Headers?

Imma Sssnaake

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I don’t mean to hijack this thread, but I have a set of slightly used KOOKS stepped LTs with catless x-pipe for sale if anyone is interested! There is a post in the GT350 specific market place with pictures. It will save you almost $1000 from buying new.





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The Rooster

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The stock exhaust flows pretty good on these cars... Im at 789 rwhp with a Whipple, only exhaust upgrade is resonator delete.
For the cost and effort to install long tubes you'd be better off spending it somewhere else imo
 

newmoon

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The stock exhaust flows pretty good on these cars... Im at 789 rwhp with a Whipple, only exhaust upgrade is resonator delete.
For the cost and effort to install long tubes you'd be better off spending it somewhere else imo
I agree they are not worth the investment in a hp/$$$ comparison. I'd consider a CF driveshaft or lightweight wheels a better investment.
 

Slamdcoop0428

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The stock exhaust flows pretty good on these cars... Im at 789 rwhp with a Whipple, only exhaust upgrade is resonator delete.
For the cost and effort to install long tubes you'd be better off spending it somewhere else imo
4hrs to install mine and your motor will thank you big time.
 

Bulldogs22

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4hrs to install mine and your motor will thank you big time.
The gain you feel is from the cat delete/high flow cats along with the tuning. The stock heads are CNC Ported and it’s the stock cats that hold back the flow.
 

Slamdcoop0428

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The gain you feel is from the cat delete/high flow cats along with the tuning. The stock heads are CNC Ported and it’s the stock cats that hold back the flow.
I know, his engine being boosted is why I said his engine will thank him later. 93 octane, 12:1 compression. Cat protection from over temp, all goes away and big power gains. Definitely worth it.
 

Angrey

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The stock exhaust flows pretty good on these cars... Im at 789 rwhp with a Whipple, only exhaust upgrade is resonator delete.
For the cost and effort to install long tubes you'd be better off spending it somewhere else imo
Maybe true for blown applications and a strictly min number perspective, but your 789 would probably gain 50 or more hp from the same setup with long tubes and no cats.

Any improvements N/A are roughly double (theoretically) for every extra atmosphere shoved through the motor.

So if you start with 460 rwhp and double the air, you'll end up with 920. If you start with 510 rwhp and double it, you'll end up with 1020. Of course there's inefficiencies and it's a crude ratio, but bottom line is every increment N/A is worth much more blown.

There's also non-hp related benefits like sound and tone.
The gain you feel is from the cat delete/high flow cats along with the tuning. The stock heads are CNC Ported and it’s the stock cats that hold back the flow.
No. The heads from the factory flow about 320 on the intake side. If you add 60 CFM of flow, and the motor breathes better (on either side) the result is stronger naturally aspirated numbers and THAT is adiabatically what gets multiplied when you add boost/charge to the system.

If you double the amount of air going into the motor, and you add the appropriate amount of fuel theoretically (all things being equal with timing, intake temps, etc) then you effectively double the amount of output from the motor.

So if you're going to double the amount of output (with say 15 psi) then it helps your final tally to start with a better performing engine.

This isn't some mysterious engineering principle. It applies to everything from electric motors to combustion engines.

While the cats are the biggest constriction on the exhaust side, they're not the only restriction. While the stock shorty's are pretty good, they're not as good as long tubes with proper merge collectors. It's no different than if you change from a 2" exhaust system to a 3".

At N/A levels, the intake side will be much more fruitful for gains, but at some point, everything gets a vote.

A simple throttle body swap may only net a few horsepower naturally aspirated. But if you blow the car and then swap you'll find the SAME modification is worth much more (because again, you're INCREASING the amount of air/fuel and consequent power you throw at the modification).

So my point stands. Every mod you do n/a yields even bigger benefits once you add the blower. OR, in some cases, the car can make equivalent power at less boost if heavily modified to breath and exhaust better.
 

nastang87xx

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Long tubes indeed do help this engine particularly with scavanging. It's a shame no one can figure out an equal length setup. Doesn't matter THAT much but it would be cool for the intrinsic and intellectual value.

