Do you have data logs from the runs? What do they show? Have you built your own tune?

I asked before, what intake do you have, is it a dual plane ? were you running the Sniper on the old combo ???

So since the chassis dyno there are spots you needed to add 50%+ fuel? Is it dropping fuel pressure?

No i didnt add 50% fuel since the dyno looking into the learn tables there were spots that had already maxed out at 50%, so I added base fuel to those spots. So if holley decides it needs more in that area it can add some, I didnt add the fuel.

to the best of my memory- it is the same combo the was on the dyno. I think it is a dual plane.

Ill have to check and see if it did save the runs. I set it up to record runs over 75% TPS. so we will see if it did capture the runs.

Yes, I have built a few tunes using Holley and other software, high boost turbo imports and classic cars. I have also been coached by well respected tuners how to use Holley EFI software. Without a dyno the next best is the track. However, I was working when my dad said he was taking to the car to the track that night. I didn't get a chance to get my laptop to plug in between runs.

i don't know a great deal about those throttle body aftermarket injection systems, but it seems like (to me anyway) they're too universal. i'm thinking the throttle body has 1 3/4" straight thru bores. if you do the math on that it's nearly identical to a 1050 dominator's venturi area. so if i suggested a 1050 dominator how many of you would scream NO,..? the only saving grace for the throttle body injection is it will supply fuel without engine vacuum. but, what about exposing too much venturi area/ or throttle bore area too soon in the power curve? wouldn't that kill torque? and, a 383 never makes enough torque. if it were me i'd try something like a 4779 holley and go back to the track. if the results are the same then the injection can be ruled out. also, checking fuel supply/pressure to the injection would be a start.

A bigger throttle body than needed with EFI will not hurt power/torque anywhere. Only possible downside is abrupt throttle response.

BUT the TB efi & a dual plane intake almost ALWAYS dont play well together !!!!!!!

I would bet you’d find something in the logs to clue you in. You’d definitely be able to see if the TPS is giving you true WOT. If the runs did not record at 75% throttle then that may be your issue. Not sure why you’d only want it to log above 75% throttle. Does not cost anything to log the entire run and all the parameters.

is this system smart enough to retard timing, throttle, or fuel if it thinks there is a large enough discrepancy? Such as it's so far out of range it puts it in some kind of limp mode?
Doug

my porky charger with my 200lb fat butt in the seat, unknown 383 with racer brown SSH25 cam, [.470 ish lift, ??? duration @.050] dp4b intake with 850 Thermo-Quad, single point factory distributor, 1 3/4 hookers and full 3" exhaust using two chamber flow masters, B&M holeshot converter [2500 stall ?] and 3.91 gears with 12.50 hoosier street tires, ran a pisspoor 13.9 @ 96mph the last time out at the airport drags.
i can't tell you what the temperature or altitude was, as that was not tracked.
playing around with the distributor later, the "butt-o-meter" felt like there was a noticeable improvement, but i have not had the car to the track in years. in fact, i am putting together a 440 to install in the car, in hopes of squeaking into the 11's.
that engine has 11.0 compression, lightly worked RPM heads, and a purple 590 cam installed at 104 degrees. i have an RPM dual plane and an old CH4B, but i haven't decided which i am going to use. still going to use the T-quad and 3.91 gears. thinking of a 3800 converter instead of the holeshot.

as to the coronet, i really think a good tune plus a distributor makeover and possibly advancing the cam, would gain noticeable results.

Try backing down the total ignition advance down to 33 or 34, at sea level, with the cool air you could be way below sea level on the air density making it need less timing for max HP

This was a stock 70 dart 318 2bbl, with headers..
That being said, you said a 520 lift hydraulic. Typically thats a fairly large cam in the upper 250's at 050 . Could it be there is no torque down low?

I'm not disputing that. I think port injection is the way to go.

I was commenting only on the size aspect.

Agreed.

May be some clues if we could see the dyno sheet

sorry about that !!!!!! I should have said,,, AND ,,, not BUT

No, definitely not.

