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View Poll Results: Changing up the exhaust...Best option or no option?
Custom Magnaflow HF Cat 3 27.27%
Stromung HF Cat 2 18.18%
Random Tech HF Cat 6 54.55%
Save my money and stop buying mods! 0 0%
Multiple Choice Poll. Voters: 11. You may not vote on this poll

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Old 09-26-2004, 11:42 AM   #1
DreddRS25
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Default Dilemma: Catback or HF Cat Converter

As I am slowly getting use to my CEL forever being lit, I have become interested in changing something on my exhaust. My current set up is: UO Lightened/Underdriven Pulley, borla headers (v2 I believe), custom 2.25"MP+WRX axleback, lastly Ganflow+K&N. Nothing to fancy so far, but I definately like better over stock. Not really looking to gain top speed, rather a little more cruising accel or general accel. Sound I can deal with.

At boxer4racing website, the stromung HF cat is said to yield upto 9% in fuel economy, plus a few extra horses. Is that true? An insight for this sot?

This topics been covered. Just wanting to see the poll and get some opinions from stromung owners experiences. Others welcome, thanks.
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Old 09-26-2004, 12:56 PM   #2
piker28
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not sure which you want, but on rs25.com there is a group buy for random tech high flow cats going down...300 bucks for one, good price
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Old 09-26-2004, 01:53 PM   #3
jamesfacts
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I'm a big fan of the RT high-flows too.
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Old 09-26-2004, 02:09 PM   #4
nySulli
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i'd say go with the random tech cat, as for those types of gains, they don't sound to far off, i've heard of 1-3 mpg increases depending on the car, so 5-10% ish, and you'll gain a few ponies, maybe 3-4 whp if i had to guess
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Old 09-26-2004, 11:20 PM   #5
subbyspeed
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thats funny.. whenever the check engine light ISN'T on, i think thats weird looking. hahaha

300 bucks for the RT cat is a damn good price IMO
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Old 09-26-2004, 11:34 PM   #6
Handsdown
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you're not going to see much more benefit with another catback, so i'd say go for the high flow cat.

though i'm very skeptical as to how well it scrubs your exhaust.
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Old 09-27-2004, 09:18 AM   #7
DreddRS25
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I just realized that I forgot to put in the catback in the poll. However, I guess it doesn't really need to be there.

Thanks Piker for telling me about the RT cat group buy. Go to that site all the time and don't know how I missed it. Seeing if I can muster up $300.

If by chance I do go the custom route should I look into 2" or 2.25" cat piping? (I need to check on the Random Tech's.)
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Old 09-27-2004, 09:44 AM   #8
LetItSnow
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If you autocross, a high flow cat is easily the difference between STS and STX.
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Old 09-27-2004, 10:57 AM   #9
PARANOID56
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the random cat one is 2.25" last time i cheked. oh, and teh group buy at 25rs.com is 300 shipped
now go buy one, as i am on that list too
Shane
www.paranoidfabrications.com
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Old 09-27-2004, 11:03 AM   #10
DreddRS25
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Quote:
Originally Posted by PARANOID56
the random cat one is 2.25" last time i cheked. oh, and teh group buy at 25rs.com is 300 shipped
now go buy one, as i am on that list too
Shane
www.paranoidfabrications.com
Hey I installed the grounding kit and it looks great. In the process I had to disconnect the battery so after a week or so I'll give feedback at rs25 on your thread.

Felt real dumb for a little while when I quickly cut all the zip ties on the wires and then looked at the directions "all wires are connected in order to be installed" Since the ring terminals are different sizes it was easy to find the proper order.

