Hey Fellow Mustang Enthusiasts!!!

[whitepony331]

I've been going back and forth about exhaust for my '01 V6 Mustang, and I've created some dillemas.

I'm currently running with a CAI from K&N and also BBK Shorty Headers.

My question is, if I'm trying to run an off road H Pipe (2.5") from Mac, am I going to lose back pressure? Even if I'm going to add FlowMaster Original 40s?

I'd like for my car to breathe freely, but with heavy loads of torque. Can that be possible? If so, how?

Thanks.

[Ghost Rider]

you will definitely lose some without the cats...but the 40's are pretty restrictive so you will gain some there...and that is about the best sound exhaust for a V6 IMO. If it starts to sound to tiny/high pitched..through a couple of hi flow cats on there...cause that is most likely the problem

Welcome to the boards

[Swiss026]

I've been going back and forth about exhaust for my '01 V6 Mustang, and I've created some dillemas.

I'm currently running with a CAI from K&N and also BBK Shorty Headers.

My question is, if I'm trying to run an off road H Pipe (2.5") from Mac, am I going to lose back pressure? Even if I'm going to add FlowMaster Original 40s?

I'd like for my car to breathe freely, but with heavy loads of torque. Can that be possible? If so, how?

Thanks.

What plans do you have?

As for the exhaust - I agree with Ghost...go with the Flows for the V6 :thumbsup:

[Niehaus5oh]

i agree with ghost also... and welcome to the boards man...

[Cobra4me]

welcome to MX! enjoy your stay

[whitepony331]

Thank you, thank you. It feels good to be welcomed.

I have a future with this car. It may seem to be a grand idea, but a supercharged pony will just have to be set aside. I don't really see myself with a supercharged V6.

But here are my goals:

JMod Shift Kit Transmission
FRPP 4:10 Gears
FRPP Traction Lock Differential
Intake Manifold spacer
42% Underdrive Pulleys
Stage 2+ Cam
Ported/Polished Heads
Roller Rocker Arms
DiabloSport Predator Tuned
Kenny Brown suspension/stability

I have everything all set out for me to check off the list. The only project that concerns me a lot is my exhaust. I'd love for my car to breathe freely, but with heavy loads of torque!!!

Now, can the FlowMasters give me enough back pressure? What if, instead of having 2.5" piping, I go with 2.25"? Or maybe 2"? How's that? Have a muffler shop build me one? OR!!! Go with the MAC off road H (2.5"), and run 2.25" or 2" pipe to connect to the Original 40s and out through the tail pipe.

I need help guys, I'm losing my brain.

[Ghost Rider]

Thank you, thank you. It feels good to be welcomed.

I have a future with this car. It may seem to be a grand idea, but a supercharged pony will just have to be set aside. I don't really see myself with a supercharged V6.

But here are my goals:

JMod Shift Kit Transmission
FRPP 4:10 Gears
FRPP Traction Lock Differential
Intake Manifold spacer
42% Underdrive Pulleys
Stage 2+ Cam
Ported/Polished Heads
Roller Rocker Arms
DiabloSport Predator Tuned
Kenny Brown suspension/stability

I have everything all set out for me to check off the list. The only project that concerns me a lot is my exhaust. I'd love for my car to breathe freely, but with heavy loads of torque!!!

Now, can the FlowMasters give me enough back pressure? What if, instead of having 2.5" piping, I go with 2.25"? Or maybe 2"? How's that? Have a muffler shop build me one? OR!!! Go with the MAC off road H (2.5"), and run 2.25" or 2" pipe to connect to the Original 40s and out through the tail pipe.

I need help guys, I'm losing my brain.


Hey bud...nice list you got going there...couple of things though...

-Shift Kit and 4.10 is good, that will give it a nice pull

-I probably wouldn't bother with the underdrive pullies...just because to be honest they aren't going to really do much for the price, they barely do anything on a stock V8, nothing really noticeable

-Stage 2 cam will give a little more HP but it will also probably give your car a higher pitched sound when you get up there in the RPM's,

-tuned is a great idea...especially if you do, do the cams and other things :cheers:

-and upgrading the suspension is always nice, get a bit stiffer ride with a much better looking stance :thumbsup:

Now as far as the exhaust...you'll be fine with 2.5" all the way, but don't go any bigger than that...I belive the 40's will give you enough that you should be okay with the off road H...again though, having the off road pipe is going to increase your "raspiness" especially when getting up in the RPM. If it doesn't give you the sound you want, then I suggest:

