Muscle Mustangs & Fast FordsHow To Engine
Tested: Holley’s Coyote Intake Manifold
What’s the first thing you look at when checking out someone’s engine bay? Chances are the intake manifold is at the top of that list. The type of intake manifold can tell a lot about it; stock without power adders and you would assume that the engine was fairly tame. Now, when you see a polished or blacked out fabricated manifold it could be game on!
A few companies have recently ventured into the Coyote intake manifold market and when we saw Holley’s fabricated version, we had to test it. “The Coyote is obviously an innovative, new engine capable of creating big horsepower numbers,” says Keith Jessee of Holley. “There was a very apparent demand for more intake manifold options for these engines. Opportunity knocked and we simply opened the door.”
While intake manifolds play a big part from an aesthetics perspective, they play an even bigger role when it comes to performance. The runner length and plenum volume will have a direct correlation on where an engine will make its horsepower and torque.
Inside the manifold is a hurricane of low and high pressure air. Without getting deep into intake manifold design and theory, typically a longer runner will provide more torque and less RPM while a short runner manifold will make more horsepower at a higher RPM. Tuning that runner’s length to your driving style is critical depending on the type of environment the engine is subjected to. Holley’s intake manifold uses an extended, bell-mouthed trumpet. “The extended trumpet not only lengthens the runner, but allows the cylinders to pull from a ‘cleaner’ or less turbulent area in the intake manifold,” explains Jessee.
Our test mule is a virtually stock 2014 Ford Performance Coyote crate engine (non Aluminator). The modifications only include a JLT Performance cold air intake, Hooker Blackheart 1-7/8-inch primary headers, a Ford Performance billet intake manifold, and a 91-octane tune by Eddie Rios of Addiction Motorsports.
“The Holley intake was designed to hold up to high boost levels and complement high RPM engines while still keeping it as light as reasonably possible,” explained Jessee. “While our intakes will work on a street car, they are really tailored toward high-RPM, maximum effort racing engines.”
In addition to the manifold in our test, Holley produces a race version with larger runners and plenum, along with a removable top to allow for porting. “The race intakes are 1mm thicker than the standard Sniper intakes along with all seams being welded on both sides,” states Jessee. “This is what allows that intake to withstand upwards of 30 pounds of boost all season long.” To add an interesting twist, we also installed a set of COMP Cams Stage III NSR (PN 191160) naturally aspirated camshafts during the install to compare how the stock and Holley manifold reacted to the camshaft change. These cams feature 236 degrees of duration at .050-inch on the intake and 239 degrees on the exhaust, with a 126 degrees of lobe separation. Valve lift comes in at .492 intake and .453 exhaust. While COMP does offer a supercharged version of these camshafts, this engine is currently slated to be all-natural.
When it came to tuning, Rios noted, “The difference between the short runner manifolds and stock manifold was extending the cam retard to 7,800 instead of 6,600 for the stock manifold. Basically, taking the camshaft table and extending it 1,000 rpm, which made the intake cams more advanced at 6,600 rpm with a short runner than where it would be with the stock manifold.”
“With the stock cams and full control over the VCT, the stock manifold intake cam settings came in at 45 degrees at 3,000 rpm and tapering down to 16 by 6,600,” Rios continued. “For the Holley I started at 50 degrees of advance tapering down to 19 at 7,800. Biggest difference is the engine will take more timing down low with short runner over the long runner, which helps gain back some of the lost torque.” After the camshaft swap you lose about 30 degrees of adjustment due to the limiters and Rios needed to account for that in the SCT software, but the changes were relative.
1. Holley’s intake comes tapped with three 1/8-inch NPT ports and one ¾-inch NPT port, plus the appropriate barb fittings. This serves as a great reference point for everything from a brake booster, regulator, boost solenoid, and air intake sensors.
2. Holley also offers a high-flow billet fuel rail kit with 3/8-inch lines and AN-8 fittings for just $110, under PN 850003. This includes the mounting brackets, crossover line, and all the necessary hardware. The injectors shown here were swapped over from the Coyote.
3. The intake manifold utilizes the OEM-style O-rings to seal against the cylinder heads, but include a new set with the manifold.
4. Troy from Westech Performance drops the intake manifold in place. Everything clears this manifold and it actually sits about one-inch lower than a BOSS 302. This means it will clear a 2011-2016 Mustang’s hood and strut tower bar.
5. To take advantage of the 90mm throttle-body bore opening we equipped the Holley intake manifold with a Ford Performance billet 90mm throttle-body. Here you can see that Holley includes fuel rail standoffs to fit the stock height injectors.
6. With the fuel rails and injectors in place, all we needed to do is connect the fuel lines and install our JLT Performance cold air intake.
7. Here’s a comparison with the stock camshafts against the factory GT intake manifold. But just like camshafts, changing the runner’s length and plenum volume affects the powerband. Above 5,900 rpm the Holley dominates the stock GT manifold and pulls for an additional 700 rpm. The stock GT intake manifold comes in at 457.0 hp, 415.3 lb-ft, while the Holley netted 488.7, 391.4 lb-ft. The stock manifold did produce 23.9 more lb-ft of torque, but the Holley manifold cleared a 31.7 horsepower gain. Once out of first gear the gains are all positive.
8. With the COMP Cams installed, the factory manifold was able to breathe better at higher RPM, and tightened the gap with the Holley manifold in that area. The Holley manifold came in at 530.5 hp, 400.4 lb-ft, a 24.7 horsepower gain over the GT but with a 26.1 lb-ft of torque loss. There’s no doubt that with the motor breathing better that a little bit of boost or nitrous would have put the Holley intake manifold in its sweet spot!
Stock intake manifold with stock cams – 3,100 rpm to 6,800 rpm Peak Power – 457.0 hp, 415.3 lb-ft
Stock intake manifold with Comp Cams – 3,100 rpm to 7,500 rpm Peak Power – 505.8 hp, 426.5 lb-ft
Holley intake manifold with stock cams – 3,100 rpm to 7,500 rpm Peak Power – 488.7, 391.4 lb-ft
Holley intake manifold with Comp Cams – 3,000 rpm to 7,900 rpm Peak Power – 530.5 hp, 400.4 lb-ft
Sniper EFI Sheet Metal Fabricated Intake Manifold
Polished silver manifold PN 829031, available in black powder coat – PN 829032
3mm (1/8-inch) thick T6061 sheet aluminum construction
90mm throttle-body bore opening
100% TIG welded
EFI intakes include 3/8-inch Fuel rail kits
Runner lengths with tapered top on EFI intakes designed to increase velocity and more evenly distribute airflow to all eight cylinders
RPM power band; 2,200-6,800 rpm
Vacuum ports: (3) 1/8-inch and (1) ¼-inch pipe