[Baldilocks01SS]

Originally Posted by whiteboyblues2001

HP/L is a crappy metric that teaches us to all drive 2.0L turbo engines rather than N/A V8. AND, the Ford faithfull MISSUSE this metric in a situation that it's not applicable, and then they can give themselves a pat on the back, even though that metric is clearly telling them that Ford should dump the N/A V8, and go with a TT V6 instead. Or better yet, a 4 cylinder turbo. Hey, want to go exotic? Get a one cylinder and add both turbo and supercharging...

Nothing wrong with 2.0L turbo 4s though. Mine makes 437 to all four wheels.

[NW-99SS]

Originally Posted by whiteboyblues2001

They have to be different. The path the intake and exhaust gasses take is switched. And you can't just make the intake the exhaust and the exhaust the intake because the intake valves are bigger. Plus the bore size will be bigger, location of the direct injection will be different, etc. The only thing that will be the same is the size and bolt pattern. And those might be different as well...

I may be thinking about this all wrong, but wouldn't GM just 180 the motor - and put all the accessories on the back to allow for ME placement. Forgive me if this is a dumb question, I haven't had my coffee yet...

[NW-99SS]

Originally Posted by Baldilocks01SS

Nothing wrong with 2.0L turbo 4s though. Mine makes 437 to all four wheels.

Friend has an AMG Merc with a 2.0l turbo - just a tune and it's a monster once spooled.

[whiteboyblues2001]

Originally Posted by Baldilocks01SS

Nothing wrong with 2.0L turbo 4s though. Mine makes 437 to all four wheels.

There is nothing wrong with most any modern engine design, it's just that they all have their own advanatages and disadvantages, and it is very disengenous to remove the advantage an engine design has, then compare. Makes no sense. You like a 2.0L turbo. What if I said, hey let's compare our engines, but you don't get to use boost becaue my engine is N/A. Is that a fair comparision? No, because in the real world, you have boost, just like in the real world, an OHV engine has more displacment. That's its advantage.

Turbo engines are great for folks who want to modify their engines for more power. You can tune the blow off valve or waste gate to increase boost. So with just a tune, and sometimes a few boltons, you can add a ton of additional power with minimal effort and cost. I love that aspect of a 2.0L (or any displacement) turbo. Great for shadetree mechanics to modifiy thier toy. Definately fun stuff.

The only issue is you tend to add more turbo-lag with the additional boost, and that makes the throttle more non-linear. You have to get used to when/where the boost kicks in. Many a folk jacked the curb leaving a cars and coffee when the boost kicks in.

I also like boost when trying to make huge HP numbers. How can you get 1,000 HP with displacement alone? The engine would be too big and heavy. At some point in the HP wars, boost makes sense. But, you give up that great throttle response that you get with a properly designed N/A engine.

Again, everything has it's advantages and disadvantages...

[whiteboyblues2001]

Originally Posted by NW-99SS

I may be thinking about this all wrong, but wouldn't GM just 180 the motor - and put all the accessories on the back to allow for ME placement. Forgive me if this is a dumb question, I haven't had my coffee yet...

No worries. No, the engine will still have the accesories in the front, because the engine is still in front of the transmission, just like in a front engine car. Only a rear engine has the engine turned around 180 degrees (like a 911).

Now, perhaps they could 180 the head, and put it on backwards, and that would put the valves and ports in the right place, but I belive that the exhaust ports in the valley of the V may need to be redesigned, for the turbo placement. There isn't much room in the vally for two turbos, and I have heard that the exhaust routing is tricky because of the lack of room, and how the turbos get laid into the valley. Of course, if you turn the head around, you have to have a differnt camshaft (as the lobes will have to be switched around), but that's no big deal. And I don't think the intake side would need too much reworking.

But, even the bigger displacement alone means the heads will have to accomodate a larger bore size, which means a different head.

[whiteboyblues2001]

The rumors are swirling the last few days. Here is an article from yesterday saying that the Z06 will be an 5.5L FPC N/A for around 600HP.

https://news.yahoo.com/know-flat-pla...171800233.html

5.5L and FPC will be a challenge for sure. But, the design would allow for the Z06 to return to it's N/A roots.

