P5 High Flow Cats and Cat-Back Exhaust Question

[SpookyP5]

Ok, I've searched around on the board and I need to post this just to make sure I have this right.

I want to intall a cat-back exhaust with highflow cats. I have found that the Cats can be found at WangerMotor sports or Tri-point.

This is how I understand the layout of the P5 exhaust:
Diagram

The first (or sometimes called the pre-cat) is installed after the "down Pipe". The 2nd cat is installed after the midpipe (this comes as one unit).

Then comes the Cat-Back itself. In my case, I am going with the Team Moon.

A. Is this right?
and:
B. Has anyone with this set up passed Calif. Emissions???


Thanks
SpookyP5

 

[Matthew]

Exhaust Manifold==Pre-Cat==Elbow piece==Mid-pipe with 2nd Cat==Main pipe==Axle back section

that is the exact setup

 

[SpookyP5]

Got it!

So the Pre-Cat is BEFORE the down pipe/elbo piece.....

Got it.

I figure just the highflow cats set up to be around $1000.00 USD?

Thanks
SpookyP5

 

[Equinox]

a header would get rid of the first cat and downpipe, and a midpipe from wagner should be the rest you need, then just get a catback muffler system and yer done. SOme header systems like the RacingMazda one actually replaces both cats, well... gets rid of the entirely.

but yeah the primary cat is under the heatshield in the engine bay, pretty much it's the bottom half of the exhaust manifold, or "header" then the downpipe then the second cat, then the midpipe then the muffler =)

 

[akhilleus]

$1000?!! I think u could do the header and hi-flow cat for less than that. But be warned that this wont pass CAlif. emissions. They test your OBD II ecu to get the readings on your cats so you cant mess with the o2 and they also do road stops and visual inspection. Your best bet is to get the wagnermotorsports hi-flow precat and just gut the second cat. the second cat doesnt do much, no 02 sensors and it can still be "inspectable"

 

[tonkabui]

i was thinking about going full on wagner set up. he's supposed to be making a shorty header, downpipe with high flow primary cat, and midpipe with hi flow cat. i think that's as good a system as a header, except you're not adding to the smog problem if you're around LA

 

[flat_black]

Spooky, mail Wagner. =) You can get a full high flow cat setup for a lot cheaper than 1k! It'll cost 330~ for the second cat, and 425~ for the first, so a total of 755 for both cats, with exhaust bungs, and everything in place. =) Also, they use Random Technology's cats, which are really efficient. Here's the web site:

http://www.wagnermotorsports.net/

They only have the second cat listed, but drop them an e-mail. The first and second cats can be had, just make it known you want to replace both. =)

 

[SpookyP5]

Thanks All

Equinox,
akhilleus
tonkabui
flat_black

Thank you all for your replies.

Yea, I read during my searches on the board that Wagner had the complete set up, (with out header) even though he does not list the primary cat replacement on his web site.

The $1000.00 fig. was just off the top of my head, when I have the cash I'll email Wagner.

flat_black: since the primary cat has the exhaust bung(s) for the 02 sensor(s), I take it that emissions won't be effected?

Or do I have that wrong?

Also: I want to do a dyno test before and after the complete exhaust set up just see what is possible with out a header and WITH cats. Anyone know of a Dyno in the SF Bay Area?

Peace,
SpookyP5

 

[tonkabui]

it's 755 for the downpipe and midpipe, both with hiflow cats... but his shorty header is a whopping estimated $500 as well... so for 2.25 tubing from the exhaust mani to the exahust tip, you're looking to spend $1600. for the pipes without a catback, you're spending $1250. i would really like to see some major dyno results for $1250 otherwise, mind as well go with a stage one spool turbo for twice that and get four times as much power (i'm exaggerating, but you know what i mean.)

 

[PaulMP3]

both the downpipe and midpipe have 2.5" piping. I have the midpipe on my car. He will also sell them without cats, for cheaper. The cat are expensive

 

[tonkabui]

isn't the 2.5" the outer diameter? making the inner diameter ~2.3"?

