Is going 3" from the primary cats back too much
Senior Member
Joined: Dec 2007
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From: Dago, CA
2003 cl55 (sold)
Fr33kn63: I have a 55. Hmm, if I deleted prims instead of second I would get a CEL though, right?
jicl55: I'm not sure if its "sluggish" like it feels fast but I don't really know how to judge cause I forgot how it felt before. When I gut the mufflers, though, that's not the same as just running straight pipes right? Because I still have the baffles and everything so my backpressure should be fine?
However, according to you, I lost ~3lbs of backpressure because I took out my 2 secondary cats?
jicl55: I'm not sure if its "sluggish" like it feels fast but I don't really know how to judge cause I forgot how it felt before. When I gut the mufflers, though, that's not the same as just running straight pipes right? Because I still have the baffles and everything so my backpressure should be fine?
However, according to you, I lost ~3lbs of backpressure because I took out my 2 secondary cats?
Senior Member
Joined: Dec 2007
Posts: 472
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From: Dago, CA
2003 cl55 (sold)
....and I would go with this setup if it weren't for California emissions..... another reason the rear cats went back in.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
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From: Atlanta
2006 E55 AMG
Well, guys I ended up gettting Kleeman headers, leaving the stock secondaries in place, 3" straight pipes that replaced the resonator, and magnaflow magnapacks with new tips outback. Magnaflow Magnapacks are basically straight pipes with some slight fiber glass packing but over time that wears down and becomes straight pipes. They car has zero rasp at all which I am very surprised but has a ton of bass. The drone inside the car is substantial which I like but if you carry passengers alot, I would not recommend this setup.
I went into a undercover garage last night as I had to get groceries from the store and set off several alarms starting the car up and cruising out the parking lot
Like I said, not many members will like this setup as it is very much in your face, loud and obnoxious, but I love it, and have had alot of smiles and frowns with it so far. If I decide to gut the secondaries, under WOT it will be as loud as open headers but cruising will just have a low rumble... I will get a clip up very soon as I want to do drive by's, reving, idle etc so you can get the full picture. Right now I am very satisfied with the setup and will let it wear itself in before I change anything else. I am sure the 180mm pulley and tune will add even more rumble.
I went into a undercover garage last night as I had to get groceries from the store and set off several alarms starting the car up and cruising out the parking lot
Like I said, not many members will like this setup as it is very much in your face, loud and obnoxious, but I love it, and have had alot of smiles and frowns with it so far. If I decide to gut the secondaries, under WOT it will be as loud as open headers but cruising will just have a low rumble... I will get a clip up very soon as I want to do drive by's, reving, idle etc so you can get the full picture. Right now I am very satisfied with the setup and will let it wear itself in before I change anything else. I am sure the 180mm pulley and tune will add even more rumble.
Member
Joined: Mar 2009
Posts: 79
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From: Saudi Arabia
2003 E55 AMG
I replaced my exhaust pipe with a 3" pipe all the way from the headers to the stock AMg muf. no cats no res. just 3" strieght pipes, but I lost the low end torq,
What should I add an H or X to get some back pressure, for the low end torq?
Thanks
What should I add an H or X to get some back pressure, for the low end torq?
Thanks
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'03 E55, Range Rover Sport Supercharged, Ducati 748R
a set of cats. a set of good 200cell count high flow buggers should do the trick.
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From: In my garage
E55, GLS450, GL63, GLE350
"Back pressure" is bad in an exhaust system. That means that there is too much restriction in the flow. What is happening when you go to an exhaust that is too large is that the exhaust velocity is slowed down thus reducing your hp. Too big is not good! It's all about exhaust velocity and exhaust flow. You want the greatest flow and the greatest velocity.
