Sonny

Hi All,

I've had the parts for this for a long time, but just had the time this past week to finally put it all together. This is a "Powercore" metal substrate cat from Dynatech. I spoke to one of their techs at length about placement of the cat, the airpump tube, etc.

It's finally done...going on the car tomorrow morning.







The airpump tube is put in the recommended location and I set it up so that NO modifcation of was needed to make the existing airpump line hook up.

This was a fun project, but using a TIG under a car is a pain in the ***!

Sonny

sub9lulu

iTrader: (7)

looks pretty good

alberto_mg

looks good man. let us know your opinion once you got it in.

Sonny

Update. It's installed!

Nice TIG bead on the cat to MP joint


Airpump hookup...came out very nice!


Impressions:
-I was really shocked at high not-loud this cat is. I think loudness depends a lot on what kind of muffler you have. I have an old school Greddy/Trust chambered muffler. I'm sure it is a lot louder on a straight-through canister style muffler. It sounds a little deeper at idle and cruise and only mildly louder when at full throttle with both turbos spooled.

-Speaking of spool...DAMN! I had to jump out of the car and turn the boost controller down. I was seeing upwards of 13 psi , so I dropped it back to 12. I have a Hallman EVO Rx MBC. It feels faster everywhere...primary spools quicker, the second turbo comes on line noticeably harder, and it just pulls harder.

Man, I am soooo happy with this mod. It has taken me a long time to finish it, but it was totally worth the time and wait. The car feels noticeably faster, it doesn't stink, it's only a little bit louder, and this cat is less than half the weight. The only problem is that I used some unknown brand MP (I bought it being told that it was a Bonez....yeah, right!). Everything lines up, but I had to shim the rear frame brace where the exhaust and cat meet. Totally worth it though! With the airpump system still working properly, this thing should last.

Sonny

Daniel577h

looks nice, if you dont mind how much everything cost you?


did you use rtv for the exhaust gaskets? i didnt know it could be used there.

Sonny

Dynatech cat was $165. I paid $110 for the MP. I spent about $15 on metal for the air pump tube/flange and whatever it costs for about 1/2 lb of 308L stainless filler rod. I'd say it cost me about $300 to build it.

I used copper RTV at the joints, but there are gaskets there, too. I put it on both sides of the gasket.

Sonny

maxcooper

Congrats on your new cat. I am glad it worked out for you.

It is interesting that it isn't much louder than the stock cat. My experience with a ceramic HF cat was that it was quite a bit louder. And I just did a metallic cat + muffler in my new midpipe and I was absolutely amazed at how quiet it turned out. It seems like the metallic cat actually makes a decent muffler itself.

-Max

Sonny

Thanks, Max. What muffler do you have on your FD?

Sonny

jeff p

Hey Sonny. Nice work, have you had a chance to get it smog checked yet. that cat looks very small. I am in the Los Angeles area and smog is a Bitch to pass. I would like to go to a high flow cat but it needs to function and clean the air enough to pass our test. right now mine passes fine with the stock cat. But I would like to see how your numbers come out.
Jeff

maxcooper

In the midpipe with the metallic cat, I have a Magnaflow 5x8x14" 3" offset/center muffler. See the other metallic cat thread for a from-the-side-of-the-car pic. My cat back is the painted RS*R dual tip that Racing Beat used to sell. Besides all the whooshing under the hood, my car is queiter than some car models come from the factory. It's freaking great!

-Max

Jesuscookies

iTrader: (1)

You mean from that jet plane turbo?

maxcooper

Yeah, the jet plane turbo does it's whistle and the BOV does it's pshhhhh-ing. I have found that those noises aren't so objectionable, though. It's the ear-bleeder exhaust rasp and open wg blat that I wanted to get rid of and it is ALL gone. You won't believe it when you hear it. The difference is astonishing.

-Max

Sonny

jeff p: Several people have already passed the CA smog test using metal cats. I think Panda RX-7 was the last person to do it. I'm more concerned with visual inspection vs the sniffer...that's why the airpump hookup was preserved.

max: I'm not getting any whooshing, but here's why:


This midpipe uses tubing that is over .125" thick...it's around 10 gauge in thickness. Most exhaust tubing is usually either 16 gauge (.063") or 18 gauge (.048"). On all of the thinwall stuff that I've used in the past, the whooshing is much more pronounced.

I have a Tsudo DP/MP combo that I will probably make another cat with. That setup is 18 gauge tubing, so we'll see if it turns out to be whoosher.

Sonny

maxcooper

Wow, I bet the thick wall tubing does help a lot to keep the noise down.

The whooshing on my car is not from the exhaust (or at least the exhaust whooshing pales in comparison), though, it is from the anti-surge compressor housing on my turbo (think "big rig turbo whistle"). And the other whooshing noise is the BOV.

-Max

Sonny

Well, I drove almost 100 miles today...mostly on the freeway and some in the city. It was hot and I don't like the way the a/c bogs down the engine, so I drove almost entirely with the windows down. If this cat has added any noise at cruise, it is almost not noticeable. I'm gonna try out my luck with the thin wall stainless tubing and see how it goes.

Sonny

jeff p

Hey Sonny. let me know how it goes. maybe you can make me one. keep me posted
Thanks
Jeff

jeff p

I bet if you weld the stock heat shield back on visual inspection won't be a problem.
Jeff

adam c

iTrader: (2)

Looks good Sonny. How about that dyno

axr6

I'm thinking about making one myself and came across the following warning from the Dynatech site, listing their Powercat:

"NOTE: These products are intended for racing and off-road applications.
Not legal for sale or use in the state of California, nor in states which have
adoptedCalifornia emission standards."

Anyone knows the CA status, if this cat would pass visual inspection (airpipe or not)?