I've got a turbo'd system, 2.5" enthuza exhaust and was thinking about getting a test pipe in replacement of my cat. Is it worth the worth in reference to performance gains? Also, what will it do to the sound? Its on the border of nice growl and loud right now, and i don't really want it to be any much louder.

 

This response is strictly coming from being NA - but will be noticeably louder and only gained 3-5 HP from it.

 

it will get louder. it will spool quicker. only you can determine if it's worth it to you. i run cats on my turbo cars as I am very happy with the spool I have and I don't want them to be louder. I run 3" exhausts though.

 

i got one, turbo spooled a smidgen quicker, whole car felt a little more lively, but it was noticeably louder

 

I will let you know what a metal core cat will do in place of the stock one, hopefully later today.

 

or Artie, Tim, Evank and I can tell you the spool improvement with the metalcore cat is ******* awesome. Hence the reason we don't run test pipes.

 

I dont know what ur talking about. My car sux. I only killed a 02 vette and a supercharged 04 GTO yesterday by A LOT.

I love the sound of my exhaust though with the metalcore cat and magnaflow. Thanks Tim!

 

As a point of data, on my Talon, just by gutting the stock cat- on an otherwise completely stock exhaust system- I was able to make 7psi of boost free revving in neutral as opposed to 0psi before.

 

Metalcore cat and cheap prices from performancepeddler.com FTW!

 

Non-emissions state= Yes

Emissions state= No

Alternative? I've looked into these metal core cats and they're worth it.

 

GRM had a very good test recently on cats. Their testbed was a NA miata normally aspirated. The metal core cats performed equally or only slightly worse than a test pipe. The results would probably scale when adding FI but the difference was small. I have a magnaflow spun metal cat and a test pipe. When I finally tune my car on the dyno I'm going to put the cat on because I'm tired of huffing fumes.

Side question--- will backfire from the tailpipe (yes I know it's technically called midfire) blow apart my cat? I'm guessing not since it's upstream...

 

Why? Because having to R&R something with four bolts every two years is hard?

 

I remember a similar discussion on m.net, where people were discussing the benefits of this and that exhaust diameter, and Corky put an end to it by saying that the cat offers the biggest restriction in the entire system.

But, don't quote me. I was probably drunk at the time.

 

I have a test pipe on my car,I will most likely be picking up a metal core hi-flow cat from ETD racing.

I love the sound & quick throttle repsonse of the test pipe,but I can't stand the smell,it ******* stinks.

 

It seems like a no-brainer. Even a fancy metal core cat is a compromise.

Sam, can you dyno with no cat at all as well?

 

I have the Racing Mazda DP going into the stock 1.6 Cat and on to a 2.5 Cat back Monza Pacesetter system.

I'm between a larger cat and a test pipe http://www.racingmazda.com/miata-exhaust.htm

Is the test pipe very loud ?

Right now my car is very quiet. Is it going to sound like a turbo fart can ?

 

since your turbo i would definitely go catless. i noticed a big difference on my GSX when i went catless, better spool up and you cant go wrong shooting flames. my s2k and miata both were NA and those i really didnt notice much difference in power

 

I realize this thread is two years old, and shame on you two, but I believe I have some pertinent information. From my turbo to the back of the car is basically a 2.5" run, with a test pipe, and it's loud as hell (droaning). So I'm living with my in-laws right now while my house is renovated, and one of the neighbors had an aneurism about how loud my exhaust is. So I happened to have a brand new 1.8 stock cat sitting in my basement. I went home and put it on. Exhaust became substantially quieter, like to the point where my head didn't hurt on trips and I didn't have to crank my music. But goddamn, the power loss was INSANE. Turbo spooled so much slower, and it just felt lethargic. I'm guessing a 30% decrease in power. After a week of that I put the test pipe back in. The power came right back and I'll live with the loud noise.

btw, screw those neighbors.

 

I feel bad for my neighbors - I drive through with a 3" strait pipe every day at 7am.

I have a strait pipe, so no cat obviously, and I'm wavering on weather or not to get one. On one hand, I very much enjoy shooting flames and popping on decel, but on the other hand I DO care about the environment.

 

3" Turbo back straight pipe or bust.

/thread