2011CS
2011 California Special
- Joined
- Apr 25, 2010
- Posts
- 215
- Reaction score
- 3
Out of shear frustration over some of the pricing increases on 2011 5.0 exhaust versus 2010 4.6 and 5.L exhaust I started to do some research.
I worked in an exhaust shop for almost 8 years. We used to talk a ton of 300HP guys out of 2.5 inch duals because of lack of need in regards to exhaust diameter.
So I found some info here to better understand flow amounts: http://speedtalk.com/forum/viewtopic.php?f=1&t=22185
Here is the one section that I paid the closest attention to and I shortened it to a more relevant sizing for us:
Pipe Diameter HP
2.0000 164.22
2.2500 207.84
2.5000 256.59
2.7500 310.48
3.0000 369.49
3.2500 433.64
3.5000 502.92
This is per pipe in a dual so 2.75 is good to 620.96 hp assuming the muffler you choose is also flowing equal to the raw pipe numbers.
Whats confusing about this (believe me I was looking for a couple hours I just liked the way this guy simplified the math) is why we need a 3 inch system that supports 738.98 HP on a 412HP car? Especially when you see thousands of guys running 550-600 hp Shelby's through 2.5 inch exhaust without issue.
Until the big push in the 2011 model year for 3 inch, we didn't even have much for 3 inch options through manufactures. There are some but all of a sudden everyone is on the 3inch bandwagon.
Look here at lethals pipe: http://www.lethalperformance.com/20...-30199?zenid=8b8c80ce845f84b9a4d8680b99b3ee75
notice the line: Most important is that the stock cats won't hold up for long to the abuse of 700+rwhp.
So does that mean the x-pipe shown can handle 700rwhp and if it can then why bother with 3 inch on a 412HP daily driver? And if it can handle 700rwhp then even 2.5 inch front to back is overkill for our 2011 cars.
I was getting wrapped up in changing my exhaust so here is what I'll do next week.
I ordered my tune from Evolution and I will burn through the crap dealer gas and get a baseline reading on HP from the local dyno shop at 91 Octane. Then I'll get a read after the tune.
I'll go back to stock tune and I'll go yank the factory cats and change out to free flow mufflers and get another baseline before returning my tune to Evo's.
That way I can see for sure if the factory exhaust is really a bottleneck.
Because from where I am standing there is a ton of bullshit out there right now.
Jeff
I worked in an exhaust shop for almost 8 years. We used to talk a ton of 300HP guys out of 2.5 inch duals because of lack of need in regards to exhaust diameter.
So I found some info here to better understand flow amounts: http://speedtalk.com/forum/viewtopic.php?f=1&t=22185
Here is the one section that I paid the closest attention to and I shortened it to a more relevant sizing for us:
Pipe Diameter HP
2.0000 164.22
2.2500 207.84
2.5000 256.59
2.7500 310.48
3.0000 369.49
3.2500 433.64
3.5000 502.92
This is per pipe in a dual so 2.75 is good to 620.96 hp assuming the muffler you choose is also flowing equal to the raw pipe numbers.
Whats confusing about this (believe me I was looking for a couple hours I just liked the way this guy simplified the math) is why we need a 3 inch system that supports 738.98 HP on a 412HP car? Especially when you see thousands of guys running 550-600 hp Shelby's through 2.5 inch exhaust without issue.
Until the big push in the 2011 model year for 3 inch, we didn't even have much for 3 inch options through manufactures. There are some but all of a sudden everyone is on the 3inch bandwagon.
Look here at lethals pipe: http://www.lethalperformance.com/20...-30199?zenid=8b8c80ce845f84b9a4d8680b99b3ee75
notice the line: Most important is that the stock cats won't hold up for long to the abuse of 700+rwhp.
So does that mean the x-pipe shown can handle 700rwhp and if it can then why bother with 3 inch on a 412HP daily driver? And if it can handle 700rwhp then even 2.5 inch front to back is overkill for our 2011 cars.
I was getting wrapped up in changing my exhaust so here is what I'll do next week.
I ordered my tune from Evolution and I will burn through the crap dealer gas and get a baseline reading on HP from the local dyno shop at 91 Octane. Then I'll get a read after the tune.
I'll go back to stock tune and I'll go yank the factory cats and change out to free flow mufflers and get another baseline before returning my tune to Evo's.
That way I can see for sure if the factory exhaust is really a bottleneck.
Because from where I am standing there is a ton of bullshit out there right now.
Jeff