ALSO, since they extended the life of the 6th gen by two years, that leaves plenty of time for this new Z06 engine to show up in a Z/28 camaro. If it will fit, that is. But since the new C8 has an LT2 and will have a 5.5 DOHC later, then perhaps they are of comperable size...

[Baldilocks01SS]

Originally Posted by whiteboyblues2001

There is nothing wrong with most any modern engine design, it's just that they all have their own advanatages and disadvantages, and it is very disengenous to remove the advantage an engine design has, then compare. Makes no sense. You like a 2.0L turbo. What if I said, hey let's compare our engines, but you don't get to use boost becaue my engine is N/A. Is that a fair comparision? No, because in the real world, you have boost, just like in the real world, an OHV engine has more displacment. That's its advantage.

Turbo engines are great for folks who want to modify their engines for more power. You can tune the blow off valve or waste gate to increase boost. So with just a tune, and sometimes a few boltons, you can add a ton of additional power with minimal effort and cost. I love that aspect of a 2.0L (or any displacement) turbo. Great for shadetree mechanics to modifiy thier toy. Definately fun stuff.

The only issue is you tend to add more turbo-lag with the additional boost, and that makes the throttle more non-linear. You have to get used to when/where the boost kicks in. Many a folk jacked the curb leaving a cars and coffee when the boost kicks in.

I also like boost when trying to make huge HP numbers. How can you get 1,000 HP with displacement alone? The engine would be too big and heavy. At some point in the HP wars, boost makes sense. But, you give up that great throttle response that you get with a properly designed N/A engine.

Again, everything has it's advantages and disadvantages...

Yep, when I upgraded my Golf R to Stage 3+, they used a larger turbo, but it is of the twin scroll design, so a lot less turbo lag than there normally would be with a turbo of that size.

[whiteboyblues2001]

Originally Posted by Baldilocks01SS

Yep, when I upgraded my Golf R to Stage 3+, they used a larger turbo, but it is of the twin scroll design, so a lot less turbo lag than there normally would be with a turbo of that size.

Yes, I love the twin scroll design. Adding twin scrolls uses no moving parts, which means the technology is bulletproof in terms of reliability. I heard somewhere that the new 2.7L turbo from Chevy takes twin scroll a step farther by putting the output of the two scrolls on opposite sides of the turbine. This reduces transient response which further reduces turbo-lag and increases efficiency. I think it's called a dual-volute turbocharger housing. Again, there are no moving parts in adding this, so it will be reliable right out of the gate.

I think the real solution to turbo-lag is an electric boost device powered by a 48 volt semi-hybrid system. Or even just using the 48-volt system to add more torque to the crankshaft directly until the turbo spools up. They have a device that goes in between the engine and transmission to add torque to the crankshaft directly using the 48-volt power. The computer can run this so the handoff is seamless. This will give N/A like throttle response in theory. And it won't drain the batteries because it will only add power for a short burst under certain circumstances.

[shaffe]

Originally Posted by BlaqWhole

So what can a DOHC engine do that a pushrod engine can't do...besides rev higher? I have not seen any evidence of DOHC engines being superior. To me, some dude raved about "oh man this thing revs soo high" even as he was getting passed by other cars and everyone drank the Koolaid. Look at it like this, ZL1 top speed 202 (198 "officially"), Hellcat top speed 204 (some have hit 205), GT500 limited at 180. Look at the oil drinking problem the Voodoo engines have. BMW DOHC engines are terrible. All these supercars with DOHC engines constantly have enough issues and high maintenance costs that they would suck as a DD. The Mustang GT is faster than the Camaro SS but only after a mile and on a dried up river bed. So where has there been any evidence that DOHC engines are good? Even with the front engine design the Z06, ZR1, Viper, ZL1, etc have been beating much more expensive supercars with DOHC engines. So where is their advantage? They cost more, have more parts that can possible break, have no torque down low, higher maintenance, run hotter, are more prone to heat soak, are physically bigger and therefore are limited on displacement, the list goes on.

