Holley/Demon Carb stumble

I did a bunch of head and dyno work for a somewhat local builder here several years ago.
I sold him quite a few cams as well.
Mostly they were Dirt modified Chevies.
Fairly high compression, roller cams, high rpm.
He had a lot of customers that would come up with these goofy carbs from all kinds of various no name carb wizards.
I never understood it really.
We had a couple of shop carbs that just ran well. Not necessarily the most power, but just good running with pretty flat fuel curves.
We’d start out with one of those, get a baseline...... then put on the owners carb......... which 90% of the time didn’t even run good, much less make any power.
Owners just didn’t want to accept it was kinda junk, so you’d waste an afternoon getting it as good as you could.
Then of course, they’d get there asses handed to them on the track and whine about it.

At the time, the best carbs I’d tested on that type of build were done by Baker carbs.
They had it figured out for that combo.

One of the motors comes to be tested, and they borrowed a Baker from another racer, and brought it along with some other swap meet type thing.
Well, it was a pretty nice build, and with the Baker carb it was as good as we’d tested.
The swap meet carb, not so much.

They take the motor, and there is talk about buying a new carb.

After two nights racing, and getting whooped...... the new carb is ordered.
A Baker?? Nooooooooo.
A new Race Demon, right from BG.

They take it to the races, engine builder is there with them, he’s pretty sharp.
Motor will hardly even run.
They can hardly even get the car around the track in practice.
Carb comes off, old carb back on....... race for the night.
Calls to BG on Monday for some tuning advice........ parts are swapped..... back to the races the next weekend.
Seems to run “better”, but still def can’t race with it....... old carb goes back on.

They give up on the Demon for a couple weeks....... but then decide to pull the motor, and bring it back up to the dyno along with the new Demon to see if it can be tuned up.

Well, that thing was totally out to lunch.
I took it all apart and didn’t find any actual manufacturing “defects”, but the overall tune just didn’t work well at all.
I messed with everything. Air bleeds, emulsion, jetting...... and the fuel curve was exactly the opposite of what you wanted.
It started out too lean, and progressively richened up with rpm.
I could change the rate at which it got rich, and I could change how rich/lean it was overall........ but I never got anything close to a flat curve, much less one that slightly leaned with rpm.
In the end, I felt like the booster response curve and the booster feed hole sizing was just wrong for the motor.
I didn’t have a Baker carb to compare with, but it was down about 8-10hp from one of my dyno mule carbs.

I did have it to where it at least ran well enough to use.
They ran it in the car for a few weeks...... wasn’t really any better than the old carb.

He had talked to them(BG) after the dyno session..... they said it was the wrong carb.
He had to remind them it was what they sold him when he called to order it.

He ended up buying a new Baker....... which worked just fine right ootb.