasional glances at the digital air/fuel gauge and which I didn't feel with my Seat-Of-The-Pants-O-Meter. I discovered them only by reviewing the recorded data.

I understand your reluctance to do the cam/engine break-in with an untested, uncalibrated FI unit. I wouldn't do it either.

When you do get ready to use the dyno to calibrate the FI unit, contact me for some specific recommendations about test conditions.

Jim

[Richard M.]

Re: Rochester FI Tuning

Thanks Jim, I will keep you up to date. Hopefully late March or early April I'll be ready for testing. I'll check with the dyno techs and see what they use.

Thanks,
Rich
p.s. Loved the photo of that J-4004 module that plugs into the laptop processor. Makes for a good heater on those chilly California mornings.

Good eye, Rich, yes that is the official Kent-Moore computing tool-J-4004 which used the then-state-of-the-art ultra miniature vacuum tube logic modules:



OK, all seriousness aside now....

I use equipment from Innovate Motorsports which comes with their Logworks software. Innovate hardware is designed with a serial port which allows daisy-chaining your choice of Innovate add-on modules and (optional) connecting to a computer for data logging. Logworks is their data logging software. Available add on modules run the gamut from additional wide-band sensor controllers, to thermocouple amplifiers, or general purpose sensor interfaces.

I can't say enough about the ability to record a test session for later, off-line review. There have been numerous times when there were transients I didn't notice from occasional glances at the digital air/fuel gauge and which I didn't feel with my Seat-Of-The-Pants-O-Meter. I discovered them only by reviewing the recorded data.

I understand your reluctance to do the cam/engine break-in with an untested, uncalibrated FI unit. I wouldn't do it either.

When you do get ready to use the dyno to calibrate the FI unit, contact me for some specific recommendations about test conditions.

Jim

[Duke W.]

Re: Rochester FI Tuning

For dialing in the A/F ratio at various speeds/loads a Mustang dyno is better than a Dynojet. The Mustang dyno can hold the engine at any speed and load. I prefer Dynojets for obtaining accurate performance data, but they can be "tricked" into providiing accurate A/F data at part load. I have a written set of test plan guidelines. If interested, send me an email through the TDB. It's important to have a good test plan that you co-ordinate with the dyno shop before you commit in order to get the most value out of a one to two hour dyno session. During road testing with the carburetor, get the spark advance map dialed in to as aggressive as you can for the installed camshaft - VAC that passes the Two-Inch Rule and as aggressive a centrifugal curve as the engine will tolerate without detonation. You can actually do some tuning on the FI system while road testing. Lean the economy stop until it pickups up some lean roughness or slight misfire at light load, then richen just enough to get rid of it. The FI should be able to operate as lean as 15.5:1 at light load and cruise. That's why FI systems can achieve about ten percent better fuel economy than the same config. with a carburetor. Due top mixture distribution variation in carb/manifold induction systems, they have to run rich enough on average so that the leanest cylinders don't get into lean misfire Duke

[Paul Y.]

Re: Rochester FI Tuning

I also have used my manometer with good success. I tune the timing and dwell first to get the basics correct. I also agree that turning one nut flat is a safe way to make adjustments. There must of course be no vacuum leaks anywhere also.

I have used the manometer with success and failure. Failure comes when the motor is not in perfect running shape to begin with such as timing and valve adjustment. Just follow the procedure in the 63 GM Corvette Shop Manual. A friend of mine (RIP) used to tell me "just turn it one nut flat at a time and you'll be OK".

JR