I'm not dishing on DOHC engines BTW. I just don't see how anyone can think they offer some advantage. Ok they rev high...so what advantage does that give when they still can't beat well built cars around a track?

I am going to take a total guess here so someone smarter than me please chime in. I would guess from an OEM standpoint maybe DOHC respond better to turbocharging. I can't think of any pushrod turbos(besides diesels). Maybe respond isn't the best word maybe its easier to set them up for driveability/performance all that stuff with a DOHC set up than an OHV set up.

displacement doesn't seem to matter as much when your throwing a pair of turbos on it. I mean the Ferrari 488 engine makes 661 at 8K RPM and 561 lb/ft of torque at 3K. Thats a twin turbo 3.9L V8. That engine seems to have plenty of low down torque while screaming in the upper RPMs.

I don't know if any of that makes any sense but thats my guess lol.

What it probably is though is because that is what the competition has. All the other ME cars have a DOHC TT set up.

Originally Posted by whiteboyblues2001

The rumors are swirling the last few days. Here is an article from yesterday saying that the Z06 will be an 5.5L FPC N/A for around 600HP.

https://news.yahoo.com/know-flat-pla...171800233.html

5.5L and FPC will be a challenge for sure. But, the design would allow for the Z06 to return to it's N/A roots.

ALSO, since they extended the life of the 6th gen by two years, that leaves plenty of time for this new Z06 engine to show up in a Z/28 camaro. If it will fit, that is. But since the new C8 has an LT2 and will have a 5.5 DOHC later, then perhaps they are of comperable size...

These rumors are driving me crazy! I still say there is no chance in hell they are going 5.5 FPC.

[NW-99SS]

Originally Posted by whiteboyblues2001

No worries. No, the engine will still have the accesories in the front, because the engine is still in front of the transmission, just like in a front engine car. Only a rear engine has the engine turned around 180 degrees (like a 911).

Now, perhaps they could 180 the head, and put it on backwards, and that would put the valves and ports in the right place, but I belive that the exhaust ports in the valley of the V may need to be redesigned, for the turbo placement. There isn't much room in the vally for two turbos, and I have heard that the exhaust routing is tricky because of the lack of room, and how the turbos get laid into the valley. Of course, if you turn the head around, you have to have a differnt camshaft (as the lobes will have to be switched around), but that's no big deal. And I don't think the intake side would need too much reworking.

But, even the bigger displacement alone means the heads will have to accomodate a larger bore size, which means a different head.

I see where I was mixed up. I know the C8 won't have the Hot-V configuration, so yes the head design will have to be different so the exhaust ports exit to the outside of the engine to drive the lower, side-mounted turbos the CAD drawing shows. I still feel the overall physical head dimension will remain the same, with the same bolt pattern, but agree that the exhaust and intake will have to be inverted compared to the Blackwing Hot-V setup.

[whiteboyblues2001]

Originally Posted by shaffe

I am going to take a total guess here so someone smarter than me please chime in. I would guess from an OEM standpoint maybe DOHC respond better to turbocharging. I can't think of any pushrod turbos(besides diesels). Maybe respond isn't the best word maybe its easier to set them up for driveability/performance all that stuff with a DOHC set up than an OHV set up.

displacement doesn't seem to matter as much when your throwing a pair of turbos on it. I mean the Ferrari 488 engine makes 661 at 8K RPM and 561 lb/ft of torque at 3K. Thats a twin turbo 3.9L V8. That engine seems to have plenty of low down torque while screaming in the upper RPMs.

I don't know if any of that makes any sense but thats my guess lol.

Yes, but more specifically 4 valves per cylinder are much better for boost. It is less restrictive to the intake gasses being forced into the cylinder.

Also, an undersquare design is also better for boost, and an oversquare design is better for high RPMs.

But, displacement still matters, as the more displacement with less boost gives better throttle response in comparsion to low displacment with high boost. It's why folks like AMG use pretty large displacment with a touch of boost.

