DJE624 Downpipe Installation

[68_GT]

do you think there's much / any power gain by removing the 3rd cat ?

I wonder what exhaust set up will give the most power and not be loud ?

my 2000 Mustang made 708 hp at the wheels and had no cats and never smelled like gas. Gas smell makes me nausious I can't have that smell esp in my family cruiser with my 3 girls.....

[BiGMaC]

do you think there's much / any power gain by removing the 3rd cat ?
Gas smell makes me nausious I can't have that smell esp in my family cruiser with my 3 girls.....

I hate a raw gas smell on a car too. I have, and many others have commented on the quick sooting of the exhaust tips.  It makes me wonder if the engine runs on the rich side at lower rpms so that maintain fuel at higher rpms or rapid acceleration.

There should be some power, but I'd bet the engine likely should be tuned for this to get max benefit. The turbo technology keeps me thinking.  Only a dyno and data logging pre and post can objectively say what the increase is or if it is significant.

[SHOdded]

Thanks Jeff.  I'm shootin' for a 12.8  Haven't heard from the neighbors but since it's kind of a retirement community (over 50)  I don't think they can even hear me. 

They're probably thinking "Those young 'uns nowadays ..."

[DJE624]

Yeah, I notice the "smell" more in colder air especially when it's warming up in the garage.  This is like my 5th car I've run catless so I'm used to it.  LOL

Yeah, I only noticed it when I backed up to the open garage.  It's not that bad.

I hate a raw gas smell on a car too. I have, and many others have commented on the quick sooting of the exhaust tips.  It makes me wonder if the engine runs on the rich side at lower rpms so that maintain fuel at higher rpms or rapid acceleration.

There should be some power, but I'd bet the engine likely should be tuned for this to get max benefit. The turbo technology keeps me thinking.  Only a dyno and data logging pre and post can objectively say what the increase is or if it is significant.

I think you are right.  The tunes run a little rich so they have more fuel up top.

do you think there's much / any power gain by removing the 3rd cat ?

I wonder what exhaust set up will give the most power and not be loud ?

my 2000 Mustang made 708 hp at the wheels and had no cats and never smelled like gas. Gas smell makes me nausious I can't have that smell esp in my family cruiser with my 3 girls.....

If you are using non catted down pipes, you probably won't gain too much more deleting the third cat.  (At least you are not pushing exhaust through two cats.)  I think though that deleting the third cat and leaving the resonator in will net you the most gain and still be audibly palatable. That's my plan.

Thanks Jeff.  I'm shootin' for a 12.8  Haven't heard from the neighbors but since it's kind of a retirement community (over 50)  I don't think they can even hear me. 

They're probably thinking "Those young 'uns nowadays ..."

Hey, that's me!

[Joleat]

Has anyone just replaced the stock mid-pipe (3rd cat and resonator) and kept the stock downpipes and mufflers? Thoughts? I know stock downpipes aren't the best for flow, but what about the sound?

[BiGMaC]

Has anyone just replaced the stock mid-pipe (3rd cat and resonator) and kept the stock downpipes and mufflers? Thoughts? I know stock downpipes aren't the best for flow, but what about the sound?

I don't understand why this alone would be done... Look at the pics of the stock and OEM DPs http://www.ecoboostperformanceforum.com/index.php?topic=2054.msg28591#msg28591

Why would you want to leave the flow restriction coming out of the turbo manifolds, then relieve restriction... might help, but can't overcome the initial restriction or offer what you need for optimal early turbo spooling.
Of course I haven't done this and have no objective or subjective data on how your idea would affect performance ... maybe you could get some! 

[black99lightning]

When you going to be able to go to the track?  I think a 12.8 is definitely in reach.  I'm gonna wait for a cold day before I go back again. 

[Joleat]

BigMac,

I think you may have misunderstood my question. The performance aspect isn't really a concern of mine. I was just wondering how it would sound. I can fabricate an x-pipe for next to nothing and was just wondering if it would be too raspy. My initial thought is that it wouldn't be bad with the stock downpipes and mufflers, but I was hoping someone had already tried it.

[BiGMaC]

BigMac,

I think you may have misunderstood my question. The performance aspect isn't really a concern of mine. I was just wondering how it would sound. I can fabricate an x-pipe for next to nothing and was just wondering if it would be too raspy. My initial thought is that it wouldn't be bad with the stock downpipes and mufflers, but I was hoping someone had already tried it.

My bad.... sorry... I get it now. Took a minute     ...  Senior moment I guess! 
Go for it and see.  I do know DJE thinks it's too raspy with the resonator and third cat removed, but he also did non-catted DPs (see his post)

[Joleat]

No worries!

I read the post about sounding raspy with the aftermarket downpipes. I was hoping that wouldn't be the case with stock catted downpipes.

I'll be honest, I'm a sucker for the sound of a gasoline-powered V8. I know I can't make the 3.5EB sound like a V8, but I would definitely like a little more rumble.

[black99lightning]

I want mine to sound like a GN.  I've heard a couple that have that sound.

[yowen]

This is why I am starting with catless downpipes and from there I can see how much sound I want to add and how. From there there are a lot of things I can change, the cat, the resonator, the muffler, the whole system.

[68_GT]

This is why I am starting with catless downpipes and from there I can see how much sound I want to add and how. From there there are a lot of things I can change, the cat, the resonator, the muffler, the whole system.

that would be my plan too.


as far as who is asking about removing the 3rd cat adding an x section and removing the stock resonator only I wouldn't expect much if any change in sound. I think others have done this with very little benefit.

[Needmoreboost]

I removed only the third cat.  Sound level went up maybe 5-8% tops.  I can though hear the turbo's spool down now at start up.  Pretty cool.  The car feels like it does spool a little faster. The Corsa system is actually not a cat back because it removes this third cat.  But, it's also a LOT of moola.  Bottom line, a good tune makes 95% of the power versus anything else you can do outside of meth or upgraded turbs.

[SwampRat]

The Corsa system is actually not a cat back because it removes this third cat.  But, it's also a LOT of moola.  Bottom line, a good tune makes 95% of the power versus anything else you can do outside of meth or upgraded turbs.

Yes $ for $ a tune is the best bang for the buck , But if you want more power than what a base tune with mostly stock intake / exhaust can provide you Need to improve on the bottle necks in the rest of the system .

The second best improvement over a tune is Better Downpipes .

Some Folks just Map the way to where they want to end up differently .

MY first Mod was the Corsa exhaust then AirAid then the BIG one .... TCE/Wilwood Brakes .

Last Night Power Mods Begun .... PPE catless DownPipes  , SCT iTSX tuner and tunes from Torrie  and      Ecoboost Performance Parts  HotPipes with TIal BOV are ordered and on the way .

No METH  and will have a Track Tune ( or the street on occasion ) for 100 octane . I only live about 10 miles from a strip and race fuel .