Who's running a full 3" with IRS, midpipe back?

[Crackerballer]

Hey everyone, I have seen many posts suggesting the benefits of a full 3" system when you get about around 600whp. I love the sound of the off-road H-pipe and flowmasters on my 2004, but I know the flows don't.... flow well.

So I want to start replacing the pieces with a full 3" system, catback first. Yet every post I read, people with 3" systems have fit problems. Seems like Bassani and Mac are the only real choices. I called Magnaflow today, they have no plans for making a 3" system for the Cobra, but they are for the Mach1 (why, who knows).

So is anyone running a 3" catback that fits well? The Bassani is $900! Also, what 3" midpipe are you using, and do you have headers?

My plan was:
Kooks 3/4-7/8 stepped LTs
Kooks 3" midpipe with HFCs (this tapers to a 2.5" outline, maybe the ball end can be trimmed slightly?)
A good quality 3" catback.

Thanks for the feedback everyone.

 

[SlowSVT]

Not sure what do you mean when you say your O/R H pipe and Flowmaster don't flow? If you want more flow your going to have to make more noise. All a 3" system is going to do is slow the exhaust velocity which won't scavenge the gasses as well. It will also have a lower resonance frequency and may "drone" at cruising speed. The 2 1/2" system will sound "crispier" and responds better at part throttle but won't hinder your top end unless you go "real big" on hp and "keep it there". Most aftermarket Terminator systems are 2 1/2", there is a reason for that.

Just something to consider.

:burnout:

 

[20SVT03]

I've got a full 3 inch system and love it. Well atleast the sound and power. I have kooks long tubes from jdm to a jdm h pipe and with the irs I had a MAC system that fit pretty good not great. The quality was the bigger issue. Under the fuel tank is where the tail pipes joined to the muffler pipes with a ball and socket couple. That rusted. Now I went sra and got another 3 in system and had the hardest time getting it to fit and if it weren't for my buddy giving me his 3.5 in tips or I would have hated the exhaust.

 

[Crackerballer]

SlowSVT, in my OP I said I planned on getting about 600rwhp which from all my reading is where the full 3" system starts to be beneficial (esp around 650). Instead of buying several products and switch as I move up, I'd rather buy the 3" catback now and then add the headers and midpipe at a more appropriate time.

I know my selections for an off the shelf system are limited to Bassani, Mac, and Flowmaster (maybe JBA, can't remember right this second). But to echo 20SVT03, I have heard TERRIBLE things about the Mac quality and fit. So it's Bassani at around $800 or the Flowmaster 3" for $560, and then it has to be welded.

The good thing about the Flowmaster system is if I didn't want to use the 40 series that came with it, it would be easier to swap them out before it is installed and welded on. I am just trying to find some hardcore evidence of the Bassani or Flowmaster system fitting well, sounding good, and performing.

 

[jrgoffin]

JBA also makes a nice 3" system. One is even meant for use with a 3" mid-pipe:

JBA 40-2626 EVOL Exhaust 99-04 COBRA EXHAUST SYSTEM - eBay (item 200461571005 end time Feb-08-11 14:39:14 PST)

...the other fits a 2.5" mid-pipe:

JBA 40-2625 EVOL Exhaust 99-04 COBRA EXHAUST SYSTEM - eBay (item 200461571000 end time Feb-08-11 14:39:11 PST)

Plenty of sound clips on YouTube as well.

 

[SlowSVT]

SlowSVT, in my OP I said I planned on getting about 600rwhp which from all my reading is where the full 3" system starts to be beneficial (esp around 650). Instead of buying several products and switch as I move up, I'd rather buy the 3" catback now and then add the headers and midpipe at a more appropriate time.

I know my selections for an off the shelf system are limited to Bassani, Mac, and Flowmaster (maybe JBA, can't remember right this second). But to echo 20SVT03, I have heard TERRIBLE things about the Mac quality and fit. So it's Bassani at around $800 or the Flowmaster 3" for $560, and then it has to be welded.

