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Old 01-14-2009, 12:13 AM   #1
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Default KPA Vs PSI?

Im currrently still running wastegate (7psi) so I have my fuel map scaled to 110. I want to add more boost in the next few days so I need to know what the max KPA I would need for say 15psi?


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Old 01-14-2009, 12:15 AM   #2
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15 PSI (relative to sea level atmo) is about 203 kPa. So go ahead and scale to ~220 or so to give yourself some headroom.
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Old 01-14-2009, 12:20 AM   #3
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Sweet, and then to fill in the rest is it best to divide the 220 by 12 and scale each row with the difference?
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Old 01-14-2009, 12:27 AM   #4
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I would a few rows around idle, then go on the pattern. Say 20, 25, 30, 34, 40, 60, 80, etc. Do some research on scaling them. I keep all my maps scaled the same (cept VE cause it's 16x16) so that it's easy to read them and they're all similar. And I keep the number simple too. And when looking at a datalog, if I'm smack in THAT cell in VE, I was in that cell in my other tables as well.

Meh, scratch that. Here's how I scalled my 12x12 tables. Copy me.


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Old 01-14-2009, 12:30 AM   #5
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Meh, take it back again. You want a few extra rows around idle IMO. That layout for spark and AFR works good though. I have 16x16 fuel tables, but this is what I did.


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Old 01-14-2009, 12:40 AM   #6
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Well, DIY has observed that more resolution is required at the lower part of the table, to provide more precise control at light to moderate cruise. Here's how theirs are scaled. I tend to agree with them. Mine's still linear, and I could use some more resolution down there:

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Old 01-14-2009, 12:49 AM   #7
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I scaled my map for cruising resolution....

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Old 01-14-2009, 11:01 AM   #8
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Quote:
Originally Posted by levnubhin View Post
Im currrently still running wastegate (7psi) so I have my fuel map scaled to 110. I want to add more boost in the next few days so I need to know what the max KPA I would need for say 15psi?


Thanks
google "15 psi in kPa" and add 101 (atmospheric pressure) to the result. teach a man to fish, right?

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Originally Posted by patsmx5 View Post
Meh, take it back again. You want a few extra rows around idle IMO. That layout for spark and AFR works good though. I have 16x16 fuel tables, but this is what I did.

pat, when you open up MS Paint to paste in your screen cap (AFTER you've hit print screen), go to the Image menu and select attributes. set it to 50 x 50 pixels. THEN ctrl-V.

I BELIEVE it will save the image attributes for next time. yay!
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Old 01-14-2009, 11:14 AM   #9
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Originally Posted by y8s View Post
google "15 psi in kPa" and add 101 (atmospheric pressure) to the result. teach a man to fish, right?


Thanks, I was wondering why I was getting such low #'s. I didn't know to add the 101.
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Old 01-14-2009, 11:20 AM   #10
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kpa = psi * 7 + 100


FWIW, I have zero issues fueling with only 3 boosted rows in my map. Watch a log in boost and see why.
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Old 01-14-2009, 11:24 AM   #11
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Old 01-14-2009, 11:37 AM   #12
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Yeah, yeah, I got it now. That an old pic from when I didn't know how to crop.

If anything, on spark, i'd recommend you have a few extra columns for RPM between idle and 3K. I my redo mine. 500 RPMs isn't perfect for me.

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Old 01-14-2009, 12:37 PM   #13
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Quote:
Originally Posted by Braineack View Post
kpa = psi * 7 + 100
6.895, actually.

For folks who have trouble with converting units, OnlineConversion.com is a great website. They have calculators for every combination of mass, weight, volume, speed, temperature, pressure, density, etc imagineable. Need to convert between parsecs and Egyptian cubits? They've got it. Got a map that's scaled in zeptobar and need to convert it to torr? They've got it. Want to find out how much you weigh in Thai baht, stones, or aincent Hebrew tetradrachm? Yup.
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Old 01-14-2009, 02:05 PM   #14
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Quote:
Originally Posted by Joe Perez View Post
6.895, actually.

For folks who have trouble with converting units, OnlineConversion.com is a great website. They have calculators for every combination of mass, weight, volume, speed, temperature, pressure, density, etc imagineable. Need to convert between parsecs and Egyptian cubits? They've got it. Got a map that's scaled in zeptobar and need to convert it to torr? They've got it. Want to find out how much you weigh in Thai baht, stones, or aincent Hebrew tetradrachm? Yup.

I am going to meet Joe at a meet one day and he's going to be the guy standing in the background, explaining some absurdly complex blinker switch to some poor new guy, and every 30 seconds he will push his coke-bottle glasses just a little bit back onto the bridge of his nose.
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Old 01-14-2009, 03:12 PM   #15
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Quote:
Originally Posted by Savington View Post
I am going to meet Joe at a meet one day and he's going to be the guy standing in the background, explaining some absurdly complex blinker switch to some poor new guy, and every 30 seconds he will push his coke-bottle glasses just a little bit back onto the bridge of his nose.
lmao.


Question on scaling the KPA numbers...if I scale it down like you guys are suggesting, how do I create VE numbers that will allow the car to run OK until I log some more? or will it attempt to scale them too?
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Old 01-14-2009, 04:00 PM   #16
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Quote:
Originally Posted by miatamania View Post
Question on scaling the KPA numbers...if I scale it down like you guys are suggesting, how do I create VE numbers that will allow the car to run OK until I log some more?
By hand. Use your eyes and brain to interpolate between existing cells and then enter the resultant values into the new cells.


Quote:
Originally Posted by Savington View Post
I am going to meet Joe at a meet one day and he's going to be the guy standing in the background, explaining some absurdly complex blinker switch to some poor new guy, and every 30 seconds he will push his coke-bottle glasses just a little bit back onto the bridge of his nose.
Hehe.

The funny thing is that my eyes are about -4.5DV, so in the days of old, I did in fact have marginally cokebottle eyeglasses- the lenses were over 1/4" at the outer edge. God bless modern high-index refractory materials.

Last night, a co-worker and I were having some discussion about the likely direction of Obama's energy policy, and what impact this might have on the clearance rate of pending construction permits for proposed new nuclear reactors. Larry's kind of a paranoid sort (we're about 10 miles from the San Onofre nuclear plant here) and he starts asking questions about TMI, Chernobyl, etc.

By the end of the conversation, I'm rattling off into void coefficients, the inherent problems of graphite moderation in light water reactors, the different between supercriticality and prompt criticality, the Windscale fire, SL1, pebble-bed reactors, breeding, "thermal" vs. "fast" neutrons (and how they're like rolling a ball across a busy road vs. shooting the ball out of a potato gun across the same road), why CANDU is cool (because it permits the use of plain ole' uranium ore, and can actually run at full power entirely on the unrefined waste product from other plants), etc etc., and at some point I think to myself "How the hell do I know all of this ****? I never studied nuclear engineering, and frankly I tried to avoid physics as much as possible."

From a purely objective standpoint, I'm guessing I probably fall into that category of "just enough knowledge to be dangerous."

And yeah, I have to be really careful not to bore the **** out of people at parties.
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Old 01-14-2009, 04:01 PM   #17
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drive with one hand on the wheel, one on your laptop. One eye on the road, one eye on both the laptop and AFR gauge...


or log on your way to work and analyze and reload the map on the way home and log again....
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Old 01-14-2009, 04:02 PM   #18
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Is there anything you don't know something about? Seriously.
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Old 01-14-2009, 04:17 PM   #19
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Is there anything you don't know something about? Seriously.
Love.
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Old 01-14-2009, 04:28 PM   #20
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Love.

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