Mac Off Road H pipe with a pair of 94106 Magnaflow Hi-Flow cats welded or ban clamped in place which will get rid of the raspiness and probably make it a little deeper sounding with the 40's

Now, the reason I suggested ban clamps is that way if you wanted to have the flexibility of being able to switch out the cats and put in a couple pieces of pipes (race pipes some people call them) you can. Band clamps are great, they do not bend or crush your pipe and it makes a perfect seal. They are expensive though compared to regular muffler clamps. If you like how it sounds with the cats in and don't want to change, then you can just weld if you want...less work, cause you don't have to create any custom pipes...of course, in the end, it's up to you and how loud you want it.

94106 Maggy Hi-Flow cats, these are the ones that I run with my exhaust and when you open it up...it sounds like Off Road, my exhaust is extremely loud

http://img.photobucket.com/albums/v606/cnitro/IMG_0517.jpg


Hope this helps dude :cheers:

Ghost,

[whitepony331]

I'm also a member of AllFordMustangs, and this one guy (jgt58) suggests to run through Magnaflow Hi-Flow Cats as well. I'm considering welding them on, but the band-clamp idea is something very interesting.

We all look for that mean sound when it comes to exhaust, and what I'm really looking in sound is the '67 FastBack era. Very aggressive, high output sound at high rpm's...sounds like the valves are exploding...but in a good way.

Do you have a sound/video clip of your ride Ghost?

[whitepony331]

I like raspiness...

Which "raspiness" were you referring to?

[Ghost Rider]

yep, here's a couple of vids...

First Vid is Mac Off Road H pipe with SLP Catback

http://www.youtube.com/watch?v=bndgIB9db08

2nd Vid is a drive by with Mac Off Road H and SLP Catback 'bout 2500 rpm

http://www.youtube.com/watch?v=NS_1taG__Eo

3rd vid is Mac Off Road H with Magniflow Cats welded in and SLP catback

http://www.youtube.com/watch?v=DPtnRJIX168

4th Vid is a compilation with the original Mid pipe and SLP catback, still very loud...but not as excessive

http://www.youtube.com/watch?v=HE1jFa2eGyE

[Ghost Rider]

I like raspiness...

Which "raspiness" were you referring to?

hmmm...everyone thinks of rasp different and kinda hard to explain without comparing in real life...but sort like a higher pitched sound with alot of popping as apposed to a lower more refind sound...

I myself like exhaust sounding Raw and Hardcore...but obviously everyone has there own opinions...:)

[whitepony331]

I can tell you love your pony as much as I do.

Very nice video, I wish I'm there to listen to her in person!

I'm taking the hi-flow magnaflow cats into consideration. How much difference is a hi-flow cat compared to no cat at all?

A little resistance, right?

[whitepony331]

I don't like the popping sound that much.

[Ghost Rider]

I can tell you love your pony as much as I do.

Very nice video, I wish I'm there to listen to her in person!

I'm taking the hi-flow magnaflow cats into consideration. How much difference is a hi-flow cat compared to no cat at all?

A little resistance, right?

yeah, they will diffinitely help...when I was running with no cats...you could feel a sluggish difference when I hit the gas at low RPM's

now you can make up for that with a set of gears...but I"m happy with the sound of mine right now...plus I don't have to be as careful with the cops as far as noise pollution or whatever they call it now

[Pain Train79]

i think ghost actually works for slp...j/k man. and welcome to the site buddy!

[nystangkid]

welcome to the site man


oh btw, u must of caught ghost on a good day. he's never this friendly to new members lol

[whitepony331]

lol, that's interesting.

With the hi-flow cats, should I slap on two or four? Stock exhaust comes with four cats. So with four, don't I get more torque if I were to just get two? I was thinking of slapping on ALL four hi-flow cats, or is that too...eh? Another set up could be, front stock cats/rear hi-flow cats. And what I meant by "front" and "rear" is the whole mid-pipe.

And would it matter if I welded GT hi-flow cats on a V6? It's just pipes welded on, I don't see why it wouldn't fit. And come to think of that matter, I would get more of a higher flow since there is a higher output on a GT valvetrain.

Kudos.

[Snotboy]

You only need 2 cats, 4 would just be a waste of money. As for using cats off a gt i really dont know if they are any more hi flowing than the cats on a v6, i would go with the hi flow magnaflows.

