I am going to get Pacemaker headers and a high flow cat installed in my Verada when the supercharger goes on in a couple of weeks.

I need some advice on which high flow cat to go for. Currently the only exhaust mod i have on the car is a Reback cat back exhaust.

Are there any particular brands of high flow cats i should be looking at? Metal or ceramic? 2.5" or 3"? Your feedback is appreciated :cool:

Metal 3" cat converter. They're $40 more than the 2.5" versions and gauranted no restriction for a 2.5" system. You'll find your exhaust if going to be much louder, I added 2 extra hotdogs to my exhaust to get it under 90db.

+1 for metal cat

+1 for extra resies.

I had a hotdog ressie put on when i had mine done (pacemakers + cat + exhaust), but ended up sounding like a fat bastard farting into a milo tin. I had a standard type resonator put on instead and that make it sound just like it did before...

+1 for metal cat

+1 for extra resies.

I had a hotdog ressie put on when i had mine done (pacemakers + cat + exhaust), but ended up sounding like a fat bastard farting into a milo tin. I had a standard type resonator put on instead and that make it sound just like it did before...

Yeah I have ended up for my exhaust, pacemakers, 2.5" flex, 3" cat, hotdog, hotdog, hotdog, Xforce PT01 muffler all with 2.5" mandral bends and piping. It just gets under 90db, but has no drove what so ever lol

If the piping before the cat is 2.5" in diameter (due to a 2.5" flex pipe), would the flow characteristics of the exhaust be effected in a negative way if you suddenly went to 3" (high flow cat) and then back to 2.5" (cat back piping)?

I would think it would be wasted because it goes back to 2.5inch anyway, and might make the airflow a bit more turbulent which could be a bad thing??? Although ive heard before that its ok for and some factory cars have exhausts that get slightly smaller towards the end, which is fine because the air is cooling down and therefore doesnt need as great a volume. Not gonna give a definite answer for any of those q's though coz im no expert, just what seems logical to me.

Ollie

no its fine!

just get them to flare the 2.5" pipe to be compatable to the 3" cat cos if they just put it in and fill the gap with weld thats just gay!

a good shop would do it anyway! but most are dodgey lol

on a N/A car there is little difference in exhausts, you wouldnt notice any gain from stock to modified bar sound in my experience

but i believe the system i had gave my car a real gain, other than the exhaust i had all the same mods etc as other sprintexed ppl but much more power!

my set up is HM stainless headders 3" metal cat 2 3" hotdogs 3" mandrel bent stainless pipe, split into 2 2.5" manrel bent pipe just past rear axle and 1 2.5" muffler either side...

under legal DB not too loud, awd's are pretty straight so would sound different on fwd, but drones too much for prettymuch everyone, although quiet when not under load... then decent when on the gas....
See vid here of it in action!! (http://www.youtube.com/watch?v=L9rGi71t6Kk)

I would think it would be wasted because it goes back to 2.5inch anyway, and might make the airflow a bit more turbulent which could be a bad thing???
That's what i was thinking but now i'm not exacty sure.

That's what i was thinking but now i'm not exacty sure.


quite the opposite cats smooth out the airflow

seen mythbusters?

when they use all the straws to smooth out the airflow, similar thing

cat pics

that is a bad picture of a cat. i haven't seen any cats like that. all the ones i have seen have the holes running from front to back. but it does give the general idea.

+1 for metal cat

+1 for extra resies.

I had a hotdog ressie put on when i had mine done (pacemakers + cat + exhaust), but ended up sounding like a fat bastard farting into a milo tin. I had a standard type resonator put on instead and that make it sound just like it did before...

Yep i agree with extra resonators.

My system is ceramic coated pacemaker headers with 3" pipe and flex to a 3"inlet/outlet metal cat the exhaust then reduces to 2 1/2" piping from just after the cat which then goes into a 14"x 6" oval style resonator (in the stock exhaust postion) then onto a 12" "hotdog" non louvered resonator (ralliart magna style & postion) near the side of the fuel tank then that goes into a 18"x6" round Magnaflow rear muffler.

The resonators and the muffler are of a straight thru design.

well MOHIT
since i am also in the market for a highflow CAT i have been calling around many places, and i have heard mixed opinions about going from 2.5" cat to 3" piping and all that

the most reccomended with PACEMAKER extractors is a 2.5" highflow cat and just leave your 2 piece redback system
the 3" is excessive, it would only make more noise and if u change the piping from your redback then its really a new exhaust system

also most people i have spoken to suggest a 2.5" cat from the pacemaker because the end piping of the extractors are 2.5" aparently

but see how you go and call up and find out, i mean my plans
already have pacemaker extractors
already have magnaflow 2.5" chrome muffler and a tip
just to get the HIGHFLOW CAT and a full 2 piece redback system BUT to chop off the black redback muffler and weld mine onto it cause the chrome muffler will look better

then again your planning supercharged so i would double check things, ESPECIALLY the pacemaker, try looking at the RPW race extractors for your supercharging needs

goodluck mate

Just my 2c

I would stick wit the hi flow 2.5 cat..... unless your going 3' from the cat back you will get no more from it apart from having to add another resonator to kep the drone out....

I'm stickin wit a standard flow 2.5 on my 3.0 to keep some backpressure because i'm not going the blown route.

Good lick wit your choice!:D