 

[FC3s Boy]

High flow cats is'nt going to get you that much power 2-4whp, i don't think it's worth it for the money.

 

[mypfizzle]

spooky.. face it.. you dont live in america or the united states.. you live in we have a big stick up our ass california..trust me i live there.
if you want to go fast. move to a real part of america like nevada.. where u can buy assualt weapons and have 0 cats. -=)

 

[SpookyP5]

....2-4whp?......

Cr*Pola!

If I am looking at only 2-4whp...forget it! $1600.00 with out the cat-back....damn......

tonkabui,
Yup, know what you mean. Your right......

sigh.....ok.....search for "turbo".....(I think Flyin Miata has a 50-state legal one)

mypfizzle,
Yea, know what you mean...oh well.....scr*w it! Time to turbo. I only have a year left on my warranty...by that time I should have the cash.

thanks all, Peace,
SpookyP5

 

[flat_black]

Actually, emissions wouldn't be affected by Wagner's setup, as it keeps all the stock sensors and the normal catalyst setup; However, the problem you may run into is that it's illegal by any emissions standard to remove those stock cats before 50,000 miles. Also, the manifold problem could be solved by porting the hell out of the exhaust manifold, then port matching it and the exhaust ports, if you're were brave enough to do so.

As for gains, it's honestly the most restrictive part of the exhaust system, and would need to be done to see any reasonable gains from a cat back. They may be minimal, but it's noticable nonetheless, and makes the cat back all that more efficient.

But yes, a turbo is much more cost effective. =) But if you want to get the most out of the turbo, you'd need a downpipe with cat, anyway. Either way, enjoy. =)

 

[tonkabui]

i really doubt that the gains are only going to be 2-4whp. traveler, who no longer traverses this forum, gained 15whp just by utilizing a shorty header and enlarging the downpipe and cat inlet/outlet. he did not change or gut his cats, nor did he remove them. all he did was enlarge the piping from the header back, running 2.5" after the second cat and 2.25" forward the second cat. so there you have it. the gains are there, but it's not as cost effective as a turbo.

High flow cats is'nt going to get you that much power 2-4whp, i don't think it's worth it for the money.

 

[SpookyP5]

Hmm.....

Flat-Black,
tonkabui,

You have both given me great info. I would like to hear if anyone else who changed their cats and what hp ratings they got. It would just seem right that the set would be more that 2-4whp. 15whp would be great. During my searches (which took DAYS of reading) no one really gave Hp figs that I could remember.

It's good to know that the Wagner products should pass emissions. I did NOT know about the 50,000 mile law as to replacing the cats though.

And tonkabui is right, I have read in the forum that the down pipe and first cat is a problem in so far as restriction is concerned. It is more cost effective for the turbo....but installations is the next problem. Even tho' replacing both cats is expensive, I still could do it in my garage.

All I know is that my first $1000.00 is going into some Eibachs and a Team Moon and what ever else I can get. I will either do the cats or get rims after that.

Thanks all
Peace,
SpookyP5

 

[Subghetto]

I have a question if I purchase the Ractive header the
4-1 and get the MIL fix which is a definite if I do get that header, and buy the wagner downpipe + the midpipe with the hi-flow cat + hks-axle-back ; I plan later on getting the full cat-back either from Greddy or Skunk2 don't know yet but would I pass emissions with this set up and how much performance would I gain?

 

[blackp5ca]

If you buy the Ractive header, you wont need a dwnpipe..the header covers that..as for the Mil. Elim. dont need the either if you move the second )2 behind the second factory cat (wich will now be the only cat) This header with one cat and the second O2 sensor moved behind it will pass emissions (In Ontario anyways..not sure about anywhere else) The ractive header itself requires no modification done to it at all!!! Installed mine in my driveway with nothing but hand tools.

 

[Subghetto]

I wonder? I live in NY, maybe I would pass but as a LEV but as long as one passes that is all that matters, as for the ractive header I think it is one of the best headers for the price. On another thread I heard that even if you move the 2nd 02 sensor behind the 2nd cat sooner or later you will recieve a CEL so the best thing would be to get a MIL fix. Well thanks for the in-put.