Hey guys,
I'm wrapping up my k24/18g build and was curious what everyone thinks of running 100cell cats vs straight pipes. I have the parts to build a cat delete, and there are zero emissions in my state, so the only thing i'm comparing is noise and performance.

I'm currently running fabspeed's gen 1 exhaust with their 100 cell cats, but wasn't sure if anyone had dyno'd a similar setup back to back with cats / without to see the performance difference. I'm also curious how much more obnoxious is the volume would be. You see the youtube videos all the time but can never tell if the camera is distorting the noise or if that's really how it sounds. A close friend has an X pipe (catless) with resonators and the drone isn't terrible, but it is about 10db louder while cruising. Would the x pipe make it louder or quieter?

If I am going to build them, should I just use stainless 3" pipe, or should I try and squeeze a small resonator in there to get rid of some drone? Any help would be appreciative!

 

I have done some dyno testing on my 18g set-up which I have posted threads on.
A good large 100 cell cat, such as a HJS rated, will not restrict peak HP and TQ at this level and carry it the entire way the same as a catless ,, at around 600 Rear wheel..
But it will spool a little bit quicker and make a few more HP more coming on to boost till you hit max boost..But I never noticed a seat of the pants difference..

 

go to dr. jekylls thread on his exhaust. unobtanium exhaust . sound is to die for!

theres a speed tech 2.5 with 100 cell cats for sale on the forum. speed tech cats have vbands so you can swap them out for catless any time you wanted. good price as well

 

Go catless. X-pipe will eliminate drone.

 

My Fabspeed 2.75'' catless X-pipe was terrible with drone,,so much so I took it off after a week and went back to my first love, again...

 

Fabspeed is why. Talk to Markski or SpeedTech.

 

Even though you may not be required to have a catalytic convertor on your car, there is real reason why they exist.
It is to keep our air clean. You know, that stuff you keep breathing in every second of your life.
Doing your small part to prevent as much pollution as possible from being generated not only helps this fishbowl of a planet we all live on...it also helps you.
Pull the cats from your car and I guarantee it WILL smell like a 1960's truck.
High quality 100 cell cats will provide your tt with all the breathing it can use AND keep the air clean at the same time.

 

To me race fuel through a catless exhaust smells as amazing as fresh grilled bacon in the morning.

 

Th Dude I could not agree more but for what ever reason people think its ok=its not the air is as important as a few extra horses and yes I know I'm in the minority.

 

not true at all. both my best friend and i are catless. he runs 93 oct and theres no smell at all. i run e85 and no offensive smell either. of course since i run corn i guess thats makes me environmentally green as well:roll eyes:

 

I agree with you my friend.


All the tree huggers better be running E85 and not this terrible ocean slicking, bird slicking environmental killing to procure oil dinosaur fuel!

 

When I ran catless,,
My friends and I noticed the smell when car was running in driveway, in city traffic when the windows were down and when I would do cold start ups in the garage,,door open, my clothes got that smell on them ...It didn't bother me though..
Just saying..

 

I have vband on my exhaust and when running catless, I get the same smell as my 500hp 1965 mustang. 200 cel cats and the smell is gone.
I will say that race gas does make it smell a little different but I don't run it all the time and don't waste it smelling my exhaust too much

 

Indeed.
The odor is obvious. Unless you have no sense of smell, it's not a debatable topic.

 

I was happier with the 100 cell cats smell and there was No noticeable difference in seat of the pants feel..
But I do love the smell of race gas in my other vehicles...