Loss of power in long high-g turns
#11
Sounds to me it's more like oil starvation. From what I understand from driving, B, K and now F-series VTEC engines, our VTEC high cams is activated using oil pressure. So if oil pressure becomes low enough in those high G sweepers, you'll drop off the VTEC. That could explain your power flattening out. This is also a safety feature that prevents your engine from getting destroyed, and hint to you that you need a baffled oil pan.
The only fuel starvation problem I ever encountered in my car is 1.3+G on braking with only 1/4 tank of fuel. Logging 1.2-1.3G on long sweepers at the track that I frequent, I don't get fuel problem even with that little fuel.
Our fuel indication system is also heavily damped. So it over reads when you finished a session on the track. From my experience, when you have about 1/3 tank indicated while gunning it on the track, it's time to fill her up.
The only fuel starvation problem I ever encountered in my car is 1.3+G on braking with only 1/4 tank of fuel. Logging 1.2-1.3G on long sweepers at the track that I frequent, I don't get fuel problem even with that little fuel.
Our fuel indication system is also heavily damped. So it over reads when you finished a session on the track. From my experience, when you have about 1/3 tank indicated while gunning it on the track, it's time to fill her up.
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Sounds to me it's more like oil starvation. From what I understand from driving, B, K and now F-series VTEC engines, our VTEC high cams is activated using oil pressure. So if oil pressure becomes low enough in those high G sweepers, you'll drop off the VTEC. That could explain your power flattening out. This is also a safety feature that prevents your engine from getting destroyed, and hint to you that you need a baffled oil pan.
Where can I purchase one at?
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Probably fuel slosh.
But, any significant bumps in these turns? The MAP connector on my car would break contact occasionally. I put some dialectric grease on the pins and ziptied it to the MAP body. You'll need to add a fender washer (cut on one side to clear the sensor) under the head of one bolt to keep the ziptie from sliding up and off. You can see a picture of it on the bottom right side of the third picture here: http://www.tristanshea.com/blog/2011...ht-corey-dyck/ It fixed the issue I was having even when running with a full tank. Now I run my fuel a little lower as I was over-compensating due to the MAP problem.
But, any significant bumps in these turns? The MAP connector on my car would break contact occasionally. I put some dialectric grease on the pins and ziptied it to the MAP body. You'll need to add a fender washer (cut on one side to clear the sensor) under the head of one bolt to keep the ziptie from sliding up and off. You can see a picture of it on the bottom right side of the third picture here: http://www.tristanshea.com/blog/2011...ht-corey-dyck/ It fixed the issue I was having even when running with a full tank. Now I run my fuel a little lower as I was over-compensating due to the MAP problem.
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I have the service manual.................. but where are the filters? Never replaced, not even on my daily drivers.
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Had another track day today. The problem is fuel related, and quite a pathetic one.
Topped-off 10 miles from the track. By end of first 30 min track session, started getting a bit of bogging ON LEFT HAND TURNS ONLY. Looked at RPM I was keeping when bogging started - usually 5k-5.5k. Took the next lap in the next higher gear, just to see if RPM related at all - rpms down to 4.5K on some of the problematic left handers.................. bogging still there.
Bogging gets more frequent through 2nd and 3rd sessions (still all left handers). By the end of the 3rd session, gauge SAID I have 1/2 tank. So, I tanked up for 4th session - no issue whatsoever. I was running just as hard as previously, and not a single issue.
So, basically, I get a single stinkin session, from full tank, before I start dealing with this problem.
I don't have a clue what to do here - it's not something I can work on then test out on the street - never happens on the street. Someone mentioned fuel filters, but should that be an issue with only 40K miles on the car?
Topped-off 10 miles from the track. By end of first 30 min track session, started getting a bit of bogging ON LEFT HAND TURNS ONLY. Looked at RPM I was keeping when bogging started - usually 5k-5.5k. Took the next lap in the next higher gear, just to see if RPM related at all - rpms down to 4.5K on some of the problematic left handers.................. bogging still there.
Bogging gets more frequent through 2nd and 3rd sessions (still all left handers). By the end of the 3rd session, gauge SAID I have 1/2 tank. So, I tanked up for 4th session - no issue whatsoever. I was running just as hard as previously, and not a single issue.
So, basically, I get a single stinkin session, from full tank, before I start dealing with this problem.
I don't have a clue what to do here - it's not something I can work on then test out on the street - never happens on the street. Someone mentioned fuel filters, but should that be an issue with only 40K miles on the car?