Vtec control - one for the enginerds
01-13-2021, 08:11 AM
#11
I was thinking of a somewhat different analogy than a garden hose. A body appendage most of us here have, that when called to duty rises to the occasion by filling with the vital, life sustaining fluid that is pumped by one of our primary organs.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
01-13-2021, 03:12 PM
#12
Typical Oil Pressure and Temp Readings - S2KI Honda S2000 Forums
"I have been logging oil pressure data for the past year, attached is some data from a recent track day at VIR.
The top, middle, and bottom plots are lateral Acceleration [g], RPM, and oil pressure [PSI], respectively. Engine is completely stock.
Observations:
1.) Above 6000 RPMS / VTEC, the oil pressure is consistently between 70-75 PSI
2.) Below 6000 RPMS / VTEC, the oil pressure would rise with RPM between ~20 (idle) to 90 PSI (just before VTEC engagement)
3.) As you noted, I consistently measure an oil pressure drop between 10-15 PSI when VTEC is engaged, and vice versa."
"I have been logging oil pressure data for the past year, attached is some data from a recent track day at VIR.
The top, middle, and bottom plots are lateral Acceleration [g], RPM, and oil pressure [PSI], respectively. Engine is completely stock.
Observations:
1.) Above 6000 RPMS / VTEC, the oil pressure is consistently between 70-75 PSI
2.) Below 6000 RPMS / VTEC, the oil pressure would rise with RPM between ~20 (idle) to 90 PSI (just before VTEC engagement)
3.) As you noted, I consistently measure an oil pressure drop between 10-15 PSI when VTEC is engaged, and vice versa."
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windhund116 (01-14-2021)
01-14-2021, 01:23 AM
#13
I was thinking of a somewhat different analogy than a garden hose. A body appendage most of us here have, that when called to duty rises to the occasion by filling with the vital, life sustaining fluid that is pumped by one of our primary organs.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
01-14-2021, 01:27 AM
#14
Never seem a graph plotting S2000 oil pressure vs rpm. Only specs available are 36psi at idle and 85psi at 3000rpm. Would be interesting.
Nor have I seen evidence VTEC engagement does more than a short, temporary change in oil pressure/oil flow all the solenoid does is divert a small bit of oil to the VTEC cam and hold it there with oil pressure. Using a water hose model turning on the valve with the other end on the hose sealed only permits a small flow until the hose is filled and pressure returns to whatever it was to start with. We're talking about no more than a couple ounces of oil not what's in 100 feet of garden hose. Higher flow means less pressure but there's no flow within the VTEC cylinder -- or my capped garden hose -- once it's full. Again using home water to illustrate; When a contractor severed one of my underground lawn irrigation PVC pipes the water just flowed out without the restriction of the sprinkler heads and pressure in the home dropped to the point my faucets just trickled and my washing machine would not run. As soon as the irrigation timed zone shut off pressure was back. This irrigation zone only ran for a few minutes a few times a week just before dawn and I didn't notice it for weeks other than a persistent wet spot in my lawn.
I don't think there's any oil flow change hence no pressure change, just diversion to the dead end VTEC cylinder. Oil pressure to the engine should not be affected regardless of VTEC or not.
I await more knowledgeable information.
-- Chuck
Nor have I seen evidence VTEC engagement does more than a short, temporary change in oil pressure/oil flow all the solenoid does is divert a small bit of oil to the VTEC cam and hold it there with oil pressure. Using a water hose model turning on the valve with the other end on the hose sealed only permits a small flow until the hose is filled and pressure returns to whatever it was to start with. We're talking about no more than a couple ounces of oil not what's in 100 feet of garden hose. Higher flow means less pressure but there's no flow within the VTEC cylinder -- or my capped garden hose -- once it's full. Again using home water to illustrate; When a contractor severed one of my underground lawn irrigation PVC pipes the water just flowed out without the restriction of the sprinkler heads and pressure in the home dropped to the point my faucets just trickled and my washing machine would not run. As soon as the irrigation timed zone shut off pressure was back. This irrigation zone only ran for a few minutes a few times a week just before dawn and I didn't notice it for weeks other than a persistent wet spot in my lawn.
I don't think there's any oil flow change hence no pressure change, just diversion to the dead end VTEC cylinder. Oil pressure to the engine should not be affected regardless of VTEC or not.
I await more knowledgeable information.
-- Chuck
You are right about the VTEC solenoid letting a fairly small amount of oil thru the VTEC dowels/pins inside the rockers which engage the big boys for the dopamine release we luv
Plenty of oil pressure available on tap in F20 and F22. If there wasn't then we'd be hearing of many tuned S2000's with lower VTEC engagement having trouble due to oil starvation. I could be wrong but I think Spoon's N1 and maybe even J's Racing's N1 ECU's lower VTEC from 6000 rpm to 4500 rpm as well. They obviously know our cars well!
01-14-2021, 05:14 AM
#15
...and Gernby's amazing research demonstrated that with the harmonics of the stock cat, lowering VTEC from stock produces a hole in the torque curve. It appears Honda set the VTEC rpm where it is because it produces the best power curve.
