Re: exhaust
 

That's a good idea - have to look into that, when I run pipe wrap further back.........

Re: exhaust
 

I have this same system with the exception of the switch, mine is just controlled by engine vacuum, in low vacuum situations like accelerating, it opens. It is awesome but people tell me it's loud, I guess too many years in the gun business!

Re: exhaust
 

finally put the new flowmaster original series 40 on my car. there is a difference in sound especially at idle. car sounds much better and throatier. There is more drone during certain rpms but if it gets too bad I can shift up or shift down and get out of the drone zone. wot is very nice. Not as raspy as the corsa but deep and loud especially out the back. I bought the flowmaster ss dual tips and they look ok. they look like the corsa but it is one into two. I wish they were bigger (3 inch each tip,,two per side) but it doesnt look bad.

Unfortunately I saw where a guy in the corvette forum just listed his used corsa system for 900 dollars after I had already bought the mufflers and tips. You never know. I am satisfied with the outcome and the car does sound much more muscular. I didnt spend 900 either. 77 per muffler and 60 per tip. Not bad.

ed ramos #3028

Re: exhaust
 

Hi Dom--
Many years ago when I was testing a Power Effects system (lots of resonance!) and researching our resonance problem in general I actually had an acoustical engineer (ironically from Outboard Marine) instrument my car and evaluate the causes and suggest a solution. He developed graphs showing precisely what RPM and frequencies the two main resonance points were and showed calculations required to make a Helmholz resonator for each of the offending frequencies, which of course is what the stock and Corsa systems use.

They also researched whether it might involve something like you mentioned called "cavity resonance". Meaning it is enhanced or diminished by the cabin itself (or maybe the tire carrier?). I had asked because it seemed less with the top off. Their conclusion was that it was not cavity resonance but solely caused by the exhaust and the natural harmonics of the engine. It seemed to be less with the top off only because it was generally noisier with it off and it was therefore not as noticeable. --Bob

Re: exhaust
 

anybody have headers, no cats and resonators removed??? maybe looking for more noise. Anybody?? I dont care about drone. dont drive it much.

Re: exhaust
 

That's my setup. In place of resonator, I'm using the C6Z06 tips with NPP controls. Also using SW Xpipe fully open. But I have tuned most of the drone out.

Re: exhaust
 

so you control yours with the adjustable c6z06 tips. If its wide open do you find it unbearable or just loud. I want to make a presence. I dont drive it much but when I do I like to know I am driving something special. I drive a Lincoln Town Car for my daily commute and i love that but I want the polar opposite when I get in my z. I want it to really sing at wot. does yours howl with your tips open at wot?? I am considering adding an x pipe and removing my resonators. It sounds good now but want more at wot.

Re: exhaust
 

Mike100 has a greater range of adjustment for the Z NPP tips. Mine is setup where I can turn them open or closed. Normally I drive w them closed but when I drive by a "ricer" I flip a switch in the console and blast both tips. If I am in a competitive situation I flip the switch and I have open exhaust. The tips are on DynoMax UltraFlow w 3" inlet. Frankly it's pretty amazing how the exhaust sounds w no resonator. WOT sounds like an old Quadrajet carb opening up. Not at all raspy like the Corsa. It has a very low deep note sounding a bit like a big block.

Re: exhaust
 

They say the old B&B triflow with x-pipe is the loudest! Or, you could use any system & electric cutouts.

Re: exhaust
 

As I mentioned earlier, I tried this deal where I continued to adjust the exhaust again and again and again, thinking that each incremental adjustment was inexpensive and therefore, it wasn't costing me anything. It never panned out. The final result sounded good but there was too much drone and I couldn't leave the house early in the morning without pissing off the neighbors. I found that you can't "have it all" without biting the bullet and investing in the expensive system...that one that has had countless R&D dollars dumped into it.

Ed, I wish you luck in your search and I hope you find the magic combo that nobody else has ever found.

