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The Official Exhaust Resonance Post!

 
Old 10-14-2007, 07:02 PM
  #41  
jaa1992
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Stock LT1 exhaust, remove resonator, replace with dual pipes.

THis is the way my exhaust is right now and I have no resonance.
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Old 02-06-2008, 05:56 PM
  #42  
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After reading this thread today, i tried the steel wool trick. Yes, without a doubt, it reduced the resonance...... but all it did was make my Magnaflows sound just like the old stock exhaust. So, basically, I had the stock sound again, except with more resonance than stock.

If I wanted the stock exhaust sound, then i would still have kept my stock exhaust, and i wouldn't have any of the resonance.

Conclusion, I'll be keeping my Magnaflows au natural.
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Old 02-06-2008, 06:14 PM
  #43  
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Originally Posted by 300HPisnotenough View Post
After reading this thread today, i tried the steel wool trick. Yes, without a doubt, it reduced the resonance...... but all it did was make my Magnaflows sound just like the old stock exhaust. So, basically, I had the stock sound again, except with more resonance than stock.

If I wanted the stock exhaust sound, then i would still have kept my stock exhaust, and i wouldn't have any of the resonance.

Conclusion, I'll be keeping my Magnaflows au natural.
I dont mind the resonance my Flowmasters have. But I have 3.75 gears so I am not staying in the rpm range where resonance is an issue. I wouldn't mind having the stock cat back in.
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Old 02-06-2008, 10:24 PM
  #44  
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Default My vote is for Force II

I put the Flowmaster Force II for the LT1 on my 90 and it got rid of the resonance I had with the stock system.
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Old 02-06-2008, 10:49 PM
  #45  
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Originally Posted by Strick View Post
It seems that a louder exhaust system will produce resonance. If resonance is a problem you can't live with, stay with the OEM exhaust. It's a good exhaust with good flow, at least for the 92-96. It also seems that you should make sure your tips are at least 1" past the rear of the car. Also, make sure the entire system is not touching any part of the Vette except the hangers. Another thing that seems to produce resonance is the diameter of the exhaust system. The larger the diameter the more resonance is produced. Why? I don't have a clue except for slower flow. Some claim an "X" pipe will reduce resonance, some (like B&B folks) say removing the resonator and replacing it with an X pipe will produce about 30% more resonance and sound. I don't think anyone has the real answer to a loud exhaust with no resonance. Please prove me wrong.
I am running EM long tubes, O/R X-pipe and B&B catback. Everything is 3" and my car is cammed along with alot of other mods.

The resonator does not resonate as much as the x-pipe but the x-pipe makes it sound so much better and a good bit louder overall. For me, its worth the little extra resonance to have that much better sound and much more volume. I love the way my car sounds! I get compliments all the time on it. I considered going Corsa for the resonance reason but personally, i havent heard a Corsa that has sounded anywhere close to my B&B. Price is not an issue as both exhaust systems are in the same price range but the Corsa is on the quiet side. The B&B just has that deep aggressive and impressive tone to it along with being a good bit louder. Both are very nice exhausts but i like to hear my car and i like my car to be heard!
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Old 02-06-2008, 11:02 PM
  #46  
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Originally Posted by jakers View Post
Would like to hear a bit more on x-pipe experiences! The effects on sound and resonance!?
Same here. Mine is 95 stock coupe, mufflers deleted. What happens if I replace the resonator with straight or X pipes?

Leave the resonator?
Go with X pipe? and why?
Just straight pipes?

Remember I am asking specifically about a 95 LT1 stock coupe with factory true dual pipes to start with.
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Old 02-06-2008, 11:38 PM
  #47  
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On an L98, leave all 3 cats in -- if you don't require duals. Behind that, you can have elims if you want.

I've had stock, elims, sidepipes, and a front "Y" w & w/o front cats. The only thing that created a lot of resonance was removing the front cats.

Also, when I put the cats back in, the shop put one further back than the other. I gotta think that changes harmonics a little (between sides) and that might help lower the combined effect of having two pipes producing the exact same "note".

I like the idea of using cats vs resonators or mufflers. They quiet and they clean -- a bonus for all.

BTW: All my cats are hi-flo, hi-performance cats my Magnaflow. So, they don't have to be hp eaters.

Last edited by GREGGPENN; 02-06-2008 at 11:48 PM.
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Old 02-07-2008, 11:21 AM
  #48  
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This thread got me thinking again. Yeah I know, it is dangerous!

http://forums.corvetteforum.com/show....php?t=1932930

I was recently e-mailed a photo of a stock LT-1 exhaust out of the car. One thing that is noticably different between the stock system and the aftermarket systems is the cross bracing. Take a look at the factory system and you will see. The factory exhaust has several cross braces that most of the aftermarket systems lack.

