the car is going to be a built lsvtec running a t3-60-1
should be 300+ whp on 91 octane and 400-500hp on rac gas
the car currentely has 2.5" cat back with a straight through magna flow muffler.
what is the power differance going to be when i switch to 3" full cat back

what is the power differance in running a 3" carsound cat versus a straight pipe or hollow knocked out cat
i'm just wonder if i should wun the 3" carsound or knock it out ot run a straight pipe

 

There will be a small power difference, having a full 3'' helps a lot though.

I say keep the cat, if you are ever pulled over it's like a $2000 fine in Cali, also if you have an option to reduce emissions I would take it. Save teh whales and koalas and panda bears mang

 

how much power differance will the hollow out 3" cat make in a 400whp car???
i'm not worryed about the law everything we do is already illegal in CA. no point is not trying to break 1 law when nothing else is legal on the engine

 

When I ran with a hollow cat, people (close friends) complained so much of the stink that i reinstalled a converter... no one wanted to follow me. It was not worth it for the minimal gain, i would not do it again.

 

i had about a 4 whp difference between my high-flow cat and my test pipe, it was all 3in

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by riceball777 &raquo;</TD></TR><TR><TD CLASS="quote">how much power differance will the hollow out 3" cat make in a 400whp car???
i'm not worryed about the law everything we do is already illegal in CA. no point is not trying to break 1 law when nothing else is legal on the engine </TD></TR></TABLE>

Yeah but having no cat is an INSTANT 2000 dollar fine.

 

I took the cat off of my car on the last build and hate it. It's a whole lot louder than it was with the cat and there is a LOT more stuff coming out of the exhaust than there ever was before. Larry

 

Its also depends on boost pressure and gas volume you're putting into the exhaust that will affect power output. I'd say keep the race cat on just to avoid the hassle but here in Ohio I run STRAIGHT 3" from downpipe back and it's loud as HELL! I love it tho. Yeah, I'll admit, when cruising around it can get annoying but when you into it, it sounds INSANE!
Ryan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by _gurusan_ &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah but having no cat is an INSTANT 2000 dollar fine. </TD></TR></TABLE>

i have never seen/heard of a police officer getting under a lowered car to check for a cat.. and ive never heard of an instant 2000 dollar fine before either... thats a lot of money for a ticket if you think about it.

most cops just give you a ticket to see the BAR and have them deal with it. Besides.. cops are not trained in the field of emissions how would they be able to give you a ticket for something they know nothing about?

 

exactely
they wouldent know if the cat is hollowed out or not anyways. if anything they would just give you the ticket for the turbo and bov and exhaust

 

These type of threads have been going around for awhile now. Anyone else got any really DATA to show us?

 

i have an e-cut out setup for this exact reason... and you can either tune it with the cutout open and have it run a little rich when closed... or have two separate tunes setup... one for open cutout.. and one for closed cutout(with the cat inline) good luck, just my .02