Become a Fan!
Login
Username:

Password:

Remember Me

Lost Password?

Register now!
Main Menu
Who's Online
171 user(s) are online (148 user(s) are browsing Forums)

more...
Guru Dictionary
Print in friendly format Send this term to a friend  C3
Abbreviation for the 3rd generation of Corvettes built from 1968-1982....
Supporting Vendors
Platinum
Mid America Motorworks
Mid America Motorworks FREE CATALOG


Gold
FIC 770-888-1662


Registered Vendors
Guru Friends
Supporting Banners

TIRERACK.com - Revolutionizing Tire Buying


Shop for Winter Tires Now!




Support This Site
 Register To Post

Schrade Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Who put on new exhaust, and got more drone inside than they were countin' on? Did you do anything (besides changing hardware) about it?

What did you do?

I put a layer of 3/16" styrofoam under the roof panel pad, in the new painted top, and it helped a little, on a media player recording on the PC, with an EQ, then a layer of cork under the rear cargo carpet, and got a little lower reading.

Now I'm running wrap further on the pipes. Had it to the back of the tranny, and gettin' ready to install the X-section, and 2 x 18" length after that, and gonna' run it all the way to the Power Effects mufflers next, to try to take off a little more drone here...

Resized Image

Resized Image
Posted on: 2014/8/21 0:38
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

Matatk Re: Interior resonance / exhaust drone...
Webmaster
SW Chicago Burbs
22792 Posts
Member since:
2008/1/7 0:00



Offline
My magnaflows were pretty bad. I put on an LT4 exhaust and the factory mufflers sound great to me.
Posted on: 2014/8/21 4:02
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc.
1989 Corvette...RIP
Transfer the post to other applications Transfer

-=Jeff=- Re: Interior resonance / exhaust drone...
Master Guru
Bartlett, IL
573 Posts
Member since:
2007/12/20 0:00



Offline
on my 89 I had more exhaust system then I can count..

on my 90 Z I have had 3

-Stock
-Borla Challenge (with stock manifolds, then headers, no cats)
-Corsa (with headers and cats)

I am happy with corsa.. no drone. Borla was not bad either but the resonator was necked down

If I were to change again, I think i would do a stock exhaust for my 90, with a 1996 resonator and some type of muffler


Oh yeah.. I would keep my headers and cats
Posted on: 2014/8/21 12:09
_________________
-=Jeff=-
1990 Corvette ZR-1 #1051
Transfer the post to other applications Transfer

bogus Re: Interior resonance / exhaust drone...
Grand Imperial Pooh-Bah
San Pedro, CA
20856 Posts
Member since:
2005/9/7 0:00



Offline
I am a fan of Corsa.

The problem is that the C4 storage area is one big resonance chamber. It really amplifies the boom.

My ears are very sensitive, and the boom about killed me when I was running muffler eliminators. Never do that again!
Posted on: 2014/8/21 22:15
_________________
The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw

Education is the best tool to overcome irrational fear. - me

Transfer the post to other applications Transfer

j3studio Re: Interior resonance / exhaust drone...
Elite Guru
Western Philadelphia Burbs
4245 Posts
Member since:
2007/9/2 0:00



Offline

The other thing to keep in mind is making sure that the new exhaust isn't even fractionally shorter than the stock exhaust.

Don't ask me how I know ...

