CatBack Systems Losing Power

[beefcake]

here is a graph a member posted in that same thread where his car went into over cat on a bone stock car.

the sky isn't falling, the system / muffler setup is the same as previous coyotes and the same as the ls cars that have been used with great success

 

[beefcake]

I have more information then just that comparison. I also have a comparison with stockings off as well. It definitely called a loss of horsepower. Let me know what information you need to see it and I'll gladly post it.

we'll have a car on the dyno tonight bone stock with 500 miles datalogging it.

 

[Deespeed99]

Again i have real world data so if anyone wants an unbiased opinion feel free to let me know. It definitely lost power putting it on.

 

[apg2369]

Again i have real world data so if anyone wants an unbiased opinion feel free to let me know. It definitely lost power putting it on.

One thing I have learned in 20 years of doing performance work on mustangs your numbers or performance NEVER equals all the manufacture and vendor claims ! Most of this industry in just B.S !

 

[beefcake]

Baseline done. 3 solid pulls back to back.

363.09 / 346.11
364.82 / 344.11
363.84 / 347.78

Knock sensor was happy throughout the pulls.

Adding about 2 degrees across the board. Fuel was spot on. At peak hp timing was about 24.5

now the results

4 - 367.1 / 351.25
5 - 364.46 / 350.58
6 - 364.30 / 345.79

so there you have it, average power gain across the board, not much, but not a loss. and the torque picked up across the board.

just as I said, on average, a cat back is mainly for sound

I also had a board member here who is thinking about an exhaust system to watch the dyno / install process, i'll be posting more info / graphs later

also, for those that believe the cores are a restriction, the inside diameter of the stock exhaust is 2.125, so the stainless works at their smallest point is 2.36 and the larger areas to the outside is 2.65 I believe

all larger than the factory pipes and connection point.

first runs were done at 6:25, 6:26, 6:27
second runs were done at 7:37, 7:38, 7:39

when I have a minute, i'll post more data for everyone. I have pics of the factory exhaust as well.

that gives us an average of the 3 runs before of

363.916 / 346

an average after of

365.286 / 349.206

again, as with previous model years, about what I've expected

that's about as real world as it gets.

dyno, install, dyno an hour later, done....

I'm happy to share all .drf files and all 6 log files with anyone that wants them.

 

[ridenfish39]

Where's the ''Like" button.. LOL The cats are the restriction in these exhausts til you put FI on the car.....

 

[beefcake]

okay,

last post before getting some rest, here is the dyno graphs for all the runs, and also a screen shot of both datalogs at peak hp (using the highest hp ones)

if you look at the dyno graphs, the numbers are almost identical to each other all the way from top to bottom at that point.

you'll see 2 differences. On the higher HP run, the coolant temp and iat's were slightly better.

however the knock sensor wasn't as happy and wasn't adding as much timing.

So, it was a tad cooler on it's best run, but, it didn't have as much timing. very very close comparison's and again, as real world as it gets.

BEFORE

AFTER

 

[HEMI LOL]

Baseline done. 3 solid pulls back to back.

363.09 / 346.11
364.82 / 344.11
363.84 / 347.78

Knock sensor was happy throughout the pulls.

Adding about 2 degrees across the board. Fuel was spot on. At peak hp timing was about 24.5

now the results

4 - 367.1 / 351.25
5 - 364.46 / 350.58
6 - 364.30 / 345.79

so there you have it, average power gain across the board, not much, but not a loss. and the torque picked up across the board.

just as I said, on average, a cat back is mainly for sound

I also had a board member here who is thinking about an exhaust system to watch the dyno / install process, i'll be posting more info / graphs later

also, for those that believe the cores are a restriction, the inside diameter of the stock exhaust is 2.125, so the stainless works at their smallest point is 2.36 and the larger areas to the outside is 2.65 I believe

all larger than the factory pipes and connection point.

first runs were done at 6:25, 6:26, 6:27
second runs were done at 7:37, 7:38, 7:39

when I have a minute, i'll post more data for everyone. I have pics of the factory exhaust as well.

that gives us an average of the 3 runs before of

363.916 / 346

an average after of

365.286 / 349.206

again, as with previous model years, about what I've expected

that's about as real world as it gets.

dyno, install, dyno an hour later, done....

I'm happy to share all .drf files and all 6 log files with anyone that wants them.

Terry, do you offer a tune or package wherein you can call my work and try to get me fired? I'm looking for a tune that comes with some drama. please respond ASAP. k thanks bye.