But now, HP numbers are so high, you are going to need both large displacment AND big boost. No way around it for high HP, and you probably will see high RPMs too. Again, this will introduce more turbo-lag, but if you want insane HP numbers, compromises have to be made.

So, the 488 engine has pretty big displacement at 3.9L V8, and high RPM's at 8k RPMs, and I'm guessing that the boost is pretty big too. It's the everything and the kitchen sink approach.

[NW-99SS]

Originally Posted by shaffe

I am going to take a total guess here so someone smarter than me please chime in. I would guess from an OEM standpoint maybe DOHC respond better to turbocharging. I can't think of any pushrod turbos(besides diesels). Maybe respond isn't the best word maybe its easier to set them up for driveability/performance all that stuff with a DOHC set up than an OHV set up.

displacement doesn't seem to matter as much when your throwing a pair of turbos on it. I mean the Ferrari 488 engine makes 661 at 8K RPM and 561 lb/ft of torque at 3K. Thats a twin turbo 3.9L V8. That engine seems to have plenty of low down torque while screaming in the upper RPMs.

I don't know if any of that makes any sense but thats my guess lol.

What it probably is though is because that is what the competition has. All the other ME cars have a DOHC TT set up.



These rumors are driving me crazy! I still say there is no chance in hell they are going 5.5 FPC.

Agreed, and the 720S is another example of a DOHC, small displacement, TT V8 with incredible power and insane acceleration, even from a dig.

[whiteboyblues2001]

Originally Posted by shaffe

These rumors are driving me crazy! I still say there is no chance in hell they are going 5.5 FPC.

Yes, this is where we both are scratching our heads. The theoretical limit to an FPC V8 engine is about 5.0L. Ford went 5.2L and has tons of problems, but let's do some math.

Even though the Voodoo has a redline of 8,250, peak power is at 7,500 for 526 HP. If you kept the same displacment and increased peak power to 8,500 RPM's (assming you can keep the same torque number), it would put out a theoretical 596 HP. Pretty close to the rumored 600 HP. And it's theoretically possible in accordance with the article I linked becasue it says that the redline was limited to 8,600 due to the transmission.

Here's another theoretical example. Suppose they went with peak power at 7,500 like the Voodoo, but used 5.5L. That would put out a theoretical 556 HP. Not enough to make it to 600 HP without reving higher.

So, who knows...

What I do know, is that if this is going to be N/A and 600 or so HP, it will have to rev pretty high, and produce peak power above 8,000 or more RPMs. This will make the engine lack the low end in comparison to the LT2, but for a track car (road course), high RPM N/A makes sense.

But these examples show that they can't really go with a significantly lower displacement than the Voodoo, or it would have to rev higher than the transmisssion can take. It will have to be at least 5.0L, but more than likely a bit more.

I guess 5.5L is still on the table...

[shaffe]

Originally Posted by whiteboyblues2001

Yes, but more specifically 4 valves per cylinder are much better for boost. It is less restrictive to the intake gasses being forced into the cylinder.

Also, an undersquare design is also better for boost, and an oversquare design is better for high RPMs.

But, displacement still matters, as the more displacement with less boost gives better throttle response in comparsion to low displacment with high boost. It's why folks like AMG use pretty large displacment with a touch of boost.

But now, HP numbers are so high, you are going to need both large displacment AND big boost. No way around it for high HP, and you probably will see high RPMs too. Again, this will introduce more turbo-lag, but if you want insane HP numbers, compromises have to be made.

So, the 488 engine has pretty big displacement at 3.9L V8, and high RPM's at 8k RPMs, and I'm guessing that the boost is pretty big too. It's the everything and the kitchen sink approach.

Thanks! I was going to say there has to be reason almost every TT set up from the factory is on a DOHC engine.

Originally Posted by NW-99SS

Agreed, and the 720S is another example of a DOHC, small displacement, TT V8 with incredible power and insane acceleration, even from a dig.

yeah just looking at the list of ME cars if they are V-8s they seem to be around 4.0L of displacement