when looking at power output I always look at mph. street driven cars are more likely not to e.t. well. 107mph doesn't reflect 400hp at the wheels. you could be going way past the power curve thru the traps. i'd check fuel supply and ditch those 4.10's first.

My observations after watching the video.....

-pretty noticeable stumble off the line
-doesn’t seem to have as much stall as I would have thought based on the Dyno Test
-seems to be laboring after the 1-2 shift.
-also seems to be laboring somewhat for much of the 660-1320.

I’d try putting a few gallons of “good” gas in it next time you head to the track, and make sure it’s got over 1/2 a tank.
I hear those Holley fuel mats work wonders.

Did you ever do a stall test?

“In theory”, 106mph is good for a 12.30.
Gonna need to work on the launch(60’) to get closer to that.

As I tell people all the time...... you have to start somewhere.

Been to the scales yet?

Did you or someone tune the sniper setup, or did it tune itself?

Andy: Yeah, I did a data log of the run - I'll attach a CSV export to this post. The board doesn't like the CSV file extension, so I renamed it to a TXT. The viewer application won't export a nice JPEG like the Dyno Jet software will.

If for some reason you wanted the raw file you can download it here: https://drive.google.com/file/d/1NKPMtipIwe9P4DjesVU3FyH3WPxvYmmg/view?usp=sharing

I do have a fuel pressure gauge, but it's under the hood.

Fast68Plymouth: I think it running rough was all due to me running the tank too low. Next time out I'll run it at half tank. I did see the Holley offering to add a baffle into the tank, but I think I'm going to try my hand at making a custom tank for the car. The factory tank won't allow for 3" exhaust on either side and is even real close to contacting the 2.5" as it is. I've got a friend that can Tig. Probably be a winter project.

On my way out to my Dad's I tried two launches on a stretch of empty road while watching the tach. It hit 4k before the tires really started screaming.

I wasn't watching the tach through the traps either. More inexperience showing I guess. The datalog shows it peaked at 5900 RPM at the end of the run. That pass was made leaving it in drive.

No idea on the weight. I'll try and find a scale this week.

I really appreciate everyone's time in helping me with this. Thanks guys...

I left timing up to the distributor and let the Holley do it's thing with everything else. No manual tuning outside of answering the initial setup questions. Has about 600 miles on it now and the plugs look great for normal street driving. Never pulled them after a WOT blast. I've just been going with what the datalogs tell me for AFR values.

You starved for fuel from the top of first gear through most of 2nd gear, starved bad. Its WAY lean there. This was due to the fuel level/supply.

There is alot of bouncing around for AFR and AFR error, with many points more than you really want to see, especially at WOT. I would dial this in manually myself. From looking at the logs I would say the engine was breaking up from 3600 RPM in 1st gear pretty much through the entire run. This could be something with the sensors you are using, but RPM should not be decreasing from point to point during a WOT run.

You should adjust your throttle cable, you're not getting 100% WOT according to the TPS.

Are you using the sniper for timing? If so, once the fuel is sorted out you can add 2 more degrees and go from there. The engine might like anywhere from 2-8 more degrees of timing.

Sniper or Super Sniper? The Super Sniper allows you to hook up oil pressure and fuel pressure to the Sniper so you can data log them. The original Sniper doesn't allow any extra data lines so you have to use other tricks to watch fuel pressure during a run. (gopro or a different data logger or some other method)

Yeah I haven't figured out a nice way to share Sniper data logs yet. I usually just take a picture of the screen and then upload that. I think I can convert it to Excel and then build a chart in Excel but I haven't done it yet.

If you have the Holley software on your desktop PC then you can just open up the datalog and play it back over your config file. You should be able to get a pretty good feel for what is going on by comparing target AFR to actual AFR and watching TPS and RPM and manifold pressure.

From what I've seen so far the TPS on the Sniper doesn't open more than around 92% but that is always one of the first things to check.

