FE Power Forums

FE Power Forums => FE Technical Forum => Topic started by: RangerRat on May 22, 2019, 08:45:08 PM

Title: Different Sound After Intake Change
Post by: RangerRat on May 22, 2019, 08:45:08 PM

Anyone else noticed that their exhaust sounds a lot different after swapping to an Edelbrock RPM intake? I previously had a cast iron 4bbl intake.

Title: Re: Different Sound After Intake Change
Post by: Nightmist66 on May 22, 2019, 10:28:15 PM

Only obvious things that come to mind are vacuum leak and ignition timing. Retarded timing will give a slightly lopier idle and advance will slightly smooth it. Lash setting the same?

Title: Re: Different Sound After Intake Change
Post by: WerbyFord on May 22, 2019, 11:00:43 PM

IIRC the RPM does not have a heat crossover?

Seems like I notice a little difference in sound when blocking the crossover, it acts like a mini-H-pipe.

I could also see where the intake might "howl" differently due to runner or plenum shape & size but never really noticed it.

Title: Re: Different Sound After Intake Change
Post by: RangerRat on May 23, 2019, 06:54:09 AM

It's not the timing. That was my first thought too. I was wondering if no heat crossover could be it. The motor runs great. And definately pulls higher up the rpm range than before. But as soon as I fired it up I noticed it really changed the sound of the exhaust. Kind of an off idle throbbing sound. Like a blurb, lol. Almost makes me think of the way an AMC V8 sounds. I really liked the way it sounded before. Full throttle still sounds the same I think. Kinda disappointed. But as long as it runs strong

Title: Re: Different Sound After Intake Change
Post by: fryedaddy on May 23, 2019, 09:27:02 AM

i noticed a different exhaust note changing carbs.650 to a 850.i would guess any time you change the intake or carb  it changes the amount of air going in it could change the exhaust note to some degree.

Title: Re: Different Sound After Intake Change
Post by: RangerRat on May 23, 2019, 12:39:32 PM

I guess so. It was unexpected though. Another thing I've noticed. I have 40 Series Delta Flows on it. And on my CJ-7 with an AMC 360. Now the CJ is kinda loud I guess. But, whoa, that 390 is unbelievably louder than the AMC motor. But the 390 probably has twice the horsepower too lol

Title: Re: Different Sound After Intake Change
Post by: wayne on May 23, 2019, 02:21:57 PM

Yes a intake will change sound some a cast iron duel plane makes a cam sound bigger at idle i went from a stock cj.To a streetmaster it sounded different at idle.Same on a 351c from stock to a torker

Title: Re: Different Sound After Intake Change
Post by: RangerRat on May 23, 2019, 03:29:04 PM

Hmmm. Well it definately changed mine. Can't say I like it as well. But the motor definately breathes better. I also haven't noticed any spark knock since changing the intake either. It was a constant battle before.