Exhaust Mid S-Pipe

[Malicar]

So we have 3" exhausts, 3" downpipes. I may be ignorant, but aren't we still being choked off at the S pipe that connects the downpipe to the rest of the system?

Anyone have any plans for a bigger unit there, or is anything preventing that?

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[JL8jeff]

Are you referring to the intermediate pipe which connects from the converter and goes over the axle to connect to the muffler? The stock i-pipe is either 2-1/2 or 2-3/4", I forget which one. I there are a couple of replacements for them but I think they still neck down at the muffler end. I went with a full 3" cat-back that replaces that pipe with a muffler and resonator.

 

[EvilJim1971]

Are you referring to the intermediate pipe which connects from the converter and goes over the axle to connect to the muffler? The stock i-pipe is either 2-1/2 or 2-3/4", I forget which one. I there are a couple of replacements for them but I think they still neck down at the muffler end. I went with a full 3" cat-back that replaces that pipe with a muffler and resonator.

No, connecting the downpipe to the exhaust... Where it crosses under the transmission.

 

[Malicar]

No, connecting the downpipe to the exhaust... Where it crosses under the transmission.

Correct, this pipe.

 

[Malicar]

Are you referring to the intermediate pipe which connects from the converter and goes over the axle to connect to the muffler? The stock i-pipe is either 2-1/2 or 2-3/4", I forget which one. I there are a couple of replacements for them but I think they still neck down at the muffler end. I went with a full 3" cat-back that replaces that pipe with a muffler and resonator.

 

[CalvinT]

This discussion reminds me of similar discussions on the WRX Subaru forums. Many people seemed to feel that it it was stock, intake or exhaust, it must be inadequate. Turns out the stock 2002 WRX intake was good for over 350 HP, same with exhaust except for the muffler and intercooler. The muffler had a lot of baffles. People easily exceeded 350 hp with stock exhaust and intake other than the muffler.

I'm skeptical of replacing anything just because it looks like it might be restrictiive. I'd like to see solid flow and dyno testing first.

My WRX makes 245 HP at the wheels, measured on a chassis dyno. It has stock intake and stock exhaust other than the intercooler and muffler. I also replaced the uppipe with the uppipe from an STI. Assuming 15-20% power train loss that means arouind 290-300 at the flywheel. But that's only a guess. That's with a 2 1/2 inch exhaust, stock cats and resonator and aftermarket straight through muffler (Stromung.)

Other changes were larger injectors, fuel pump and dyno tuning. I even kept the stock turbo so I wouldn't lose low end response. Need all you can get when you only have 2.0 liters.

Stock it had 167 hp at the wheels.

Think about this before making changes, it may save you money that can be better spent elsewhere.

 

[Malicar]

This discussion reminds me of similar discussions on the WRX Subaru forums. Many people seemed to feel that it it was stock, intake or exhaust, it must be inadequate. Turns out the stock 2002 WRX intake was good for over 350 HP, same with exhaust except for the muffler and intercooler. The muffler had a lot of baffles. People easily exceeded 350 hp with stock exhaust and intake other than the muffler.

I'm skeptical of replacing anything just because it looks like it might be restrictiive. I'd like to see solid flow and dyno testing first.

My WRX makes 245 HP at the wheels, measured on a chassis dyno. It has stock intake and stock exhaust other than the intercooler and muffler. I also replaced the uppipe with the uppipe from an STI. Assuming 15-20% power train loss that means arouind 290-300 at the flywheel. But that's only a guess. That's with a 2 1/2 inch exhaust, stock cats and resonator and aftermarket straight through muffler (Stromung.)

Other changes were larger injectors, fuel pump and dyno tuning. I even kept the stock turbo so I wouldn't lose low end response. Need all you can get when you only have 2.0 liters.

Stock it had 167 hp at the wheels.

Think about this before making changes, it may save you money that can be better spent elsewhere.

I'm not even thinking of power. I'm primarily thinking temps and volume. More volume=less resistance or pressure, helps keep in/out temps down.

It's been proven time after time, a larger turbo can make the same HP with less pressure, due to more, cooler volume. The same goes for intake airflow and exhaust flow.

Keep in mind, manufacturer's don't design their systems purely for performance, they have to make emissions/noise/fuel economy needs as well. Especially for something like the bronco.

All I know, is when I'm baggin on it, my turbo will literally be glowing red, and my timing is reduced due to high iat's. Anything I can do to keep temps down.

 

[MWILD]

I’ve been wondering about this as well. I don’t believe there is an aftermarket solution being sold as of yet. When I’m done with a lot of my power mods I may take it to an exhaust shop to see if they can fab something up for me.

 

[JL8jeff]

CVF makes a downpipe but it looks like it necks down where it gets to that S pipe. They could probably do a full 3" downpipe and S pipe with the stock size flange to bolt up to a 3" catback but the demand is probably pretty small. I have the V6 so it doesn't have the S pipe, it has a y-pipe that is pretty narrow as well.

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