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boost question

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Old Mar 11, 2006 | 01:51 PM
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20G-4G63's Avatar
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What is a safe amount of boost to run on a evo 8. nothing done to the guts of the motor. just you r basic bolt ons. with no problems?
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Old Mar 12, 2006 | 12:36 AM
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While your obviously looking for a "14psi is the max you should run" type of answer, I can't give that to you.
What I can do, however, is explain what parameters you need to keep track of as you raise your boost. You will need some kind of datalogging equipment- there are a few models available that run from a palm pilot, and then there are many that run on a laptop. Without having datalogging capability, you cannot know for sure that your car can actually handle any boost increase.

Once you have your datalogger hooked up, you want to keep an eye on a few things as you crank the boost up;
first and foremost is your knock count- if your motor starts detonating, the ecu will pull timing, cutting HP production.
Next, keep track of your oxygen sensor voltage- if this starts to drop, your fuel system cannot keep up with the turbo, and your "leaning out". (too little fuel, too much air) A lean fuel mixture burns hotter, and if it gets hot enough, it has the potential for melting piston tops.

Once you have the ability to monitor those two sensors, you should be able to set a boost level which wouldn't be detrimental to the long-term operation of the car.
If you have absolutely no desire to monitor your own car, I suggest taking it to a comptetent tuner, and have it professionally tuned on a dyno.

Having a datalogger also helps you in diagnosing future problems with the car- rather than pulling 'trouble codes', you can look at real-time sensor data.

Do a google search for "PDA datalogger"+"Evo VIII" and i'm sure you'll find a couple compatible with your car.
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Old Mar 12, 2006 | 03:48 AM
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Some girl in Orlando got a manual boost controller and brought it up to 21psi with no previous mods. Evo 8's can handle quite a bit of boost on their stock engines.
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Old Mar 12, 2006 | 06:51 AM
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ebay has an assload of dataloggers for alot of different cars.
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Old Mar 12, 2006 | 06:55 AM
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Originally Posted by JDMevo
Some girl in Orlando got a manual boost controller and brought it up to 21psi with no previous mods. Evo 8's can handle quite a bit of boost on their stock engines.
yea, but its not good to raise boost level with nothing to monitor, theres a chance it might be good, but probably not, i dont know much about evo's, but i have evo8 injectors, and a 255lph pump, and if your gonna raise it that high, you are gonna have to add fuel. i put mine to 18 and had to add fuel.
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Old Mar 12, 2006 | 01:35 PM
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Thanks, John. I'd heard 21 psi thrown around, but I've never researched it.
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Old Mar 13, 2006 | 02:00 PM
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Thanks for all your help with the car. and i will look into to a dattalogger. but iam for sure going to send my ecu to get flashed at the place john sent me a link to also. Also if my ecu does get a flash is it still good to have a logger.
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