Engine Air suction and stumble on acceleration

Driver460sz

5 Year Member
Jan 14, 2019
145
53
38
New Hampshire
Motor is in, car starts, tune is NOT spot on but it idels nicely, not backfires through 5500. So, obviously the motor is going to suck some air when you hit the gas and the TB opens but DAMN is it loud. Is this typical? Like supercharger and maybe more loud. Also, the motor will stumble for a split second....ever so slightly but it is there. What is the best fix for this? I am using a reducer at the moment from the 90mm TB to the CAI, 4 inch to 3. Just waiting to get what I need to run a 4 inch all the way to the wall (Could be that?). Nothing else seems to be compressing (Line wise) anywhere else. I understand there will be some noise through the CAI versus the standard air system, but this is like Jenna J is sucking on a the intake. I have heard, not yet ready to try, but drilling a 1/8th hole in the TB helps/works, but man..... that hurts to do.

Suggestions!!!

1986 Mustang with a 351w, stroked 427....and please, I don't need the, they don't make a 427 stroker convo thing to come up. Either way, it's not stock.
 
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If the TB doesn’t have a hole in it, then I’d say you are just breaking the suction against the blade when you crack it. If it was my car that’s probably the way I’d be leaning right now is to drill a hole.