Posted on: 2014/8/22 0:04
_________________
Grace, 2003 50th Anniversary Convertible

Louis, 2012 Centennial Edition Coupe
Transfer the post to other applications Transfer

jonszr1 Re: Interior resonance / exhaust drone...
Senior Guru
Lone Pine, CA
453 Posts
Member since:
2010/10/25 22:42



Offline
the best way I found to keep the drone down was to extend the tips of the exhaust 2in past the rear valance. a buddy who has been doing exhaust for 30years got me to try it and the difference is amazing . might not look quite as pretty as flush mounted . but my 23 in system in cruise mode is almost as quiet as stk. my system is headers no cats 3in with x pipe and dyno max 3 in super turbos with dual exits
Posted on: 2014/8/22 15:41
_________________
i have a blast playing with my 4 babies 2 zr1s and 2 mustangs 68 coupe with a jon bennit 408 art car fully rollered c4 with a gearvendors over drive .88 mustang built by my kids with a ported lt5 and a bill boudreau blue printed zf 6 spd. with these 4 ...
Transfer the post to other applications Transfer

jonszr1 Re: Interior resonance / exhaust drone...
Senior Guru
Lone Pine, CA
453 Posts
Member since:
2010/10/25 22:42



Offline
opps should be 3 in not 23 in sorry .finger malfunction
Posted on: 2014/8/22 15:42
_________________
i have a blast playing with my 4 babies 2 zr1s and 2 mustangs 68 coupe with a jon bennit 408 art car fully rollered c4 with a gearvendors over drive .88 mustang built by my kids with a ported lt5 and a bill boudreau blue printed zf 6 spd. with these 4 ...
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
Quote:

Schrade wrote:
Who put on new exhaust, and got more drone inside than they were countin' on? Did you do anything (besides changing hardware) about it?

What did you do?


Hi Schrade,

I swapped out the stock mufflers on my '96 LT1 for a set of Allen Stainless "chambered" muffler eliminators. The exterior sound is incredible but... so, too, was the interior sound!

Researching "Corvette drone" and "Corvette resonance" on the web, I learned that resonance can be cancelled out with either a "resonance canister" attached to each exhaust run (on dual exhausts) or, by attaching a pipe between the two runs to help cancel out the individual resonance. I chose the latter, as the following pics will show. The holes drilled are 1/2" (as one of the web posts had suggested) and the "H" Pipe (as the muffler folks call it) is 1-1/2" diameter.

I still have some drone but now it's about 1,000 RPM higher up the scale and much "softer" than before the mod. For $50.00 at my local muffler shop, I'm very happy with the results!

EDIT - Not sure why the pics didn't show up... just click on "torn" image.

Attach file:



jpg  IMAG0817.jpg (96.51 KB)
21152_53f9120f07228.jpg 640X475 px

jpg  IMAG0818.jpg (109.70 KB)
21152_53f912246611f.jpg 640X475 px

jpg  IMAG0819.jpg (98.39 KB)
21152_53f9123383cda.jpg 640X475 px

jpg  IMAG0820.jpg (89.42 KB)
21152_53f912421654b.jpg 640X475 px
Posted on: 2014/8/23 22:15
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
Here's a link to another thread with pics and more info...

http://forums.corvetteforum.com/c4-ge ... nance-control-w-pics.html
Posted on: 2014/8/23 22:37
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Quote:

DrDyno wrote:
Here's a link to another thread with pics and more info...

http://forums.corvetteforum.com/c4-ge ... nance-control-w-pics.html


That's VERY interesting there DD... VERY INTERESTING.

I just got done wrapping the end section an hour ago (besides the X section, and 2 x 18" sections) - gotta' see what that does, if anything...

Resized Image

As you can see here DD, I DO have an X-section, and I DON'T have a resonator.

What effects might that have, already existing, with the new crossover section added in the rear?

Ronnie, at FlowMaster, gave me a bunch of phone time one day last week, without pimpin' his own FM hardware as my drone / resonance fix. I told him that I think my X section makes it sound like an exhaust leak (I KNOW there is NO LEAK); he said YUP - it can do that, but an H pipe will NOT do the same...
Posted on: 2014/8/24 1:10
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

jonszr1 Re: Interior resonance / exhaust drone...
Senior Guru
Lone Pine, CA
453 Posts
Member since:
2010/10/25 22:42



Offline
the 96 cars had the rear crossover from the factory
Posted on: 2014/8/24 17:58
_________________
i have a blast playing with my 4 babies 2 zr1s and 2 mustangs 68 coupe with a jon bennit 408 art car fully rollered c4 with a gearvendors over drive .88 mustang built by my kids with a ported lt5 and a bill boudreau blue printed zf 6 spd. with these 4 ...
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Quote:

jonszr1 wrote:
the 96 cars had the rear crossover from the factory


Did they do it only for drone? Anyone owned a '96, and also an earlier LT1, and noticed how much less?