[Ghost Rider]

lol, that's interesting.

With the hi-flow cats, should I slap on two or four? Stock exhaust comes with four cats. So with four, don't I get more torque if I were to just get two? I was thinking of slapping on ALL four hi-flow cats, or is that too...eh? Another set up could be, front stock cats/rear hi-flow cats. And what I meant by "front" and "rear" is the whole mid-pipe.

And would it matter if I welded GT hi-flow cats on a V6? It's just pipes welded on, I don't see why it wouldn't fit. And come to think of that matter, I would get more of a higher flow since there is a higher output on a GT valvetrain.

Kudos.

No, you need a perfect ballance...too much = loss of torque, too little = loss of torque. The two Hi Flow Maggies will be perfect

And the GT exhaust doesn't have Hi-Flow cats...trust me on that one...lol, so don't even bother with that...it will be more hassle than it's worth to you, the GT exhaust is really restrictive on flow

-H pipe
-Two Magnaflow cats like the ones I showed you (not the only choice in cats...but I've had good experiences with them, I know a few people that have those exact cats)
-40 series

and you'll be laughing :cheers:

[whitepony331]

Hey Ghost,

Should it be the rear cats that should be replaced by those hi-flow cats?

And which diameter should I go with the cats?

[whitepony331]

Oh and one more thing Ghost.

Instead of an H Pipe, what would happen if I ran divorced duals?

[Pain Train79]

they would probably fight over custody of the cats....LOL god i crack myself up

[whitepony331]

I thought you were serious for a second.

lol...geez.

[Ghost Rider]

they would probably fight over custody of the cats....LOL god i crack myself up

LOL, jackass

pay no attention to the man behind the green curtain...lol

[Ghost Rider]

Hey Ghost,

Should it be the rear cats that should be replaced by those hi-flow cats?

And which diameter should I go with the cats?

You want to get rid of all the cats that are on there now and put in the Hi Flow ones

and the diameter will depend on what your doing with the mide pipe...if you going to leave the stock pipe in and cut all the cats out and then....you no what, forget that...it will be way too much work...

I would do one of two things here:

-First...get an Off Road H (MAC is what I have...but there are others)
-Get your Two Hi Flow cats
-Weld them into the O/R pipe
-Get the 2.5" H pipe and the 2.5" cats

Or

-Buy a catted H...the downside being that catted H's are faily expensive, positive side, they are easier cause they already have cats in and you don't have to do any welding. The only other thing is that you don't really know how restrictive the cats are that come in the pipe, now I garuntee they will be much less restrictive then the stocker pipe...

but the only reason I suggest, doing the O/R and get your own cats, is that, me and a few others have used these cats for a while now and couldn't be happier, so I'm just speaking from experience on that part...if I had never used them before I wouldn't' recomend them cause I wouldn't know...but I have and that's why I am...lol, sorry if this got a little confusing, sometimes it's hard to explain in writing what your thinking in your head


Now, that I think of it, there is a third option you could go with here:

You could leave your Y pipe on there and just get the catback that bolts to it...like the one below, now those are MAC Flowpaths...but they sound almost identicle to the 40's...maybe even a little more RAW

http://www.brenspeed.com/mustang_v6/images/tk3848.gif


But personaly, I think I would still go the other way, depends how much work or money you want to put into it :dunno:

[Ghost Rider]

Oh and one more thing Ghost.

Instead of an H Pipe, what would happen if I ran divorced duals?


Ummm...I don't think it will really make much of a difference...reason being, I'm pretty sure the V-6's fireing order is even, where as the V-8 is uneven so that's why they put the H pipe in there in the first place, it's supposed to balance out the pressure

So, in your case I don't think you'll notice a difference at all, in which case it's probably easier just to get the H that fits your car :thumbsup:

But, up to you man, it's your baby :cheers:

Just my suggestions :)

[nystangkid]

they would probably fight over custody of the cats....LOL god i crack myself up

hahahaha:jest:

[Ghost Rider]

hahahaha:jest:

Hey, you get outa here...I'm trying to help this guy and you guys are no help...lol

:jest:

[whitepony331]

You guys are amazing.

Thanks Ghost.

I see why it's either H/X or Divorced. I get it now. Yeah, the firing on our V6s are even so, I know where to go from there.

