Calculating the HP from known 12psi Of Boost

[Gogoggansgo]

What would that be?

Because both dodge and Chevy have gone beyond 750hp already and it’s a bit late Ford

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[Darkane]

The issue with trying to figure out the hp before launch is we just don’t know a lot about the engine. I bet you it’s 11:1 and how big are the cams 14mms or less. And a bunch of little things. But if this engines makes less than 750hp we gotta problem

It’s 9.5:1.

And it’s port injection. Never would it see anything higher than that CR with premium fuel available. Just doesn’t work unless you retard it too much.

 

[Hack]

It’s 9.5:1.

And it’s port injection. Never would it see anything higher than that CR with premium fuel available. Just doesn’t work unless you retard it too much.

You are replying to someone I'm ignoring, so I may miss some of the point of this conversation.

However, one other point I wanted to make about compression ratio is that with variable cam timing the manufacturer can choose when the intake valve will close. If the intake closes late it will allow some cylinder pressure to bleed off. As RPM increases, the intake can close earlier to provide more power when detonation is less likely. This allows for more power to be made even with crappy modern pump gas.

 

[Darkane]

You are replying to someone I'm ignoring, so I may miss some of the point of this conversation.

However, one other point I wanted to make about compression ratio is that with variable cam timing the manufacturer can choose when the intake valve will close. If the intake closes late it will allow some cylinder pressure to bleed off. As RPM increases, the intake can close earlier to provide more power when detonation is less likely. This allows for more power to be made even with crappy modern pump gas.

There’s more to it like overlap, but it doesn’t matter.

The GT500 is 9.5:1. It’s not in Ford’s interest to nickel and dime it higher. It’s a port engine.

By the way, increasing intake timing (variable) will make more low end power. If ford does this too much the car will have zero traction.

 

[Hack]

There’s more to it like overlap, but it doesn’t matter.

The GT500 is 9.5:1. It’s not in Ford’s interest to nickel and dime it higher. It’s a port engine.

By the way, increasing intake timing (variable) will make more low end power. If ford does this too much the car will have zero traction.

Agreed that higher compression is not needed with boost. Lower CR helps make room for more fuel and air to fit in the combustion chamber. With forced induction you don't need high compression to get power. Just stuff more F/A mix in there.

Are you talking about overlap between the exhaust and intake? That can be varied as needed as well. Both cams are controlled independently.

 

[Darkane]

Agreed that higher compression is not needed with boost. Lower CR helps make room for more fuel and air to fit in the combustion chamber. With forced induction you don't need high compression to get power. Just stuff more F/A mix in there.

Are you talking about overlap between the exhaust and intake? That can be varied as needed as well. Both cams are controlled independently.

Yep agree.

Problem is, most OEMs are trying to reduce overlap for emissions and fuel economy.

The way I understand it: lots of timing, lots of CR, lots of overlap will make all the bottom and midrange power at the expense of MPG and emissions. But can’t have a lot of that in a modern engine, therefore - lower CR.

 

[markmurfie]

When you guys think of compression ratio, you know it also determines how well the engine pulls air into the combustion chamber right? You also know boost is from the engine restricting the airflow of the supercharger? The higher the CR the more efficient the engine is, octane and detonation is the only limiting factor. If you can keep things moving heat out of the combustion chamber that makes it much less detonation prone, Ford is putting a ton of R&D into doing this. The more efficient the engine is the more air the supercharger would need to flow to build 12PSI of boost on it. You would hurt MPG and emissions by lowering the CR.

There is no "lots" of timing, there is the optimal timing for most torque where more or less advance will do nothing but make less torque or there is detonation limited timing. Then there timing where you don't need all the torque the engine can produce but thats for idle, TC, hardware safety things.

Nothing good comes from a lower CR in any engine, other than its an easy way to avoid a bunch of heat and detonation. Old fashion lazy engineering isn't going to cut it in today's demanding climate friendly regulated market. Its in Fords best interest to not nickel and dime it, but fully fund solutions to over coming these kind of efficiency problems. Otherwise smaller engine hybrids/ full electric motor cars are the only options, and they know how much the market thinks of that. If the GT500 isn't higher than 10.5:1 you will know what to expect in the near future.

 

[Darkane]

When you guys think of compression ratio, you know it also determines how well the engine pulls air into the combustion chamber right? You also know boost is from the engine restricting the airflow of the supercharger? The higher the CR the more efficient the engine is, octane and detonation is the only limiting factor. If you can keep things moving heat out of the combustion chamber that makes it much less detonation prone, Ford is putting a ton of R&D into doing this. The more efficient the engine is the more air the supercharger would need to flow to build 12PSI of boost on it. You would hurt MPG and emissions by lowering the CR.

There is no "lots" of timing, there is the optimal timing for most torque where more or less advance will do nothing but make less torque or there is detonation limited timing. Then there timing where you don't need all the torque the engine can produce but thats for idle, TC, hardware safety things.

Nothing good comes from a lower CR in any engine, other than its an easy way to avoid a bunch of heat and detonation. Old fashion lazy engineering isn't going to cut it in today's demanding climate friendly regulated market. Its in Fords best interest to not nickel and dime it, but fully fund solutions to over coming these kind of efficiency problems. Otherwise smaller engine hybrids/ full electric motor cars are the only options, and they know how much the market thinks of that. If the GT500 isn't higher than 10.5:1 you will know what to expect in the near future.

It IS 9.5:1.

Ford has released this!

https://www.dropbox.com/s/f5ng2xiasgkfhke/2020 Shelby GT500.pdf?dl=0

 

[markmurfie]

A "leaked" document dated January 2019, in a dropbox account is you source for released information from Ford? I have a bridge for sale.

 

[Darkane]

A "leaked" document dated January 2019, in a dropbox account is you source for released information from Ford? I have a bridge for sale.

That was the official brochure for dealers just after NAIAS.

Believe what you want lol.

Look at the URL at the bottom of the document.

 

[Epiphany]

It's legit. Don't know why anyone would ever argue to the contrary.

 

[Darkane]

It's legit. Don't know why anyone would ever argue to the contrary.

Saving face. It doesn’t make sense for it to be higher. Ford is not reinventing the wheel with this engine. Will it be amazing? Damn rights!

Game changer? Heck no, in fact it’s last generation coyote tech. Not even gen three like the 2018+ mustang gt

 

[GT Pony]

It doesn’t make sense for it to be higher.

A CR of 9.5 will just make it easier to put a different supercharger pulley on and increase the boost pressure for even more HP.

 

[V00D00]

A "leaked" document dated January 2019, in a dropbox account is you source for released information from Ford? I have a bridge for sale.

day ( months?) late and a dollar short..

 

[MaskedRacerX]

I have a bridge for sale.

Tell me about this bridge, I'd like to cut directly over to US1 across the intracoastal - does it include installation?

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