Shorty headers vs OEM exhaust manifolds ??

[Stangra]

Since mine will be a street/track car in CA, long tube headers are off the table for me. It's frustrating to hear tuners talk about leaving significant power on the table without them on my supercharged/E85 Coyote. There are some CARB compliant shortys available. I've been reading diverging stories, power gained or imperceptible improvement over the stock manifolds. Until now I've settled for the stock exhaust but with my engine out of the car I'm revisiting the idea. This would be the perfect time to upgrade, if it is indeed an upgrade. I was considering having my stock manifolds ceramic coated for heat control, but some of these shortys are available with ceramic. Much of the cost of an upgrade would be offset by not needing to coat my manifolds. So I put it out to the knowledgeable folks here on TMO.
Shortys or OEM?

 

[PatientZero]

OEM. The only time I would ever use shorty headers is if it was an engine swap situation and that is the only thing that would fit.

I agree that there is lots of power to unlock with a set of longtubes.

 

[Stangra]

OEM. The only time I would ever use shorty headers is if it was an engine swap situation and that is the only thing that would fit.

I agree that there is lots of power to unlock with a set of longtubes.

I'm not a big fan either, I rejected the idea when it would have been a stand-alone mod in an otherwise running car.. I consider it now only because I'm completely dismantled, thinking about ceramic coating my stock manifolds, and it's my only legal header option.
If I knew they"d provide even a marginal performance gain for a supercharged application I'd look twice at the ceramic coated ones since I'd be halfway there with the cost of coating mine.

All this brings another question: Any thoughts on the benefits of ceramic coating for heat control? Aesthetics alone isn't worth it to me. If that's another pipe dream (pun intended!) I may just leave the stock manifolds as they are.

 

[Roger1981]

Since mine will be a street/track car in CA, long tube headers are off the table for me. It's frustrating to hear tuners talk about leaving significant power on the table without them on my supercharged/E85 Coyote. There are some CARB compliant shortys available. I've been reading diverging stories, power gained or imperceptible improvement over the stock manifolds. Until now I've settled for the stock exhaust but with my engine out of the car I'm revisiting the idea. This would be the perfect time to upgrade, if it is indeed an upgrade. I was considering having my stock manifolds ceramic coated for heat control, but some of these shortys are available with ceramic. Much of the cost of an upgrade would be offset by not needing to coat my manifolds. So I put it out to the knowledgeable folks here on TMO.
Shortys or OEM?

You can use the kooks 1 7/8 in super shorty headers that are for the 11 or 14 mustang they bolt right up to the 15-22 mustang you just got to shave off a quarter inch off the driver side motor mount other than it's a
straight bolt on you can use a set of Mac midpipes all you got to do is just clock the flange 90° street legal to

 

[Dave_W]

Any thoughts on the benefits of ceramic coating for heat control?

White Lightning Exhaust Coatings – Swain Tech Coatings | Industrial Coatings | High Performance Racing Coatings

White Lightning™ is applied about .015” thick compared to about .002” thick for the cosmetic coatings.
White Lightning™ insulating headers typically reduces radiant heat by about 35-55%. This reduction in radiant temperature will decrease under hood and cockpit temperatures. Lower under hood temperatures lead to lower intake temperatures. A 10°F reduction in intake air temperature provides a 1% increase in horsepower. A 30°F reduction equates to a 3% horsepower increase.

IIRC, the S197 intake has a snorkel that passes air around the core support, so it's not pulling 100% intake air from inside the engine compartment. So take the marketing quote above with a grain of salt.

 

[Stangra]

White Lightning Exhaust Coatings – Swain Tech Coatings | Industrial Coatings | High Performance Racing Coatings

IIRC, the S197 intake has a snorkel that passes air around the core support, so it's not pulling 100% intake air from inside the engine compartment. So take the marketing quote above with a grain of salt.

Yes, the intake air is fed from upstream of the radiator, likely ambient temp with any speed.
When I pulled the engine from my wreck there were mild signs of heat discolored paint near the manifolds. Since I'm supercharged I'm guessing the manifolds might get a little hotter than NA. The supercharger itself is a big heat source and keeping it cooler might help some. With all the exiting heat from oil, trans, & supercharger intercoolers, and radiant heat from the supercharger and exhaust manifolds I worry about heat damage to my new carbon fiber heat extracting hood too, . Maybe ceramic coated exhaust might mitigate some of this? I'm sure wrapping them would work well, maybe even better although bulky and not as pretty.

 

[mwjscn]

I've heard mention that the Coyote benefits from a slightly larger primary tube volume in order to get exhaust gas out of the chambers at high RPM, so I do have a set of shorty headers in my basement. Using shorties was important to me since we're an emission state, so I wanted to keep my catalytic converters and not have to deal with the chance that high-flow cats might not correctly set the emissions monitors and I wanted to keep my Corsa X-pipe and everything downstream the same. Mind you I didn't go with the cheap versions with the delicate 'ceramic coat' tinfoil. Instead I got a good deal on bare finish Hooker Blackhearts - tuned length, nice bends and construction, and an actual mitered merge collector that I then coated in Cerakote V-series (they're having what appears to be a discontinuation sale now for $450 on Beefcake Racing, so if you want a set now would be the time to consider it. They're also CARB approved if that's a hurtle for you, D-115-28). Will it do something over stock? Not quite sure. It's always that tube size versus tube velocity thing. The stock pieces are often underappreciated, but from factory the Tri-Y design is quite nice with designed scavenging and good torque despite their compact size. I'd be a proponent of ceramic coating headers if you have them off, even if it's just to save the wiring harness and other under-hood plastics from getting brittle with heat over time. Sorry I don't have any empirical data to share, but figured I'd at least share my state of mind with how I approached it.

My one piece of advice if you do go shopping for exhaust is to always check the collector. It's usually a good way to estimate quality, since subpar manufacturers will hide their crimes in there. Take this Pypes shorty header, for instance:

 

[Dave_W]

Even better if it has a merge spike in the collector.

Stolen from

Note that this video, like many others, gets "equal length" wrong for cross-plane cranks. The example is correct for evenly-spaced exhaust events (inline 4, flat-plane v8) but cross-plane V8s "mix up" the bank firing order. To get the exhaust pulses evenly timed at the merge collector, the primary tubes need to be different lengths, not equal lengths. Or one (or more depending on firing order) need to cross to the other side (see "180 degree header").

 

[Stangra]

If nothing else maybe shortys sound better than stock manifolds?
I'm having a hard time figuring out what make these things sell.
Leaning towards keeping the stock setup and focusing on other issues.

 

[PatientZero]