The good thing about the Flowmaster system is if I didn't want to use the 40 series that came with it, it would be easier to swap them out before it is installed and welded on. I am just trying to find some hardcore evidence of the Bassani or Flowmaster system fitting well, sounding good, and performing.

Exhaust velocity can be just as important and flow. Carefully go back and re-read my post. 600 hp is not considered "big numbers" on this engine. Keep in mind the majority of the time engine will be operating in the mid-range rpm's where having such a big set of pipes won't work as well. I am building a high-end Boss 5.0 and have a set of JBA shorties, 2 1/2" MRT catted H and a 2 1/2" Magnaflow catback. NO LT's or a 3" systems will find it's way on my car but that is just me.

Give this some more thought. "Bigger" is not always "better" especially with exhaust systems.

 

[Crackerballer]

^^ I am not saying you are wrong, but I would like to see dyno proof of this. Has anyone done a back to back comparison of a 3" system vs. 2.5" system? I know what theory and physics say, but it'd be nice to see a standardized comparison.

 

[11secCobra]

Hey everyone, I have seen many posts suggesting the benefits of a full 3" system when you get about around 600whp. I love the sound of the off-road H-pipe and flowmasters on my 2004, but I know the flows don't.... flow well.

So I want to start replacing the pieces with a full 3" system, catback first. Yet every post I read, people with 3" systems have fit problems. Seems like Bassani and Mac are the only real choices. I called Magnaflow today, they have no plans for making a 3" system for the Cobra, but they are for the Mach1 (why, who knows).

So is anyone running a 3" catback that fits well? The Bassani is $900! Also, what 3" midpipe are you using, and do you have headers?

My plan was:
Kooks 3/4-7/8 stepped LTs
Kooks 3" midpipe with HFCs (this tapers to a 2.5" outline, maybe the ball end can be trimmed slightly?)
A good quality 3" catback.

Thanks for the feedback everyone.

i had those exact headers with a 3" collector the necked down to the 2.5" offroad midpipe...and back to some 3" mac pro dumps. i loved it, sounded great, but did drone quite a bit. EVERYONE that heard the car had nothing but good things to say, always!...forget talking on your cell phone in the car. good luck finding a company that makes a catback...i had to rig up some stepped pipe after the mid pipe to get it to fit up to the 3" mac mufflers dumped before the axle

 

[Crackerballer]

I like the 3" JBA sound, but if I buy the one that fits to stock manifolds then if get a 3" midpipe/header setup, I have to have it modified. I think the best thing for me to do is keep what I have (Mac offroac prochamber midpipe and flowmaster mufflers) and do everything at once, 3" catback, 3" mid and the Kooks headers.

It's frustrating everyone makes 3" systems that then taper to adapt to 2.5" components. I may but the headers and the JBA catback, and have a custom 3" midpipe made. Damnit people, make stuff that works together!

 

[Crackerballer]

Just wanted to bump this thread as an alert to the JBA exhaust. This vendor on Ebay is selling the 3" catback that bolts up to JBA's 3" midpipe for $369 shipped! This is the same exhaust Summit and others sell for anywhere from $470 to $500 plus shipping. For the price, you can get the catback and midpipe cheaper than most catbacks!

JBA Cat Back Mustang 99-04 Cobra 4.6 True 3" Exhaust SS - eBay (item 350426659511 end time Feb-27-11 13:24:06 PST)

 

[Satyr]

^^ I am not saying you are wrong, but I would like to see dyno proof of this. Has anyone done a back to back comparison of a 3" system vs. 2.5" system? I know what theory and physics say, but it'd be nice to see a standardized comparison.

I can't find it right now, but I am pretty sure that someone actually did do this test. They found that the 2.5" exhaust had higher numbers. As I said, I can't find it right now, but I am almost positive of the details and results.

