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jlee8196
01-11-2005, 10:43 PM
I seem to having hard time targeting my boost.
It's either ~9psi or ~17psi or higher. I can't get in between like 14 or 15psi. no matter how I adjust the boost map.
When i have the utec it requires the mbc to work with stock boost controller or get 14+ psi. I think my stock boost controller is either complete closed therefor 9psi or complete open ~17psi.
Anyone could help?

Element Tuning
01-11-2005, 11:49 PM
Have you read this yet in tuning guide 1?

"Boost Control

The Element Hydra EMS uses a closed loop boost control system and offers very fine adjustment. Each of these settings is not cut and dry and some overlap occurs, requiring harmony among the settings. Always make very small adjustments while fine tuning the boost control system. Be cautious of running boost levels higher than your turbo, fuel octane, fuel system, ignition curve, engine, and transmission can handle. Just because you can tune for a higher boost level without detonation does not make it ideal.
http://elementtuning.com/technical/BoostTarget.jpg

Boost Control Start RPM: This value determines when the boost control system turns on. Setting this too low a) is noisy and b) won’t help spool the turbocharger any quicker. For optimal control and smooth operation you should set this about 1000 rpm before your Boost Target level can be achieve by your turbocharger. Doing this will allow the boost to ramp up smooth and quick. Under this value boost will be relegated to wastegate spring pressure.

Proportional: Controls how active the closed loop system reacts to off target boost pressure. If boost pressure is oscillating then it’s likely the proportional value is set too high and the system is too active. Lowering this value should lessen boost oscillation.

Integral: This controls boost “spike” or when boost pressure exceeds the target boost value set in the Boost Target map. The value should be adjusted so that boost pressure ramps quickly to your target boost value without overshooting. If you encounter boost “spike” then lower the Integral. If boost response is too slow then increase the Integral value.

Derivative: This controls how much oscillation is allowed before the system corrects to reach the target boost value set in the Boost Target map. If the Derivative value is set too high then the boost may oscillate but if the value is set to low then the system may not correct for off target boost levels.

Boost Target: Even if you’re not using the Element Hydra boost control system make sure you set the Boost Target. This is the desired level of boost you want to tune the boost control system for. Over-boost fuel cut is 3 psi over the Boost Target so make sure to set this appropriately regardless of the boost control system used.

PWM MAP 4:

This map controls the duty cycle of your boost control solenoid. It is ideal to get the duty cycle as close to your target boost level so the closed loop boost control system has to perform only minimally to maintain your Boost Target.

The simplest explanation I can give is that you're adjusting the duty cycle of the solenoid based on the effort required to attain the Boost Target. PWM Map 4 is defined by load sites 0% - 100%. When the boost control system is off such as when you are under your Boost Start RPM the load site will be 0% and when the system is active but under the Boost Target the system will be in the 100% load site. Once the system reaches the Boost Target the load site will start to decrease from 100% to 90%, 80%, 70% and so forth.
http://elementtuning.com/technical/BoostPWM4.jpg "

Thanks,
Phil
www.elementtuning.com

jlee8196
01-12-2005, 01:40 AM
Yeah, i've read that before. But after playing around with the pwm4 map. I notice the jump from 9psi to 17psi. and no in between. I didn't mess around with the PIDs, I remember you (phil) said not to change that, as they are good values set.
Does weather change the boost? Couple times that after I get set it to 17psi (dry day), it would not pass 9psi on the next day with different weather (rain).
Would it help to get a MBC in conjunction with stock soleniod?

Element Tuning
01-12-2005, 11:00 AM
It sounds like you may have a sticking boost control solenoid. Clean it out the internals and electrical connection thoroughly with contact cleaner and try again. Look at the duty cycles of the boost control solenoid when you get 9 psi vs. 17 psi. If they are the same you have a bad solenoid.

Thanks,
Phil
www.elementtuning.com

jlee8196
01-13-2005, 10:38 PM
I'm thinking I might have bad solenoid. Can bad solenoid be fixed? or buy new
one.