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Coyote Engine Tech: 4 Bumpsticks for Big Power
We dyno test Comp’s NSR Stage III camshafts on a variety of Ford Performance intake manifolds
Coyotes are like a fine wine, simply perfect right out of the box…or at least that’s how we drink wine. Their four valves per cylinder allow all 302 cubic inches to breathe fantastically and even better with some boost. But if you plan to get drunk on horsepower without a power adder, camshafts offer the biggest gains than any other single modification on a Coyote.
“But I thought an intake manifold will gain more power?” While close, our testing figures (and fingers) still point to a set of camshafts, like those offered by Comp Cams. For our test we turned to their NSR (No Springs Required) Stage III bump sticks but Comp also offer a more aggressive CR-series that do require valvesprings.
When the question arose when it came to picking between the CR and NSR cams, Billy Godbold, master cam guru at Comp Cams said, “Really, the valvespring is the major deciding point on 2012-2014 applications. Changing the springs in a car might not seem too bad, but it really takes us about twice as long as you might first assume (even after you already have the cams removed). If you are going to change the springs and you can look at the follower to adjuster stand clearance, I would always recommend the CR-series camshafts.”
But what are the differences between the two series of cams, you ask? “The CR profiles are roughly 10% higher acceleration off the seat, but they out run the older NSR profiles throughout the curve,” explains Godbold. The reason why we went with the NSR series was mainly because we didn’t want to change the valvesprings in the mist of testing other parts on the engine dyno. Our goal was to cram as many tests as we could into a two-day period. Good news for those with 2015+ Mustangs: the stock valvesprings are stiffer than the 2011-2014s and don’t require a spring change to take advantage of the CR series camshafts.
As we mentioned, we tested a variety of intake manifolds from Ford Performance to see what manifolds produced the best gains with Comp’s cams. Keep in mind our engine was an otherwise box stock 2014 5.0 non-Aluminator crate engine.
"One thing to keep in mind with any variable valve timing tuning is when the intake lobes are tuned properly they should have the intake closing (IC) point chasing the reflected positive pressure wave in the manifold to push just a little extra charge in right before IC,” explains Godbold. “Hence, with a shorter runner you will probably need slightly more advance (earlier IC) than with a longer runner. In such a case, the same duration could make a longer runner tune a little better, especially if we are dealing with rather mild, street oriented durations.”
Comp Cams NSR Stage III Camshafts PN 191160
Duration at .050: 236 degrees intake, 239 exhaust
Valve Lift: .492 intake, .453 exhaust
Lobe Separation: 126 degrees
Installing cams in a Coyote isn’t for the faint-hearted, but it’s not overly complicated as well. We’d give it a seven out of ten on the scale of difficulty. On the engine dyno the installation can take about three hours and close to a full day affair in the car. We enlisted the help of Eddie Rios of Addiction Motorsports to help with the tuning and cam change. Rios is affluent in the art of swapping Coyote cams and tuning Coyotes in general. We started by running the factory GT, BOSS 302, and Cobra Jet intake manifolds on the stock cams. With that test complete, we installed the Comp camshafts and reversed the rotation of manifolds.
1. The CR profiles are roughly 10% higher acceleration off the seat, but they out run the older NSR profiles throughout the curve. Take a look at the overlay of the 267 seat duration NSR cam vs the 267 seat duration CR camshaft (#191630) if you set the phasers on both for 110 ICL and 116 ECL.
2. First step, remove the valve covers that are made from recycled carpet. Yes, yours are too.
3. Remove the damper with a proper puller and all the perimeter bolts that hold the front cover on. Keep in mind a few attach through the oil pan on the bottom as well. Coyote damper bolts are one time use so make sure you get a new one in advance.
4. The primary timing tensioners will need to be removed next. If you’re working on an 2011-2014 car, we recommend an upgrade to BOSS 302 tensioners while swapping cams. They are known to hold pressure better under high RPM abuse.
5. Three bolts hold each phaser onto the cam. Back out the intake and exhaust bolts together and remove the phasers as one assembly. You may need to depress the secondary tensioner or turn the guide to the side to remove the assembly. While some people reuse the phaser bolts, they are designed for single use.
6. Each cam has a filter inside the oil hole that needs to be transferred to the new camshafts. The Ti-VCT system is very sensitive to debris so these screens are especially important.
7. Remove all the cam caps and place them in order on a marked piece of cardboard. These are directional and need to be reinstalled in the same order.
8. Comp’s Coyote cams drop right in place. The cam cap bolts are reusable but we decided to upgrade to ARP hardware. They are offered in a 12-point (PN 156-1004) or hex (PN 156-1005 head configuration.
9. Due to the increased lift and duration of the camshafts, mechanical limiters are required to keep the valves and pistons from meeting each other. Perimeter bolts and a snap ring hold the cover in place. Be careful when removing the cover because the small spring and yellow plastic piece can become stuck to the underside of the cover. COMP’s limiters back the Ti-VCT swing range down from 50 degrees to 19-23 degrees.
10. Remember that the phasers and secondary chain must be installed together. The chain has an odd number of links so the dot will line up with the off color chain link on one side and in between the two off color links on the other.
11. We used ARP’s cam phaser bolt kit 256-1003 to secure the cams (torqued to 33 lb-ft) to the phasers and their 156-1006 kit (torqued to 15 lb-ft) to assemble the covers back onto the phaser body. Rios snugs up the driver’s side fasteners before moving to the other side.
12. We will also recommend a billet oil pump gear upgrade while everything is apart. Rios lines up the primary chains between the guides and primary tensioners.
13. A dab of silicone on each top corner of the cylinder head (you’ll see the spot when the cover is removed) and the cam cover goes back on.
14. Reinstall the damper, water pump, valve covers and its time to make some pulls! We used an ARP damper bolt (PN 156-2502) torqued to 100 lb-ft.
15. Here you can see how the COMP cams really extend the powerband of the stock GT manifold by 1,400 rpm. Intake manifolds and camshafts change the effective powerband of an engine so torque and horsepower loss at lower RPM is always a given. Peak horsepower skyrocketed to 505.8, up 48.8 horsepower over the stock cams. 7.5 lb-ft gain of peak torque with the cams as well. Average power across the cover came in at 370.4 hp and 394.1 lb-ft with the stock cams and 392.2 hp and 375.1 lb-ft with the Comp cams.
16. The BOSS was the first short runner manifold we tested that’s already designed for better peak power. Numbers came in at 542.9 hp, a 50.8 hp gain over stock – the biggest horsepower gain in our test. Two lb-ft of torque was added with the Comp cams as well. Average power across the cover came in at 380.1 hp and 381.2 lb-ft with the stock cams and 390.0 hp and 369.6 lb-ft with the Comp cams. Interesting that the stock GT manifold wins the average power numbers across a 3,000-peak RPM pull.
17. Then the test everyone has probably been waiting for, the Ford Performance Cobra Jet. While it was the least peak gains out of all the manifolds, the Comp cams came out 42.2 hp ahead of stock with 546.9 hp. A torque loss was measured with the new cams – a 1.9 lb-ft decrease. Average power across the cover came in at 392.1 hp and 389.2 lb-ft with the stock cams and 393.2 hp and 372.2 lb-ft with the Comp cams.