From the BBKs: MAC 2.5" Off-Road H Pipe/Two 2.5" Magnaflow Hi-Flow Cats (94106)/FlowMaster Orginal 40s 2.5" o/o (42543)/3" tips. [sighs]

I'm looking at $425+, and that's without installation. I've checked many sources and found cheap parts.

Again, Ghost, thank you. Thanks for the suggestion about duals from the Y. I don't know, to me the Y-Pipe isn't very "True Dual." In my opinion at least...

Thanks again.

[Ghost Rider]

You guys are amazing.

Thanks Ghost.

I see why it's either H/X or Divorced. I get it now. Yeah, the firing on our V6s are even so, I know where to go from there.

From the BBKs: MAC 2.5" Off-Road H Pipe/Two 2.5" Magnaflow Hi-Flow Cats (94106)/FlowMaster Orginal 40s 2.5" o/o (42543)/3" tips. [sighs]

I'm looking at $425+, and that's without installation. I've checked many sources and found cheap parts.

Again, Ghost, thank you. Thanks for the suggestion about duals from the Y. I don't know, to me the Y-Pipe isn't very "True Dual." In my opinion at least...

Thanks again.

yeah...I hear ya, about the Y pipe...however it is a nifty little set up they have built for it...very easy...and it will still go into dual muffs at the back so the only way anyone will know is if they lift up your cars skirt...lol and take a peak underneath...

I agree...very expensive...especially if you need to have it done by a shop.

Just for my catback alone cost me $680 to get up here :(

[whitepony331]

Back from the DEAD!!!!!!!!!!!!!!!!!!!!!!!!!

I got my H Pipe yesterday, and I'm waiting on my hi-flow cats to come this week. This Friday, my flowmaster 40s and tips should be ordered.

I was thinkin' since the firing order on our V6 are pretty much even, I'm going to run divorced duals. I'll just have the muffler guy cut them off. Should I? Still debating about that choice.

[Ghost Rider]

Well they won't be divorced if you put the H pipe on...that is the whole point...divorced means...you have two sets up pipes...one on each side all the way from your exhaust manifolds or headers...back to the tail pipes...they don't meet or anywhere along the way...

Your H pipe is gonig to have a cross over in it though...so it won't be seperate duals...or am I missing something here?

[whitepony331]

I know the term "Divorced duals."

What if I had the muffler guy cut off the "H" (crossover) pipe so that way I can run divorced duals? The firing order is even on our six's, so why not?

Will there be any difference?

[Cobra4me]

I know the term "Divorced duals."

What if I had the muffler guy cut off the "H" (crossover) pipe so that way I can run divorced duals? The firing order is even on our six's, so why not?

Will there be any difference?
I did that with a former V6 that I owned with no problems

[Ghost Rider]

I know the term "Divorced duals."

What if I had the muffler guy cut off the "H" (crossover) pipe so that way I can run divorced duals? The firing order is even on our six's, so why not?

Will there be any difference?

Wasn't implying that you didn't know what it meant...I just was curious as to why you would get an H if you weren't going to use it for your intended purpose...

No, IMO, you will not notice any difference in running Divoced or with the H...so I would just leave the H as it is...

Going to be very messy for a muff shop to cut the crossover out

[whitepony331]

My bad, my bad...sorry about that Ghost.

But yeah, I mean if there isn't so much of a difference, then why cut the crossover pipe. I was just wondering that's all.

Hey Cobra4me, how did that v6 of yors ran with divorced dualies?

[whitepony331]

And where could I get those oversized side scoops you have? I'm dying to find a pair.

[Ghost Rider]

^^^those are just the stock GT/Cobra side scoops...my car has the same ones...from 2001-2004 I believe

[whitepony331]

Yeah...

That's what I thought. I'm trying to get them whenever I decide to work on "show" part of my car....but as of right now, I'm working on the GO!!!!!!!!!!!!!!!!!!!!!!!!

[nystangkid]

come on guys, stop wasting MX paper will ya.



lol jk

[Cobra4me]

My bad, my bad...sorry about that Ghost.

But yeah, I mean if there isn't so much of a difference, then why cut the crossover pipe. I was just wondering that's all.

Hey Cobra4me, how did that v6 of yors ran with divorced dualies?well couldnt tell any difference in power but it sounded good. I put magnaflows on it

[whitepony331]

Hey Ghost...

You're running with a Mac off-road H, aren't you? You catted them with the Magnaflows?

Well, how well did the cats fit onto the H-Pipe?

