Hey guys i just want to know what is the highest boost i can set on my evo not damaging my engine.
My mods: RSR downpipe and exhaust, AEM intake, Forge BOV, AMS custom flash and Greddy profec b-spec II boost controller.

Without a boost controller my boost spiked at 24psi and hold at 20. I want to set it to 27psi but i don't know if it's not gonna be too dangerous for my engine. I'm running on 100octane gas

 

AMS knows what they are doing, leave it where they set it at 24 psi.

 

dont pass 25 PSI !!! thats the limit!!

 

you can do it but it won't be good for the stock turbo. it will eventually go "BOOM". Most people run 21-22psi with out alky.

 

Talk to your tuner. They will tell you. It depends on a variety of things, most have to do with the tune.

 

AMS didn't set it on 24psi it was like that before flash. I bought my evo brand new 6 months ago and i had 21 psi stock when i put downpipe and exhaust it went to 24psi and AMS left it like that

 

Call AMS and ask them.

 

Basically, you shouldn't have touched anything after AMS did. If you have changed ANYTHING (octane, boost, new parts) you need to take it back and get it retuned.

After you get a custom tune done, they will have the car tuned to be as productive as possible. If you tinker with anything, it needs to be retuned.

 

Stock turbo will spike at 29psi if you want but will not and i will say again will not hold no more then 24psi on the stock w/g your b/g will read higher it always will read higher then what it really is. If you put a data logger on your car you will see for yourself. At one point i thought i was running 25psi with a mbc and i could see it on my b/g but when i put the data log on the car i was only boosting 20 the hole time and no there where no leaks everything was well put in b/g was put in the right way. Summing up you got to tune your if your going to run your boost past 20.7 psi becasue the ecu starts to pull timeing and thats why it drops down on top end well one of the many causes.

 

thankx for all answers guys it's really helpful. I think i'm gonna put cams and then go to AMS to retune it

 

How do you monitor that "data log" you are talking about? Which sensor did you "log" it from? So if you say your gauge reads 25 PSI while your "log" reads 20 PSI, what would it(your log" then read if you adjust your gauge (with a MBC I assume) to read 20 PSI?
And to answer the Original question, you should let your tuner decide on a safe boost level. Only with proper monitoring equipments that you can determine the car's health. Every Car Is Different. Don't just take *boost* advice from the internet.

 

If you're always on 100oct, go ahead and run 27psi all day while tuned for it. Your car will be fast as hell...

 

27 psi on all of the stock internals and stock turbo? How long is that engine gonna last until at least the head gasket goes if not something worse. My friend Tom was running tons of boost with his BR500 until he broke his crankshaft. Rebuilt the car and then spun a rod bearing not much later. Better him than me....

But I was curious of this myself. I was debating on flashing my car for 21 or 22 psi for 93 octane. Do you guys think I can safely go with 22? Thanks in advance!

 

I run 30psi on mine quite often. It is a completely stock motor. Not sure what your friend is doing wrong but its obviously something.

 

get a water/alky injection kit and turn up the boost son.