Exhaust question: Resonators or cats

[x Spades x]

Hey Everyone

I have an xpipe with primary HFCs and dual resonators (forward x). I have low end rasp that I was to get rid or, but love the tone of the exhaust currently. Adding two more resonators (quad) may deepen the the tone some, so thinking of welding in two more HFCs (total of 4).

My question is, if I'm currently on a Stage 2 tune, will adding two more HFCs push me down to a Stage 1 tune? Are four HFCs (200 flow) the same as the OEM 400 cell w/ 200 cell secondary?

[CrudeM3]

Personally I would stay away from adding a second set of high flow cats and would opt for another set of resonators if need be. Another set of HFC will be much more restrictive and be like an OEM set up. Another set of resonators will cut out rasp and will be less restrictive than HFC. I am not certain, but with 2 sets of HFC I would believe it would make closer to stage 1 power due to the restrictive nature of cats. Just my take on it.

[jp1984]

Hey, I will buy that x pipe off you before you ruin it!

[jp1984]

Hey, I have a dinan x pipe with HFCs in the primary position (so 2 cats 4 resonators) It could be the perfect sound you are looking for. I would love an ESS pipe, would you be interested in a swap?

[rjsiciliano]

Not to thread hijack but I have a similar predicament to OP. I have a valvetronic forward x pipe no cats with resonators. Want to add some HFC's and another set of resonators. Where should I place them? HFC's in primary and resonators in secondary spot after the X? Might be tough to weld here as the pipe bends after the X. Has anyone put resonators in the primary spot? Might not be possible here either as the holes for the sensors are there.

[drwankel]

I mean the ideal thing I would think from a sound perspective, forward x, a resonator before the x, so you still get flow, then HFC after the x, then another set of resonators. Generally you want to avoid cats in the primary position. (before the x)

That being said- I wasn't happy with the sound of the valvetronic x pipe amongst other issues even with HFCs. My suspicion is one of the issues is the resonators are really short on that thing. There isn't alot of space there to add anything. There were resonated test pipes made in the past, so a resonator in the primary position sounds at least possible with a clean sheet design.

ESS x pipe has much longer resonators and sounds alot better, but its not in production anymore, and the cats are in the primary position.

[x Spades x]

Originally Posted by drwankel

I mean the ideal thing I would think from a sound perspective, forward x, a resonator before the x, so you still get flow, then HFC after the x, then another set of resonators. Generally you want to avoid cats in the primary position. (before the x)

That being said- I wasn't happy with the sound of the valvetronic x pipe amongst other issues even with HFCs. My suspicion is one of the issues is the resonators are really short on that thing. There isn't alot of space there to add anything. There were resonated test pipes made in the past, so a resonator in the primary position sounds at least possible with a clean sheet design.

ESS x pipe has much longer resonators and sounds alot better, but its not in production anymore, and the cats are in the primary position.

Cats in the primary position sounds cleaner, than in the secondary... however, should be avoided in primary if tracking. The VT has two factors against it... the harsh X design (adds rasp) and the tic tac sized resonators. To get the VT to have a smooth sound, you need to add two cats and six resonators (4 on the xpipe and two small ones on the exhaust connecting pipe... ala the Corsa).

[jp1984]

Did you honestly ever consider like an Akra?

Has the front H HFCs then the x and nice resonators.

I just wonder if there is a fundamentally better x pipe out there for you before you hack that one up.

[rjsiciliano]

Originally Posted by drwankel

I mean the ideal thing I would think from a sound perspective, forward x, a resonator before the x, so you still get flow, then HFC after the x, then another set of resonators. Generally you want to avoid cats in the primary position. (before the x)

That being said- I wasn't happy with the sound of the valvetronic x pipe amongst other issues even with HFCs. My suspicion is one of the issues is the resonators are really short on that thing. There isn't alot of space there to add anything. There were resonated test pipes made in the past, so a resonator in the primary position sounds at least possible with a clean sheet design.

ESS x pipe has much longer resonators and sounds alot better, but its not in production anymore, and the cats are in the primary position.

I think you are correct, resonators before x, then cats, then another set of resonators. The resonators are very small on this pipe though and that probably contributes to the sound it makes. Since you were not happy with this pipe what did you end up switching too?

Originally Posted by x Spades x

Cats in the primary position sounds cleaner, than in the secondary... however, should be avoided in primary if tracking. The VT has two factors against it... the harsh X design (adds rasp) and the tic tac sized resonators. To get the VT to have a smooth sound, you need to add two cats and six resonators (4 on the xpipe and two small ones on the exhaust connecting pipe... ala the Corsa).

This is what I was afraid, looks like this thing would need a lot of work to get the sound I want. This is the trouble with relying on sound clips online and not having much to go off. Now I know why people change exhausts so much haha.

Originally Posted by jp1984

Did you honestly ever consider like an Akra?

Has the front H HFCs then the x and nice resonators.

I just wonder if there is a fundamentally better x pipe out there for you before you hack that one up.

I agree, I have decided I am not going to hack this pipe up but rather sell it. I am thinking of going with evolve's x pipe with high flow cats and a corsa-cat back.

[drwankel]

Originally Posted by rjsiciliano

I think you are correct, resonators before x, then cats, then another set of resonators. The resonators are very small on this pipe though and that probably contributes to the sound it makes. Since you were not happy with this pipe what did you end up switching too?

I went back to the factory x pipe with test pipes. If another interesting x pipe option comes along, I might be willing to give it another try, but for now I'm just going to stick with the factory x pipe with test pipes.

[drwankel]

Originally Posted by x Spades x

Cats in the primary position sounds cleaner, than in the secondary... however, should be avoided in primary if tracking. The VT has two factors against it... the harsh X design (adds rasp) and the tic tac sized resonators. To get the VT to have a smooth sound, you need to add two cats and six resonators (4 on the xpipe and two small ones on the exhaust connecting pipe... ala the Corsa).

The other thing you need to consider, is you don't want cats in the primary position if you are supercharged. Track or street, the advice given to me was don't do it.

[jp1984]

Originally Posted by drwankel

I went back to the factory x pipe with test pipes. If another interesting x pipe option comes along, I might be willing to give it another try, but for now I'm just going to stick with the factory x pipe with test pipes.

Hey I cross posted this in another thread, but with the MS X pipe and some cats welded into the secondary position, arent you effectively making the Evolve pipe?

Other post :

I have literally been thinking this through and came up with maybe a superior option.

Macht Snell X pipe ~ $1,000
HFCs welded in where the pipes connect ~ $400 with parts and labor

wouldn't that bring you shocking close to the evolve piece at a fraction of the cost? (around $2,500)

I just can not help but think that a quality x pipe brought to an exhaust shop with HFCs can not basically recreate the Evolve one, am I crazy? Because I am thinking this is what I might do and give up on the forward x position pipe.

https://www.vividracing.com/-p-153119235.html

https://www.amazon.com/dp/B000VX96IS?tag=wvdot-20