Gutting mac catted prochamber vs O/R H

[06 T-RED S/C GT]

I'm debating installing an old mac catted prochamber in which I recently gutted out the cats.. My reason for gutting them, is I don't want to risk causing possible damages by running ceramic cored cats with FI..

I'm not really looking for any substantial power gains, but rather looking to reduce cabin drone from my Borla Stingers.. Anyhow I've read quite a few posts from previous threads claiming that running an O/R prochamber works really well for reducing the amount of resonance drone..

Currently I'm running the stock catted mid pipe with the Borla S type (stingers) but the resonance drone is horrible between 1500-2000 RPM in both 3rd and 4th gears around town at 25-50 MPH..

So my questions are this.. Will the sound of running a gutted catted prochamber produce any resonance drone from the larger opening inside the shell of the gutted cats or will the sound be similar to running an O/R prochamber that doesn't include cats ?

In the meantime, any type of feedback and support will be really appreciated..


-Thanks..

 

[eighty6gt]

Why not just put some pipe in place of the gutted cats on the chamber? I realize getting this fabricated can be profoundly difficult in certain locales.

 

[06 T-RED S/C GT]

Why not just put some pipe in place of the gutted cats on the chamber? I realize getting this fabricated can be profoundly difficult in certain locales.

Agreed, it might be better to just cut the cats off and weld in piping in their place rather than cut the shell casings in half, weld pipe in and then re-weld the shell casings back together again..

Should've thought about doing that before gutting the cats out to begin with

 

[eighty6gt]

A skilled and willing fabricator would have no problem doing this in mandrel bent stainless. I have never encountered such an individual.

 

[06 T-RED S/C GT]

I've never encountered one either.. It probably wouldn't be worth the hassle and cost to find a shop to fabricate piping and then weld the shell casings back together anyhow.. Better off to just purchase off road extension pipes from Mac performance for the prochamber, providing of course they're offered separately for the OEM exhaust manifolds/short tube headers

 

[eighty6gt]

Why are you welding on these shell casings, visual inspection???

 

[AnotherS197GT]

You're better off having resonators welded in your over axle pipes. When I ran S-types with long tubes and a pro chamber, it droned like hell. Some resonators (staggered) really killed a lot of the drone.

 

[06 T-RED S/C GT]

Why are you welding on these shell casings, visual inspection???

Yes, just for visual inspection.. Here in PA they can fail the car for not having cats on the vehicle

You're better off having resonators welded in your over axle pipes. When I ran S-types with long tubes and a pro chamber, it droned like hell. Some resonators (staggered) really killed a lot of the drone.

Other than the S-types, my exhaust is stock including the OEM exhaust manifolds.. As of right now the S types drone between 1500-2000 RPM in 3rd-4th gears when driving around town between 25-50 MPH.. Once I'm on the highway at 2000 RPM and higher at 60-65 MPH in 4th-5th gears the drone stops.. So I figure that running a mac prochamber without the cats will hopefully reduce the resonance drone without having to weld in resonators, but if not, then resonators will be the next option

 

[eighty6gt]

A pair of cherry bombs look like cats. Just stamp into the side with a machinist punch set: "CATALYST"

 

[06 T-RED S/C GT]

Didn't think of that either.. Seems like another good alternative as well

 

[06 T-RED S/C GT]

You're better off having resonators welded in your over axle pipes. When I ran S-types with long tubes and a pro chamber, it droned like hell. Some resonators (staggered) really killed a lot of the drone.

Are you still running the pro chamber with your S-types, long tubes and resonators or just the resonators by themselves with the S-types and long tubes ?

I just ordered a pair of Vibrant 18" resonators, part # 1793 from Summit Racing.. I'll be having a shop weld them in the over axle pipes on Tuesday..

They'll also be added to a Mac off road pro chamber.. My only concern is will the S-types lose a significant amount of volume from outside of the cabin by adding resonators with the o/r pro chamber, or would I have much better results by just adding an off road mid X/H pipe section with the resonators instead

 

[BNH4.6]

The pro chamber is perfect for cutting down rasp and the blatty machine-gun fart of the rear muffler set up. I've ran it with Corsa extreme, Mac, bullit, and fr-500 axle backs. Nothing but deep from all of them and all off-road. You can't go wrong with a pro-chamber. It takes away rasp and gives almost any mufflers a DEEP sound. Can't describe it, but trust me it's good.

 

[06 T-RED S/C GT]

The pro chamber is perfect for cutting down rasp and the blatty machine-gun fart of the rear muffler set up. I've ran it with Corsa extreme, Mac, bullit, and fr-500 axle backs. Nothing but deep from all of them and all off-road. You can't go wrong with a pro-chamber. It takes away rasp and gives almost any mufflers a DEEP sound. Can't describe it, but trust me it's good.

Are you also running resonators with the pro chamber and if you are, how well do they sound together ?

 

[1sloGT]

What about *big finger quotes* cats? http://www.siliconeintakes.com/dsm-intercooler-piping/catalytic-converter-p-331.html

 

[06 T-RED S/C GT]

What about *big finger quotes* cats? http://www.siliconeintakes.com/dsm-intercooler-piping/catalytic-converter-p-331.html

Never heard of this company before.. So where do you connect the rear 02 sensors on these, or do you weld/clamp them on an off road pipe that already have front and rear 02 sensor connections

 

[1sloGT]

Never heard of this company before.. So where do you connect the rear 02 sensors on these, or do you weld/clamp them on an off road pipe that already have front and rear 02 sensor connections

I think they were a vendor here for a minute. Some of the turbo guys were running them that are no longer active on the site. I've purchased hose clamps and tbolts from them. All good stuff.

I haven't done these myself. I'm tempted to. If I were doing it I'd be trying to mount them oe-ish with some defoulers to keep the 02 sensor away from the dirty. I'd probably go way over board and use something like this.

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html?gclid=CjwKCAjw_8jNBRB-EiwA96Yp1kd84_XGKoch1K9Josjcdof0tMko0wYIkGGEQzBHLyr2KZP4CekohxoCcKUQAvD_BwE

I don't know of people running them in the domestic scene but I have a couple dsm/evo and a couple bimmer buddies that swear by them.

 

[07 Boss]

I think they were a vendor here for a minute. Some of the turbo guys were running them that are no longer active on the site. I've purchased hose clamps and tbolts from them. All good stuff.

I haven't done these myself. I'm tempted to. If I were doing it I'd be trying to mount them oe-ish with some defoulers to keep the 02 sensor away from the dirty. I'd probably go way over board and use something like this.

http://www.bigdaddiesgarage.com/min...f0tMko0wYIkGGEQzBHLyr2KZP4CekohxoCcKUQAvD_BwE

I don't know of people running them in the domestic scene but I have a couple dsm/evo and a couple bimmer buddies that swear by them.

I use those and pass the OBD smog test every year. I had to get the 90* extensions as there was not enough room for my rear O2 configuration.

 

[1sloGT]

Bad ass man! Someday I'll go this route. I'm afraid of the added power at this point. Already pushing about 490/420 on stock bottom end.

 

[06 T-RED S/C GT]

I've already had Brenspeed e-mail a revised tune file with the rear 02 sensors turned off.. Being that I put 5000 miles or less per year on my car, I don't have to go through emissions inspection.. As my car meets the requirements under PA state emissions exemption law..

 

[eighty6gt]

Can someone with a pro chamber on or off the car take a few photos with a tape measure sitting on top of it?