Thrust Curve ANALYSIS
Here is a graph of the Thrust vs Speed comparing the PP3 (in Black) to the PP2 (in Blue). These lines represent the torque at the wheels which is calculated by taking the torque curve and rev range of each package and multiplying it by the gear ratios, final drive, and rear tire diameter. Notice the (black) PP3’s line extends further to the right in each gear due to its higher rev limit, and note how the PP2’s blue torque curves fall off more significantly near its redline in each gear due to the stock GT’s restrictive manifold.
At 45mph in 2nd gear, PP2 makes 128lb-ft more torque than PP3 due to its higher midrange. However, from 55mph to redline, PP3 makes more torque. At 68mph, PP3 makes 245lb-ft more torque in 2nd gear than PP2 does in 3rd gear.
In each gear, PP2 starts a torque advantage but then evens out mid-gear before losing at redline. Once PP2 shifts into the next gear, the torque loss becomes significant compared to PP3.
This Thrust curve is a common analysis professional race teams use to determine the best gear ratios for a given track, or to learn the effect on acceleration if their powerband is changed. One major takeaway that’s blatantly obvious, is that due to the factory gear ratios, both PP2 and PP3 would benefit from raising the rev limit.
Even though PP2’s torque drops significantly at redline, there is no intersection of the lines from one gear to another on that thrust curve, so despite losing torque and HP as revs increase, there would be a net benefit in torque at the tire and improved acceleration from revving out a stock engine, PP1, or PP2 equipped cars. PP3 would have an even greater benefit.
Looking at the math behind the thrust curve may be more telling and easier to digest for some readers. In 2nd gear, PP2 has a 128.18lb-ft of torque advantage at 5,000rpm, however that advantage goes away as the revs increase and by the time PP3 reaches its redline, there is a 198.70lb-ft of torque net advantage over PP2.
The chart above makes it easy to look at a given speed range to determine which Power Pack would result in better acceleration with more torque to the tire. For certain rev ranges, one Power Pack may be better than the other and vice-versa.
Since most road courses don’t have corners below 45mph or straights above 165mph, Power Pack 3 would generally result in better performance on most tracks. I’m admittedly not an autocrosser so I don’t know the mid-corner speeds or needs for autocrossing. However, it’s important to look at the torque at the wheel and see if your tires are capable of putting down the power. For example, if there’s a corner that is 40mph, and your tire can’t put down 3,000lb-ft of torque, PP3’s torque advantage of 3,362lb-ft vs 3,296lb-ft would be irrelevant. The use of 2nd gear, especially if the tire can handle 2,630lb-ft that PP2 puts down would be a better choice.
-Due to the Mustang’s MT-82 gear ratios, increasing the redline of the S550 5.0L Coyote will improve acceleration despite the significant HP & TQ drop above 6,500rpm due to the restrictive stock intake manifold.
-Power Pack 3 would greatly benefit from an even higher redline.
-PP3 offers no benefit over PP2 without shifting at its higher redline.
-Compared to Power Pack 2, on a road course and likely drag strip, Power Pack 3 will yield better acceleration and lap times due to its higher Power Under the Curve, higher peak power, and higher rev limit.
Bonus Dyno Comparisons:
PP3 vs PP2 vs PP1 vs K&N vs Baseline
Here are all of the different combinations we ran compiled on one overlay.
PP3 vs Project E90 M3
Compared to our Project E90 M3, PP3’s torque curve is about as flat as the M3’s giving the engine a very similar feel in character, but making substantially more power at a slightly lower rpm. It would have been nice to continue revving PP3 out to 8,000rpm.
With a similar X-pipe and exhaust, our 5.0L Coyote V8 Mustang GT equipped with PP3 has virtually every bolt-on component in common with the 5.2L Flat-Plane-Crank Voodoo GT350 engine. Here is what the difference the 5.2L longblock makes:
PP3 vs GT350R
Compared to our PP3 equipped Mustang GT (green), the GT350R (red) makes a noteworthy 52.13whp and 35.48lb-ft more torque. The GT350 is down an average of 15whp and 28lb-ft of torque below 3,400rpm, but the 3,400-5,000rpm mid-range sees a massive increase with 30whp and 36lb-ft advantage before widening the gap all the way to its 8,250rpm redline.
It’s quite interesting that both engines have a very similar torque curves down to each dip, despite the GT350’s 200cc more displacement, 1mm more valve lift, 1mm larger intake valves (38.3mm vs 37.3mm), 0.7mm larger exhaust valves (32.5mm vs 31.8mm), 12:1 compression ratio (vs the GT’s 11:1) and of course the Flat Plane Crank. It goes to show that the general architecture of the engines is very similar, but the efficiency and power gain that’s created from all of these modifications that turn a Coyote in to a Voodoo.
Page 1 – Power Packs
Page 2 – Baseline Dyno
Page 3 – K&N and Power Pack 1 Dynos
Page 4 – Power Pack 2 Install
Page 5 – Power Pack 2 Dynos
Page 6 – GT350 Intake Manifold Analysis
Page 7 – GT350 Intake Manifold Analysis & Install
Page 8 – Power Pack 3 Dynos
Page 9 – Thrust Analysis of PP3 vs PP2, and Bonus Dynos (M3 & GT350R)
Page 10 – Road Test Review and Overview