2009 Corvette ZR1 LS9 Engine

[culver]

Well...then no it's not worth noting

It is if you are going to use the race results to claim one type is faster than the other. I do not know why the C6R was behind at the time but if it's catching then clearly it's faster at that point in time. Also, you would have to say that either some of the DB9Rs were less powerful because the C6R beat them. This is kind of like figuring out which college football team is number one when most of the "top" teams will never play each other. There are simply too many variables to conclusively say especially when we can pick scenarios from the data to show either side of the equation.

[The_Canuck]

It is if you are going to use the race results to claim one type is faster than the other. I do not know why the C6R was behind at the time but if it's catching then clearly it's faster at that point in time. Also, you would have to say that either some of the DB9Rs were less powerful because the C6R beat them. This is kind of like figuring out which college football team is number one when most of the "top" teams will never play each other. There are simply too many variables to conclusively say especially when we can pick scenarios from the data to show either side of the equation.

All true, cept you missed the point completely. The DBR9's won the race this year, therefore the C6.Rs do not "dominate".

[henk4]

What conclusion can be drawn from this? Well it looks like the promoters are doing a good job balancing out the two different engine types.

in the current LMS regulations, the LMP1 petrol engine can either be a 3.4 litre DOHC turbo, a five litre DOHC normally aspirated or a 6 litre OHV normally aspirated engine. Apparently the rule makers think that an OHV engine needs 20% more capacity to make the same BHP. We did indeed see one car entering with a 6 litre Ford engine, and it was the Lavaggi. All the others had OHC engines. You may want to check the results from this year....

[culver]

in the current LMS regulations, the LMP1 petrol engine can either be a 3.4 litre DOHC turbo, a five litre DOHC normally aspirated or a 6 litre OHV normally aspirated engine. Apparently the rule makers think that an OHV engine needs 20% more capacity to make the same BHP. We did indeed see one car entering with a 6 litre Ford engine, and it was the Lavaggi. All the others had OHC engines. You may want to check the results from this year....

The Corvette C6-R is 7L. The Aston Martin is 6L. So we might conclude that the rule makers think 16% more displacement is needed to equalize OHV to OHC. Well remember, I've said the drawback to OHV is limited high RMP breathing.

But, that 16% isn't the whole story. The Aston runs 31.2mm restrictors. The Corvette runs 31.3mm restrictors. It seems they think the OHV engine only need an extra 0.6% in intake cross sectional area. As I've said before, OHV trades high RPM breathing for more displacement without increasing the total package size of the motor (assuming a V-block). The only way this is truly bad from an objective point of view (not from a feel or "I just like it" POV) is if you have a tax/rule system that optimizes for displacement. Of course most racing series do and most countries with a native auto industry also do. This certainly would explain why the US manufactures historically do not "conserve displacement" while others do. One isn't right or wrong, just different.

BTW, I always like the in-line liquid cooled motors better than the radials but both are cool in there own right.

[Wouter Melissen]

in the current LMS regulations, the LMP1 petrol engine can either be a 3.4 litre DOHC turbo, a five litre DOHC normally aspirated or a 6 litre OHV normally aspirated engine. Apparently the rule makers think that an OHV engine needs 20% more capacity to make the same BHP. We did indeed see one car entering with a 6 litre Ford engine, and it was the Lavaggi. All the others had OHC engines. You may want to check the results from this year....

The maximum displacement for petrol cars is 6 litre, regardless of valvetrain. The current Judd is 5.5 litre. The maximum displacement for forced induction engines is four litre. The new AER V8 will be a full four litre.

[henk4]

BTW, I always like the in-line liquid cooled motors better than the radials but both are cool in there own right.

true, and they could also be much more easily installed in cars

[harddrivin1le]

That is fantastic packaging of the charger and intercooler
Liek it.
Anyone know what they do to prevent heat trasnfer from the blocks to the intercooler over long term ? It looks liek the water interchange pipes are run along the top and no buffer on the bottom. Any pics of the bottom casting ?

GM has used a similar arrangement in other supercharger applications (e.g. Cadillac).

Heat transfer is constant (via the flow of coolant - just as it is with cylinder heads (that are bolted directly to the block.

[henk4]

The maximum displacement for petrol cars is 6 litre, regardless of valvetrain. The current Judd is 5.5 litre. The maximum displacement for forced induction engines is four litre. The new AER V8 will be a full four litre.

so what does stop them from going all the way in order to compete with the diesel engines?

[Wouter Melissen]

so what does stop them from going all the way in order to compete with the diesel engines?

