Would it be possible to get a list of all the exhausts and their power gains?

[leszek]

Also remember that at WOT the engine is running in an open loop and the O2 sensor data is ignored.

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[BathS550]

People need to stop looking at dyno numbers in terms of output, and should only be comparing delta.

 

[Tommy V]

Yes sir!!!!!

 

[anotherneon]

Also remember that at WOT the engine is running in an open loop and the O2 sensor data is ignored.

yep

 

[Grimace427]

A tune is needed because ford uses a 14.1 or about 14.1 as a target A/F ratio ...14.1 is great for gas mileage and not so great for making power ... A A/F ratio at 13.1 to 13.2 makes more power .. So the tuner adjusts the Map to run at 13.1 to 13.2 .. The duty of the 02 doesn't change , the change is to the target A/F in the ECU mapping ..

You are close but not 100%

Ford changed the stoich from 14.7 to 14.079 back in 2011 to account for the increased ethanol content in pump gas. This is not the commanded A/F ratio at WOT, just what you would see at cruise.

You are correct that the commanded A/F ratio should be more rich(lower number) at WOT for more power and especially for safety. A lean A/F ratio(14:1) is very dangerous for the engine as the combustion chambers will run very hot and increase the chance of detonation. An A/F ratio of around 12.5:1 for N/A will be safer and make more power.

However that has nothing to do with longtube headers. There have been several people who claim no tune is necessary. I believe there are adjustments that should be made to correct for the change in O2 sensor location(further downstream) to provide optimum performance.

Also remember that at WOT the engine is running in an open loop and the O2 sensor data is ignored.

yep

This is not correct. Since the debut of the Coyote engine the O2 sensors have been widebands which are always reading. There is no more open loop.

 

[Tommy V]

Yep that is correct,the older 02s would change to open loop not only at wot but at around 2500 rpms.Not the case with the new wideband 02.

 

[Cascadia_302]

Thanks, as I more or less figured.
Thus I shall probably call on the all-mighty god of "patience" before I mess with a car I don't even have yet.

 

[cbrtrx]

So much wrong information in this thread I dont even know where to begin, please listen to this poster he is correct.

You are close but not 100%

Ford changed the stoich from 14.7 to 14.079 back in 2011 to account for the increased ethanol content in pump gas. This is not the commanded A/F ratio at WOT, just what you would see at cruise.

You are correct that the commanded A/F ratio should be more rich(lower number) at WOT for more power and especially for safety. A lean A/F ratio(14:1) is very dangerous for the engine as the combustion chambers will run very hot and increase the chance of detonation. An A/F ratio of around 12.5:1 for N/A will be safer and make more power.

However that has nothing to do with longtube headers. There have been several people who claim no tune is necessary. I believe there are adjustments that should be made to correct for the change in O2 sensor location(further downstream) to provide optimum performance.







This is not correct. Since the debut of the Coyote engine the O2 sensors have been widebands which are always reading. There is no more open loop.

 

[VTECSAUCE]

So much wrong information in this thread I dont even know where to begin, please listen to this poster he is correct.

I am a complete noob when it comes to Ford and modifications. I keep reading threads and posts trying to get information that isn't contradictory. I really do not have the time and money to blow on parts to dyno and research for myself. Honestly the only thing I want to do right now is an exhaust. I have been leaning towards doing a custom x-pipe and higher flowing mufflers to save money, hold on to my warranty and have a better sound. I cannot get a straight answer on these catbacks that are out. (love the sound of corsa and frpp sport) but $1200+ for a catback is outrageous if there are no gains to be had over stock. If they make significant gains with Intake, tune and headers then maybe it might be worth it, but it'll be awhile before I get to all that other stuff and I'm thinking the prices for catbacks will significantly drop by the time I am ready to do the basic bolt-ons. I really just want clarification on this before I lose my mind lol.

 

[GigaHz]

I know NPP on corvettes from the factory on a LS3, are rated at 430 hp closed and 436 open. So it would seem if you totally got rid of the mufflers and put straight pipe there you could gain about 6 hp.

 

[stoli]

I'm thinking the prices for catbacks will significantly drop by the time I am ready to do the basic bolt-ons. I really just want clarification on this before I lose my mind lol.

Not sure how much they will drop since they also include the x or h pipe, but I'm sure there will be some drop.

Get whatever cat-back or axle back you think sounds good and fits your budget.

I know NPP on corvettes from the factory on a LS3, are rated at 430 hp closed and 436 open. So it would seem if you totally got rid of the mufflers and put straight pipe there you could gain about 6 hp.

How can you compare a Corvette exhaust setup to this one? Talk about apples and oranges.

 

[GigaHz]

Not sure how much they will drop since they also include the x or h pipe, but I'm sure there will be some drop.

Get whatever cat-back or axle back you think sounds good and fits your budget.



How can you compare a Corvette exhaust setup to this one? Talk about apples and oranges.

They are both exhausts?

 

[Grimace427]

I am a complete noob when it comes to Ford and modifications. I keep reading threads and posts trying to get information that isn't contradictory. I really do not have the time and money to blow on parts to dyno and research for myself. Honestly the only thing I want to do right now is an exhaust. I have been leaning towards doing a custom x-pipe and higher flowing mufflers to save money, hold on to my warranty and have a better sound. I cannot get a straight answer on these catbacks that are out. (love the sound of corsa and frpp sport) but $1200+ for a catback is outrageous if there are no gains to be had over stock. If they make significant gains with Intake, tune and headers then maybe it might be worth it, but it'll be awhile before I get to all that other stuff and I'm thinking the prices for catbacks will significantly drop by the time I am ready to do the basic bolt-ons. I really just want clarification on this before I lose my mind lol.

You can get any of the top catbacks for significantly less than MSRP listed on the manufacturer's website if you purchase from any of the vendors here. MSRP on a Borla catback is over $1300ish and guys have been spending less than a grand from vendors. Pick a catback based on sound, don't worry about HP gains.

 

[BathS550]

I am a complete noob when it comes to Ford and modifications. I keep reading threads and posts trying to get information that isn't contradictory. I really do not have the time and money to blow on parts to dyno and research for myself. Honestly the only thing I want to do right now is an exhaust. I have been leaning towards doing a custom x-pipe and higher flowing mufflers to save money, hold on to my warranty and have a better sound. I cannot get a straight answer on these catbacks that are out. (love the sound of corsa and frpp sport) but $1200+ for a catback is outrageous if there are no gains to be had over stock. If they make significant gains with Intake, tune and headers then maybe it might be worth it, but it'll be awhile before I get to all that other stuff and I'm thinking the prices for catbacks will significantly drop by the time I am ready to do the basic bolt-ons. I really just want clarification on this before I lose my mind lol.

I think its been fairly well established at this point that the restrictive exhaust component on these cars (atleast n/a) is prior to cat-back section of the exhaust. Otherwise you would really see manufacturers/vendors jumping all over threads like this with dyno results.

Next week I will be installing my exhaust (ARH H-Pipe Catback) and dynoing after ... even with my supercharger, without changing headers, I will be surprised if I gain more than ~5-7whp at peak ... and even if I "gain" that much, I could easily chalk it up to different ambient conditions to when I dyno'd yesterday.

If you want power for the cost of an exhaust, its been shown over and over again that tune and intake will get you a LOT (In my opinion on a n/a setup) of power gained, for less (or the same money) than a cat-back exhaust.

 

[Shawn@Corsa]

catbacks aren't really worth any power, pick based on sound is what I tell everyone

Our axle back made 5-8 rwhp on all pulls... mid section added made an additional 1-2... weight / sound / look and some flow to aid in future mods is the investment

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