I got everything today (O/R H-Pipe & Hi-Flow Cats), and as I'm laying everything on the floor to get a good picture...was there enough room to weld those cats on there? Or did it require some "extra piping"..?

[Ghost Rider]

Yep...there was plenty of room...no need for additional piping, just cut out the pipe wher the cat will go and weld it up...the cats I have a very short so there was no problem...which ones did you go with? What H pipe did you get also?

[whitepony331]

I went with the MAC 2.5" o/r H's with the Magnaflow 2.5" Cat convertors (94106).

Sorry if I may have gotten the same cats as you did, but they were they only ones that would physically fit my H-Pipe. I'm not copying...lol.

But yeah, I'm sure they'll fit well without any extra modifications. I just can't wait to get my 40s and 3" Tips next week, then I'll be on my way to the muffler shop to drop my pony off.

Anyone in here can weld these for me?

[whitepony331]

I'll be sure to post a video (hopefully at the end of the month) of my new exhaust...

Thanks everyone, and thanks a bunch Ghost!

[Ghost Rider]

^^^No problem dude

[whitepony331]

And we're BACK!!!!!!!

I visited the local muffler shop down the street from me, and I told them if they can create a custom exhaust...

They asked me which cats did I have and they said that model#: 94106 was not OBDII compliant. I really didn't care, but what they also added was that the cats would melt after a while of driving. Which they recommend using my stock cats.

Is that true?

They drew out an exhaust system for me which is basically cutting the Y-Pipe, adding on an H adapter, then running the mufflers, tailpipes, etc...

I don't want to get the feeling that I bought that H-Pipe for nothing. OR the cats.

But would the MagnaFlow 94106 melt?

[Ghost Rider]

^^^LMAO, what a bunch of BS dude...no the cats aren't going to melt...lol I've had my on for 3 years now and I run my car hard hard...maybe I should go check, see if they are still there...lol

My brother is a Mechanic and they use those cats on alot of OBDII cars...so either they have no idea what they are talking about or they are just shooting you a line of BS man

so to sum up...

No they won't melt
They will be lest restrictive...free up some air flow to let the engine breathe a little better
They will sound good if the exhaust is done properly

You may need to check a different shop man...:dunno:

[whitepony331]

Thanks man.

I know I've done more homework than he did, and he's the one that owns the damn place.

I'm going back to him to show him what I'm talking about, maybe it'll get clear to him.

It's weird because at first he asked me, "What model number?" like he knew I got Magnaflows...then after I said the number he was like, "model numbers from 94 and up are not OBDII, and plus they'll melt. You're better off using your stock cats, they'll give you more flow than those."

I'm like, "What..? Ohhhhhhhhhkay?"

Straight up Bee-Essin' me man.

[Ghost Rider]

LOL...well one thing is for sure...your stocker cats will NOT give you more flow...

I'm not sure what the guy is talking about :dunno:

[whitepony331]

An update: 2001 V6 Mustang "The White Pony"

Exhaust Specs:
-- 2.5" MAC Off-Road H-Pipe
-- 2 MagnaFlow 2.5" Hi-Flow Cats
-- FlowMaster 40s O/O 2.5"

Well, all I can say after MONTHS of blueprints...WOW! Love that sound! There are some pros and cons about this exhaust project of mine that I will explain, but here are some experiences I've had for the past two days...

After months of preparation of saving money and time being well spent, I've come to realized some things. Overall the sound is amazing! People look, and they look for a very long time. I can't really argue about the sound, but on the performance part, it totally set my mind on a very different state. I'm just getting adjusted to this modification, and already I feel like I want to modify it again. As Edison quoted about 10,000 ways of how to NOT do it, I'm back to the drawing board.

The problem that I have is that I want my low-end torque back. Don't get me wrong, my Pony BREAHTES...but a bit too much where I'm losing back pressure. Maybe it doesn't work for our 3.8s, but well enough for our big brother's 4.6s. I drive an automatic, and usually at 4000+ rpms it'll switch to second. On this new addition, she'll switch off to second at 5000+ rpm, how did that happen? How did my shift patterns differ from more air-flow? She totally feels like a different Pony. I volunteered to bring her to the shop at my Auto Tech class, and when they hoisted her up, my Instructor added his two cents. "Not only they did a LOUSY job with the installation, you're never going to pass smog (which I already knew), which your 'check engine light' will come on at all times leaving your engine's performance to lag, and no more bottom-end torque..."