I am no physicist! But, I am thinking that some of the resonance comes from some type of tuning fork effect created when the exhaust gases are forced through the system.

I am wondering if you have a good welder brace these systems up, it may help? I am planning to do this myself. I will let you know.

Anyone else try this?
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Old 02-07-2008, 12:00 PM
  #49  
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i have after alot of trial and error found the answer to your guys problem. i have posted this on the zr1 registry. my friends own spintec. a aftermarket exhaust co in so cal. first off if your car is not producing 550 hp at the flywheel or 450rwhp on a dyno your car will run slower at the strip. this was proved to me on my own car. actually the 23/4 in piping on the zr1s and 92-96 lt1s is perfect size wise . my zr1 makes 426.7rwhp . heres what we ended up with after trying 4 different set-ups.we used the stk pipe23/4 took out the factory resonator and put in a Dyno max wlk17554 its an xpipe in a muffler that has roving fiberglass in it . then we used 2 3in flowmaster 530602 mufflers that we attached the stk zr1 outlets to to keep it stealthy. other notes . use hard nylon washers in between the hangermounts . keep at least 12mm from the rear end housing and back facia. also extend the tips 2in past the facia. this combo on my car made a 2tenths difference and 1.6mph improvement over even open headers , which was a mind blower . this may be too quiet for some. but what i like most is that those that want to race me think that the car isnt fast as its too quiet . till they find the only thing they see is my bumper. the car has run a best of 11.88 @121.25 @ Famoso in bakersfield . what the guys at spin tec think is that if you want to just remove the resonance from the interior try putting in the dyno max xpipe muffler . for those that have a sumit cat. its on page 63 and sells for 132.95. hope this helps you guys .and saves some cash too .i spent 3k in exhaust changes to find this
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Old 02-07-2008, 01:12 PM
  #50  
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Originally Posted by terryszr1 View Post
i have after alot of trial and error found the answer to your guys problem. i have posted this on the zr1 registry. my friends own spintec. a aftermarket exhaust co in so cal. first off if your car is not producing 550 hp at the flywheel or 450rwhp on a dyno your car will run slower at the strip. this was proved to me on my own car. actually the 23/4 in piping on the zr1s and 92-96 lt1s is perfect size wise . my zr1 makes 426.7rwhp . heres what we ended up with after trying 4 different set-ups.we used the stk pipe23/4 took out the factory resonator and put in a Dyno max wlk17554 its an xpipe in a muffler that has roving fiberglass in it . then we used 2 3in flowmaster 530602 mufflers that we attached the stk zr1 outlets to to keep it stealthy. other notes . use hard nylon washers in between the hangermounts . keep at least 12mm from the rear end housing and back facia. also extend the tips 2in past the facia. this combo on my car made a 2tenths difference and 1.6mph improvement over even open headers , which was a mind blower . this may be too quiet for some. but what i like most is that those that want to race me think that the car isnt fast as its too quiet . till they find the only thing they see is my bumper. the car has run a best of 11.88 @121.25 @ Famoso in bakersfield . what the guys at spin tec think is that if you want to just remove the resonance from the interior try putting in the dyno max xpipe muffler . for those that have a sumit cat. its on page 63 and sells for 132.95. hope this helps you guys .and saves some cash too .i spent 3k in exhaust changes to find this
http://store.summitracing.com/egnsea...8+115&x=27&y=7
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Old 02-07-2008, 02:33 PM
  #51  
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Have a 87' convert. with lots of top end improvements. Went with Melrose long tubes with no AIR, no EGR, no CATs, and Eliminated the airpump. Have 3 " with a H pipe all the way until the system necked down to 21/2" to take any good Muffler. Reused my Ansa mufflers and had resonance at 1200-1600RPM. Had the Exhaust shop set me up with some eliminators and some megaphone tips and made sure they where past the bumper. Idles nice sounds great you can carry on a conversation while crusing and hear the radio the Resonance is
but it is a little loud when you punch it but if you just cruise by it is nice. Just can't beat the sound of that SBC .
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Old 02-07-2008, 04:00 PM
  #52  
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If considering mufflers containing an X-pipe and if stainless is preferred
over aluminized steel, then Magnaflow offers three or more choices to
look at.
MagnaFlow Performance Mufflers
Stainless Steel (Polished Finish)
Oval with Built-in X-Pipe

