I said I was going to put cats on the....

[whats77inaname]

....MRF X-pipe, and I meant it. Malek said they tested it with HJS 100 cell cats in prototyping and it didn't lose any power, so....

HJS 100 cell cores, 4" in diameter:



SS 2" to 4" reducers will be here next week.

http://www.verociousmotorsports.com/s.nl/sc.3/.f

Should be an interesting few weeks as everything comes together.

[Vic311]

In my experience secondary cats don't really reduce fumes enough to warrant using them. That said HJS are top notch cats, so please report back if they do the job.

[whats77inaname]

Originally Posted by Vic311

In my experience secondary cats don't really reduce fumes enough to warrant using them.

These will be used as primaries, not secondaries. They will be placed between the O2 bungs.

[Vic311]

Originally Posted by whats77inaname

These will be used as primaries, not secondaries. They will be placed between the O2 bungs.

Gotcha. In that case they should work well. Maybe do a baseline dyno to see if you lose power with them in the primary section.

[whats77inaname]

Originally Posted by Vic311

Gotcha. In that case they should work well. Maybe do a baseline dyno to see if you lose power with them in the primary section.

Probably won't do that. I plan on getting a baseline of the car in the next couple weeks, as over the next few weeks I'm looking @ a full exhaust, AA air filter, and (after a Blackstone report) a tune. As I'm doing all the install work (save the welding) I don't know if I want to install/dyno/uninstall/reinstall/dyno. That's a big time sacrifice. I'm also working around my welder's schedule.

[BPMSport]

Very nice! High quality stuff.

[Petros]

Originally Posted by whats77inaname

These will be used as primaries, not secondaries. They will be placed between the O2 bungs.

would these be enough to prevent the check engine light or would you still need to get a tune or Akra Delete R? And would the car pass emissions testing?

[whats77inaname]

Originally Posted by Petros

would these be enough to prevent the check engine light or would you still need to get a tune or Akra Delete R? And would the car pass emissions testing?

100 cells won't do either, a tune or Akra Delete R will be necessary. BUT, it will stop the smell associated with straight pipes, and I feel more environmentally friendly having them

[aus]

This should be cool but why put them in the primary position? Evolve did flow test and said there was less back pressure if the cats are in the secondary position.

IMO, 100 CPI cats in the secondary location still stick pretty bad.

.

[whats77inaname]

Originally Posted by aus

This should be cool but why put them in the primary position? Evolve did flow test and said there was less back pressure if the cats are in the secondary position.

IMO, 100 CPI cats in the secondary location still stick pretty bad.

.

Evolve tested on their setup, not MRF's. Since Malek designed this pipe and has the most experience with it, and because I talked to Malek before embarking on this journey, I'm replicating what he did so that I can make sure I get the same result: no loss in power.

[JEllis]

Cool idea... keep us updated

[Longboarder]

Awesome!

Different applications altogether but after a couple days of testing, my HJS 200 cel are working fantastic on my BBI straight pipe exhaust on my 911. Even though my tune requires no cats, so far it's working fine as the HJS just flow so well. I think mine are rated over 400 hp each so 800+ together. This is a cool idea and now that I see how well these cats flow, I'm thinking this going to work exactly as you intended. Although part of what I loved so much about the MRF was the higher rpm high pitch sound that it makes (some similar tones to a flat plane'd crank car), You've done a lot of planning and homework and I'm really curious how this is going to sound with the cats and your planned slip on. Also would be awesome of you could get a baseline and after dyno.

[mkPOTO]

in for more, sounds like a good plan!

[pbonsalb]

There was another tuner, M3DCTBT, who did some testing with cats and found very little to no power loss. He was not using the very expensive HJS cats, but rather ebay 300 cell metallic core cats.

If you need to pass visual or sniffer test emissions or to reduce smell, you have no choice but to run cats. It would be great if there was little to no power loss.

I know that Evolve did some back pressure testing and found a significant reduction from removing the long 400 cell primary cats. It makes sense that short 100 cell cats would have less back pressure.

