Took 1st in NASA TT1 - Electric Vacuum Pump question
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Driv200 (Jul 12, 2018)
Jun 19, 2018, 06:45 PM
#47
Likely both. I was looking back at my last video and unfort that boost sensor didn't log negative pressure like my current one does. That and due to the issue I was purposely lifting early so I can see 0.00 boost for a second before I hit the brakes. I'd also be curious exactly how much vac the booster "requires" to function.
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Driv200 (Jul 12, 2018)
Jun 20, 2018, 07:38 AM
#48
I replaced OEM check valve line with new OEM check valve line awhile ago.
Never thought about the The turbo or blow off valve effecting problem.
Bought a vacuum pump. Will install and test. Will look for a higher caliber check valve. If doesn’t work, then I will just go to manual brakes.
Never thought about the The turbo or blow off valve effecting problem.
Bought a vacuum pump. Will install and test. Will look for a higher caliber check valve. If doesn’t work, then I will just go to manual brakes.
Jun 29, 2018, 08:50 AM
#49
maybe i was reading too quick and misunderstood some replies, but dry sump and crank case pressure shouldn't have anything to do with it. brake boost gets vac from intake manifold when throttle body is closed. evo 9 have cable throttle, so when you let off throttle, the throttle should close instantly and create vac in intake manifold, even if the rpm doesn't drop quickly. if anything the higher the rpm while throttle is closed, the more vac there is in the manifold. so heel toe while braking will created more vac. i late brake on every corner, from gas to brake instantly, never had hard pedals. only time i feel hard pedal is left foot brake while still on gas to scrub speed on some corners. you said the problem is worse at higher boost, maybe try to double up the check valve, install two oem check valve in the line.
if you have a boost gauge in the car or logger, can you see how fast it goes into vac when you let off the throttle from full boost. what ever vac your intake mani see the brake booster should see at the same time.
if you have a boost gauge in the car or logger, can you see how fast it goes into vac when you let off the throttle from full boost. what ever vac your intake mani see the brake booster should see at the same time.
Last edited by honda-guy; Jun 29, 2018 at 11:12 AM.
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Driv200 (Jul 12, 2018)
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Driv200 (Jul 12, 2018)
Jun 29, 2018, 09:20 AM
#51
maybe i was reading too quick and misunderstood some replies, but dry sump and crank case pressure shouldn't have anything to do with it. brake boost gets vac from intake manifold when throttle body is closed. evo 9 have cable throttle, so when you let off throttle, the throttle should close instantly and create vac in intake manifold, even if the rpm doesn't drop quickly. if anything the higher the rpm while throttle is closed, the more vac there is in the manifold. so heel toe while braking will created more vac. i late brake on every corner, from gas to brake instantly, never had hard pedals. only time i feel hard pedal is left foot brake while still on gas to scrub speed on some corners. you said the problem is worse at higher boost, maybe try to double up the check valve, install two oem check valve in the line.
if you have a boost gauge in the car or logger, can you see how fast the it goes into vac when you let off the throttle from full boost. what ever vac your intake mani see the brake booster should see at the same time.
if you have a boost gauge in the car or logger, can you see how fast the it goes into vac when you let off the throttle from full boost. what ever vac your intake mani see the brake booster should see at the same time.
based on what you said then, you think it could be the throttle body sticking a little? That's the only thing that would make sense to me at this point?
Jun 29, 2018, 02:05 PM
#54
How much pressure does it take to keep out TBs open? Seems like a lot.. but If a turbo is flowing enough CFM @ 28-30psi and the DV isn't venting fast enough.....? Just throwing out unlikely "what-ifs", since it doesn't seem to be a "normal" problem.
I think we discussed the throttle cable earlier and that was ruled out.
I think we discussed the throttle cable earlier and that was ruled out.
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Driv200 (Jul 12, 2018)
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Driv200 (Jul 12, 2018)
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Driv200 (Jul 12, 2018)
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Driv200 (Jul 12, 2018)