Category engine

[Backagain]

Originally Posted by Casper

Power under the curve would be an issue, not how much but the curve itself would have a totally different shape.

It might be possible to match max power but
as you say, the shape of the in phase diagram would produce totally different characteristics.

[V8 Fireworks]

Originally Posted by Casper

Power under the curve would be an issue, not how much but the curve itself would have a totally different shape.

Once you scale them to the same road speed at the redline as below, they are actually very similar in power delivery in the relevant road speed range in the same gear -- neither engine is turbocharged, they are both very linear, so it is not the big problem as implied IMO.




As you can see, the scaled Ford has no problems keeping up with the Chevy -- the Ford actually has slightly more mid-range, and all-but identical top-end! The only difference would be off the line, which is wheel spin central territory anyway and not a big issue IMO.

Ignore the torque at the engine, only the torque at the wheels is important, and the Ford with a 24% shorter diff ratio will have 24% more torque at the wheels relative to the Chevrolet than what the curve shows, which should make them about equal.

Of course fitting an exactly identical engine to both would save parity debates, but I like the idea of each vehicle have it's own distinct character -- the low-revving barotone Chevy vs the screaming Ford.

Gotta be better than Supercars' plan to give the Ford an unfavourable rod-to-stroke length ratio compared to stock, and then expect it to make the same power with less displacement and the same maximum rpm as the Chevrolet.

[V8 Fireworks]

Oops, I noticed I didn't scale the Ford quite perfectly and the editing time expired, it's actually an even closer match than I thought:

Originally Posted by Backagain

the shape of the in phase diagram would produce totally different characteristics.

They are actually a very good match.

They don't quite match below 3000rpm on the Chevy which is 3500 rpm on the Ford, but I don't think that's relevant for a racing application -- if your revs have dropped that low, you're in the wrong gear!

Of course, these are the 500hp road models and it would change a bit when they tuned up to 600 hp -- but matching Coyote and LS engines is what Supercars are trying to do anyway. You've got the flexibility of variable cam timing on the Ford engine after all, so you can use that to adjust cam angles at certain rpm (even to detune the Ford in places) to try to get it as close as possible.

[Backagain]

Originally Posted by V8 Fireworks

Oops, I noticed I didn't scale the Ford quite perfectly and the editing time expired, it's actually an even closer match than I thought:





They are actually a very good match.

They don't quite match below 3000rpm on the Chevy which is 3500 rpm on the Ford, but I don't think that's relevant for a racing application -- if your revs have dropped that low, you're in the wrong gear!

Of course, these are the 500hp road models and it would change a bit when they tuned up to 600 hp -- but matching Coyote and LS engines is what Supercars are trying to do anyway. You've got the flexibility of variable cam timing on the Ford engine after all, so you can use that to adjust cam angles at certain rpm (even to detune the Ford in places) to try to get it as close as possible.

Please google "in phase diagram" and its significance in power measurements and characteristics which should also explain the term "power under the curve".

[Casper]

I need more recent data than 2015.

[V8 Fireworks]

Originally Posted by Backagain

Please google "in phase diagram" and its significance in power measurements and characteristics which should also explain the term "power under the curve".

Would you care to elaborate? Googling "in phase diagram" only returns results about this phase changes from solid to liquid, or austentic phases of steel...

The power under the curve is the same, that is the curve shown above when people talk about power under the curve, is it not?

Source -- I'm an engineer. The only other time I've heard of phase is when it is used to describe any reciprocating function -- control theory, acoustics, electrical etc.

Edit -- Do you mean the uneven power strokes desired in MotoGP and the cylinders having different phases to each other? The 'big bangers' etc? I hardly think that's relevant to an 8-cylinder engine in a car.

Originally Posted by Casper

I need more recent data than 2015.

They are the same crate engines which are available now.

Matching engines that operate in different rpm ranges is eminently doable IMO.

[Casper]

Originally Posted by V8 Fireworks

They are the same crate engines which are available now.

Matching engines that operate in different rpm ranges is eminently doable IMO.

As long as you believe it then all is good.