When the exhaust slows down due to an over-large exhaust, the air cools and does not move as fast as it should. A hot air mass will move much more quickly than a cold/cooling air mass. Remember, a larger exhaust is not always a good thing but one that is too small is bad too!
http://www.veryuseful.com/mustang/te...Scavenging.pdf
http://www.miata.net/garage/KnowYourCar/S4_Back.html
http://www.popularhotrodding.com/eng...exh/index.html
When the exhaust slows down due to an over-large exhaust, the air cools and does not move as fast as it should. A hot air mass will move much more quickly than a cold/cooling air mass. Remember, a larger exhaust is not always a good thing but one that is too small is bad too!
http://www.veryuseful.com/mustang/te...Scavenging.pdf
http://www.miata.net/garage/KnowYourCar/S4_Back.html
http://www.popularhotrodding.com/eng...exh/index.html
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Member
Joined: Mar 2009
Posts: 79
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From: Saudi Arabia
2003 E55 AMG
I have noticed the temp of the engine droped by about 3 to 5 digrees with the 3".
Some guys are telling me to get and H pipe for the lowend tq.
So you guys think i should get it tuned? Do I have to send my ecu or i can get a good pulg and play chip?
I only have K&N filters, 3" strieght pipes with stock AMG muff.
sorry for going of the topic.
Some guys are telling me to get and H pipe for the lowend tq.
So you guys think i should get it tuned? Do I have to send my ecu or i can get a good pulg and play chip?
I only have K&N filters, 3" strieght pipes with stock AMG muff.
sorry for going of the topic.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
Posts: 7,659
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From: Atlanta
2006 E55 AMG
No problem, it is my thread and want to help. A tune will help as it will get the most out of your combo as possible. I pulley will greatly increase your lost low end torque. I would do that before you do the 200cel cats as it should be cheaper and yield a ton of power and torque.
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Joined: Jan 2007
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From: PA
S600, GL450, GLC 43
"Back pressure" is bad in an exhaust system. That means that there is too much restriction in the flow. What is happening when you go to an exhaust that is too large is that the exhaust velocity is slowed down thus reducing your hp. Too big is not good! It's all about exhaust velocity and exhaust flow. You want the greatest flow and the greatest velocity.
When the exhaust slows down due to an over-large exhaust, the air cools and does not move as fast as it should. A hot air mass will move much more quickly than a cold/cooling air mass. Remember, a larger exhaust is not always a good thing but one that is too small is bad too!
http://www.veryuseful.com/mustang/te...Scavenging.pdf
http://www.miata.net/garage/KnowYourCar/S4_Back.html
http://www.popularhotrodding.com/eng...exh/index.html
When the exhaust slows down due to an over-large exhaust, the air cools and does not move as fast as it should. A hot air mass will move much more quickly than a cold/cooling air mass. Remember, a larger exhaust is not always a good thing but one that is too small is bad too!
http://www.veryuseful.com/mustang/te...Scavenging.pdf
http://www.miata.net/garage/KnowYourCar/S4_Back.html
http://www.popularhotrodding.com/eng...exh/index.html
Espically the first link, but keep in mind that we are talking about FI motors here so there is a positive pressure present any time the intake valve comes off its seat. Hence NO vacume ie ever present during the overlap face.
See yeah
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From: In my garage
E55, GLS450, GL63, GLE350
Not the case, the engine is actually only under boost for, most owners, less than 1% of the engines life. The other 99% of the time the engine acts as a normally aspirated powerplant. I know what you are trying to say but exhaust basics of flow and velocity are still valid....even in a forced induction engine.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
Posts: 7,659
Likes: 67
From: Atlanta
2006 E55 AMG
Not the case, the engine is actually only under boost for, most owners, less than 1% of the engines life. The other 99% of the time the engine acts as a normally aspirated powerplant. I know what you are trying to say but exhaust basics of flow and velocity are still valid....even in a forced induction engine.
Senior Member
Joined: Aug 2008
Posts: 360
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From: Riverwoods, Il
2005 E55 AMG
I'm installing dual 3" ss from after market header back. All v-band, no crappy welds or compression fittings. This will make for easy removal when I sell the car. I have not decided on which cats yet. I was thinking of something from http://www.randomtechnology.com/ Mufflers are still up in the air.
MBWorld Fanatic!
Joined: Aug 2003
Posts: 8,882
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From: In my garage
E55, GLS450, GL63, GLE350
If you fit an exhaust that is too large, you will lose velocity and lose power. If you fit one that is too small, you will lose flow and lose power. You want the highest flow with the highest velocity. If that equation works for removing the cats, so be it. Obviously the exhaust on the Mustang has a restriction, catalytic converters, that can be removed and thus increases flow while not hurting velocity.