Re: exhaust
 

I understand and you are right. I had already invested in the mufflers and tips when somebody posted a used corsa for 900 in the corvette forum yesterday. I was already stuck so I installed today. The good thing is that I hardly ever drive my car. Maybe once every two weeks. I cant see my neighbors complaining too much since I am not driving it that much. I am now considering resonator removal with x pipe or electronic cutouts. the cutouts dont seem too bad. I can have the muffler shop weld it in place and I can go home and get the wiring done. Just another possibility. That system will give me the flexibility to be very very loud or as loud as I am now. I am leaning toward these cutouts. we'll see. Thanks for your advice.

ed ramos #3028

Re: exhaust
 

That would be the B&B Fusion catback system,right? ;) Ed isn't looking to "have it all",Chris. He wants a loud exhaust. Drone doesn't seem to bother him,either.
Sounds like an easy man to please.

Re: exhaust
 

Hey Clint,

My comment had to do with the fact that Ed had just installed his new Flowmasters and then only a few hours later, was asking if any other guys were running...?

Re: exhaust
 

If you don't care about drone, then find some PE's, like I got from Jeff. The SPL, in dB's, HAS TO be 3 figure range. Ironically, it doesn't seem very loud at all, listening as my neighbor drove off around the block, after the last bolts were tight. I think Jeff might still have the link posted to the boards here... (in a moment here)
Jeff does still have his video on 'Public' setting here...

I'd have guessed, NOT from experience, that this hardware has more drone than any other aftermarket pipes. And now it seems that Bob WT has qualified that guess.

If mine wasn't running so much cooler, I think I'd have been looking for different hardware.


edit:
And I think mike100 said that drone could probably be reduced with a single outlet open, as opposed to both outlets, each side.

I can't see that reducing drone, but he knows more than me, so I won't argue.

Re: exhaust
 

Um, yeah... THAT is what all the chatter about the NPP's has been about for quite some time now doanchaknow?? Where ya been??:razz:

Re: exhaust
 

Chuck,

I posted this video earlier this year showing the difference between full open and closed for the NPP actuators. Makes a significant difference, maybe 40% less

Here's the video again

http://i187.photobucket.com/albums/x...ps8f8c4c9a.mp4

Re: exhaust
 

Thanks; will give it a listen shortly here...

Does it change INSIDE, and outside sound? Or just outside? Can you get a sound meter on it?

I don't have one; I'm using a camcorder recording, played on a media player with an EQ. Problem with that is, is that the lower band on the EQ is still above the level of the drone - I'm guessing drone (interior resonance) is below 20 hertz, which is normal lower end of human hearing. Normal audiometer won't even do this...

Re: exhaust
 

On mine there is still drone at 1900-2000 rpm if you dwell there, but is quite a bit lower than with all 4 outlets trumpeting. If I had chosen a more restrictive muffler like some typical turbo muffler, I'm sure the result would have been even quieter. As it was, the SW 3" system is crazy loud without any resonator, NPP help, or acoustic gimmicks.

A guy on the other forum showed his 25.5 inch 1/4 wave resonator tubes built into the spare tire area. My guess is that's pretty much the same length as a Corsa resonator. Closing off one outlet of the muffler creates a much shorter acoustic reflection that attenuates other frequencies, but it also forces the gas to flow through the more convoluted part of the muffler lowering the amplitude of the sound somewhat just by not being a straight pipe outlet.

Re: exhaust
 

You got vids posted of your hardware's sound too there Mike?

Re: exhaust
 

It changes both. Not sure what muffs mike100 is using, but the DynoMax are straight thru. Flows 2000SCFM. If there is any resonance it is in the 1200rpm range. Anything above that not an issue. That video was shot w a iPhone.

Re: exhaust
 

Here's probably a better video showing the difference between open and closed actuators and what exhaust sounds like both ways.

http://i187.photobucket.com/albums/x...th_Z06Tips.mp4

Re: exhaust
 

Sounds reasonable from outside... But so does mine.

I don't have cutouts to seal off (or open even, if they would muffle the drone).

I got some more sections wrapped and clamped. (minus the clamp marking tape)

https://lh5.googleusercontent.com/-k...0/IMG_6678.JPG

Those straight sections might take sheet cork, with another layer of wrap, once I put an IR thermometer to them...

Next, leftover wrap onto the tail sections at the muffler, then the spare tire space.

Anyone ever open the PE mufflers?

Re: exhaust
 

thanks for all your comments on exhaust. In the beginning I was trying to be prudent with my exhaust and accepting my flowmaster system as just fine. It is a good exhaust but... if you want more sound changes need to be made. After i changed mufflers I realized that it still was not enough sound and the drone was not that bad. I wanted more.. Now I am all in on maximum noise.

