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Old 12-19-2012, 08:35 AM   #141
nnacpil
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Is there a way to test the wastegate without removing it?
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Old 12-19-2012, 03:11 PM   #142
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have you tried putting the old exhaust back on?
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Old 12-19-2012, 04:32 PM   #143
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have you tried putting the old exhaust back on?
No, I sold it already.
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Old 12-19-2012, 04:37 PM   #144
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Sounds like the reduction in back pressure from the new exhaust has caused a need to alter the wastegate duty cycle.
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Old 12-19-2012, 06:59 PM   #145
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Sounds like the reduction in back pressure from the new exhaust has caused a need to alter the wastegate duty cycle.
Would that cause my wg to not open at all
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Old 12-19-2012, 09:22 PM   #146
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Quote:
Originally Posted by nnacpil View Post
Would that cause my wg to not open at all
Yeah, think of your wastegate duty cycle like injector duty cycle. Increase the IDC and you spray more fuel. Increase the Wastegate Duty Cycle and you bleed more pressure through to the wastegate which opens it faster and wider.

The boost spikes are because the duty cycle is too low and the wastegate is too slow to respond, so the boost spikes before the gate opens all the way.

You get boost creep from the gate not being open far enough and it doesn't bleed off enough exhaust gasses.

At least, that's how I understand it.
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Old 12-19-2012, 10:02 PM   #147
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Originally Posted by Scooby24 View Post
Yeah, think of your wastegate duty cycle like injector duty cycle. Increase the IDC and you spray more fuel. Increase the Wastegate Duty Cycle and you bleed more pressure through to the wastegate which opens it faster and wider.

The boost spikes are because the duty cycle is too low and the wastegate is too slow to respond, so the boost spikes before the gate opens all the way.

You get boost creep from the gate not being open far enough and it doesn't bleed off enough exhaust gasses.

At least, that's how I understand it.
Thanks for explanation. Will talk further with HPF on sending my ems to them for a new tune.
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Old 12-20-2012, 12:06 PM   #148
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more duty cycle puts more pressure on top of the gate keeping it closed, not open.

you get a boost spike becuase your initial duty cycle is too high, keeping the gate closed

You get boost creep from poorly designed manifolds and is hardly due to duty cycle on the gate.



Quote:
Originally Posted by Scooby24 View Post
Yeah, think of your wastegate duty cycle like injector duty cycle. Increase the IDC and you spray more fuel. Increase the Wastegate Duty Cycle and you bleed more pressure through to the wastegate which opens it faster and wider.

The boost spikes are because the duty cycle is too low and the wastegate is too slow to respond, so the boost spikes before the gate opens all the way.

You get boost creep from the gate not being open far enough and it doesn't bleed off enough exhaust gasses.

At least, that's how I understand it.
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