Got the sound link there DD - really sounds great. http://forums.corvetteforum.com/1586970204-post6.html

Didn't notice if you had Before N After, with the cross-over section???


ed.:
THis is what I have now: (can't get the link right here - Matt - help? )


http://s446.photobucket.com/user/2man ... c28f4.mp4.html?sort=3&o=2

The vid is the hardware on another guy's Z, same year, same headers, same no mods, exact same everything, almost ID mileage too - 35k, +/- a few.

Like I was saying, outside sounds pretty slick, not even TOO loud, ESPECIALLY considering it's straight pipes.

But inside is not pretty at all...
Posted on: 2014/8/24 18:38
Edited by Schrade on 2014/8/24 18:56:29
Edited by Schrade on 2014/8/24 18:58:22
Edited by Schrade on 2014/8/24 18:58:53
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

hcbph Re: Interior resonance / exhaust drone...
Senior Guru
269 Posts
Member since:
2014/4/4 2:24



Offline
So the other question is with that much wrapping, did it help reduce heat to the floorboards?
Posted on: 2014/8/24 20:11
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
Quote:

jonszr1 wrote:
the 96 cars had the rear crossover from the factory


My '96 LT1 CE had no crossover pipe that I saw.

Exhaust Manifolds -> Cats -> Resonator -> Mufflers.

Unless you mean the central resonator (seen on the right in the pic, below), there was no other connection between the two sides and, I can't find an internal schematic of the resonator.


Attach file:



jpg  IMAG0816.jpg (868.03 KB)
21152_53fa56a0b5dff.jpg 2048X1520 px
Posted on: 2014/8/24 21:13
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Quote:

hcbph wrote:
So the other question is with that much wrapping, did it help reduce heat to the floorboards?


Never noticed heat there hc, although I never put my hand on the rear cargo floor to see. Or the center console, on the tunnel...

But heat IS a big deal, because my motor is running MUCH cooler now. Marc H chip, set for on @ 205, has NOT come on once this summer. (I haven't done stop n go with A/C tho').
Posted on: 2014/8/25 1:13
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

pianoguy Re: Interior resonance / exhaust drone...
Guru Emeritus
Apple Valley, MN
14762 Posts
Member since:
2007/12/29 0:00



Offline
The factory exhaust on my '96 has a little H-pipe just ahead of where the support bolts up behind the resonator:

Resized Image
Posted on: 2014/8/25 1:34
_________________
1996 LT4

�Before you criticize someone, you should walk a mile in their shoes. That way when you criticize them, you are a mile away from them and you have their shoes.�- Jack Handey
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
[quote]
pianoguy wrote:
The factory exhaust on my '96 has a little H-pipe just ahead of where the support bolts up behind the resonator:


Not my LT1... click on my pic, above, (Post #14) for a full sized view.
Posted on: 2014/8/25 3:44
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Maybe it's an LT4 thing?
Posted on: 2014/8/25 5:10
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

Matatk Re: Interior resonance / exhaust drone...
Webmaster
SW Chicago Burbs
22792 Posts
Member since:
2008/1/7 0:00



Offline
As far as I know it's an LT4 thing, my exhaust is from a 96 LT4 and has it.
Posted on: 2014/8/25 11:44
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc.
1989 Corvette...RIP
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
Quote:

Matatk wrote:
As far as I know it's an LT4 thing, my exhaust is from a 96 LT4 and has it.


