Headers = resonance? - ZR-1 Net Registry Forums

1990 quasar blue · 01-07-2008

Title says it all. I had a Flowmaster cat-back and stock manifolds. Sounded great outside and quiet inside. Added headers and random tech cats, now it sounds incredible outside but I picked up a fair amount of resonance around 1800 rpm's. From everything that I ever read, I didn't think headers would make it resonate. Guess I was wrong. Corsa anyone?

GOLDCYLON · 01-07-2008

Quote:

Originally Posted by 1990 quasar blue

Title says it all. I had a Flowmaster cat-back and stock manifolds. Sounded great outside and quiet inside. Added headers and random tech cats, now it sounds incredible outside but I picked up a fair amount of resonance around 1800 rpm's. From everything that I ever read, I didn't think headers would make it resonate. Guess I was wrong. Corsa anyone?

What headers are you running?

1990 quasar blue · 01-07-2008

SSW.

GOLDCYLON · 01-07-2008

I wonder if a set of corsas would mellow them out some? Your not running a resonator correct?

1990 quasar blue · 01-07-2008

The Flowmaster has a resonator built in. When the exhaust shop welded everything up they had to shorten the cats as well as the inlet pipes to the mufflers. I know I'm grasping at straws there but, the whole thing seems strange.

GOLDCYLON · 01-07-2008

Quote:

Originally Posted by 1990 quasar blue

The Flowmaster has a resonator built in. When the exhaust shop welded everything up they had to shorten the cats as well as the inlet pipes to the mufflers. I know I'm grasping at straws there but, the whole thing seems strange.

Hmm dont know... but at some point im about to do the same thing with a set of Jeals and a corsa system. I would hope to not pick up any resonance either.

bradslt5 · 01-08-2008

i ahd a set of flowmasters on my black car with headers and no cats . once i adjusted the hangers (those spring things that hold up the exhaust ). mine were too loose and the muffler tips so that there was a min. of 12mm below rear opening the inside of the car got alot quieter. how i found out was the passenger muffler moved and got real close to the opening which made it very loud inside the car.hope this helps

flyin ryan · 01-08-2008

Quote:

Originally Posted by 1990 quasar blue

I know I'm grasping at straws there but, the whole thing seems strange.

once you have it, can be a real PIA to get rid of, if you can do anything about it at all. not what you want to hear, i know. i've built a bunch of different headers & to a lesser extent complete system's with a fabricator friend of mine for engines i've built. to say your scenario seems strange, that's just the beginning of the whole exhaust world. IMO the most mis-understood piece of the higher performance food chain. very few, if any absolutes. it's kinda a moving target to a degree. in closing i will say the vast majority of individuals still go too big & that for sure will not help resonance, again IMO.

tccrab · 01-08-2008

I bought a set of Flowmaster mufflers and installed them in place of the stock '90 mufflers.
Resonated like a bad dog at highway speeds in 6th gear.

The drone would drive you nuts.
It also burbled and popped on deceleration (which I didn't mind).
I put a complete Flowmaster setup on and the resonance and pop are pretty much gone.
Next step will be x-pipe in place of the resonator later when the weather warms a little.
Don't want to argue with the Smog Nazi's so no plans for headers or removing/replacing the cats in my near future.

flyin ryan · 01-08-2008

Quote:

Originally Posted by tccrab

It also burbled and popped on deceleration (which I didn't mind).
I put a complete Flowmaster setup on and the resonance and pop are pretty much gone.

usually a chip done properly for headers, exhaust or both will clear that up a ton. you got chip?

01-07-2008	#1
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Headers = resonance? Title says it all. I had a Flowmaster cat-back and stock manifolds. Sounded great outside and quiet inside. Added headers and random tech cats, now it sounds incredible outside but I picked up a fair amount of resonance around 1800 rpm's. From everything that I ever read, I didn't think headers would make it resonate. Guess I was wrong. Corsa anyone? __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19

01-07-2008	#3
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Re: Headers = resonance? SSW. __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19

01-07-2008	#4
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Headers = resonance? I wonder if a set of corsas would mellow them out some? Your not running a resonator correct? __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

01-07-2008	#5
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Re: Headers = resonance? The Flowmaster has a resonator built in. When the exhaust shop welded everything up they had to shorten the cats as well as the inlet pipes to the mufflers. I know I'm grasping at straws there but, the whole thing seems strange. __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19

01-08-2008	#7
bradslt5 Join Date: Oct 2007 Location: lone pine and mammoth lakes ca. Posts: 544	Re: Headers = resonance? i ahd a set of flowmasters on my black car with headers and no cats . once i adjusted the hangers (those spring things that hold up the exhaust ). mine were too loose and the muffler tips so that there was a min. of 12mm below rear opening the inside of the car got alot quieter. how i found out was the passenger muffler moved and got real close to the opening which made it very loud inside the car.hope this helps

01-08-2008	#9
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,655	Re: Headers = resonance? I bought a set of Flowmaster mufflers and installed them in place of the stock '90 mufflers. Resonated like a bad dog at highway speeds in 6th gear. The drone would drive you nuts. It also burbled and popped on deceleration (which I didn't mind). I put a complete Flowmaster setup on and the resonance and pop are pretty much gone. Next step will be x-pipe in place of the resonator later when the weather warms a little. Don't want to argue with the Smog Nazi's so no plans for headers or removing/replacing the cats in my near future. __________________ TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B]