Exhaust size

[stripSHO]

I'd be willing to bet it's somehow temperature related.

In venting gas appliances from buildings, there are VERY strict rules and tables to follow when sizing the vents, and a lot of it has to do with maintaining gas temperatures. Too big a pipe introduces excess surface area, and slows gases down which means they lose much more heat to the surroundings. The combination can cause the flue gases to lose buoyancy and not vent at all. Instead they fall back down the pipe, building fills with CO, people die.

Same applies with car exhaust. As the gases cool and gain density they become more difficult to move. Then if it cools enough for condensation you also have to deal with the water laying up in the pipes.

I can't imagine losing enough power from oversized exhaust to actually be concerned about it though. Would be interesting to see actual numbers.

 

[SilverSH0]

It all depends on the turbo efficiency from my understanding. Scavenging can be a thing.

Finally got to watch this. I think we're talking two different things here. What that video is referencing is scavenging in the exhaust manifold. That will be exhaust port to turbo. What this post seems to be about is turbo back exhaust. Due to what the turbo is doing, it removed those pulses and you get a continuous smooth spooling. If never seen anything about scavenging on a turbo system after the turbo.

 

[Zpak]

Here is an interesting read that aligns with you SilverSHO. And, for turbo cars the ‘bigger is better’ school of thought.
Really wish I could find that other one but no luck yet.
https://www.tercelreference.com/tercel_info/turbo_exhaust_theory/turbo_exhaust_theory.html

 

[802SHO]

It was my understanding the best exhaust was none post turbo(s)

 

[Zpak]

It was my understanding the best exhaust was none post turbo(s)

That would be absolutely true.

 

[b4black]

The stock size is likely best for stock motors (ford put a lot of thought into it). Must of us are tweaking for more power, so moving up at least one size would make sense.

 

[yaycandy]

The stock size is likely best for stock motors (ford put a lot of thought into it). Must of us are tweaking for more power, so moving up at least one size would make sense.

Yea i dont know. The more power with turbos the more emissions i would think. Thats why chevy and dodge did superchargers. Turbos are exhaust driven. More boost more exhaust. Or at least keep the wastegates closed longer then stock. Ford still had to meet emission standards with a twin turbo setup so thats probably how the exhaust is setup. Ford did not market the car as a performance car, wasnt in the 2013 ford performance line up when i bought my 13. Maybe it was maybe it wasnt.

 

[SilverSH0]

The stock size is likely best for stock motors (ford put a lot of thought into it). Must of us are tweaking for more power, so moving up at least one size would make sense.

The stock size is best for the factory vehicle and their requirements. Their requirements include balancing power, emissions, mpgs, drivability, noise, durability, etc. If your priorities don't align with Ford's, the stock choices may not be the best for you.

That's the problem with determining what's the best. It's subjective based on needs.

 

[802SHO]

My goal was just the least restriction possible. I didn't want any cats or mufflers. Sound wasn't really my goal although I added X pipes to enhance whatever it might sound like. I didn't want to mess with my existing catless 2.5" downpipes and decided just to match it. In the end I paid about $1,300 for the custom work with the tips that cost $175. Catless downpipes were $770 IIRC. Overall nearly $2,300. It's loud/obnoxious but I don't mind that. I don't love it all the time but I do most of the time.

 

[yaycandy]

My goal was just the least restriction possible. I didn't want any cats or mufflers. Sound wasn't really my goal although I added X pipes to enhance whatever it might sound like. I didn't want to mess with my existing catless 2.5" downpipes and decided just to match it. In the end I paid about $1,300 for the custom work with the tips that cost $175. Catless downpipes were $770 IIRC. Overall nearly $2,300. It's loud/obnoxious but I don't mind that. I don't love it all the time but I do most of the time.

Same here, catless downpipes and i have pipes made that i can switch between mufflers or pipes in a few minutes. Sounds like weedwacker ropes but i dont mind lol

Actually sounds exactly like throttling a weedwacker. With straight pipes

 

[802SHO]

 

[skyshadow07]

I would love to see a picture of a $2300 exhaust.. good god.

 

[SHOdded]

https://solomotorsports.net/blog/maserati-levante-exhaust-install/

 

[802SHO]

I would love to see a picture of a $2300 exhaust.. good god.

That's pretty much the extent everyone pays that has afermarket downpipes and aftermarket catback.

 

[yaycandy]

That's pretty much the extent everyone pays that has afermarket downpipes and aftermarket catback.

I paid 800$ for custom 3inch exhaust all welded on my caddy from a pretty good custom shop. Around 35ft of stainless pipe installed. I bought the mufflers separate on my own

 

[802SHO]

I paid 800$ for custom 3inch exhaust all welded on my caddy from a pretty good custom shop. Around 35ft of stainless pipe installed. I bought the mufflers separate on my own

Nice. Didn't know this was about Caddy exhausts. My bad.

 

[SM105K]

Nice. Didn't know this was about Caddy exhausts. My bad.

Including my DPXs and my custom Magnaflow set up, I am in $800.

 

[802SHO]

That's a good deal and your exhaust work is stellar! I'm just saying for the cost of downpipes and a typical cat back its about the same price I have ended up paying. Am I wrong?

Downpipes roughly 6-800?

Cat back system 1,100 - 1,300?

If I mounted a Corsa cat back to my catless downpipes and opted for black tips I would have paid almost an identical amount.

 

[yaycandy]

That's a good deal and your exhaust work is stellar! I'm just saying for the cost of downpipes and a typical cat back its about the same price I have ended up paying. Am I wrong?

Downpipes roughly 6-800?

Cat back system 1,100 - 1,300?

If I mounted a Corsa cat back to my catless downpipes and opted for black tips I would have paid almost an identical amount.

Our cars a bought bolt on system is around 2k. A custom exhaust header back wouldnt be over 1000$ for stainless or steel. Even at normal shop hour rate and material around or over 2k$ would be over a week of work. And exhausts are pretty easy for shops the specialize in them. Ive had many exhausts made over the years. Bought bolt on is always more then custom, unless you wanna do gold plated

 

[802SHO]

Our cars a bought bolt on system is around 2k. A custom exhaust header back wouldnt be over 1000$ for stainless or steel. Even at normal shop hour rate and material around or over 2k$ would be over a week of work. And exhausts are pretty easy for shops the specialize in them. Ive had many exhausts made over the years. Bought bolt on is always more then custom, unless you wanna do gold plated

A bolt on system for our cars is around 2k if you round down. My LMS Catless downpipes + my custom 2.5" stainless work with integrated x pipe, rear valance cut for my 4" Quad Tips that were also welded on was a $900 quote that snowballed a bit. They were also supposed to remove my 3rd cat at that time and they didn't touch it. Their labor rate $90-95hr, something like that. Overall, Skyshadow07 thought the amount was insane...and I came in about 150-250 over a complete bought kit.

There are shops all over the world. I've seen amazing work for much less than what I've paid. My shop used crap welds too. Custom should be cheaper no matter where you go but in my case it wasn't, it was about the same as buying a complete kit.

Nothing you said proved me wrong. What do you have for exhaust work done to your SHO? I wonder if any of it is gold plated or is it just your keyboard skills that are?