You LT4 Guys get all the good stuff!
Posted on: 2014/8/25 12:28
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

Ultraman Re: Interior resonance / exhaust drone...
2015 Memorial Day Car Show Winner!
Huskerland
14706 Posts
Member since:
2009/9/12 19:16



Offline
When I had my 90 L98 I put headers on it with 3" cats hooked to the collecters and then down to 2.5" back into an X pipe and on out to Sound Master mufflers from NAPA....not very sexy on the mufflers but it sounded good and had no drone at any rpm......and only 96 bucks each for the sound masters......of course LT1's are a different cat altogether......
Posted on: 2014/8/25 12:39
_________________
2010 Grand Sport Coupe Gone but not forgotten...

Vote DeSantis in 2024.... Make the IRS go away...
Transfer the post to other applications Transfer

BillH Re: Interior resonance / exhaust drone...
The Stig Moderator
Reno
22702 Posts
Member since:
2007/12/25 0:00



Offline
No drone.............no mufflers.

Attach file:



jpg  881_4a93f8847570e.jpg (571.22 KB)
881_53fb464b374e0.jpg 1408X1056 px
Posted on: 2014/8/25 14:21
_________________
Every man dies but not every man lives.
Transfer the post to other applications Transfer

DrDyno Re: Interior resonance / exhaust drone...
Guru Newb
St. Petersburg, FL
45 Posts
Member since:
2013/12/21 1:05



Offline
Quote:

BillH wrote:
No drone.............no mufflers.


WHAD'YA SAY???
Posted on: 2014/8/25 15:12
_________________
John G.
St. Petersburg, FL

"If it seems like you're in control... you're not going fast enough!" Mario Andretti
Transfer the post to other applications Transfer

BillH Re: Interior resonance / exhaust drone...
The Stig Moderator
Reno
22702 Posts
Member since:
2007/12/25 0:00



Offline
Quote:

DrDyno wrote:
Quote:

BillH wrote:
No drone.............no mufflers.


WHAD'YA SAY???


Ha, it's an interesting system (chambered cat back).

Under 2,800 it's quiet enough that neighbors/police officers don't even glance at the car when I go by.

When it hits 2,900, it's like a valve opened, sound level doubles. And sounds really good.

At 70mph in 5th or 6th, it's not much louder that stock, hardly noticeable.

And no drone.
Posted on: 2014/8/25 15:29
_________________
Every man dies but not every man lives.
Transfer the post to other applications Transfer

jonszr1 Re: Interior resonance / exhaust drone...
Senior Guru
Lone Pine, CA
453 Posts
Member since:
2010/10/25 22:42



Offline
on both my zr1s I extended the tips 2 in past the valance ,and that was the single best thing I did to quiet down the exhaust. I also think the super turbo mufflers work great with the 3 in exhaust to keep things in a decent level without costing any power
Posted on: 2014/8/25 17:35
_________________
i have a blast playing with my 4 babies 2 zr1s and 2 mustangs 68 coupe with a jon bennit 408 art car fully rollered c4 with a gearvendors over drive .88 mustang built by my kids with a ported lt5 and a bill boudreau blue printed zf 6 spd. with these 4 ...
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Quote:

pianoguy wrote:
The factory exhaust on my '96 has a little H-pipe just ahead of where the support bolts up behind the resonator:

Resized Image


I like those tips.

If I could put them on the PE muffler ends, I wouldn't think twice...

Resized Image
Posted on: 2014/8/25 21:03
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Drone is almost gone. Wrap did a great job, much more so than I thought it would...