 

[Budwise]

Thanks for all your work Terry, not many shops would go out of their way for their customers like that.

 

[Deespeed99]

So you are basically saying it is restrictive just in a technical way to try & promote SW lol. Any catback will pick up more HP then that. Did you do comparisions with a full system with headers? I know i have tons of data on that too. The restriction really shows when you add long tubes.

Let me know what you need? Stock dyno? Dyno with catback (roush) only? Full system (sw) dyno? Dyno with only (sw & arh) headers? Dyno with headers & stock catback? I have it all...

 

[beefcake]

So you are basically saying it is restrictive just in a technical way to try & promote SW lol. Any catback will pick up more HP then that. Did you do comparisions with a full system with headers? I know i have tons of data on that too. The restriction really shows when you add long tubes.

Let me know what you need? Stock dyno? Dyno with catback (roush) only? Full system (sw) dyno? Dyno with only (sw & arh) headers? Dyno with headers & stock catback? I have it all...

I'm not saying that at all??

I promote SW, ARH, KOOKs, Magnaflow, mbrp, dynatech, etc...

In no real world scenario, should a catback pick up a bunch of horsepower, a catback is for sound, until you get to a certain horsepower level

Here is your factory connection point,

Here is your factory exhaust

that is a 2.12 connection point. So please explain to me how going anything larger than that, in reality, should give you a gain?? Anyone with common sense knows, your limited by your smallest flow point

it's simple physics.

Maybe the laws of physics cease to exist where you live and work, but for the rest of us they don't.

as far as the "gobs of data"

the only data I would care about is a back to back with the factory exhaust. which I just did. there was no restriction there. are you now calling me a liar?

I knew there wouldn't be a restriction, as the smallest point inside the louvre's is 2.36 and the outer parts where the rotating motion is created is about 2.65".

None of that matters, as the factory connection point, is 2.12.

Why do you think the ford racing exhaust is only 2.5". Do you not think they did there research or know what they are doing either?

I know you like to pick fights with me.

But we just tested this system against the stock system last night, with proper datalogging ,within about an hour from first pulls to second pulls, it doesn't get any more real world than that.

I could care less about open header tests. It's just a silly comparison. Do a open header test against any system.

Now, at some point could it be a restriction, sure, all of them could be. If I put that on my 2011 car, of course it would be a restriction, were making over 1000rwhp with the car, that's why we run 2" headers, into a 4" muffler then dump it.

For the high horsepower guys that don't care about how loud it is, SW offers a larger core resonator / muffler setup. On the average car though, it's not needed and is too loud and most won't like it.

Does that mean I should go around saying that kooks, or arh, or sw , or mbrp headers with 1 7/8 are a restriction on my 2011?? no. You build the exhaust for what your plans are for the car.

 

[Deespeed99]

I'm not saying that at all??

I promote SW, ARH, KOOKs, Magnaflow, mbrp, dynatech, etc...

In no real world scenario, should a catback pick up a bunch of horsepower, a catback is for sound, until you get to a certain horsepower level

Here is your factory connection point,

Here is your factory exhaust

that is a 2.12 connection point. So please explain to me how going anything larger than that, in reality, should give you a gain?? Anyone with common sense knows, your limited by your smallest flow point

it's simple physics.

Maybe the laws of physics cease to exist where you live and work, but for the rest of us they don't.

as far as the "gobs of data"

the only data I would care about is a back to back with the factory exhaust. which I just did. there was no restriction there. are you now calling me a liar?

I knew there wouldn't be a restriction, as the smallest point inside the louvre's is 2.36 and the outer parts where the rotating motion is created is about 2.65".

None of that matters, as the factory connection point, is 2.12.

Why do you think the ford racing exhaust is only 2.5". Do you not think they did there research or know what they are doing either?

I know you like to pick fights with me.

But we just tested this system against the stock system last night, with proper datalogging ,within about an hour from first pulls to second pulls, it doesn't get any more real world than that.

I could care less about open header tests. It's just a silly comparison. Do a open header test against any system.

Now, at some point could it be a restriction, sure, all of them could be. If I put that on my 2011 car, of course it would be a restriction, were making over 1000rwhp with the car, that's why we run 2" headers, into a 4" muffler then dump it.

Does that mean I should go around saying that kooks, or arh, or sw , or mbrp headers with 1 7/8 are a restriction on my 2011?? no. You build the exhaust for what your plans are for the car.

