Here is a partial video from a dyno pull. The video started in the middle: https://www.youtube.com/watch?v=yGsLjqRCRnc

Shot of the data log for a dyno pull. The green line is the throttle position, the red is RPM. Pink wavy line is the actual air fuel ratio. The blue is manifold pressure and if you look close you can see that it drops slightly as the rpm goes up which shows that the throttle body is a bit of a restriction.

Andy have you tried or done any step testing while on the dyno?

Did you try pulling back some timing after peak torque?

No, I'm not controlling timing with the Sniper.

No, I have never done any step testing.

what is "Step Testing"

Step testing is process used in EFI tuning. You use the dyno to load the engine. You work you way through the KPA and RPM grid and go through your Auto Tune. You can a mess with different AFRs and Timing. For something like the Sniper. Probably set your timing and AFR. Then just Dyno through the Auto Tune. Will use 3500 RPM as a Example. Bring the engine up to 3500 put some load on the engine hold it say 3-4 sec 30 KPA@ 3500 RPM. Then back it back down each time then roll up to the next KPA@ 3500. Say it's 35 KPA@ 3500 RPM then 40@ 3500 45 50 55 60 KPA@ 3500 so on. Of course the dyno Op will have to keep applying load to reach the upper KPAs. Thats whats nice with a dyno and a Auto Tune feature or what ever Holley calls thiers. You can go through the Auto Tune in a few hours. Where it would take days or weeks for the engine to see all areas of the map. Way Safer too. I probably didn't explain as well as someone else could. but that's ballpark explanation. Anyone wanting to read some good stuff on EFI. Highly recommend the EFI books by Greg Banish. Helped me alot with doing EFI on Harleys.

The Holley system learns fast enough that you don't need to do all of that. Just bolt it on and let it rip. It helps if the fuel map is close. In this case the learn table was mostly single digits at WOT. We fired the engine up and let it warm up then started to make dyno pulls. The Sniper learned as we went. No need for step testing.

The nice thing about step testing is it finds out the 'best' values for the entire table in one session.
Auto-learning only 'fills' the cells in the table the engine has just used.

Similar:
https://www.youtube.com/watch?v=35bZTekQGE8&list=LLtrx_z3PXNJYuLEui9O-hkg&t=0s&index=9

But it isn't necessary with a system that learns quickly like the Holley unit. All you really need are just a few points in the map and then you can interpolate the rest. That gets you close enough that learn can handle the rest.

For this 470 engine I started with a known good map so I didn't even have to bother with any of that. Just loaded the map in, warmed up the engine and starting the dyno pulls. These days there should be enough known good maps floating around that you wouldn't need to do a step test unless you were working with a very odd engine combination.

It kind of is in my opinion. The "auto tune" only tunes to the AFR it is told. Doing step testing would let you know what AFR the engine is the happiest at. After that you can set your auto tune to those values so in the event a change is made it can tune back to those AFRs.

I agree with Andy, seems pointless to do that since it will learn under real-world driving conditions. Furthermore, those 'real world' driving scenarios would likely not be the same as a dyno cell so you'd be muddying the waters before you even put the thing in a car. An engine dyno can't simulate differences in driveline frictional losses, weather, car weight, aerodynamics etc. A chassis dyno might be better suited to that type of testing if you were trying to establish a specific fuel map since you can simulate load better. But like he said, if you have a known 'good' curve' to plug in, it accomplishes the same thing (establishes a baseline) and the auto learn would adjust appropriately as you drive it.

With a Speed Density system like the Sniper. The KPA is the engine load in the map. So if Andy had the engine on the dyno and loaded the engine to hit will say. 30 40 50 60 KPA at 4000 RPM an be at 13.2 AFR. When he put it in the car and got to those KPA points and RPM. It will be 13.2 AFR. The system don't care if it's running through the tranny and rear end. It just knows at this KPA and RPM it's got a target AFR 13.2 in that cell of the map. I was just wondering since he had it on the dyno if he had done any step testing. To try different AFRs at different KPAs & RPMs to see what makes the best HP & TQ. What he has now is what is called a Canned Map. Or a known good map. From there to me while on the dyno he had a chance to fine tune the Map. Theres is NO magical AFR for every KPA & RPM. Every engine demands something a little different. I've seen half a AFR point pick up 3 HP. That's why you can't put the same carb on a different engine. Sure it maybe close. But you still tune it to the engine it's on. EFI no different.

I'll most likely do some optimization of freeway cruise once I get the car running again. I think it would be fairly simple to try some different air fuel ratios at cruise and see what happens with fuel economy, engine temp, etc.

I think it is better to do that testing in the car rather than on the dyno since I don't know what the dyno settings should be to duplicate freeway driving.

That will work Andy. Fast Man EFI. Has a excellent Holley EFI Tuning module online for 75 bucks. Highly recommended. For those who have Holley EFI or looking to maybe go Holley EFI.

Okay. Where do I send the donut and the beer?
http://www.fastmanefi.com/classes

I installed the Trick Flow intake and the Hyperspark ignition system. Just need to button up the wiring and then she'll be ready to go again.

Notice any difference going to single plan intake?

Andy, would you say the Sniper is on par now with a multi port system as far as drivability? Of course it's apples to oranges between the two types of systems but all things being equal - are you leaving anything on the table by not going to a full multi port system?