And hell it is almost the start of the month, so I should have some cash for the hf cat.
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Old 09-27-2004, 11:04 AM   #11
DreddRS25
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I got three votes toward the Magnaflow Cat but no replies on it. Any experience, just wondering?
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Old 09-27-2004, 07:40 PM   #12
powerlabs
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I have a Random Tech High Flow Cat and I'm happy with it. My exhaust set up is Borla Headers and Catback, RT cat and a Magnaflow 14 x 3.5inch lifetime warranty stainless steel resonator. One thing I noticed with the high flow cat was that it made my exhaust sound a lot raspier; it acquired a metallic tone to it that I didn't like. It was also louder and backfired more, but not enough to really bother me. The raspyness did bother me though, and the resonator completely got rid of it, and only cost $64. Now I'm very happy with the way it sounds.
I don't know about it improving gas mileage, but on my car it improved my top speed. Now I can hit the rev limiter in 5th on an inclined road. Not very scientific, but I know the cat converter had something to do with it and that makes it worth the investmet. Oh, that and the awesome boxer sound my car now makes. You can listen to it on this video:
Autocross spinout / launch
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Old 09-28-2004, 09:43 AM   #13
DreddRS25
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Quote:
Originally Posted by powerlabs
I have a Random Tech High Flow Cat and I'm happy with it. My exhaust set up is Borla Headers and Catback, RT cat and a Magnaflow 14 x 3.5inch lifetime warranty stainless steel resonator. One thing I noticed with the high flow cat was that it made my exhaust sound a lot raspier; it acquired a metallic tone to it that I didn't like. It was also louder and backfired more, but not enough to really bother me. The raspyness did bother me though, and the resonator completely got rid of it, and only cost $64. Now I'm very happy with the way it sounds.
I don't know about it improving gas mileage, but on my car it improved my top speed. Now I can hit the rev limiter in 5th on an inclined road. Not very scientific, but I know the cat converter had something to do with it and that makes it worth the investmet. Oh, that and the awesome boxer sound my car now makes.
Initially do you think that the raspiness will more of a negative in relation to the positive increase in top end power? Guess I mean to say, were you only satisfied once you got the resonator?

This will be the first piece of exhaust for me to try and replace by myself. If I absolutely need that resonator, then I may just have everything installed at a muffler shop.

290...291...292...293...damn need to look for change in my couch
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Old 09-28-2004, 11:43 AM   #14
DreddRS25
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Suggestions.

When/if I get my new cat should I swap in the stock headers or just leave the borlas on, at first? Also would it be better to put the stock intake back on with a HF cat or is worth trying it out with the Ganzflow? (hoping maybe that will cut down on raspiness or backfires)
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Old 09-28-2004, 08:18 PM   #15
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I guess it depends on how much you value your exhaust sound. I had my resonator installed after hearing the car without it for about 20 seconds (didn't even bring it down from the lift). I figured that for 64 dollars it was well worth it. I've heard the exact same set up without a resonator and its not that bad; not too loud or anything, but its not as nice to listen to.
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Old 09-29-2004, 03:26 PM   #16
DreddRS25
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Say I do get the RT cat and replace my cats as is. That would be borla headers - RT Cat - straight midpipe+WRX axleback. Soon I hope to be picking up a stock midpipe incase I ever (knock on wood) have to sell the car.

If the cat makes the car too loud or noisy, would it make that much of a difference in performance or sound to put the stock catback back on? Or should I stick to the above setup and use a resonator if need be?

Since my headers and midpipe have been replaced recently I don't expect the bolts on either end of the cat to be too hard to remove. So I'll probably do this install myself. I'm just wondering if might be better to have a shop do everything.

Thanks for all the replies so far!
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Old 09-29-2004, 03:29 PM   #17
piker28
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putting the stock catback with the headers and cat on would be a bad idea

very reestrictive and prob make the thing rattle like no tomorrow with all that flow, not sure if id even bolt up with the diff sizes
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Old 09-29-2004, 03:47 PM   #18
DreddRS25
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Quote:
Originally Posted by piker28
putting the stock catback with the headers and cat on would be a bad idea

very reestrictive and prob make the thing rattle like no tomorrow with all that flow, not sure if id even bolt up with the diff sizes
If I do truely get a RT Cat then I'll probably just put it in as is. Since it is also such a large investment, if I don't really like it I may just sell it off. My car is never gonna race or autocross. Just a daily driver. So I'll see how much my car feels different.

Come to think of it I should probably be more worried about the bolts to the o2 sensors as opposed to the pipe connecting bolts.
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