Exhaust Pressure Testing

[15Oxford5oh]

I've learned quite a bit of knowledge from this thread, but aren't as in tune with the material like you guys are. I have recently purchased and ESS G3 Blower for my Gen 2. Awaiting it's arrival as we speak.. couple questions. Car will be on 93 for the remainder of the year.

1.) I currently am running Stainless Power 1 7/8'' Catted LongTube headers with resonator delete, SR performance X-pipe and Roush Axelback.. I imagine all of this is stock sized piping 2.25'' . Once boost is on the car am I in danger of hurting the motor with High Flow aftermarket cats on it? Do I need to be removing these relatively soon and having the tune revised?

2) As the demand for a more free flowing system because of boost I imagine I am going to need a better flowing exhaust system now.. I love how magnaflow sounds and was looking into their catback. It is as advertised 3" Catback. I see that many are saying that it is actually bottle necked inside the system.. Would that alone be enough to be sufficient for a better flowing exhaust?

Thanks in advance as I am still learning as I build.

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[engineermike]

If you are supercharged I would make every effort to ensure it’s true dual 3” all the way. The magnaflow cat back only necks up to 3” after the supplied resonator.

 

[15Oxford5oh]

If you are supercharged I would make every effort to ensure it’s true dual 3” all the way. The magnaflow cat back only necks up to 3” after the supplied resonator.

So after the headers it’s best to go with the Stainless Brothers True 3” resonators then Magnaflow 3” Catback for true full 3”?

 

[Performance nut]

How is it that I have never seen this thread until now. Very cool stuff.

Out of curiosity, has anyone done anything like this for naturally aspirated? I've been looking at ways to optimize the exhaust but honestly just have guesses at this point.

 

[K4fxd]

Fiberglass or Ceramic Fiber ?

The guy I talked with on the phone said it is fiberglass.

I believe fiberglass packing attenuates noise better and is commonly used in motorcycle mufflers.

Yes, I have re packed many MC mufflers

 

[TEXAS HEAT]

I've learned quite a bit of knowledge from this thread, but aren't as in tune with the material like you guys are. I have recently purchased and ESS G3 Blower for my Gen 2. Awaiting it's arrival as we speak.. couple questions. Car will be on 93 for the remainder of the year.

1.) I currently am running Stainless Power 1 7/8'' Catted LongTube headers with resonator delete, SR performance X-pipe and Roush Axelback.. I imagine all of this is stock sized piping 2.25'' . Once boost is on the car am I in danger of hurting the motor with High Flow aftermarket cats on it? Do I need to be removing these relatively soon and having the tune revised?

2) As the demand for a more free flowing system because of boost I imagine I am going to need a better flowing exhaust system now.. I love how magnaflow sounds and was looking into their catback. It is as advertised 3" Catback. I see that many are saying that it is actually bottle necked inside the system.. Would that alone be enough to be sufficient for a better flowing exhaust?

Thanks in advance as I am still learning as I build.

How is it that I have never seen this thread until now. Very cool stuff.

Out of curiosity, has anyone done anything like this for naturally aspirated? I've been looking at ways to optimize the exhaust but honestly just have guesses at this point.

Your best bet for NA would be long tubes minus the cats, or a cat delete which is pretty tough to find these days. The stock system flows well enough for non-boosted cars. You may gain a little just adding a cat-back 5-6hp tops, but if you want better flow, you will need to remove the biggest restriction.

 

[GT 550]

Your best bet for NA would be long tubes minus the cats, or a cat delete which is pretty tough to find these days.

Absolutely in terms of getting 'an' improvement but I haven't seen a before/after LTs NA 93 test with or without cats so I still wonder if LTs are actually worth it from a cost perspective.

 

[TEXAS HEAT]

Absolutely in terms of getting 'an' improvement but I haven't seen a before/after LTs NA 93 test with or without cats so I still wonder if LTs are actually worth it from a cost perspective.

To be honest, I did not see as much of an improvement running catted headers as I had hoped, however the FFE pipes seemed to make a bigger difference NA, especially in low end torque. Now that I'm boosted I suspect I'm leaving some power on the table without long tubes, but with the new 3" Borla exhaust I recently installed, I don't think it's much more than 10hp that I'm missing out on. Other's may be able to chime in with their experience which may differ from mine.

 

[18psi]

I finally fixed my exhaust per this thread. 100% 3" all the way now. the most amazing discovery after the fact was how much quieter it got with proper mufflers, despite eliminating two 2.5" bottlenecks. Proper mufflers >>> resonators, that's for sure.
Power testing to follow.

 

[Proshop]

@18psi did you reuse the same bullets of different ones?

 

[18psi]

The resonators right after the x are different ones, full 3". Not re-using the 2.5" bullets

 

[Proshop]

The resonators right after the x are different ones, full 3". Not re-using the 2.5" bullets

That’s right I forgot they were 2.5” before. I see the mufflers are MF what brand are the bullets?

 

[TEXAS HEAT]

@ engineermike
I just recently upgraded to a 3" Borla S-Type exhaust paired with the Borla resonator 60661, which has 2.25" dual inlet made to mate with the factory connect pipes with 3" dual outlet with an internal diameter of 2.5" with an integrated H-pipe. I currently run this in combination with the 3" MAK free flow pipes that neck down to 2.25" to mate with the factory exhaust.

My question for you good sir is this, do you think it would be enough of flow improvement to be worth the effort to remove the 2.25" connections and go straight from the 3" portion of the MAK pipes into each of the 2.5" inlet on the resonator using the 3" to 2.5" reducers shown?

Right now the biggest restriction is the 2.25", so if I change it the biggest restriction will be 2.5" going into and out of the resonator.

 

[Mach9310]

Do you think there would be a power restriction with this resonator running 19-20psi? I don’t want to run dumps right after the headers (way too loud). I’ve been considering replacing my Magnaflow tru x for this then running some 3” turn downs immediately after the resonator for weight savings. The car has Kooks catless headers but the catback is 2.5”.

 

[engineermike]

@TEXAS HEAT at one point I just increased the 2.25” factory connect to 2.5” and saw a measurable reduction in backpressure.

@TEXAS HEAT and @Mach9310 i found that 2.5” jist isn’t big enough to support a forced induction coyote. If the goal is to be under 5 psi backpressure, as recommended by Vizard years ago and substantiated by my own testing, I found it’s going to take a true dual 3” or bigger front to back.

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