I want my zr1 experience to be wild and out there. I want the look, the performance and the sound. Most guys say.. what is so special about that lt5 motor?? I want them to hear me coming. When I punch it I want them to hear ther revs in full blast mode. Like I have said before, I dont spend alot of time driving around my zr1. When I choose to drive it I want it to fill my senses so it will last me till next time. I really like to drive alone just so I can take it all in and enjoy my drive. this is a very selfish hobby on my part but I dont care. I worked for it and now I want to enjoy it. My wife understands. The first two did not and that is why they are ex's. I thought about the electric cutouts and I decided I just dont want more electronics on my car. It has enough. I will install an x pipe and remove my resonators and hope it has the raucous sound I want.

ed ramos #3028

Re: exhaust
 

Hey Ed,

Does your car have headers? Before I went to the Corsa system, I had straight pipes...the stock '90 manifolds with cats ran into the stock ZR-1 exhaust pipes, with the resonator replaced by an H-pipe and the mufflers replaced by LT1-tip muffler eliminators. The only "mufflers" were the stock cats. I LOVED, absolutely LOVED the sound the car made and I highly recommend it. It sounds like it may be the sort of sound you want. The only reason I changed to my current setup is because I wanted headers and I knew when I did that, I'd have no "mufflers" at all and I'd be pissing off the neighbors and getting tickets. That's why I got the Corsa when I did headers. If you have stock manifolds and want AWESOME, cheap sound and don't care about drone, I highly recommend straight pipes. Jon Porter (Rex Ruby) will tell you the same thing.

Good luck!

Re: exhaust
 

Yes Chris I have headers. The only mufflers I have besides the resonators is the two chamber flowmaster pieces. I expect a good sound without the resonators. I will have them installed next week. A good sound is something that is not very easy to attain. Most exhaust systems dont have that real mean sound because it needs to appeal to the masses. I am sure your exhaust using the cats as the mufflers sounded great but like you said you wanted the benefits of long tube headers for performance gains. I think I will get that sound since headers are loud and no resonators makes the system louder with a higher pitch and some crackling. cant wait.

Re: exhaust
 

I posted the entire process at the other forum, but you saw it here first (2-3 months ago) if you are a member and get the newsletter.

here's the video link where the audible resonance can actually be heard by my camera mic.
http://vid29.photobucket.com/albums/...ps97199d80.mp4

Re: exhaust
 

I x-piped a stock pipe and muffler set and while still quite pleasant compared to some sets out there, it definitely got more grumble. If headers, x-pipe, no cats, and flowmasters aren't loud enough for you, I would recommend seeing a hearing specialist;):-D

Re: exhaust
 

Forgot about this video. Its more along the lines of mike100s video w a better
audio track I think.

http://i187.photobucket.com/albums/x...psp2t5gnbi.mp4

Re: exhaust
 

One person has opened up the tips, that I know of here...

Open:

https://lh4.googleusercontent.com/-q...8/IMG_6681.JPG

and closed:

https://lh4.googleusercontent.com/-_...8/IMG_6680.JPG

Re: exhaust
 

I finally modified my exhaust and now have long tube headers going to a 4 inch y pipe then out to two 2.5 inch duals exiting into 2 2-chamber flowmaster mufflers. I will tell you that removing those flowmaster resonators have given my car a tremendous performance seat of the pants feel. It is felt very hard after 4k rpm's. It almost feels like it wants to break the tires loose. The sound is tremendous!!! All hell is breaking loose back there while in wot. I would love to be able to follow my car as someone floored it. There is serious drone at 2k rpms. It is bad but I dont care. The car makes a statement even at idle. Being a black menacing car and now with that sound and after tearing off my window films so you can see my roll bar inside, it looks like a very serious Corvette not to be messed with. This is just what the Doctor ordered. It will stay this way.

Re: exhaust
 

by the way, those resonators weigh a ton. With the removal of the large 3 chamber mufflers, spare tire carrier and tire and now the super heavy resonators my car feels much lighter. It feels like I can roast the tires any time I want. It is good to lose weight.

Re: exhaust
 

A Y-pipe???