Likely they would have made it lower if they didn't have to deal with the stock cat. They couldn't change the cat without compromising emissions.
Perhaps they could have found a compromise that would still pass emissions, but not achieve the ultra low emissions rating, and allow lowering VTEC some. But maybe they made a marketing decision that rating was more important than a smoother torque curve. That could make sense, since it wouldn't affect the all important published hp rating, and the 'bug' of a sudden, strong power hit could be seen as a feature.
It doesn't appear that oil pressure at different rpm's had anything to do with factory VTEC threshold.
Likely they would have made it lower if they didn't have to deal with the stock cat. They couldn't change the cat without compromising emissions.
Perhaps they could have found a compromise that would still pass emissions, but not achieve the ultra low emissions rating, and allow lowering VTEC some. But maybe they made a marketing decision that rating was more important than a smoother torque curve. That could make sense, since it wouldn't affect the all important published hp rating, and the 'bug' of a sudden, strong power hit could be seen as a feature.
It doesn't appear that oil pressure at different rpm's had anything to do with factory VTEC threshold.
01-14-2021, 06:07 AM
#16
...and Gernby's amazing research demonstrated that with the harmonics of the stock cat, lowering VTEC from stock produces a hole in the torque curve. It appears Honda set the VTEC rpm where it is because it produces the best power curve.
Likely they would have made it lower if they didn't have to deal with the stock cat. They couldn't change the cat without compromising emissions.
Perhaps they could have found a compromise that would still pass emissions, but not achieve the ultra low emissions rating, and allow lowering VTEC some. But maybe they made a marketing decision that rating was more important than a smoother torque curve. That could make sense, since it wouldn't affect the all important published hp rating, and the 'bug' of a sudden, strong power hit could be seen as a feature.
It doesn't appear that oil pressure at different rpm's had anything to do with factory VTEC threshold.
Likely they would have made it lower if they didn't have to deal with the stock cat. They couldn't change the cat without compromising emissions.
Perhaps they could have found a compromise that would still pass emissions, but not achieve the ultra low emissions rating, and allow lowering VTEC some. But maybe they made a marketing decision that rating was more important than a smoother torque curve. That could make sense, since it wouldn't affect the all important published hp rating, and the 'bug' of a sudden, strong power hit could be seen as a feature.
It doesn't appear that oil pressure at different rpm's had anything to do with factory VTEC threshold.
Glad to know that oil pressure at different rpm's didn't have anything to do with the stock VTEC threshold.
01-14-2021, 06:52 AM
#17
Yes, you did say it first. Wanted to concur with emphasis, and elaborate on the details behind what you said.
I've never been accused of being a man of few words. Perhaps my username should have been The Elaborator.
I've never been accused of being a man of few words. Perhaps my username should have been The Elaborator.
01-14-2021, 09:22 AM
#18
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I was thinking of a somewhat different analogy than a garden hose. A body appendage most of us here have, that when called to duty rises to the occasion by filling with the vital, life sustaining fluid that is pumped by one of our primary organs.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
When this most cherished feature is being engaged, we don't suffer a noticeable loss of blood pressure. Once fully operational, similar to VTEC, a valve closes things off from the rest of the system. The rest of the system doesn't seem to care about a small amount of fluid that is now missing from its regular circulation.
Of course, the bodies equivalent of motor oil also serves an important role of conveying oxygen to each of our vital organs. So don't ever let your bodies version of VTEC stay engaged for more than 4 hours at a time. Lest that particular organ die from oxygen deprivation. A condition medically known as priapism.
Its not uncommon for engineering to copy something found in nature. There is even a term for it. Biomimetics.
I can't say for certain that Honda engineers were inspired by this feature that is unique to the male gender when they created VTEC. But interestingly, when engaged they both seem to trigger a similar release of dopamine in the brain.
01-14-2021, 11:02 AM
#19
Typical Oil Pressure and Temp Readings - S2KI Honda S2000 Forums
Observations:
1.) Above 6000 RPMS / VTEC, the oil pressure is consistently between 70-75 PSI
2.) Below 6000 RPMS / VTEC, the oil pressure would rise with RPM between ~20 (idle) to 90 PSI (just before VTEC engagement)
3.) As you noted, I consistently measure an oil pressure drop between 10-15 PSI when VTEC is engaged, and vice versa."
Observations:
1.) Above 6000 RPMS / VTEC, the oil pressure is consistently between 70-75 PSI
2.) Below 6000 RPMS / VTEC, the oil pressure would rise with RPM between ~20 (idle) to 90 PSI (just before VTEC engagement)
3.) As you noted, I consistently measure an oil pressure drop between 10-15 PSI when VTEC is engaged, and vice versa."
01-14-2021, 01:48 PM
#20
Pressure and flow are not the same thing. Lowering pressure by increasing size of tube (like the pill does) can increase flow rate. Its only because the tubing in our cars doesn't change that we can equate pressure with flow.