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I will have to say ahead of time, i am no expert bout car and probably the dumbest person to ask this question, i have ebc profic II at the moment, car tuned with nistune...it had 13 psi (1 bar) or 66% set on it... Had problem on that setting so i turned the % down to 61% which is 12 psi or .90 bar and now its running fine.. Turned it down more to %56 = 11 psi Or .80 bar.. Correct me if im wrong on the figures.. Now my question is , i thought to be able to turn the boost up or down u need a tuner to do it?? So if u have boost controller , either manual or ebc, u can actually do it urself?? I guess thats why its called electronic boost controller!!

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1 bar is 14.5psi. 0.9 bar is about 13psi. 0.8 bar is about 11.5psi.

With the boost controller you can set boost to what you like. Turning it down is fine, that won't affect your tune. In fact with the B-Spec II you can have a high boost setting and a low boost setting with just the push of a button.

But turning it up is risky. You need a retune if you turn the boost up higher than it has been tuned for.

You need a tuner to "turn" your boost up because the car's air fuel ratio (the amount of air the engine combusts per stroke to the ratio of the amount of fuel used in that same stroke) needs to be set and optimised. The tuner also needs to set the ignition timing (basically exactly when the spark plug will fire causing the combustion). There are a few other variables as well. Plus the tuner can set your electronic boost control properly as there are options in it to bring boost on earlier/ramp harder etc that are outside of just turning the percentage up or down.

Once your car is tuned for e.g. 14psi, you can almost guaranteed safely run lower boost if you want to without needing a retune as your car was tuned for 14psi anyways and running 10psi will only be mostly nicer to the engine but running more than what the air fuel ratio and ignition timing was tuned for is dangerous as you will likely lean the car out causing detonation etc (piston/rings killer)

If you're running the factory ECU/computer then they usually accept a moderate increase of boost ok but gains are still to be had from getting all the variables optimised but if you're running a programmable computer such as nistune, apexi pfc, safc etc etc, then chances are it will instantly need a retune as alot of these computers only have static maps and can't really compensate for changing conditions like extra boost (beyond what it was tuned for).

Enjoy the car, sounds like you're having fun with it thumbsup.gif

I will have to say ahead of time, i am no expert bout car and probably the dumbest person to ask this question, i have ebc profic II at the moment, car tuned with nistune...it had 13 psi (1 bar) or 66% set on it... Had problem on that setting so i turned the % down to 61% which is 12 psi or .90 bar and now its running fine.. Turned it down more to %56 = 11 psi Or .80 bar.. Correct me if im wrong on the figures.. Now my question is , i thought to be able to turn the boost up or down u need a tuner to do it?? So if u have boost controller , either manual or ebc, u can actually do it urself?? I guess thats why its called electronic boost controller!!

Out of curiosity, what do you have your "Gain" and "Set boost" percentages at??

Do you get full boost all the way to redline with your current settings?

You need a tuner to "turn" your boost up because the car's air fuel ratio (the amount of air the engine combusts per stroke to the ratio of the amount of fuel used in that same stroke) needs to be set and optimised. The tuner also needs to set the ignition timing (basically exactly when the spark plug will fire causing the combustion). There are a few other variables as well. Plus the tuner can set your electronic boost control properly as there are options in it to bring boost on earlier/ramp harder etc that are outside of just turning the percentage up or down.

Once your car is tuned for e.g. 14psi, you can almost guaranteed safely run lower boost if you want to without needing a retune as your car was tuned for 14psi anyways and running 10psi will only be mostly nicer to the engine but running more than what the air fuel ratio and ignition timing was tuned for is dangerous as you will likely lean the car out causing detonation etc (piston/rings killer)

If you're running the factory ECU/computer then they usually accept a moderate increase of boost ok but gains are still to be had from getting all the variables optimised but if you're running a programmable computer such as nistune, apexi pfc, safc etc etc, then chances are it will instantly need a retune as alot of these computers only have static maps and can't really compensate for changing conditions like extra boost (beyond what it was tuned for).

Enjoy the car, sounds like you're having fun with it thumbsup.gif.

Comprendo.... Well basically i didnt want to up the boost more than wat it was tuned to take which was at 13 psi... Just had problem running at 13 .. Dialled it down to 12psi its running smoothly now... Hanaldo thanks for the clarification ...yes im loving the nistuned!!!! Best bang for buck!! Super responsive and no lag!!! Thank u guys for ur responses!!

Edited by myRB25DETT

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