However, since the OP is not doing a baseline and is doing multiple mods at once, we will not know the effect of the cats on his power.

[whats77inaname]

Originally Posted by pbonsalb

There was another tuner, M3DCTBT, who did some testing with cats and found very little to no power loss. He was not using the very expensive HJS cats, but rather ebay 300 cell metallic core cats.

If you need to pass visual or sniffer test emissions or to reduce smell, you have no choice but to run cats. It would be great if there was little to no power loss.

I know that Evolve did some back pressure testing and found a significant reduction from removing the long 400 cell primary cats. It makes sense that short 100 cell cats would have less back pressure.

However, since the OP is not doing a baseline and is doing multiple mods at once, we will not know the effect of the cats on his power.

I'm doing:
-baseline dyno for the car stock;
-filter, then dyno, since AA says their filter is dyno proven to pick up a couple hp
-filter + catted full exhaust, then dyno, as I don't see where the rear is going to make that much of a difference. The x-pipe will make the biggest gains.
-filter + catted full exhaust + tune, then dyno. I'd like to see how a good tune will take advantage of the air flow.
-filter + catted full exhaust + tune + PWM, then dyno. I'm interested in seeing how much better the car will perform w/other mods in addition to the methanol.

The cats weren't really that bad, as they're just the cores. I was shopping around for them and was seeing $550+. I picked up cores only for $275/each w/free shipping from a seller on eBay. He has a bunch of them. http://www.ebay.com/itm/170770102289

[spool twice]

wonder how these will sound? Keep us updated. The S55 engine has similar looking primary cats, wonder if that's the cause of the ugly noise it makes versus the N55?

[///Matthew]

Originally Posted by Longboarder

Awesome!

Different applications altogether but after a couple days of testing, my HJS 200 cel are working fantastic on my BBI straight pipe exhaust on my 911. Even though my tune requires no cats, so far it's working fine as the HJS just flow so well. I think mine are rated over 400 hp each so 800+ together. This is a cool idea and now that I see how well these cats flow, I'm thinking this going to work exactly as you intended. Although part of what I loved so much about the MRF was the higher rpm high pitch sound that it makes (some similar tones to a flat plane'd crank car), You've done a lot of planning and homework and I'm really curious how this is going to sound with the cats and your planned slip on. Also would be awesome of you could get a baseline and after dyno.

My AE Performance with HJS E554712201 200 Cell HFCs in the primary location also mimics flat plane tones. I absolutely love this thing. No check engine light on my previous 2011 M3 or current 2013 M3 with this setup either (so far). Neither car was/is tuned.

[aus]

Is it safe to say, any decent exhaust shop couple weld in these core units?

For the OP, what's your goal by adding the 100cpi cats? I'm just curious since it'll still smell pretty strings and won't prevent check engine light. I guess it will help with the smell to some extent and will probably work faster than the Akra since they'll light up faster.

.

[pbonsalb]

Does the x-pipe in Post 17 closely resemble the MRF x-pipe or is my recollection not right?

[whats77inaname]

Originally Posted by aus

Is it safe to say, any decent exhaust shop couple weld in these core units?

For the OP, what's your goal by adding the 100cpi cats? I'm just curious since it'll still smell pretty strings and won't prevent check engine light. I guess it will help with the smell to some extent and will probably work faster than the Akra since they'll light up faster.

My friend is a certified welding instructor, and welds Ti. Although I can take it to a regular exhaust shop, I'll be visiting him. And yes, the cat will function better as the primary b/c it will heat up faster in the primary vs. secondary position.

Originally Posted by pbonsalb

Does the x-pipe in Post 17 closely resemble the MRF x-pipe or is my recollection not right?

AE Performance:






MRF:

[jagman]

Very interested!

[pbonsalb]

MRF sure looks pretty much identical to AE, apart from the AE high flow cats in the primary cat position. While I agree 100 cell are the least restrictive cats available, I am still curious about the loss of power from 100 cell cats in the primary position versus no cats.