The results are in! 2015 Mustang with Boss intake vs stock, with boost!

[Eric@BBR]

We decided to settle a long standing debate today with direct back to back testing

As some of you may remember, we tested an N/A 2015 GT with a stock intake manifold, then with a Boss intake. In that test, the Boss intake actually made less power than the stock manifold.
We have since wondered, what would happen on a boosted application?
Today we had the opportunity to test this and find out. This automatic trans equipped 2015 GT has a completely stock motor, custom single turbo kit and e85 fuel system. We made an impressive 810whp and 715 Ft lbs.

We then left the car strapped to the rollers and swapped to the Boss manifold. We left the boost level the same, and just made minor tweaks to the tune for the intake. On the first pull, this made an astounding 854 whp and 759 ft lbs!

So in short, from the info we gained we have shown that on a boosted 2015+, the Boss intake netted a gain of 45whp and 45ft lbs of torque. That is impressive!

Hopefully this will put some rumors and uncertainty to bed!

 

[oldstv]

Great info. Thanks for posting that. That is some real power, and with a stock motor too....

 

[svtfanlv]

nice testing! did the car have headers? exhaust?

 

[TaraFirma]

nice testing! did the car have headers? exhaust?

Custom single turbo system, so I would guess custom turbo headers and custom exhaust down to intermidiate pipe or axleback.

 

[nosscort]

Looks like it hits a brick wall at 6000 rpm. That power falls off fast

 

[Eric@BBR]

Correct, this was a custom fabricated system that used the stock passenger side manifold and a stock 11-14 driver's side manifold. The downpipe is 4" and runs to an open outlet under the car, but has a cap to run back through the full 3" exhaust out the back. These pulls were made with the cut-out open and on 15psi of boost

 

[zinc03svt]

Looks like it hits a brick wall at 6000 rpm. That power falls off fast

Interesting that the boss manifold had exact same power curve as stock manifold...? Most boss manifolds will continue making power past 6300 rpms.

 

[Dcrypter]

Turbo power curves are so underwhelming. Why is that turbo dropping off like mad at 6.3k?

 

[03Sssnake]

Seems to be a re-occurring theme with some single setups on coyotes, have seen EDP kits do the same thing with power and boost quickly dropping off after 6K. In this case I am guessing backpressure is a non-issue with that 4" sewerpipe/downpipe being dumped.

 

[5PointOHNO]

That HP falloff is not what I would expect from a boss manifold car.

 

[elevenfivezero]

I would have to say the drop off is because the Turbo is passing its efficiency, after 6k only "blowing hot air". Why you won't see this on a twin setup because 2 turbos are sharing the work load.

 

[Eric@BBR]

We are doing some testing to find out what that drop-off is. We measured backpressure which came out to be 27psi at 15psi of boost, so a 1.8 bp ratio. While it is not ideal, it is not a major red flag either.

 

[wakebum2507]

If that's a 7675, the exhaust side is too small. Needs bigger exhaust wheel. But 854hp on 15# is also slightly underwhelming.

looks like valve float too. stock valve springs?