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700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 cars |
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Boost cut?Views : 795 Replies : 12Users Viewing This Thread : |
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Apr 21st, 2019, 00:25 | #1 |
Junior Member
Last Online: Jun 24th, 2020 13:07
Join Date: Jan 2019
Location: Northampton
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Boost cut?
My 98 940 2.3 lpt is hitting a boost cut at 0.6 bar(8/9 psi). I have read about people taking the little 13c to 1bar without any issues. Anything specific to check that could be causing this? Or is there any way to bypass it? Or is this normal? Tia
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Apr 21st, 2019, 10:44 | #2 |
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Last Online: Yesterday 23:44
Join Date: May 2012
Location: Lakenheath
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The clue is in the "LPT" bit - Low Pressure Turbo.
Most only run to about 4-6psi from what i understand and the HPT runs to about 8-9psi. The other question is, do you really mean boost cut? That is controlled by the ECU and (depending exactly how it's set up) cuts the fuel and/or spark when boost exceeds a certain level. It sounds as if you already have an HPT wastegate in there, allowing it to boost to 8-9psi, i might be wrong on this as i'm not that well up on the turbos - i subscribe to the "there ain't no replacement for displacement" theory!
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Apr 21st, 2019, 11:21 | #3 |
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Last Online: Jan 1st, 2023 16:44
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Location: Blackpool
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Are you using a manual boost controller to set the boost?
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Apr 21st, 2019, 12:11 | #4 |
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Last Online: Jun 24th, 2020 13:07
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Location: Northampton
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Sorry should have mentioned running a manual controller. Definitely some sort of boost/fuel cut just like hitting a wall for a brief moment
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Apr 21st, 2019, 14:59 | #5 |
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Last Online: Jan 1st, 2023 16:44
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Location: Blackpool
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You're right in your inital post about running the 13c to 1 bar easily, I did so in my LPT without issue. Can you boost past 8/9PSI in any gear? Like drive at 40 in 3rd and do a slow, smooth acceleration to slowly raise the boost?
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Apr 21st, 2019, 16:34 | #6 |
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Last Online: Jun 24th, 2020 13:07
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Location: Northampton
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Unfortunately not, however its driven it will do it. Only way around is to turn the boost back down
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