High flow cats?

Anyone in town sell the high flow cat manifold to center of system replacements? I was thinking it would help the breathing ability with the supercharger.

I run a saleen supercharger 0n my 4.6 and lost torque and hp on the dyno,so i put the old cats back on.

Dont know of anyone local, but online always has deals!

i'd run it catless if you can deal with the noise increase.

like jarrod said the best deals for highflow cats will be online. whichever you go a retune will be required to see performance gains. greg can hook you up on that.

carcrazy53 wrote:I run a saleen supercharger 0n my 4.6 and lost torque and hp on the dyno,so i put the old cats back on.

YIKES!!! Plan B ??? Would like a little more noise, its way too quiet!

Tom I dont see you losing Tq and Hp from freeing up the exhaust. You should GAIN HP and Tq due to free flowing exhaust being able to escape faster.

Tony's results are not typical and on the contrary are almost unheard of.

06GTR wrote:

carcrazy53 wrote:I run a saleen supercharger 0n my 4.6 and lost torque and hp on the dyno,so i put the old cats back on.

YIKES!!! Plan B ??? Would like a little more noise, its way too quiet!

So you installed the high flow cat exhaust? And its too quiet? Looks like you need to go catless!!!

I probably gained 10-15rwhp on mine going to off road x-pipe.

Mine is typical according to brenspeed and greg.The back pressure is needed to help build boost.When brenspeed changed the cats and left the boost the same the numbers dropped and so did boost.They recommened putting them back on or retune the car.468rwhp and perfect air fuel was good enough for me.

carcrazy53 wrote:Mine is typical according to brenspeed and greg.The back pressure is needed to help build boost.When brenspeed changed the cats and left the boost the same the numbers dropped and so did boost.They recommened putting them back on or retune the car.468rwhp and perfect air fuel was good enough for me.

My research tells me different. Must be an isolated thing.

You are correct when saying back pressure is connected to boost. When freeing up the exhaust gasses you effectively decrease back pressure, which intern lowers the boost level output, BUT should increase power or at least sustain your HP.

Basically with decreased boost due to decreased pressure (less stress on the motor) you can actually sustain or gain power. I have not seen too many people lose power by going with a high flow cat or no cat system.

This is why I say its not typical as speaking with Justin at VMP and also dealing with lethal performance I have found that you gain more than you lose.

*** Rule of thumb to anyone that is supercharged....anything you do to add more airflow on the intake side will effectively increase boost, anything on the exhaust side should free up HP but decrease boost.

Boost is a measure of restriction. Boost pressure does not always equeate to a certain HP level. Boost is the internal pressure of air being forced into the motor. All your doing by adding a high flow or cattless exhaust is allowing that pressure to escape the motor more efficiently. Which intern lowers boost pressure BUT increases HP. All a motor is, is an air pump. Physics apply.

Probably depends on the motor and how efficient the exhaust already is. Of douse when your over 450 hp I'd say your not going to notice a loss of 5-10 hp or torque. Your motor will be less restricted to move though. Keeping in mind that an engine is basically just a large air pump.

o/r x FTW! leter breath

loweredf1 wrote:o/r x FTW! leter breath

x2!! Ive been thinking of throwing on an o/r X but I really dont want the poppy sound. I would like the added sound at WOT and the power it would free up....but I want to hear one on a 2010+ GT500 with an off road setup with stock mufflers to decide

might i recommend an offroad H?

I liked the sound of my O/R H on my 06 GT with flows.

i happen to have an off-road x for sale.

The best sound i ever heard was jarrod's set up on the GO.

carcrazy53 wrote:The best sound i ever heard was jarrod's set up on the GO.

Thanks Tony!!!

UPR O/R X pipe with Roush Off Road mufflers (Borla Stingers basically)

I have the UPR o/r X on the terminator with Magna flows and love it. Would like to hear a similar setup on a GT500.

Tom, have you decided on a direction yet?

carcrazy53 wrote:The best sound i ever heard was jarrod's set up on the GO.

yea, fueling that ego fire is always a good idea.

fst06stg wrote:

carcrazy53 wrote:The best sound i ever heard was jarrod's set up on the GO.

yea, fueling that ego fire is always a good idea.

I have used JBA high flow cats for sale off my car they are for long tube headers

KBCal wrote:I have used JBA high flow cats for sale off my car they are for long tube headers

ahh so thats your new tramp stamp.

Guest wrote:Tom, have you decided on a direction yet?

Not yet, Lots of good feedback from everyone here though. Not been driving it much lately. With Christmas and all the work stuff going on I haven't had time to think about it. I really loved the High flow Cats on my Saleen. I know I don't want to go Offroad H though, it would be too loud and I don't like the Check Engine light on all the time.

Hey Tom...that thing is supercharged right? If it is it must have a tune on it....and most tuners when they write a tune regardless of what you have for exhaust turn off the rear Oxygen sensors. So more than likely you will not have a check engine light if you went O/R

But like you said...it would be too loud. A good High flow catted X would sound decent :)

Yea it is Supercharger and has the tuner with it but with the mufflers it has it would be obnoxious with no cats! I may wind up selling it anyway. My old 40 coupe is back up for sale and I really regret selling it!