[Z06] BTR Stage IV N/A Cam VS Black Widow R
03-23-2015, 07:50 PM
#41
I've got a Widow-R in my car. 442ci PRC 265s etc.
First start - YouTube
With the BTR cam, you lose about 0.3 in dynamic compression due to intake timing. Exhaust timing is similar from what I can tell.
First start - YouTube
With the BTR cam, you lose about 0.3 in dynamic compression due to intake timing. Exhaust timing is similar from what I can tell.
Dynamic can be a bit misleading....it's called dynamic for a reason.
.
03-23-2015, 10:02 PM
#42
Melting Slicks
Sounds great!
Why did you guys pull the front end off?
03-23-2015, 11:20 PM
#43
03-24-2015, 12:23 AM
#44
It made it easier to clean things up. The car had 54k miles on it and sat for 3 years waiting for me to put it back together.
As for dynamic compression, it's just math. You lose effective stoke the later the intake valve closes.
https://www.corvetteforum.com/forums...worksheet.html
You can also calculate effective compression based on DA as well, but I think that's not really going to help unless you build a car for Denver and never intend on running it at much lower altitudes. (BTW, 3000ft DA is equivalent to about 0.6 compression points)
As for dynamic compression, it's just math. You lose effective stoke the later the intake valve closes.
https://www.corvetteforum.com/forums...worksheet.html
You can also calculate effective compression based on DA as well, but I think that's not really going to help unless you build a car for Denver and never intend on running it at much lower altitudes. (BTW, 3000ft DA is equivalent to about 0.6 compression points)
03-24-2015, 08:38 AM
#45
Not misleading you say......dynamic calculators offer a glimpse of what you scr is doing with a perticular cam. They can not account for what's happening dynamically @ rpm.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
03-24-2015, 12:08 PM
#46
Not misleading you say......dynamic calculators offer a glimpse of what you scr is doing with a perticular cam. They can not account for what's happening dynamically @ rpm.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
Way to argue your point though. You should get a cookie.
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c5maniac2 (05-20-2021)
03-24-2015, 12:36 PM
#47
You are correct, you cannot calculate cylinder pressure without a complicated computer program and modeling the entire system. But when it comes to DYNAMIC COMPRESSION, it is simply a calculated compression based off of the valve events (intake closing) relative to the rest of the system and it is NOT dynamic by any other means than that relation to the valve closing.
Way to argue your point though. You should get a cookie.
Way to argue your point though. You should get a cookie.
But nice deflection.....
So.....Mr cr133r, would you like more dcr from the calculator or the proper IVC for a given combo ??
I chose not to "argue" with Carlos because I respect him as a vendor. But I disagree with the "no specs" theory.
But this thread proves....in order to make a educated decision, you will need as many pieces of the puzzle as you can gather.
Lol....next thing you'll hear is, power is power, it doesn't matter what rpm it's made at....lol.
And please try to stay on topic, I understand you would like to make it personal when your "facts" fail you.
.
.
03-24-2015, 03:45 PM
#48
Not misleading you say......dynamic calculators offer a glimpse of what you scr is doing with a perticular cam. They can not account for what's happening dynamically @ rpm.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
So...cam A has a 54 IVC @.050
And cam B has a 50 IVC @ .050
Cam B will calc higher dynamically and read a higher cranking compression. But if you use that logic...then a cam with 46 IVC would have an even higher dynamic number.
The "ideal" IVC is where the inertia and velocity of the incoming charge is high enough that it continues to flow into the cylinder ABDC at the beginning of the power range (and certainly at torque peak) - regardless of what the piston is doing.
And at what rpm are we trying to make power ?? Don't forget your trying to sync the IVC event to proper rpm and induction system size. Which mean trapping the greatest quantity of mixture at that rpm.
Do you think an earlier IVC caters to a 7000+rpm engine or would a later closing event help with cylinder filling....when it counts most ?? How long do you think the intake valve is off its seat at 7000+rpm ??
Carry on.....
.
All very true. Thank you for elaborating on your statement.
03-30-2015, 12:26 AM
#49
Drifting
Here is my BTR Stg 4 cam. Stock manifolds, cats and H-pipe. Once headers go on itll sound much more evil.
03-30-2015, 01:48 PM
#51
Drifting
well about that. OK this is what happened, I have Frankenstein stg 1 heads which consist of their cnc port and fixed exhaust valve guides and ss valves. ok they open up the exhaust floor and make the port round. So no longer having a "D" port and still running the stock manifolds with the "D" port still in them there is a wall in the way of smooth flow. So what my tuner, Frankenstein and me all think is that there is some exhaust gas reversion happening, starting at 6000 rpm up. So the motor went into knock and pulled 11 degrees out and it flat lined on the dyno curve. So uncorrected 550 rwhp, corrected 577 rwhp. those numbers were with 100% stock exhaust. I think once I get headers and an o/r x-pipe itll increase greatly and no longer have knock above 6000 rpm. I am on a "preliminary " tune, until I get headers. That being said it likes to "buck" at low speeds thats where the drivability issues derive from. But over all I love this cam, It pulls real hard on the highway, hard enough that supercharged H/C/I Z06's were no match at tx2k15. i was very surprised and impressed. when I opened the hood those guys were confused.
03-30-2015, 02:06 PM
#52
well about that. OK this is what happened, I have Frankenstein stg 1 heads which consist of their cnc port and fixed exhaust valve guides and ss valves. ok they open up the exhaust floor and make the port round. So no longer having a "D" port and still running the stock manifolds with the "D" port still in them there is a wall in the way of smooth flow. So what my tuner, Frankenstein and me all think is that there is some exhaust gas reversion happening, starting at 6000 rpm up. So the motor went into knock and pulled 11 degrees out and it flat lined on the dyno curve. So uncorrected 550 rwhp, corrected 577 rwhp. those numbers were with 100% stock exhaust. I think once I get headers and an o/r x-pipe itll increase greatly and no longer have knock above 6000 rpm. I am on a "preliminary " tune, until I get headers. That being said it likes to "buck" at low speeds thats where the drivability issues derive from. But over all I love this cam, It pulls real hard on the highway, hard enough that supercharged H/C/I Z06's were no match at tx2k15. i was very surprised and impressed. when I opened the hood those guys were confused.
I thought I heard Dru beat you in his non cammed z06??
And that your Cammed car only trapped 127? In the quarter?
03-30-2015, 02:16 PM
#53
Drifting
me and dru never raced and that is true on the mph. the highway is a different story. now on the other guys at tx2k idk exactly what was done to their cars but I heard through the rumor mill that I had a supercharger too.