Turbocharging is also the only way to get close to this double the air, double the power theory as well because you don't have increasing parasitic loss from a supercharger drive belt. 2 bar through a supercharger will net contextually less power than 2 bar through a turbo as efficiency ratio goes down.
 

Bulldogs22

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Long tubes indeed do help this engine particularly with scavanging. It's a shame no one can figure out an equal length setup. Doesn't matter THAT much but it would be cool for the intrinsic and intellectual value.

Turbocharging is also the only way to get close to this double the air, double the power theory as well because you don't have increasing parasitic loss from a supercharger drive belt. 2 bar through a supercharger will net contextually less power than 2 bar through a turbo as efficiency ratio goes down.
I thought ARH utilized equal length which is why they sound different compared to others?
 

honeybadger

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I thought ARH utilized equal length which is why they sound different compared to others?
Nope. The front tubes are definitely longer than the rears, unfortunately. Equal length headers would be super challenging in this package. Not a lot of room
 

nastang87xx

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Kooks made a set of true equal length long tube headers for 2011 - 2014 cars but they were an install and maintenance NIGHTMARE. The way they routed would prevent you from doing starter swaps, tolerances between the tubes and other parts of the car were scary tight, and the tubes weren't as long as other offerings. Granted I think the length was a great match for the engine, the tradeoffs were a hard pill to swallow.
 

Rev Happy

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Kooks made a set of true equal length long tube headers for 2011 - 2014 cars but they were an install and maintenance NIGHTMARE. The way they routed would prevent you from doing starter swaps, tolerances between the tubes and other parts of the car were scary tight, and the tubes weren't as long as other offerings. Granted I think the length was a great match for the engine, the tradeoffs were a hard pill to swallow.
I'm curious if the sound would be that much different with true equal length on this car. More high pitched like a FPC Ferrari at WOT? Or can that never be achieved do to the Up-Down-Up-Down design?
 

RPDBlueMoon

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I'm curious if the sound would be that much different with true equal length on this car. More high pitched like a FPC Ferrari at WOT? Or can that never be achieved do to the Up-Down-Up-Down design?
It might help a bit but one of the design engineers from Ford Performance said that it sounds different than the Ferrari because of the firing order, so it's probably a combination of that and the different headers why it sounds different. It would be interesting to hear how it sounds with an equal length header though.
 

Angrey

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Long tubes indeed do help this engine particularly with scavanging. It's a shame no one can figure out an equal length setup. Doesn't matter THAT much but it would be cool for the intrinsic and intellectual value.

Turbocharging is also the only way to get close to this double the air, double the power theory as well because you don't have increasing parasitic loss from a supercharger drive belt. 2 bar through a supercharger will net contextually less power than 2 bar through a turbo as efficiency ratio goes down.
Agreed, turbos are more efficient, so it takes less charge to get to double power.

Even with a theoretical double taking into account the blower parasitics, there's inefficiencies if the intercooling isn't adequate and there's reductions in timing, etc.

Bottom line is that if you start with a motor that makes 200 hp and shove twice as much air in it, you'll theoretically get around 400 hp. If you start with a 400 hp motor and double the air, you'll get around 800 hp.

So starting with a voodoo motor that's stock/oem and doubling it, you'll end up with around 1050 at the crank.

If you modify your voodoo and you're making near 600 hp and you send the same amount of boost to it, you'll end up around 1200 at the crank.

OR as I said, in order to get to 1050 crank, you won't have to push as much boost pressure (same amount of air, just less built up pressure because it flows better).
 

Angrey

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It might help a bit but one of the design engineers from Ford Performance said that it sounds different than the Ferrari because of the firing order, so it's probably a combination of that and the different headers why it sounds different. It would be interesting to hear how it sounds with an equal length header though.
It's a weird chicken/egg affair. For a cross plane firing order, much of the header design for those is intended to even out the pulses which yields more performance and better sound (in most people's opinion).

If Ford already discovered that the triple 2 in 1 shorty's already modify the sound/pulse crowding, then by adding long tubes or equal length it's gonna smooth it back out again.
 

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104 - Cervini's Auto Designs - 1


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