The restrictor / displacement ratio is probably at an optimum at that displacement, or the engine has grown to maximum displacement allowed by the block design. In GT2 most manufacturers intentionally enter smaller displacement engines for the optimal restrictor / displacement ratio.

[harddrivin1le]

The Corvette C6-R is 7L. The Aston Martin is 6L. So we might conclude that the rule makers think 16% more displacement is needed to equalize OHV to OHC.

That's a flawed conclusion because you are overlooking other variables:

Corvettes Qualify Second and Third at Lime Rock Park - Corvette Racing

"As a result of performance adjustments imposed by the sanctioning body last week, the Corvettes are now 199 pounds heavier than their Aston Martin rivals and have a 10-liter smaller fuel capacity."

Those fancy V12 DOHC Astons can't compete with the Corvettes on an equal basis, so the sanctioning body handicapped the Corvettes to make the racing more competitive and "interesting."

[harddrivin1le]

Fancy Euro performance/super cars can't compete with the pushrod Corvettes in terms of the fuel economy - HP multiple, either.

Standard 'Vette:
HP: 436
Fuel Economy: 16 city/26 highway (21 average)
436 X 21 = 9,156 HP-MPG

Z06:
HP: 505
Fuel Economy: 15 city/24 highway (19.5 average)
505 X 19.5 = 9,848 HP-MPG

I had a 1999 LS1/6 speed Camaro. The car got better mileage than the two 2 wheel drive, 4 cylinder Toyota pick-ups I've owned...

[henk4]

Fancy Euro performance/super cars can't compete with the pushrod Corvettes in terms of the fuel economy - HP multiple, either.

Standard 'Vette:
HP: 436
Fuel Economy: 16 city/26 highway (21 average)
436 X 21 = 9,156 HP-MPG

Z06:
HP: 505
Fuel Economy: 15 city/24 highway (19.5 average)
505 X 19.5 = 9,848 HP-MPG

I had a 1999 LS1/6 speed Camaro. The car got better mileage than the two 2 wheel drive, 4 cylinder Toyota pick-ups I've owned...

Really?

Porsche 911 Turbo 480 BHP, 18.8 l/100 km city driving, 9.5 highway, 12.8 average
Corvette Z06: 22.8 city driving, 10 highway 14.7 average...

These figures are based on the ECE cycle, the "realistic" version of your current EPA standards, which are about to be adapted...

[henk4]

Fancy Euro performance/super cars can't compete with the pushrod Corvettes in terms of the fuel economy - HP multiple, either.

Standard 'Vette:
HP: 436
Fuel Economy: 16 city/26 highway (21 average)
436 X 21 = 9,156 HP-MPG

Z06:
HP: 505
Fuel Economy: 15 city/24 highway (19.5 average)
505 X 19.5 = 9,848 HP-MPG

I had a 1999 LS1/6 speed Camaro. The car got better mileage than the two 2 wheel drive, 4 cylinder Toyota pick-ups I've owned...

Really?

Porsche 911 Turbo 480 BHP, 18.8 l/100 km city driving, 9.5 highway, 12.8 average
Corvette Z06: 22.8 city driving, 10 highway 14.7 average...

These figures are based on the ECE cycle, the "realistic" version of your current EPA standards, which are about to be adapted...

and for conversions: Check here

Unit Conversions

[culver]

That's a flawed conclusion because you are overlooking other variables:

Corvettes Qualify Second and Third at Lime Rock Park - Corvette Racing

"As a result of performance adjustments imposed by the sanctioning body last week, the Corvettes are now 199 pounds heavier than their Aston Martin rivals and have a 10-liter smaller fuel capacity."

Those fancy V12 DOHC Astons can't compete with the Corvettes on an equal basis, so the sanctioning body handicapped the Corvettes to make the racing more competitive and "interesting."

I figured there was yet more to the story. My intent was simply to point out that displacement alone doesn't tell the whole story.

[harddrivin1le]

Really?

Porsche 911 Turbo 480 BHP, 18.8 l/100 km city driving, 9.5 highway, 12.8 average
Corvette Z06: 22.8 city driving, 10 highway 14.7 average...

These figures are based on the ECE cycle, the "realistic" version of your current EPA standards, which are about to be adapted...

and for conversions: Check here

Unit Conversions

Using the average mileage figures you provided:

911 Turbo: 480 HP * 12.8 = 6144

ZO6: 505 HP * 14.7 = 7423

The Z06 is superior, since a higher product is better.