Boost Taper
#3
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not so... the ecu also aids the boost controller sollenoid/waste gage/whatever else makes the boost taper. you need to get a stand alone or a flash that specifically takes it out. i've been askin' around for the longest time about what exactly or whats exactly causes the taper... this is what i've found so far... anyone know for sure?
#4
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some say boost leak, some say built in ECU prog, some say it's leaking somewhere.
I'm thinking it's the BOV not holding and I'm sure it's done by Mitsu purposefully.
It's always safer to run rich then lean.
People with MR BOV (Metal) is seeing it not taper down to 16psi.
Then again, if you know how to drive it right, your boost stays up there without tapering with stock BOV.
I'm thinking it's the BOV not holding and I'm sure it's done by Mitsu purposefully.
It's always safer to run rich then lean.
People with MR BOV (Metal) is seeing it not taper down to 16psi.
Then again, if you know how to drive it right, your boost stays up there without tapering with stock BOV.
#5
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tapering of the boost was set from the manufacturer for warranty isues and also to cover for their butt.if it didnt taper it would mean more gas to support the boost then the emmision level goes higher which woul make the evo a non-lev.
as for a boost controller the ebc comes with the solenoids to control the boost so you bypass the stock solenoid.which in turn flexibility of controlling the boost but some of the reflashes now can control boost using the stock solenoid.
as for a boost controller the ebc comes with the solenoids to control the boost so you bypass the stock solenoid.which in turn flexibility of controlling the boost but some of the reflashes now can control boost using the stock solenoid.
#6
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I have a DynoFlash, HKS EVC V, and HKS SSQV BOV and I STILL have boost taper, the facory wastegate appears to just not be capable of holding anything over 19 psi at 6,500 rpm and up. It sucks. I can make 22psi+ from 4,000 - 5,500 rpm, but after that, there is just too much pressure on the wastegate from what I have found.
#7
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it's not about the wastegate holding anything, it's about the waste gate opening, it would be a bad thing if the wastegate just held it all in, something is tripping it, and it might just be that it is made to trip not that it can't handle it. a failed wastegate is a wastegate that overboosts, the PROBLEM is that it CAN bleed it off and you don't want it to!
now for the bov thing, tightening hoses i've heard is crucial, ok... done... plastic bov will still leak, but some have after market, check. ebc or mbc removes boost pill in the vac lines, people have done that, check. flashed removes ecu tapering action, check. anyone have all these and still have taper? if not, then that's the recipe.
now for the bov thing, tightening hoses i've heard is crucial, ok... done... plastic bov will still leak, but some have after market, check. ebc or mbc removes boost pill in the vac lines, people have done that, check. flashed removes ecu tapering action, check. anyone have all these and still have taper? if not, then that's the recipe.
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#8
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Dynoflash cannot eliminate the tapering, it can only delay it. When my car was dynoed, the boost chart shows that at 3,500rpm, full boost kicks in, then tapers very slowly and gradually. If you sustain full boost at high rpm, then things might start to break.
#10
I have heard adjusting the wastegate spring a bit tighter can help hold boost. I have not done this but have heard it suggested. My car on race fuel peaks at 26-27 and tapers all the way to 21 at redline.
Shane
Shane
#11
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Originally Posted by Dr. Fob
Dynoflash cannot eliminate the tapering, it can only delay it. When my car was dynoed, the boost chart shows that at 3,500rpm, full boost kicks in, then tapers very slowly and gradually. If you sustain full boost at high rpm, then things might start to break.
#12
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Originally Posted by jbrown
I have a DynoFlash, HKS EVC V, and HKS SSQV BOV and I STILL have boost taper, the facory wastegate appears to just not be capable of holding anything over 19 psi at 6,500 rpm and up. It sucks. I can make 22psi+ from 4,000 - 5,500 rpm, but after that, there is just too much pressure on the wastegate from what I have found.
#13
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Originally Posted by trinydex
uhm... how do you figure that if you have sustained boost at high rmp you'll break things? on any other turbo charged car on earth there is sustained boost all the way up to and past high rpm.
#14
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Originally Posted by jason@NTEC
i had a works p2 on my 03 evo and it hit 20psi and just stuck there i loved that p2 flash it was great!!!
A Dynoflash, a Xede, or an MBC just try to trick the current ECU and force it to make more boost. You'll never hold peak boost with any of these unless you also replace the stock solenoid (I believe that's what it's called) to get rid of that pill.
The factory BOV is really more of a DV, but either way it's not the issue. It will hold boost up to around 24 psi I think. But, please don't try to run 24psi everyday on pump gas if you're stock...
#15
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Wow, that's wrong.
First of all, the restrictor pill is removed when an Xede is used, and no MBC is required either.
Secondly, a Dynoflash, Xede, and MBC are very different items. Of the three, an Xede provides the user with a comprehensive means of tuning in real time. A Dynoflash (and P2 flash) is a static reflash that is not user adjustable. An MBC is simply a mechanical boost controller and nothing else.
To say that a Dynoflash or Xede are ineffective at holding boost due to a failed attempt to trick the ECU is false. Nothing will overcome the limitations of the factory turbo, which cannot effectively provide greater boost pressure at higher cfm demand. The more air a particular setup can flow, the more power potential it has, and the greater the boost taper will be.
This is the primary reason for the boost taper.
First of all, the restrictor pill is removed when an Xede is used, and no MBC is required either.
Secondly, a Dynoflash, Xede, and MBC are very different items. Of the three, an Xede provides the user with a comprehensive means of tuning in real time. A Dynoflash (and P2 flash) is a static reflash that is not user adjustable. An MBC is simply a mechanical boost controller and nothing else.
To say that a Dynoflash or Xede are ineffective at holding boost due to a failed attempt to trick the ECU is false. Nothing will overcome the limitations of the factory turbo, which cannot effectively provide greater boost pressure at higher cfm demand. The more air a particular setup can flow, the more power potential it has, and the greater the boost taper will be.
This is the primary reason for the boost taper.