Resized Image

I don't know if a cross pipe behind the diff, or Peel N Seal can improve what I got now.
Posted on: 2014/8/28 5:12
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

hcbph Re: Interior resonance / exhaust drone...
Senior Guru
269 Posts
Member since:
2014/4/4 2:24



Offline
One thing I don't know if ever has been addressed. Many years back wrapping the exhaust with asbestos tape to cut down on heat also seemed to cause the exhaust system to rust and wear out quicker than if nothing was used.
Admittedly this was simple steel exhaust pipe but wondering if the same issue persists?
Posted on: 2014/8/28 12:33
Transfer the post to other applications Transfer

Schrade Re: Interior resonance / exhaust drone...
Elite Guru
eastern NC / e-i-e-i-o
1909 Posts
Member since:
2008/8/15 2:01



Offline
Quote:

hcbph wrote:
One thing I don't know if ever has been addressed. Many years back wrapping the exhaust with asbestos tape to cut down on heat also seemed to cause the exhaust system to rust and wear out quicker than if nothing was used.
Admittedly this was simple steel exhaust pipe but wondering if the same issue persists?


One of the techs at FlowMaster that I talked to said that wrap is bad because of heat buildup / cooldown cycling. Said it can cause them to crack after time.

Also said moisture / rust was NOT an issue.

If he WAS right, I can't imagine that OBX - being pretty heavy-duty Stainless hardware, is susceptible, as is lower $ stuff.

Don't know either way, for certain here.........
Posted on: 2014/8/29 1:15
_________________
LT5, Marc Haibeck ECM module, AUTOMATIC!!!

Resized Image
Transfer the post to other applications Transfer

bogus Re: Interior resonance / exhaust drone...
Grand Imperial Pooh-Bah
San Pedro, CA
20856 Posts
Member since:
2005/9/7 0:00



Offline
I cut to the chase... I went with Corsa.

This was in 2002!

I have been impressed and satisfied with Corsa. They have a good warrantee and they back it up. I had the resonator section rot out (known problem with the first version) and they sent me new forward pipes and resonator to fix it, because I had welded it up.

The Corsa system works. It does reduce drone... at 80mph in 6th, the engine is no longer the noise maker; the tires are. And we have lots of loud concrete roads around here! Get on asphalt and it's totally quiet.

Expensive? YES. Does it work? DAMNED STRAIGHT!
Posted on: 2014/8/30 14:26
_________________
The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw

Education is the best tool to overcome irrational fear. - me

Transfer the post to other applications Transfer

GRIS Re: Interior resonance / exhaust drone...
Elite Guru
OKLAHOMA
7582 Posts
Member since:
2013/1/27 22:26



Offline
Quote:

bogus wrote:
I cut to the chase... I went with Corsa.

This was in 2002!

I have been impressed and satisfied with Corsa. They have a good warrantee and they back it up. I had the resonator section rot out (known problem with the first version) and they sent me new forward pipes and resonator to fix it, because I had welded it up.

The Corsa system works. It does reduce drone... at 80mph in 6th, the engine is no longer the noise maker; the tires are. And we have lots of loud concrete roads around here! Get on asphalt and it's totally quiet.

Expensive? YES. Does it work? DAMNED STRAIGHT!


DARLING WIFE WAS COMPLAINING ABOUT THE DRONE IN THE '96. TOLD HER I COULD MAKE IT GO AWAY FOR ABOUT $1500. SHE DECLARED THAT IT WAS NOT SO BAD, AFTER ALL. THE BUMBLEBEE STILL DRONES :-)
Posted on: 2014/8/30 23:11
_________________
REMEMBER THE GOOD OLD DAYS WHEN NOUNS HAD GENDER AND PEOPLE HAD SEX?

---"yellow is for folks who think a bright red Corvette is too restrained."
Transfer the post to other applications Transfer

You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.

[Advanced Search]


CorvetteForum.guru is independently owned and operated. This site is not associated with or financially supported by General Motors.

Copyright 2008-2015 CorvetteForum.guru

CorvetteForum.guru is a Guru Garage Site (Coming Soon!)

If you have any questions about our site, please contact us at Andy@corvetteforum.guru.

Powered by XOOPS 2.56 Copyright 2001-2014 www.xoops.org

Hosted by GoDaddy.com.