 

[CobraStruck]

If 3in. systems will hurt our cars performance because of the size then why do the new 5.0L GTs have 3in. systems from Ford? The 5.0L engine makes 412 flywheel and ours probably make 420-430 flywheel. Why would it hurt our engine and not theirs?

I have the Stainless Works 3in. Exhaust manifolds back and love it. My car is upper only and has a best 1/8th mile time of 7.05@100 on 17' drag radials. I don't think its hurting me a bit!

 

[Satyr]

If 3in. systems will hurt our cars performance because of the size then why do the new 5.0L GTs have 3in. systems from Ford? The 5.0L engine makes 412 flywheel and ours probably make 420-430 flywheel. Why would it hurt our engine and not theirs?

I have the Stainless Works 3in. Exhaust manifolds back and love it. My car is upper only and has a best 1/8th mile time of 7.05@100 on 17' drag radials. I don't think its hurting me a bit!

I don't disagree. There is a fine line being walked between the proper diameter for scavenging and too small a pipe to allow for flow at higher RPM's, when backpressure is obviously unwanted. Also, the fact that the new 5.0 has larger displacement and is N/A renders the comparison useless.

I am just relaying the information that I think I read. I will try to find the post this afternoon.

 

[CobraStruck]

I don't know why you say the fact that the engines are different renders the comparison useless. Engines are air pumps plan and simple. If anything this comparision only proves my point. Our engines have a supercharger forcing air into it while the new 5.0L has to rely on volumetric efficiency to pull its air into it. I can almost guarantee a new 5.0L is not flowing as much air at wide open throttle compared to a stock Cobra motor under boost at wide open throttle yet its okay if they have 3in. systems but not us. If a Cobra engine flows more air it also has to get rid of more air via. a larger diameter exhaust. I understand the scavenging affect in an NA engine but I also understand that under boost and during the Valve Overlap in a cycle boost also helps to push exhaust out of the cylinder. This has been a debate for a long time. Buy what you want. I would go for the 3in. system. Especially if you want it to be big enough for future modifications.

 

[GodStang]

Many people have posted track times before and after with .2s and 5mph gains (About a 60rwhp gain) from just this swap. Also 99% of the exhaust companies say 2.5" is good for around 500bhp. Many of us are past that.

 

[Crackerballer]

GodStang that is everything I am reading too. I know on my S2000, switching from a 2.5" to a 3" help a bit, and I was only NA.

I will do some searching tonight. The stainless works is the setup I want, but it's $2,500 for headers-back.

 

[SlowSVT]

Many people have posted track times before and after with .2s and 5mph gains (About a 60rwhp gain) from just this swap. Also 99% of the exhaust companies say 2.5" is good for around 500bhp. Many of us are past that.

Are you suggesting a 3" system is worth 60 hp over a 2 1/2" system?

 

[x NOODLES x]

Are you suggesting a 3" system is worth 60 hp over a 2 1/2" system?

Thats what it reads like. :read:

I dont buy it for 2 seconds.

 

[stang23456]

I just installed a mac 3" catback with mac o/r h, took sometime to get aligned right but its pretty good now. Rubs SLIGHTLY on gas tank shield, tips SLIGHTLY flare to the side and pipes SLIGHTLY arent even by gas tank. Overall, the sound is amazing and fitment is ok, however it works.

 

[black03_cobra]

If 3in. systems will hurt our cars performance because of the size then why do the new 5.0L GTs have 3in. systems from Ford? The 5.0L engine makes 412 flywheel and ours probably make 420-430 flywheel. Why would it hurt our engine and not theirs?

I have the Stainless Works 3in. Exhaust manifolds back and love it. My car is upper only and has a best 1/8th mile time of 7.05@100 on 17' drag radials. I don't think its hurting me a bit!

7.05 at 100 with a upper only. hmmm thats a fast 1/8th for a upper, irs cobra