Datalogs exported as CSV or TXT, can be viewed with MegaLogViewer.
It can read those files, you can select the fields in the logs you want to see and even make (zoomed) screenshots if you want.

https://www.efianalytics.com/MegaLogViewer/

The paid-version will also do scatter plots which is a nice feature.
You can also open multiple logfiles at once and view them as a combined scatter plot.

It's mostly used with MegaSquirt setups but the MegaLogViewer can be used with just about anything that exports text-based logfiles.

Converter sounds real tight and definitely sounds like a fuel starvation issue.

More info for comparison, my car on a dynojet making 340 hp to the wheels went 11.87 at 112 mph at 3700 lbs.

First time out...... had some issues...... make some tweaks...... go back and try it again.

Rear tire diameter?

If that 5900rpm is accurate for the finish line, with a 28” tire it shows 13% slip, with a 27” tire it’s 9%.

Neither of those numbers is great for a 10” converter.

I don’t think I’d make any type of combination changes until you have the tune/fuel supply situation really sorted out.

I’d set the camera up so you can record the tach during a few passes.

Some cars/tanks have more control issues than others.
My suggestion was to install a hydramat if running the fuel level up around 1/2 tank doesn’t cure it.

Tires were Mickey ET Streets - 275-60-15, 28" diameter. The datalog shows 5600 to 5900 RPM at the end of the run. I can't get anymore accurate than that since I wasn't watching the tach.

It's just a regular Sniper EFI unit.

I doubt I'm going to be able to get out to the track again this year with the drag radials. I borrowed those tires for that day and I can't ask the guy again. It would be a few weeks, but I could get back out with my street tires, but they don't hook very well. Nitto NT555, 285-40-18.

Motor has 24 degrees initial and 34 total right now.

I'll get another track day put together and be sure to run on at least half a tank this time.

You don't really need to go to the track since you have the data logger in the Sniper. Shouldn't be too hard to jump on the freeway to test the fuel delivery issue. The torque converter issue will be a little more work to sort out. I wouldn't worry about the track times anyway. It isn't a race car so just enjoy it for what it is. Get the street manners sorted out and have fun.

Hey Mark, good to see you last night. Agreed that it would be good to know the fuel pressure. You can see in the video and also in your data log after running through 1st gear that the AFR goes extremely lean "Cycle A/F", and the injector % over 100 that you are probably out of fuel pressure.

Not sure what pump setup you're running but it sounds like an external pump.

I think you're probably a great candidate for the Aeromotive Phantom 340 lph pump - you can either put this in an original tank (dried out, filled with water before drilling), or a brand new tank so long as it has some flat spots on the top. Otherwise on a new tank you can always fabricate it. Make sure you do a bypass regulator after the EFI if it allows and use at least a 3/8" feed and return.

Here's what I'm talking about. RPM on the Y axis, Time on the X with the blue chart and the second chart has the Injector % and A/F.

You can see you're running out of fuel at approx 7 seconds and it does not return to normal until about 12 seconds. This corresponds to the top of 1st gear through when you hit 3rd. When I see the yellow curve get flat at 50%, I'm thinking this is actually fully maxing the injectors on the sniper (orange curve). During this time you get well over 20:1 AFR so the car will miss and run like crap.

Mark, any updates on the car?

Here is a video of my Coronet on the chassis dyno: https://youtu.be/xG3-_YJGdZ8

Hey, it sounds great Andy!

Nothing to report right now. I got a Hyperspark distributor for the car and a few other odds and ends. Rear brakes need attention and the power steering pump sprung a leak at the shaft. Still need to get it weighed too. Work is settling down finally, so I might be able to find time to get back out to the garage soon here.

I'll definitely bump the thread when I got something to report back.

The Hyperspark should be a big step forward. Once I added the Hyperspark to my setup I was able to solve a bunch of tuning issues. I reduced fuel by 30% at freeway cruising speed and about 20% at idle. There is probably more fuel reduction to be had once I spend more time with the timing map.