#14385 4" x 9" x 14" Body, 2.25" Dual In/Out

#14386 4" x 9" x 14" Body, 2.50" Dual In/Out

#14468 5" x 8" x 18" Body, 2.50" Dual In/Out


I don't know whether Magnaflow uses the same design for the X-pipe in
their muffler as they do for their free-standing X-pipe shown below. If
they do, then my vote is that Magnaflow's stamped center section is
superior to other designs that insert one piece of perforated tubing into
another.

versus

.
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Old 02-07-2008, 05:17 PM
  #53  
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wow . magna flow makes an x pipe muffler what are ther part numbers .it would be fun to get one and cut it apart and see. on the dyno max the reason as explained to me it works so well in my car is the fact that the pipe inside is 3in which cancells out the turbulance that might happen due to the perferations . the thing i like about my system is the fact that my car is .2 faster at the strip verses open headers . the test was done the same day in case anyone wanted to know .
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Old 02-07-2008, 05:41 PM
  #54  
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See the previous post for part numbers.

The catch is that, as far as I can see, the maximum dia appears to be
2.50" while the Dynomax #17554 that you mentioned is 3.00" dia.

I do not think it would be necessary to section the Magnaflow. A visual
through the passageways would probably reveal which style of X-pipe
has been used.

.
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Old 02-07-2008, 10:42 PM
  #55  
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sorry , the sectioning thing my poor attempt a dry humor
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Old 02-08-2008, 03:42 AM
  #56  
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Default Chambered Exhaust

Originally Posted by ps374 View Post
Why couldnt Chevrolet just have come up with something like they did in 1962 called Off road exhaust system, and just give C4 and C5 owners a specific sound which would stop all this tension of trying to get their exhaust system right.The closest I ever heard a car have that specific old Corvette sound was my sons 85 Z28 with headers and one flowmaster muffler which sat in front of the rear axle, And there was NO resonance at all. My 84 has flowmaster 40s with gutted cat and does not sound as good as his car and the resonance is very loud.His did have a 305 if that makes any difference?
When I bought my 94 coupe, it came with Flowmasters. The resonance was so bad, I referred to them as "Dronemasters" Crusing at 70 to 80 MPH in 6th gear on the freeway, would really cook your brain on a long trip. My solution was to buy a chambered exhaust system from Corvette Central, and I'm very pleased with this system. The sound is similar to the side exhaust systems on the C2's. I should have done it a long time ago. Nice idle sound, great going through the gears..very mellow at cruising, cool burble when backing off...and NO resonance.


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Old 02-08-2008, 01:10 PM
  #57  
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Great Info. That is exactly what I am looking for my 87 which on the blocks for a make over ! cool



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Old 02-08-2008, 01:26 PM
  #58  
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I have long tube headers with straight pipes back to Magnaflows. I've got more resonance that most people could imagine, until you get in the car
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Old 02-08-2008, 10:39 PM
  #59  
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Originally Posted by Slalom4me View Post
If considering mufflers containing an X-pipe and if stainless is preferred
over aluminized steel, then Magnaflow offers three or more choices to
look at.
MagnaFlow Performance Mufflers
Stainless Steel (Polished Finish)
Oval with Built-in X-Pipe

#14385 4" x 9" x 14" Body, 2.25" Dual In/Out

#14386 4" x 9" x 14" Body, 2.50" Dual In/Out

#14468 5" x 8" x 18" Body, 2.50" Dual In/Out


I don't know whether Magnaflow uses the same design for the X-pipe in
their muffler as they do for their free-standing X-pipe shown below. If
they do, then my vote is that Magnaflow's stamped center section is
superior to other designs that insert one piece of perforated tubing into
another.

versus

.
I just installed the above shown Magnaflow resonator and Magnaflow SS Mufflers. The X Pipe is a X, not a cross over. I call it the Magnaflow Cat-X-Back
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Old 02-09-2008, 11:03 AM
  #60  
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Originally Posted by PLRX View Post
The X Pipe is a X, not a cross over.
I've never thought of 'X-pipe' and 'Cross-over' as being anything
more than different terms used by marketers to differentiate their
version of a generic product from the next guy's. So the meaning
of your remark is unclear for me.

Can you clarify: are the passageways of your Magnaflow resonator
shaped like the stamped, non-muffled Magnaflow part above on the
left or is it like the intersecting perforated tubes of the Dynomax on
the right?

Thinking about this now from the perspective of manufacturing ease,
sound dampening effectiveness and overall size, perforated tubes
make more sense in a muffler/resonator than a stamped section.

.
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