Factory Exhaust Resonator Removal and Free Flowing Alternatives

[mike100]

One thing I am sure of that if you are worried about losing the resonator due to extra dB's out, you will be horrified with many of the aftermarket systems (including the Corsas- they are just plain loud when you stand on it).
I like Sammy's idea with the 3" turbo mufflers, but I haven't been able to find any dual outlet kind that are smaller in overall length. For now (since i don't have headers) the stock mufflers make about the same power as any other pipe. My restriction is the factory manifold so I will run it the way I have it now.

At some point, I may sell my Corsa cheap (the resonator was welded previously) and the pass side flange is custom so welding may be required to install that.

[sammy]

part number WLK17674 is what i used . the case length is 13in and total length is 17.in. price is 67.45 ea.. i just love this set up . i dropped 2.5 tenths and gained 1.7 miles an hr at the drag strip over the corsa set up . and to me it was quieter also ,but had a nice sound when you put your foot to the floor .JMHO

[GOLDCYLON]

Originally Posted by mike100

many of the aftermarket systems (including the Corsas- they are just plain loud when you stand on it).

Lol thats kind of the point mild at idle and cruise and wild at open throttle otherwise whats the point of having an aftermarket system?

[SteelBlueZR1]

I am going to speak to Dynomax and Magnaflow, both who manufacture a resonator with a built in exhaust crossover to see if there is a size that has the right dimensions and inlet center measurements to replace the stock restrictive resonators. If I find a 2.5" or 3" resonator that works I will share this with anyone else who wants to just replace their oem highly restrictive resonator, but not risk drone and noise of an X pipe.
*DynoMax® Ultra Flo™ X performance stainless steel mufflers feature 100-percent welded construction for lifelong durability. Ultra Flo™ X incorporates a 3-in.diameter X-pipe balance tube inside the muffler - promoting exhaust scavenging and equalizes flow
-or-
Magnaflow Tru X Perforated Core- PART#: 12599 with 5.75" inlet center spacing
Inlet/Outlet Size: 3in./3in.
Body Shape: 5in.x11in. Oval
Core Size: Dual 3in.
Body Length: 22in.

Any input or ideas?

[mike100]

The resonator x-pipe combo in my previous picture may or may not be like that magnaflow p/n you listed. The resonator itself merged in the center into one big glass pack of sorts. I'm not sure why they sell it with the x ahead of it, but I had heard that it is capable of supporting a fairly high rwhp (400 and below). I did not use it because it was fairly large and would have been the lowest part on the undercarriage.

[Gunny]

I tried the 3" dynomax x-pipe resonator and it was a tighter fit than I wanted so I abandoned that idea ... whatever you decide on, be sure to carefully check your measurements for fitment.

Have you looked at the dynomax vt mufflers (internal flapper)? The claim is "absolutely no drone" while retaining all the performance characteristics ... sounds too good to be true but I haven't heard them yet. Might be worth looking at ... just a thought.

[tomtom72]

just a fwiw I didn't really have the $$ to spend on a Corsa system. So I looked around and found these guys:
http://www.classicchambered.com/classic/products.html

I was going to buy two of these and cut out the OE 90 resonator and splice two of these in it's place and keep the rest of the OE exhaust on my 90. I don't know how loud these are, but I was thinking these parts reminded me of my factory side pipe mufflers on my 72 LT-1. No restriction, or not much going on with these, and I figured going thru the stock mufflers the noise should be kept to a tolerable level. Don't know if this helps you out or hinders the resolution of your search for flow and no noise.


Tom

[Paul Workman]

Originally Posted by mike100

I bought this from Hans when I got the stock exhaust, but ended up only using the x-pipe. You could just have your exhaust guy make one, but you could also buy this pipe for $85 from Summit.

Ah HA!! So THAT's where my MF system ended up!

I bought that 3" MF system, thinking it was as advertised. But, I discovered several neck points and the resonator is a single pipe, making the sharp bends in the X pipe section redundant and resitrictive (the pipes are NOT 3" in diameter, in and out of the X section...grrrrrrr. Hans wanted to try it, so I sold the resonator and X pipe sections to him (the muffs are on my car still...for now)).

To the OP: Dominic used a MF system with success, up to the point of porting his heads. The system proved too restrictive; impeding performance after installing ported heads and re-ground cams. But, as I recall it had no resonance, and it sounded rich and deep. (Corsa sounds a bit "tinny" to me and others. Sound is a subjective thing, but resonance is prolly universally disliked.)


P.

[SteelBlueZR1]

So, I decided to resolve the restrictive 1991 exhaust resonator issue on my ZR1 by purchasing an LT4 resonator, which does not have the restrictive 1 5/8 inlet and appears to be very close to 2 3/4" straight thru. Bought this piece from "Jeff" here on our forum and am looking to have installed by Maryland exhaust shop.

Does anyone have a recommendation for a Baltimore County/Maryland custom exhaust shop who can fabricate 2 3/4" pipes to join the resonator with the existing exhaust?

[secondchance]

Originally Posted by efnfast

I'm running a brand new OBX system, headers and exhaust. No drone. If you're coming to BG, you are welcome to come for a ride with me and listen. Maybe you can drive, maybe.

Agree 100%. I am also running OBX headers and exhaust - completely happy w/ the result.

Bert - if you want you can try my car next time we meet. Any custom conversion you do removing resonator or switching to other resonators will cost at least $100-200. OBX exhaust can be had for $350.
One more thing. Factory exhaust is 2.75" system. However, depending on the year 2.75" pipe reduces by 1/2" or so at transitions to resonators and mufflers - not a true 2.75" system.