Resonator Questions

As most of you know, I've got that Hogan 3" DP on my car now.

I'm just wondering if I'd see an improvement in performance if I removed the resonator. It'd probably be really cheap. The cat, I'm not so sure about. The stock one doesn't seem to be too bad.

So has anyone removed their resonator and was actually HAPPY with the results? I did it on my Regal (had to, it had a hole in it) and it made the exhuast a little grumblier, but barely.

So, thoughts?

the cat being replaced with a highflow or straightpipe will improve performance. How much? It dpends on your mods and how much intake work you have.

the resonator being removed probably wont increase performance, but highway drone will be more noticeable. The resonator probably has little effect except on the highway. A loud drone is annoying as hell though.

You will probably get a little "popping" when you let off the gas if you remove the cat from unburned fuel.

the resonator is pretty restrictive. It is 2.25" at it's largest point. I am doing the exhaust at the same time as I will install my headers, which have a built in 3" DP. I will be using a larger resonator.

Where do you get the larger resonator?

ebay or any store that sells mufflers.

I have a pair of 2.5" SS resonators with polished SS turndown tips made for the impala SS that I ended up not using on my roadmaster. If I can't find a way to use those, I'll just get a 3" glasspack or long body muffler and use it in the stock location.

I deleted my cat, but have completely intact stock exhaust from there back. Still sounds stock except when I get on it, but not raspy at all. I don't think the OEM system is that restrictive after the cat. The resonator is worth keeping imo. If you think it's worth opening up for a few extra hp (a few, not several), be prepared to enjoy the symphony of a 90 deg V6.

Eh, I think I'll keep the resonator. A high-flow cat (damn e-check) sounds like it'll be in the future, but the res will remain.

Buapo wrote:

Eh, I think I'll keep the resonator. A high-flow cat (damn e-check) sounds like it'll be in the future, but the res will remain.

I've got the high flow cat with no res and flowmaster 40 series mufflers. I think it sounds great at idle but there is a good drone on the highway. I've kinda been debating to put on a res or keep it off for a couple weeks now. Still don't know what I'm going to do.

My Regal sounds good, most people like it... but it's got some drone. Took me a long time to get used to it. I like being able to cruise down the road without having to ramp up the volume on the CD that I'm listening to.

Plus, when you start up the Riviera, it kind of purrs. So quiet, someone asked if it was running.

Buapo wrote:

Plus, when you start up the Riviera, it kind of purrs. So quiet, someone asked if it was running.

Not mine. :O You know when it starts.

SpaceBar wrote:

Buapo wrote:

Plus, when you start up the Riviera, it kind of purrs. So quiet, someone asked if it was running.

Not mine. :O You know when it starts.

yea, rocks in the intake....lovely cold morning sound.

The gutted intake is still noticeable for me, and I have the K&N drop-in. I probably would enjoy the sound of a fenderwell too, but I'm guessing a fenderwell would give an increase in boost that I wouldn't be able to use. I think with my current setup, I don't have any KR.

You're correct in assuming the FWI will give you more air flow. My boost went up 1 PSI. But the FWI gives you a potentially cooler intake air temp, so the extra air might be usable, because cooler air helps lower KR.

Imo, if it's knocking with a 3.5" SC pulley + FWI, I'd switch up to a 3.6" SC pulley. Blower will make less boost, but doesn't have to suck as hard to get the needed air. Would seem like the better way to go.

Damn, I need to scan.

Buapo wrote:

Damn, I need to scan.

I think the stock resonator is pretty bad. I'll get a pic of the inside when I do my headers. it is 2.25" at its widest point. less area then the 2 mufflers put together, and the mufflers are pretty lame. IMO it is barely capable of supporting a stock engine.

Buapo wrote:

As most of you know, I've got that Hogan 3" DP on my car now.

I'm just wondering if I'd see an improvement in performance if I removed the resonator. It'd probably be really cheap. The cat, I'm not so sure about. The stock one doesn't seem to be too bad.

So has anyone removed their resonator and was actually HAPPY with the results? I did it on my Regal (had to, it had a hole in it) and it made the exhuast a little grumblier, but barely.

So, thoughts?

I left the Cat in, took out the resonator and put a set of Magna-Flow mufflers on my 98. not much improvement in performance that i can tell. Nice sound though

A while back I said I would cut through my riviera's stock resonator to show you how crappy it actually is. I just got around to removing it this week while doing the headers and was about to cut it up when I saw this post over at regalgs.org

I was just going to cut it transversely to show the small diameter, but this is even better as WildDM cut it longitudinally. Here is the photo for those to lazy to click on the link.



I'll still be submitting photos of the DP and mufflers as soon as I get my camera back from my S/O.

I'd imagined it worse that it looks in that photo. Is it the same resonator we have on the Riviera?

yikes that's restriction!

It doesn't look like much restriction to me. Only that the whole thing uses 2.5" pipe, the rest looks like a pretty clear flow through.

I can't stand the way these cars sound without a res though. I want to try the whisper resonator that ZZP sells. I'm waiting for something in my exhaust to let go so I can justify redoing the whole catback...

thats not nearly as bad as the double walled DP or front mani's on these cars.
you probably wouldnt notice much gain removing the resonator and swaping it for a 3" pipe.

the stock res is 2.25" at its widest point. I agree that the stock downpipe is the most restrictive part..

oh right, 2.25. But still it doesn't look too restrictive beyond the diameter...