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-   -   overboost protecion settings help (https://www.miataturbo.net/megasquirt-18/overboost-protecion-settings-help-60293/)

Clos561 09-07-2011 09:50 PM

overboost protecion settings help
 
i have my kpa max set at 55.2 which is 8 psi and that should cut me at about 11 psi correct? what do i need to put for the other settings?

hysteresis -
cut from x -
at y event -


also, i removed the egr tube, do i need to disable the valve in ts?

hornetball 09-07-2011 10:37 PM


Originally Posted by Clos561 (Post 768778)
i have my kpa max set at 55.2 which is 8 psi and that should cut me at about 11 psi correct?

Uhhhh . . . atmospheric pressure at Sea Level is 14.7psi (~100kPa). Check out your MAP gauge before you start the car.

8psi of boost is 14.7 + 8 = 22.7psi (~155kPa).

Clos561 09-07-2011 10:45 PM

what about the other settings?

ok, i understand the kpa now

hornetball 09-07-2011 10:53 PM

In MSPNP and MS-1, overboost only has the kPa setting. Not familiar with the more advanced MS variants. Sorry.

bmxfuel007 09-08-2011 12:16 AM

i think i read somewhere that kpa to psi conversion is kpa value, -100, and then divided by 6.895 is your psi rating

18psi 09-08-2011 12:28 AM

Wrong. But its something like -100 /7 or something.
OP just set the limiter at 160kpa and start reading up on the ms. if you cant set up overboost cut then you shouldn't be tuning the car yourself. And I dont mean this in an insulting way just trying to make sure you dont blow your shit up

bmxfuel007 09-08-2011 12:42 AM

oops, yup, divide by 6.895... not 10

hustler 09-08-2011 12:56 AM


Originally Posted by bmxfuel007 (Post 768831)
i think i read somewhere that kpa to psi conversion is kpa value, -100, and then divided by 10 is your psi rating

information provided most likely from the great braineack

https://lh5.googleusercontent.com/-D...5Q4/kpapsi.gif

bmxfuel007 09-08-2011 01:02 AM

yeah, edited. but then that also means I've been boosting way more than my boost gauge has been telling me..... hmmmmmmm :facepalm:

Techsalvager 09-08-2011 01:14 AM

in MS you are using absolute pressure in KPA.
When you turn the car to the on position, not started look at your MAP reading, its probably somewhere near 100, depends on your location. Anything above that value you saw before startup is what you consider boost

So when people ask how much boost you are pushing, you tell him 1 bar or 14.5psi that is gauge pressure. gauge equals absolute minus atmo

http://www.asknumbers.com/psi-to-kilopascal.aspx

18psi 09-08-2011 01:30 AM


Originally Posted by bmxfuel007 (Post 768841)
yeah, edited. but then that also means I've been boosting way more than my boost gauge has been telling me..... hmmmmmmm :facepalm:

Doesn't really matter.
If you're not running lean or pinging there's no real set limit or anything like that.

Clos561 09-08-2011 08:41 AM


Originally Posted by 18psi (Post 768833)
Wrong. But its something like -100 /7 or something.
OP just set the limiter at 160kpa and start reading up on the ms. if you cant set up overboost cut then you shouldn't be tuning the car yourself. And I dont mean this in an insulting way just trying to make sure you dont blow your shit up

This is all new thats why i want to make sure i set the overboost right. What do i need to input for the other values

Techsalvager 09-08-2011 08:45 AM

I'm just using 10kpa for hysteresis
0 for the rest underneath

Zaphod 09-08-2011 09:01 AM

How do you get an overboost protection, when you cut 0 from 0 ignition events?

I have i at cut 4 from 5 - other suggested 9 from 10 or such.

Braineack 09-08-2011 09:38 AM

I do 10 out of 10. Completely stops any ignition or injection.

I think when I did like 7 out of 10, you could keep the pedal mashed, and it would kinda bounce off the overboost like a rev limiter. I cut fully just so I know to take foot off go fast.

Techsalvager 09-08-2011 09:57 AM


Originally Posted by Zaphod (Post 768913)
How do you get an overboost protection, when you cut 0 from 0 ignition events?

I have i at cut 4 from 5 - other suggested 9 from 10 or such.

I have to look at what it does again, but I think it pulls back timing. It still works.

Braineack 09-08-2011 09:59 AM

sounds like that's all it would do...not really great protection...you should at least pull a few spark events to stop it from over boosting...you know, since we are tlaking over boost protection.

Techsalvager 09-08-2011 10:01 AM


Originally Posted by Braineack (Post 768932)
sounds like that's all it would do...not really great protection...you should at least pull a few spark events to stop it from over boosting...you know, since we are tlaking over boost protection.

it still stops it from overboosting, I know because I've flown into few times with this crappy boost controller

Clos561 09-08-2011 10:03 AM

ill run 10 of 10 then. do i leave hysteresis at 10? read up on it and hysteresis means that after the kpa drops x value the overboost will turn off?

so say im using 155 max kpa and my hysteresis is 10 the overboost will turn off once my kpa drops down to 145. is this correct?

Braineack 09-08-2011 10:04 AM

correct. it'll feel like a brick wall when you hit it, just fyi.


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