I asked him what are my options? And he clarified with me to put my Y-Pipe back on, adapt it to an H, and go on from there. Now, if possible, since I'm running FOUR cats on my stock mid-pipe, could I replace the last two cats with my Hi-Flows? Which of the four cats should I replace with a pair of the Hi-Flows? I'm really considering this, because small blocks like us could only put out an amount of exhaust that we DEFINITELY need that bottom-end torque. It feels as if I traded my bottom-end torque for my top-end. Correct me if I'm wrong though.

I'll see what'll happen to my current exhaust when I add my Trac-Lock and 4:10s. I hope it'll give me my push back, though those 4:10s will create better acceleration.

Pros: SOUND! More air-flow. Finally I got it done!
Cons: Too much flow. Some back pressure gone. Probably went to the WRONG muffler guys.

Thanks guys for all of the information. You guys have been a great help, especially you Ghost.

[Ghost Rider]

couple of things man...

1. Why would you not pass emissions? Are the cats not in there or what? Cause the are OBD II complient...up here they pass no problem :dunno:

2. Sucks they did a lousy job, I don't see how you could have lost that much back pressure unless they really phucked something up and you have some exhaust leaks...at any rate...gears can usually fix that problem

I don't see why you have to change anything though?

Did your engine light come on, or did somebody just say it would?

Glad you like the sound though

[whitepony331]

The cats aren't even on there...

It's the whole mid-pipe, then on the middle of the chassis the two cats, then the H, then the mufflers.

I seriously think they funked up the set up I wanted. I'll be seeing those guys within a couple days or so.

Yeah Ghost, there is so much air-flow but there's not restriction to create back-pressure. It's really making my driving style different. I have my stock Y-Pipe here, so I'm going to see where I could go from there.

Which of the four cats that I have be replaced with the two Hi-Flows? (MagnaFlows) The fronts or the rears? As you can see, I'm tyring to get my push back. Maybe with two front stock cats, then two rear hi-flow cats will not only allow smog-lega, but my push back as well.

Right? Thanks.

[whitepony331]

Here's an update with video:

I took her to the same shop this morning asking if they can make any adjustmenst with my current set up that I had at the moment.

I told them what I wanted, and for $90 I was hoping I was going to get it. I came back to them about 4 hours later to find out that they didn't do what I asked in the beginning. Their set up was this...

Stock cats________gap________hi-flow cats/H pipe crossover/mufflers/tailpipes.

I spoke to the manager right away telling them that they did it wrong. As I was told by the manager, he said that they couldn't accomplish what my orders were because adding thos two hi-flow cats right after my stock cats was difficult being that the frame of my chassis was in the way, and that could result damages.

I gave a sigh, and just took her and drove off confused and pissed.

Once I got home, I took a video of her through my camera phone. It may be muffled, but it's basically the concept of what I'm having right now.

Here it is:

http://youtube.com/watch?v=vS-iwaFot_g

What do you all think? Ghost? What do you think?

I visited some friends of mine that owns a battery/mechanic/restoration shop, and told them my dillema. Hoepfully, one of my boys will come through and find my answers through his connections.

All I'm dealing with right now is having my last two hi-flow cats scooted up right next to my stocks. Wouldn't the set up right now create a flow-restriction because of that gap?

Thanks in advance.

[blueblazes]

1) have you had the car tuned yet? this can help with check engine lights and such problems that arise from exhaust changes
2) even the 4.6 cars love back pressure they are not torque monsters and rely on backpressure to create torque but there is a point where to much restriction is a bad thing
3) as long as you have an egr and cats you can pass emissions
4) I would go with a H or X pipe configuration with the header back exhaust and keep in some high flow cats this will keep backpressure and also allow you to pass emissions. I make close to 700 flywheel hp 600 to wheels with high flow cats and stock headers. Going offroad without cats isnt necessary to make power. I definately wouldnt go any larger than 2.5in exhaust on a v6
5) where you located if i missed it

[whitepony331]

1) have you had the car tuned yet? this can help with check engine lights and such problems that arise from exhaust changes
2) even the 4.6 cars love back pressure they are not torque monsters and rely on backpressure to create torque but there is a point where to much restriction is a bad thing
3) as long as you have an egr and cats you can pass emissions
4) I would go with a H or X pipe configuration with the header back exhaust and keep in some high flow cats this will keep backpressure and also allow you to pass emissions. I make close to 700 flywheel hp 600 to wheels with high flow cats and stock headers. Going offroad without cats isnt necessary to make power. I definately wouldnt go any larger than 2.5in exhaust on a v6
5) where you located if i missed it

