Full-Race Formline Manifolds vs OEM Log Style EcoBoost 3.5L Back-to-Back Dyno Test

It’s no secret the OEM log style EcoBoost 3.5L exhaust manifolds are restrictive. There’s consensus among the top EcoBoost tuners that the OEM logs will choke the engine at higher flow rates and hold back power. But the question remained: exactly what power level and RPM does the choke happen at, and how much power is left on the table compared to Formline Turbo Manifolds? 

Our goal: to pinpoint exactly where the OEM log manifolds fall short and how much power they're holding back.  We decided to put our Gen2 3.5L test mule on the dyno in a back-to-back shootout and evaluate the changes from our new Formline Turbo Manifold.

Our test truck is tuned by MPT and equipped with our Complete Power Pack, which includes Garrett PowerMax™ Turbos, Full-Race Intercooler, Radiator, Inconel Studs, and more. The only components from the Power Pack not installed are the Formline Manifolds. Additionally, it features an SPD exhaust and Turbosmart BOV. This setup retains its original Ford OEM longblock and fuel system, including stock fuel pumps and injectors, mirroring what many Raptor and F-150 enthusiasts have under the hood.

->  Worth noting: this is not an all-in bragging rights setup. Stock fuel system and 91 octane means we are limited to 20psi max boost, this is a safe range for the unopened OEM engine on pump gas, something that most Raptor and F-150 enthusiasts can relate to.

Our testing conditions were challenging: Arizona summer heat at 102-105°F and an elevation of 1100 feet, translating to a density altitude (DA) of approximately 3600 feet.  We’re running on a Dynojet 424 and analyzing the dyno runs on their WinPEP8 data center (a great tool to visually show before and after).  Fuel used is west coast AZ 91 octane gas *some of the worst quality fuel in the USA* and the tune is MPT’s 91 octane PR-X on SCT X4 set to a conservative 20 psi max boost target (<note: logging is done via HP tuners because HPT has the most user-friendly data logging format of any available option).  Also worth mentioning is that we used SPD catted downpipes plus their HX/trombone loop exhaust.

We started by installing a fresh set of NGK ruthenium HX spark plugs and then conducted the baseline run with the OEM manifolds. 

The result (red line below) was a respectable 461whp  @ 4100rpm and 469wtq @ 6100rpm at a safe 19-20 psi boost;

This is a truck engine and it needs to be tough, so despite our desire to increase power, the key requirement that we value and look at is a desire to not lose any lower RPM powerband or torque.  

• 250tq = 2300rpm @ 2.5psi
• 300tq = 2600rpm @ 6psi
• 350tq = 3000rpm @ 13psi
• 400tq = 3250rpm @ 17psi 

This is the region where a truck owner really needs some get-up-and-go.  In this part of the powerband, the wastegates are 100% closed and the engine is doing everything it can to get the turbos online (laggy turbos are not acceptable for this application).  If you’re used to seeing other F-150 EcoBoost dyno charts, this is consistent with what we’d expect on a properly set-up customer vehicle. Overall there’s a slightly stronger lowend power compared to OEM and significant gains on the top end.

Now that the baseline was completed, we proceeded to pull the OEM log manifolds off and swapped to the Formline Manifolds.  

*yes, our fingers were burned in the process

The next morning we drove to get breakfast before hitting the dyno. One thing that was immediately apparent on the drive was the engine sounded so much better than before. I dont know if these microphones can do the Formline / SPD Trombone loop exhaust note justice but we absolutely LOVE the way the truck sounds now compared to the logs. As we sat there eating breakfast, the anticipation was palpable - we knew there would be gains, but how much? And why were we sitting here when we could be on the dyno?  We quickly headed back and got the truck strapped in.

Right off the bat, the Formline Turbo Manifolds delivered (green line)

The initial boost curve showed virtually identical spool (aside from minor fluctuations) with no loss of lowend powerband.  

The real difference emerged beyond 3200 rpm, where the OEM manifolds began choking. Despite both runs being at the same boost level, the Formline Manifolds let the engine breathe and by 6100rpm, we saw an impressive 508whp, proving the Formline Manifolds' superior flow capability.  

Gains were seen across the board:

• 3250rpm: +20tq / +10hp
• 3500rpm: +50tq / +32hp
• 4000rpm: +90tq / +63hp
• 6000rpm: +46tq / +54hp

As the day heated up, the engine did too. We decided to take a break and cool the engine, intercooler, and turbos off with fans before one final "glory pull." Generally, a cold engine tends to spool the turbo a tiny bit later than a warm one, and a cool engine can make more power than a warm one (for obvious reasons). This is fairly common knowledge in the turbo world, and often exaggerated on big turbo builds with complex exhaust routings.

We gave it an hour to cool off and it did not disappoint.  The final result (blue line) confirmed: slightly later boost onset with significant power gains over the hot engine.

This resulted in a max 558 WHP and 550 WTQ. A massive peak gain of +97 WHP over the OEM log manifold. (We said 92 on the video, but it's actually 97). 

In the end we can confidently say that Formline Manifolds can gain power. How much power will depend on the vehicle and setup. Our testing was performed on 91 octane gas and in the Arizona summer heat.  As seen on the boost log, we experienced no loss of turbocharger spool or torque. After letting the engine fully cool down, the result was an impressive 558 wheel horsepower - all on the stock engine with stock fuel system. 

Swapping to Formline Turbo Manifolds resulted in significant gains across the entire powerband, with a peak of +97 WHP and no loss of spool.  This testing, conducted on 91 octane gas and in intense Arizona heat, highlights the manifolds' real-world benefits. For those looking to unlock their EcoBoost's potential, these manifolds are a game-changer.

For more information, check out our detailed video below: