I thought that I posted this earlier but apparently not. I want to install an AF Meter in my Model A. This would be a permanent install, not just for testing/tuning exclusively. I tent to go with middle of the road in the price vs quality department. If there is a good quality meter available in the 2 1/16” range but if not available I can live with a larger meter. I’m looking for some advice re what to buy, I know very little about this subject. Thanks
Once you've selected the meter, make sure you understand where to install the O2 sensor bung and that the exhaust system needs to have no leaks before it! The location and angle of the bung/sensor is critical for helping the sensor continue to operate as it should.
I run an Autometer ****og AF gauge. I find that the ****og gauges are easier to read at a glance than the digital ones. One really good tip I got from a guy, in regards to actually using an AF gauge for real tuning, is to set up a camera (or have a p***enger hold one for you) and go for a drive. Call out throttle positions as you go, so that when you get back to the shop and watch the video, you can actually make sense of what is going on. This was you can cruise st various throttle positions and make a couple WOT pulls and really see what is happening and when/where. It's can be difficult to just watch it with your eyes and make adjustments off the cuff. Plus, if you make a video after each adjustment, you can do direct A-B comparisons to where you were vs where you are now. You could do this in conjuction with data logging off of the gauge if you really wanted, but the video itself tells you what you need to know. Plus, for accurate data logging you'd also need to rig up some kind of throttle position sensor, and figure out how to data log that at the same time and make sure that the timelines perfectly matched.
On Amazon for approx $200? Is that the one? That is a reasonable price I think. I am about to install a new muffler and header pipe so now’s the time to add a bung.
Install the one you decide on, tune on it until you’re happy with the idle, cruise, then take it off and plug the bung. If you make any big changes then repeat the process. I have the AEM digital and it’s only a plug to the Bosch sensor and a switched positive and a ground.
I leave mine in for jet changes at a drag strip and only for wide open throttle. For street driving I find myself staring at this gauge constantly, swinging from 11.80 to 14.80 AFR with a tap on the throttle.
@ '28 RPU You have 2 or 3 threads going about AFR Gauge ? You will would need to read threw all 2 or 3 ... When it comes to monitoring gauge for tunning To make if easier on you for turning purposes , Seeing Gauge is Necessary along with a TACH , Filming both @ same time or Data logging Compatible with RPM's. Name band O2 gauges model have Data logging , but not all . O2 gauges Do Not hold steady small reading like a Oil or Water. Just trying to point out what will go on Until you get a Base on Carb tunning . I mention in one of the other threads you started , Carb is Not EFI . You are only going to get the AFR close. A typical used carburetor does not have all the adjustment of a Carb that can have Many adjustments Out side of the Mixture screws Jets P Vale Ect .. Pics below are just for reference of all the adjustments you can make and there's more in the body itself.. In a non idle to WOT Tune , You want good transactions from Idle , cruise to WOT . This why for None standard out box Typical carburetor,, I think a typical carburetor you can get about 60% economy performance tuning With out a Complete adjustable carburetor.
I have an Autometer, I install under the dashes with zip ties when I make changes. Bungs in all the old cars. Makes jetting a breeze now, but you can chase your tail as carbs are always jumping around. You soon realize how far off they are as they transition, and yet they seem to run fine.
When I was tuning with mine, I made a cardboard throttle position gauge. I used a stiff cardboard with a slot cut in it, folded a cardboard pointer that slid up and down the slot. I hooked a soft pull spring to the top and piece of string to the bottom. With the gauge taped to the dash where I could see it, I tied the string to the throttle pedal arm under the dash.I marked idle location next to the pointer, then full throttle. I divided up the space between with a few marks. When driving around I found I used mostly the first 1/8 of throttle travel and few 1/3 throttle getting on the highway. The W-1 Carter's use three step metering rods, and with some digging on the web I found rods with the right diameter to correct the A/F ratio where needed. With out the throttle position gauge, I wouldn't have know which steps needed changing. https://speedhut.com/categories/gauge-type.html makes fully customized gauges to match what you have. Mine matches in color and the font is close.
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