Let's try at a collective thread of info on the new 2008 - free of comments or opinions - just the facts.
We got a lot of info on these motors last week and a lot were taking notes so let's post what we learned.
<ul type="square"> [*]The VCA has influence - The original goal was 560 hp.
***600 hp was in large part due to SRT listening to VCA members and stepping up to the challenge. A 100 hp increase on an already impressive motor is fantastic. Thank you SRT!
Gen 1 motor = 50 hp per Liter
Gen 4 motor = 71 hp per Liter
[*]That yielded a massive jump in power:
[*]This motor is strong low and high- with the high extended several hundred rpm higher. As we saw firsthand on the dynos:
RPM HP TQ
2400 225 495
3700 410 550 (Power is already beyond a standard vette)
4800 524 570 (Power is now beyond a z/o6)
6000 613 535
[*]Friction takes a lot of power: The dyno turned the crank with the motor off. It required 175 hp to spin it 6,000 rpm. (That's not 100% from friction, but most all of it is)
[*]There was a stable 10 degree (+/- 1 deg) delta between the incoming coolant temp and the outgoing coolant temp at the higher rpm loads.
[*]Driveline loss: They measure a lot of things and the answer was between ~12% depending on what gear and what rpm
[*]One of the dyno test runs is to run the motor at 100% power for 8 hours - with glowing red exhaust
[*]Big valves with new angles: 52.8mm (2.078") intake and 40.5mm (1.59") exhaust
[*]Exhaust cam can change up to 40 deg. This will smooth the idle a lot - to much reduce mis fires and meet EPA needs- but allows for more aggressive profile in mid and upper power bands. Variable exhaust on allows increase in upper power band while a variable intake would increase low end tq.
[*]Massive flow rate increases as demonstrated by:
Gen 1 as a base
Gen 2 +17% over Gen 1
Gen 3 + 6% over Gen 2
Gen 4 +23% over a Gen 3
Add them all up and you see where a lot of the 400 hp to 600 hp is coming from
[*]Knock Sensors and Octane: There are 2 knock sensors. they back off the timing if needed. the ecu is calibrated for 91 octane. The ecu will only back off timing - it will not just advance it until it detects a ping so 100 octane will not give any power increase
[*]The piston/rod assembly is the unit from a 6.1 hemi. Floating pin now. Stronger and better than the Gen 3 unit. That is the reason for the 1mm bore increase
[*]74mm Throttle Bodies!
[*]A new oil filter that will also work on all Vipers. Less pressure drop and better filtration. Napa filter was the base but a relief valve was added specific for the Dodge brand unit.
[*]All metric bolts now
[*]They have tuned an 8.4 motor to put out 675hp/650tq with some performance parts
[/list]
There is a lot more for others to add. So what other details did you all pick up on? ............
We got a lot of info on these motors last week and a lot were taking notes so let's post what we learned.
<ul type="square"> [*]The VCA has influence - The original goal was 560 hp.
***600 hp was in large part due to SRT listening to VCA members and stepping up to the challenge. A 100 hp increase on an already impressive motor is fantastic. Thank you SRT!
Gen 1 motor = 50 hp per Liter
Gen 4 motor = 71 hp per Liter
[*]That yielded a massive jump in power:
[*]This motor is strong low and high- with the high extended several hundred rpm higher. As we saw firsthand on the dynos:
RPM HP TQ
2400 225 495
3700 410 550 (Power is already beyond a standard vette)
4800 524 570 (Power is now beyond a z/o6)
6000 613 535
[*]Friction takes a lot of power: The dyno turned the crank with the motor off. It required 175 hp to spin it 6,000 rpm. (That's not 100% from friction, but most all of it is)
[*]There was a stable 10 degree (+/- 1 deg) delta between the incoming coolant temp and the outgoing coolant temp at the higher rpm loads.
[*]Driveline loss: They measure a lot of things and the answer was between ~12% depending on what gear and what rpm
[*]One of the dyno test runs is to run the motor at 100% power for 8 hours - with glowing red exhaust
[*]Big valves with new angles: 52.8mm (2.078") intake and 40.5mm (1.59") exhaust
[*]Exhaust cam can change up to 40 deg. This will smooth the idle a lot - to much reduce mis fires and meet EPA needs- but allows for more aggressive profile in mid and upper power bands. Variable exhaust on allows increase in upper power band while a variable intake would increase low end tq.
[*]Massive flow rate increases as demonstrated by:
Gen 1 as a base
Gen 2 +17% over Gen 1
Gen 3 + 6% over Gen 2
Gen 4 +23% over a Gen 3
Add them all up and you see where a lot of the 400 hp to 600 hp is coming from
[*]Knock Sensors and Octane: There are 2 knock sensors. they back off the timing if needed. the ecu is calibrated for 91 octane. The ecu will only back off timing - it will not just advance it until it detects a ping so 100 octane will not give any power increase
[*]The piston/rod assembly is the unit from a 6.1 hemi. Floating pin now. Stronger and better than the Gen 3 unit. That is the reason for the 1mm bore increase
[*]74mm Throttle Bodies!
[*]A new oil filter that will also work on all Vipers. Less pressure drop and better filtration. Napa filter was the base but a relief valve was added specific for the Dodge brand unit.
[*]All metric bolts now
[*]They have tuned an 8.4 motor to put out 675hp/650tq with some performance parts
[/list]
There is a lot more for others to add. So what other details did you all pick up on? ............
I guess they didn't listen about the body styling. 