Re: exhaust
 

yes the y pipe goes where the headers would dump into the flowmaster resonators, so in place of the resonators he placed a 4 inch y pipe where the exhaust combines much like an h pipe or an x pipe and then it comes out into 2 2.5 inch pipes. the 4 inch pipe flows like a mother. I just dont sense any restriction on this setup over what I took off. I can tell the car just wants to rev and go effortlessly. It fits very nicely in the middle in the exhaust tunnel perfectly. I would have thought he would have used an x pipe but he said this would flow if not the same better. After the headers, flowmaster had two 2.5 inch pipes going into one opening in the resonator. It is at that point where the 4 inch pipe is welded and it shoots out to 2 2.5 inch duals straight out.

Miami muffler is the biggest custom exhaust business in south florida and probably the whole state of florida. They do semi's, race cars. etc.. anything with exhaust. all types of grade steels and solid aluminum exhaust also. He sells to other exhaust companies since he has a several mandrel pipe benders. He also sells on the internet as vrs exhaust for all types of cars. I am pleasantly surprised at the outcome.

Re: exhaust
 

:blahblah: yeah yeah yeah - mine will be Black too pretty soon (with Black rims on the corners too, which EVERYone knows are faster), except mine will be even ... slower ... with the super heavy-duty 4L60e tranny fluid pump suckin' HP + TQ.

Re: exhaust
 

Ok - this went right over my head before here http://www.theologyweb.com/campus/im...ies/whoosh.gif (as does lots of stuff, but we won't go there too much...

But let's see if I got this right - if I open ONE side of my PE's, and leave closed the OTHER side, then I can reduce resonance???

https://lh4.googleusercontent.com/-q...8/IMG_6681.JPG

THAT I CAN see, and with an X section near the front, I'm not creating an IMbalance in exhaust flow, between L + R banks???????????????????

Re: exhaust
 

At least you wont miss a shift! You must be a heavy duty drag racer if you are installing a auto trans in your z. there was a while there where the big time engineers were putting auto transmissions in race cars. I remember a couple of Jim Halls Chaparrals had them and also zora duntov put a auto trans in the cerv 2 prototype car with 4 wheel drive and two torque converters. I believe that car was at the Corvettes at Carlisle this year. It was donated to a museum by GM but the museum later sold them. Zora was pissed and so was GM.

I am sure your z will run just fine with one. Make sure you have a high stall.

Re: exhaust
 

Why would you not replace the resonator w an X pipe?

Re: exhaust
 

The owner of the exhaust shop said that a y pipe with the dimensions that he had with a 4 inch inlet and out with 2 2.5 inch pipes would be a cleaner install, would allow me to use what pipes I had of my system and going back to the original flowmaster would be a snap if I ever wanted. The way the flowmaster system was designed it had the pipes that came off the header going into the resonator into one pipe. I looked inside the resonator and was surprised how restrictive it looked. It appeared to be two pipes since 2 pipes exited the resonator but it was only 1 pipe going in and it wasnt 4 inches either. I believe it was 2.5 inch inlet. the inside of the resonsator had the left side going off and through the resonsator while the right side went off to another smaller pipe which just bounced the waves around to reduce drone which was the job of the resonator anyway but it lacked any direct outlet into the exiting 2.5 inch pipes.

the proof was in the pudding when I drove the car right after I had driven it with the resonator in place and it was night and day. I still can believe the difference. It works kind of like an x pipe since both pipes exit the header, meet at a 4 inch pipe junction and exits out in 2 2.5 inch pipes. I remember in my drag racing days that one large pipe can out flow two small pipes, for example 1 3 inch pipe outflows 2 2 inch pipes. I knew that the 4 inch junction would not be problem what so ever. It is unconventional but makes sense as far as flow and cost. The cost to modifiy this was much less than an x pipe that would go from the headers to the mufflers and I can return it to the flowmaster force 2 configuration by welding it back together if I wanted to.

The idle noise is noticeable and people will notice. the wot is as loud or louder than a corsa with long tube headers and no cats. also the system weights less since there is less pipe. I think it was clever on the part of the shop owner and he's done many thousands of custom systems in his 30 years of business. I believe I was a little lucky to achieve the sound I was after for such little money and with the flexibility of bringing it back to how it was along with the weight savings.

ed ramos #3028