You have the ability to tailor individual timing table cells to whatever end you want but ostensibly you'd need enough data to make those choices as it's not an automatic feature. The nice thing is you don't have to adjust the entire curve, it's only the cells you want to affect. The inputs for the Sniper ECU are the TPS, MAP sensor, CTS and 02. That's why the F.A.S.T. guys can use Holley ECUs because even though there is an interaction between the two systems the timing is controlled separately from the fuel. Sniper will even work with non-digital timing devices but then the timing control feature is lost. To me it doesn't make much sense to run the system that way but some guys do it.

There is no limp mode per se. However, if the tune is pretty well locked in to where the ECU is only making minimal adjustments you can turn off the learn feature so the ECU can't adjust it anymore and save it as a "good tune". If you had an issue where the car wouldn't run right, like say an O2 goes bad real far from home etc. you load the saved good tune with the learn off and drive it like that until you can fix the 02. I had a locked-in tune and drove around with learn off for a while just to see what would happen - nothing happened, it just didn't learn. At some point during this time without me realizing, the 02 took a dump. It just stopped switching, I checked it. Moral of the story, it was actually lucky I was driving around with the learn off because had it been relying on the bad 02 it would have been a problem.

There are other more sophisticated ECUs like the Dominator that allow for more inputs like oil and fuel pressure, knock sensors, stuff for boost, etc. You have to program the sensors to "do something" though, it's not an automatic feature like it would be in OBD2. The Sniper does not have that capability though, it's more of a basic system. That's not to say it wouldn't work for drag racing, the other ECUs are just more programmable. The Holley laptop software is essentially the same for all the ECUs though.

One thing to keep in mind is that unfortunately the Sniper can be affected by RFI and it will really screw with the tune if it's bad enough. The OP should check for RFI in the data logs. You can see evidence of RFI in the trace lines when you right-click and choose "mark data points". It shows up as longer gaps in the traces. In some instances it will even reset the ECU but that does not sound likely in this situation. RFI could be anything - crossed wires, the air cleaner stud etc.

OP should also be sure to go through the static timing check and make sure it's right.

Naturally the data log didn't record. Of course. The dyno shows MPH and HP /TQ no rpms. We just did a quick few pulls to see where the car was at. This was my fault for not getting the tuner to put RPMS on the sheet.

Since I had to Data log I went to the learn tables. I had recently cleared them (imported to base) So there wasn't much learning to read. that showed me that at 5k RPMS and above the car didn't add any fuel. We did some street testing today.

Around 5k it was going lean, like, 14 and 15 to 1. I added a bunch of fuel up there and did several 1st gear pulls. got the afrs to stabilize around 12.5 I added a few degrees of timing and then pulled some, doing seat of the pants tuning and listening to how the engine was running.

After a few hrs the engine is more responsive and pulls much harder at the top end than it did before the work today. One thing that is bugging me is the TPS shows 80% However the throttle is wide open. On my Holley HP ECU the TPS autoset feature works and adjusts this. However with the sniper, there isnt a TPS autoset feature, at least one I can find. Ive got an email to my old tuner who taught me on my HP setup.

I think that's your answer right there. If the ECU thinks the throttle is only open 80% it's obviously not going to add the right amount of fuel for the demand. That could affect the entire sweep. Fix that before you start messing with anything else.

Regarding the data logs - Holley needs to update the way the Sniper software handles them. First, there is no time stamp, only a seemingly random sequential number so you have to figure out which one you want to look at when going through the directory. You can save them with proper file names on the laptop though. Also, if you have logging start automatically at startup or whatever parameter you choose while the car is running that's OK but you have to go into the handheld and stop the log before you shut the car off or it won't save. That's probably why you don't see your runs on the SD card.

Couple basic questions -

Have you checked the static timing against the balancer?

Have you verified that you have 60spi of fuel pressure?

Have you verified you have no intake or exhaust leaks?

Where is the 02 sensor installed?