Seems that 8's are set to something like 18.7 lbs from the factory. I'm assuming Mitsu came up w/ this number through a combination of engineering, testing balanced against warranty concerns.

My question: for upgrades such as mine (Buschur/Warrtalon package), how was the 20 - 21 lbs number derived? Is there any latitude on this based upon non-standard factors such as altitude and climate?

The main reason I'm asking is that my mbc was set, for a day, to allow 22.5 lbs and I LOVED IT. The car just felt like it was in it's sweet-spot - exhaust sounded better, motor response seemed beyond the supposed 10 hp/lb expected by increased boost.

I noticed no detonation though not being an expert on things mechanical I might have missed the knock. I certainly didn't see any other bad behavior.

Please, no comments on my setting the boost up for a day. I'm a big boy and understand the potential consequences of this action.

Thanks - I'm very interested in relevant replies.

 

Based on years of experience with data logging and track times.

What Mitsu sets the stock boost at is irrelevant to the question, though.

 

I disagree. Beyond that, this comment was irrelevant to the response I requested.

 

Wow...ok, nevermind then.

 

i'm sure warrtalon will elaborate on his post, but those boost levels (20-21)are "safe" because they have proven time and time again that your car will not knock nearly as much as if you have 23 psi. he is right though, its pretty much all info gathered from data logs (knock) and vendors, etc.

you may like the power levels now at 22.5 but when the motor dies after too much detonation, it wont be fun.

i just hope youre using 93 octane when you are at that boost level.

 

Experience is a good teacher but, as mentioned in my post, it would seem other factors can come into play.

Altitude? Temperature? Wouldn't these have an effect? Aren't these numbers "generic" findings?

Also, is it possible I experienced detonation and didn't know it. For some reason I was under the impression a person could feel and/or hear it.

 

Warr,

I had no issue w/ your first statement. I'm just not sure why you felt like you had to make the second one.

 

[QUOTE=Warrtalon]Based on years of experience with data logging and track times.QUOTE]

+1

hell, even 22psi isn't TOO much boost considering your upgrades and Walbro.

 

I think what Warrtalon was trying to say is that the Buschur/Warrtalon package has its seting based on years of experience with data logging and track times.
And that the mitsu setting does not matter as you are no longer stock and have already changed the setting.
If I have mis spoken on anybodys behalf I am sorry. I was also wanting to know how to determin what are safe settings.

 

i would say that at altitude since its harder to get oxygen because of the lack of pressure to breath...so possibly your car is the same way. Since your car depends on A/F ratios, if your car is having trouble getting air then you wont completely burn all of the fuel.

this may cause some detonation...but im not a full combustion guru yet

but how this applies to setting the mbc...it might require slightly lower boost settings than at sea level

 

Living in the Seattle area I'm pretty near sea-level. That's why I wondered if the 22.5 was okay... Sounds like it's not so I'll wait until I can add the meth injection.

 

based on turbo efficiency, a/f tuning, and knock. ..

 

Actually, what he said was perfectly relevant. Mitsu does not set stock boost to the max safe level. They set it a few notches below to be extra conservative. If Mitsu set everything to the maximum safe level then there wouldn't be anything to gain from a reflash on a stock evo. Therefore, the stock boost does not make a good reference point when determining maximum safe boost.

-Paul

 

He has a point, your comment wasn't needed for what he asked. He didn't ask what is stock boost from mitsu. Thats like any car, the companies don't max out their potential. He asked how do you determine what is safe boost.

 

Now for your question, I really don't think there is a way to say you know what, if it hits 25 psi it is gonna blow unless you build it until someone actually pushes those limits.... Now tuning wise you can monitor temps, knocks etc, but to actually say how to determine it beyond that, such as blowing the motor it is really hard to tell.