I agree it should not pick up a ton of HP but picking up 2-3hp on average over the stock exhaust is showing either the stock exhaust flows really well or the SW is a restriction. The only way to verify that is with back to back testing like you said with other types of exhaust. Physics also factor in air flow turbulence not just size so something that is bigger doesn't always flow better. Definitely not calling you a liar but in all fairness you haven't done enough testing with different brands for comparisons. I don't like picking fights with you I just like people being told the truth about products so they don't waste money.

 

[acrbill]

Terry, do you offer a tune or package wherein you can call my work and try to get me fired? I'm looking for a tune that comes with some drama. please respond ASAP. k thanks bye.

LOL aware

 

[beefcake]

I agree it should not pick up a ton of HP but picking up 2-3hp on average over the stock exhaust is showing either the stock exhaust flows really well or the SW is a restriction. The only way to verify that is with back to back testing like you said with other types of exhaust. Physics also factor in air flow turbulence not just size so something that is bigger doesn't always flow better. Definitely not calling you a liar but in all fairness you haven't done enough testing with different brands for comparisons. I don't like picking fights with you I just like people being told the truth about products so they don't waste money.

A restriction would be a loss of power. the system didn't lose power, it picked up power and torque, not much, but a little. Again, you are limited by your factory connection point of 2.125 inches.

You could throw a 5" system on there, and it isn't going to make power, it just isn't. I don't know why that is hard to grasp.

The SW mufflers also created a spinning / scavengine effect to increase power as well.

However, being limited at the factory point, that isn't going to matter. I don't care what brand it is, sw, arh, kooks, magnaflow, mrbp, bassani, corsa.

bolting on a cat back is for sound. period.

Just like bolting on a big set of 20" wheels is for looks, it doesn't help performance, but they look great.

catbacks usually have a nicer looking tip, and better sound, that's why your buying them.

Pick whatever catback you like the sound of the most, and enjoy it.

 

[Deespeed99]

A restriction would be a loss of power. the system didn't lose power, it picked up power and torque, not much, but a little. Again, you are limited by your factory connection point of 2.125 inches.

You could throw a 5" system on there, and it isn't going to make power, it just isn't. I don't know why that is hard to grasp.

The SW mufflers also created a spinning / scavengine effect to increase power as well.

However, being limited at the factory point, that isn't going to matter. I don't care what brand it is, sw, arh, kooks, magnaflow, mrbp, bassani, corsa.

bolting on a cat back is for sound. period.

Just like bolting on a big set of 20" wheels is for looks, it doesn't help performance, but they look great.

catbacks usually have a nicer looking tip, and better sound, that's why your buying them.

Pick whatever catback you like the sound of the most, and enjoy it.

We agree to disagree on this one. I think a lot of people buy catbacks for performance as well as sound.

 

[beefcake]

We agree to disagree on this one. I think a lot of people buy catbacks for performance as well as sound.

lol, in the 15 years I been doing this, that is not my experience, but like I said, maybe things work different in MD, I don't ever sell a catback promoting a performance gain of more than maybe, maybe 5 hp

I'm not into misleading people

 

[AustinSN]

Terry, do you offer a tune or package wherein you can call my work and try to get me fired? I'm looking for a tune that comes with some drama. please respond ASAP. k thanks bye.

Lmao

 

[beefcake]

lol @ HEMI, I plead the 5th.

 

[Alien STI]

I can tell you over at Revolution Automotive we did extensive back to back testing and we did verify that the SW catback is a restriction. We picked up 15-20rwhp from dropping the catback and running through the SW headers/cats. We did a few things to test it but it's legit that it cost HP.

Haven't read the whole thread yet..but when I had the sw cat back install only with a tune..I could definitely feel a lost of power. It felt like I had more tq..and less hp though. Did a few videos and I wanna say it seemed that way as well. After putting the headers on from SW I felt like the car was just a Lil bit faster than it was stock but with a mean sound!

 

[beefcake]

Haven't read the whole thread yet..but when I had the sw cat back install only with a tune..I could definitely feel a lost of power. It felt like I had more tq..and less hp though. Did a few videos and I wanna say it seemed that way as well. After putting the headers on from SW I felt like the car was just a Lil bit faster than it was stock but with a mean sound!

the system doesn't lose power, and even if by some chance you lost 5 hp, it would not be anything you can feel.

there isn't any system that we've seen / installed that looks like there is any reason it would lose power. Without a tune , with the same throttle response, car is going to feel exactly the same. Other than if it's pulling a bunch of timing for fuel, or really hot and pulling power.