I'm curious as to effect the oil squirters have on the chosen ring gap. The predator uses larger squirters than the 2018+ coyote (they are interchangeable) and I assume that the ecoboost engines use suitably sized squirters. Is it possible that the increased heat in boosted coyotes can overwhelm the squirters used in them.
There are a million details in engine design that can help or hurt engine reliability. However, what I’ve found is there are some “not to exceed” in-cylinder pre-spark pressure and temperature limits if the expectation is reliability. Spark plug location, piston cooling, ring pack dimensions, injector timing, CHT, materials, cam timing, head gasket design, etc all play a role but none of the above can help you if in-cylinder pressure and temps exceed the threshold. All of those things must come together if you want to live near the threshold.
If we focus on the oem life expectancy and power then we can absolutely learn from them. I can’t imagine why someone wouldn’t want to learn from what the oem can teach us about reliable power.
This is true and kind of relevant to the discussion. Ford didn’t build the coyote for boost, but IIRC the OP started the thread to discuss options for rebuilding his pump gasoline supercharged coyote. So now is his chance to do something Ford didn’t do for low or no net cost.
The point is that the GT500, in spite of its horribly low compression ratio, has performed at least on par with but likely better than supercharged high compression coyotes. If low compression was so terrible, this wouldn’t be possible.
Where did I say or even imply that?
What's wrong with wanting max power on pump gas? I think lots of folks out there for various reasons don’t want to or can’t switch to E85. The OP is one of them, as am I. And who said anything about upgrading the fuel system? I’m talking about lowering the compression ratio at net zero or low cost.
Can we leave the personal attacks and insults out of the technical discussion please? If you want to insult me, just PM it and don’t pollute the thread.
That’s a false parallel. Mil spec would be the equivalent to "leave it stock" which is not my argument at all. A better equivalent would be me arguing to stay within established chamber pressure and muzzle velocity limits, and you saying it's ok to exceed the limits but gun parts just break sometimes.
The great thing is that you don’t have to buy the $70k “halo car” to get the low compression it offers!
Not on pump gasoline. You seem to keep pulling E85 into this discussion.
I never said the two happened on equal power. I'm saying the raised-boost E85 GT500 is making more power and going faster than boosted E85 Coyotes even with much lower compression ratio and less aftermarket development history.
This is probably the most valid argument you've made. Reducing compression by 1 number will reduce torque by about 4% across the full rpm range, or around 20 ftlb in the midrange and 30 hp up top . Raising boost by 2 psi will get you about 50 back up top, resulting in a net change of +20 hp. However at mid-range, you will only get 1 psi increase, so it would be very near break-even. At low rpm, it would likely net a loss in torque.
I will leave the rest out of it because honestly, as soon as you tune and mod a car you're going past what OEM intended the car to be, even if it holds better on some than others. This why if you hurt the motor and you're tune Ford will say well this is on you. Now you somehow want OEM reliability at twice the stock engine power. So we'll agree to disagree there.
Good luck!
Looks like low compression is your thing!
Call me crazy, but I thought the goal here was more power and reliability. Have you never done modifications in hopes of achieving one, the other, or both? Why would you be so dead-set against a change that will improve both power and reliability? Why wouldn't we want to learn from the engineering teams at the OEMs about how to make an engine powerful AND reliable?
I can see you are a bit lost in the argument, so I'll try to break down the logic. You say that lowering compression is crap and will hurt performance regardless of fuel. The onus is on me to prove otherwise, so I can bring any data in that proves otherwise, regardless of fuel. I say that lowering compression and raising boost will improve performance on pump gasoline, so the onus is on you to prove that performance is worse on pump gasoline. Therefore, showing that low-compression on E85 performs well disproves your point. However, showing that high-compression on E85 performs well does not disprove mine.
I supplied this earlier, but even the magazine tests are pulling 132 mph with the GT500 stock on pump gasoline. It's a rare supercharged Coyote that exceeds 130 with just a bolt-on supercharger kit on true pump gasoline and no octane booster, let alone do it time after time with stock-like reliability. Brenspeed, for instance, pulled I believe 132 with his 2018 and Whipple stage 2, but he was running octane booster. Another fellow on this forum was pulling 136 or so with a supercharged 2018, but he pullied it down and was also running octane booster. If low-compression was so terrible, horrible, no good, really bad then the 11 and 12/1 Coyotes should easily outrun the GT500 by at least a few mph on true pump gasoline.
I'm sorry, but this is just incorrect. You must agree that at some compression ratio, no boost can be added at all, no? At, say, 14/1, if you add boost and run pump gasoline, then you will instantly have to reduce timing to a point that the net power is negative. Start there, reduce compression, add boost and power increases every time.
What I've said from the beginning is that lower compression with boost allows more power and reliability. If any of my examples had sub-par performance, then it wouldn't support my point.
