LS1GTO Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
180 Posts
Discussion Starter · #1 ·
Anyone running a Magnaflow 3" Competition system? How loud is it vs. the standard Street Magnaflow? Looking for guys with H/C cars with no Cats. I know there's a lot on the table for me going to 3" free flowing exhaust with the HP level I'm at, just hate to drop the coin on the 3" and realize its too loud for me so any videos or feedback would be great!!

Thanks!!
 

·
Registered
Joined
·
2,434 Posts
I have the 3inch system on my car with JBA catless midpipes and stock manifolds. Its pretty loud. I don't have any videos of it though. Its mellow at cruising and gets real loud when you get on it. If you look at the mufflers, they are small and straight through. The car isn't my daily driver. I just put the catless mids on it and it really woke it up. I like it but it is kind of loud.
 

·
Registered
Joined
·
3,484 Posts
I have the 3 inch Competition as well. I've heard the 2.5 inch and the 3 inch is a good bit louder while cruising and at WOT,but tame at idle.

I had Spintech which was louder which I thought was the best sounding exhaust for a GTO until I heard my car with the Magnaflow while standing along the street while someone drove it past me.

Magnaflow sounds alot better and does not drone except for around 1500 rpms.
 

·
Registered
Joined
·
26 Posts
I have them but keep in mind that the 3 inch is choked to 2.5 at the x pipe. i think kooks is the only one that makes the only 100% 3 inch exhaust.
 

·
Registered
Joined
·
3,484 Posts
I have them but keep in mind that the 3 inch is choked to 2.5 at the x pipe. i think kooks is the only one that makes the only 100% 3 inch exhaust.
That is true,I had the 2.5 inch neckdown cut out and had short 3 inch pipes and 3 inch flange welded in to make it a true 3 inch system.
 

·
A 24hr brake obsession...
2006 GTO
Joined
·
421 Posts
I have the 3inch Magnaflow. It's loud. My friends (who aren't car guys) tell me "bring the quiet one when you come over" :mad:
No Cats, N/A

https://youtu.be/u_RfNIZlkDs
 

·
1 LITER DUC EATER
Joined
·
2,606 Posts
And videos Rob?
 

·
Administrator
Joined
·
8,745 Posts
I have them but keep in mind that the 3 inch is choked to 2.5 at the x pipe. i think kooks is the only one that makes the only 100% 3 inch exhaust.
Kooks and Spintech make full 3" systems. Let's be serious though; that reduction to 2.5" isn't going to hurt the vast majority of buyers.
 

·
Banned
Joined
·
3,230 Posts
Like I told you this morning...the 3" Magnaflow Comp series is one of the loudest exhausts we sell. There is no way I would take off a too loud SpinTech and replace it with that.
 

·
Registered
Joined
·
180 Posts
Discussion Starter · #13 · (Edited)
if I were to buy the system I would cut the flange off and put a 3" on so it wouldn't neck down in that area and remains 3" all the way from the ARH headers back........based off my numbers the 2.5" exhaust is small for the power the car makes, I did a negative hp test on the dyno and it showed a 76hp drivetrain loss at 7000rpm in 4th which is 150mph, with 515 at the wheels that means the motor is making just shy of 600 which is dual 3" territory...........regardless if anyone has videos of the exhaust it would be awesome, I'm trying not to get pulled over once a week with the competition exhaust, nor have the wifey complain about it when we go for a ride lol

here's what it sounds like right now, not that loud for what it is really....the 2.5" system keeps it quite tame especially at idle....

https://www.facebook.com/blacklabeltuning/videos/vb.247360501943741/912020078811110/?type=3&theater
 

·
11's or bust!
Joined
·
237 Posts
Anyone running a Magnaflow 3" Competition system? How loud is it vs. the standard Street Magnaflow? Looking for guys with H/C cars with no Cats. I know there's a lot on the table for me going to 3" free flowing exhaust with the HP level I'm at, just hate to drop the coin on the 3" and realize its too loud for me so any videos or feedback would be great!!

Thanks!!
It's not the same set up as you but can give you some idea. I'm cam only and I have cats in the video. On your car without cats it will be a bit louder.

https://youtu.be/jmtPTk4C5-c

This one is at the track under acceleration

https://youtu.be/62hJOSBTjr0


My only 2 cents I will give is that under 2K RPM you get some serious drone. At and above 2K RPM it's fine.

Hope this helps.
 

·
Registered
Joined
·
3,484 Posts
if I were to buy the system I would cut the flange off and put a 3" on so it wouldn't neck down in that area and remains 3" all the way from the ARH headers back........based off my numbers the 2.5" exhaust is small for the power the car makes, I did a negative hp test on the dyno and it showed a 76hp drivetrain loss at 7000rpm in 4th which is 150mph, with 515 at the wheels that means the motor is making just shy of 600 which is dual 3" territory...........regardless if anyone has videos of the exhaust it would be awesome, I'm trying not to get pulled over once a week with the competition exhaust, nor have the wifey complain about it when we go for a ride lol

here's what it sounds like right now, not that loud for what it is really....the 2.5" system keeps it quite tame especially at idle....

https://www.facebook.com/blacklabeltuning/videos/vb.247360501943741/912020078811110/?type=3&theater
I'm at 510 rwhp,but haven't gone back to the dyno to see if switching to the 3 inch added anything.

I guess it really depends on the law enforcement where you live because I've never been pulled over for being too loud even when I had Spintech which is louder than the Magnaflow.
 

·
Rockin the Bakken
Joined
·
320 Posts
Before I bought my magnaflow I had some kind of an abortion exhaust system that was not mandrel bent and did not follow the oem path very well. To quiet that system down I added a 3" H-pipe. I ended up having to use that 3" pipe with the magnaflow because the flanges were cut off the Kooks midpipe. I find the car is louder inside now and quieter outside. I am going to try Aero-Turbine mufflers before too long, they sound great on my L92 in my truck!!
 

·
The New 4-4-2
Joined
·
50 Posts
Anyone running a Magnaflow 3" Competition system? How loud is it vs. the standard Street Magnaflow? Looking for guys with H/C cars with no Cats. I know there's a lot on the table for me going to 3" free flowing exhaust with the HP level I'm at, just hate to drop the coin on the 3" and realize its too loud for me so any videos or feedback would be great!!

Thanks!!
I installed the Magnaflow 3" comp catback earlier this year. I replaced the 2.5 inch SLP loudmouth catback that I had for several years (I had both the LM1 and LM2 mufflers that I would alternate ever so often). I like the Magnaflow a lot better. The exhaust tone is deeper, not as raspy. I also like that the exhaust tips are 4 inch, like the original stock exhaust. The only thing that disappointed me is that the flange that connects to the stock exhaust system behind the cats is only 2.5 inches AND the Magnaflow pipes are collared down to fit through the flange. According to my calipers, the inner diameter at that point is only about 2.3 inches in diameter. That doesn't seem to impact performance, though, as it seems like I can break the tires loose as good, or better, than I ever could. I would like to put headers on at some point to make the system a complete 3 inch system. If I do, I will have to follow the example of others and have the restrictive flange replaced. Hope this helps.
 
1 - 17 of 17 Posts
Top