1. My car isn't tuned yet, I know it'll be better if it was. But I'm looking to tuning my car when I get my 42% pullies.
3. I do have those, it's just the way my cats were setted up. This new set up will defnitely not allow me to pass.
4. Header back exhaust? What is that? Yeah, I'm sticking to 2.5" all the way through.
5. Pasadena, CA. Emission Law central.:screwy:

[Ghost Rider]

I still don't understand exaclty what's going on here...you said the cats aren't even there...what do you mean...didn't they put them in?

Okay here's the deal...I don't know if you seen this before but I put this up a while back

http://www.mustangexhaust.com/forums/showthread.php?t=11

Okay below is the picture from that thread.

This is the basically what you looking to do and should do...don't let the muffler shot phuck you around...Now most people with V6 get a GT take off which is basically the stock GT catback that someone no longer wants cause they've upgraded to something else...now, this is basically what your doing except you went ahead and bought the Flowmaster catback right?

Okay...the mid pipe...if you look at the V8 mid pipe (I didn't label it) but the Mid pipe (green in picture) has 4 cats...well it's two cats and two pre-cats to be more correct...now your offroad H should look very similar except it won't have any cats at all correct? Now, if the shop new what they were doing they then you pipe should look exactly like the green on in the picture except it won't have the pre cats in it wich are the funny shaped ones on the left of the picture. The hi flow cats should be pretty close to where the other two stock cats would normaly be. With me so far my man?

that should be plenty of backpressure for you...another reason people go with the GT take off system is it's actually a littl smaller than 2.5" cause of it not being mandrel bent...so some parts of the pipe are actually alot closer to 2". This can help with the V6 backpressure. Also...then people can weld in a pair of Original 40's (flowmaster) instead of the stocker muffs. The cat back you got has the 40's but they would be the delta 40's which aren't quite as loud or deep as the original 40's.

^^^with the above...there should be no emissions failing and no engine light coming on...so tell that muff shop to get their sh*t together.

I listened to your vid...and yeah, it's hard to tell cause of the camera phone I think you said you used...but it sounded pretty good when it started up...but then was destorted when you reved so hard to tell...but I mean ultimatley what your going for is something you like and can live with...I lot of people don't like noisy cars...but I LOVE EM'

Here's my car with NO CATS AND SLP REZZY'S absolutely no backpressure at all but she was loud...

http://www.youtube.com/watch?v=bndgIB9db08

Hope this helps dude :cheers:

http://i2.photobucket.com/albums/y2/GstRdr/exhaust_system_01copy.jpg

[Ghost Rider]

^^^oops...it was just brought to my attention that I already posted that vid in this thread...ah well...lol

[whitepony331]

The V8 setup is what I have goin' on, but!!! There is a space (gap) of 2.5" piping between the pre-cats (stock) and the last cats (hi-flows). That's what's bothering me. It's like, a flow-restriction from the first cats, then flow travels through the gap. Then ANOTHER flow-restriction from the second cats. I'm starting to realize that that's probably the reason why it sounds more muffled, because there isn't that gust of flow traveling through my 40s. I figured, if my cats were together more air-flow would travel doesn't get filtered out so much...you know? I should've recorded my Pony when I only had TWO cats on, she was LOOOOOOOOOOOOOOOUD!!!

After that setup, dual catback FlowMaster 40s exhaust. I asked them to scoot my last cats near my pre-cats, but they couldn't do it. And I still paid them...=\

I have to apologize, you may have been so confused because of my terminology. I'm barely getting the hang of these things, it's like I know what I'm talking about, but I don't know what they're called. Which gets so confusing to many.

I LOOOOOOOOOOOOOOOVE loud ass American Muscle. But out here, it's noise pollution, which sets off bacon radar.

Where can I get ORIGINAL 40s? I thought I bought them, American Thunder Original 40s model#: 42543?

[Ghost Rider]

^^^Nope, those are the Delta 40's, not quite as loud as the originals

Unfortunatly I don't think Flowmaster macs the originals anymore...unless you can find a pair on ebay...the other just is to pick up a set of MAC Flowpaths...they are almost identicle in sound