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-   -   AFR's and Powah (https://www.miataturbo.net/ecus-tuning-54/afrs-powah-29979/)

what miata? 01-07-2009 09:27 PM

m2cup car and y8 are on point... i basically said it in my first post on this topic also....... also i talk to all my friends that work in the tuning industries, motec, efi tech all the time about the race cars and street cars they had played with and they all for street app 11.5-11.8 is best for street. im just getting into the boost stuff now with my own car and playing around. i use to work for a koni cup rx8 team in grand am and i did data acquisition and in charge of the mapping. i achieved 214 to the wheels on a stock rx8 intake and exhaust... and competing with speed source at the time when they were running koni st. anyways getting off topic set your afr's anything under boost 13.8 to 14.7 with the stock spark adv(not sure what 99 is but early 1.8 is about 29-30 at atmos) then pull .75-1.5 per lbs depending on turbo app (meaning size). then go to dyno play with load control (if the dyno has it) watch the live torque and add until it stops and back off a deg or two then go on to next cell. once you do a couple cells you kinda see where you are going and can guess the value close to narrow it down and waist less time...(granted its kinda scary on a turbo car with turbo spooling and waste gate opening). but thats the best way to do it. or the old fashion way.. full throttle pulls and keep bumping up that timming until you start losing torque or not gaining any and back off 1-2 to be safe. then scale your table according. man i could go on all day i got a pool match to go to.

good luck with the tune

patsmx5 01-10-2009 12:37 PM

1 Attachment(s)
Ok, I leaned out the AFR table a spec for off boost. It does drive a spec smoother I guess. The car definately feels like it "falls on it's face" when I'm first going into boost and AFR's hit 11:1. I'm gonna change that to 12.5:1 or 12:1 for the first few boost cells. I can tell 11.5:1 is hurting it. Anyways, what I'm running now:

Attachment 209172

m2cupcar 01-10-2009 01:21 PM

post up your ign map - afr is nothing without ign when it comes to making power from the afr

patsmx5 01-10-2009 01:28 PM

2 Attachment(s)

Originally Posted by m2cupcar (Post 351556)
post up your ign map - afr is nothing without ign when it comes to making power from the afr

Alright. I actually just made a new AFR table to try. It's a bit leaner everywhere, more like what everybody else runs. Here's the AFR table I'm gonna try and my timing table.

AFR TABLE:

Attachment 209170

Timing Table:

Attachment 209171

Braineack 01-10-2009 01:33 PM

is your cpu set at 640x480?

patsmx5 01-10-2009 01:40 PM


Originally Posted by Braineack (Post 351558)
is your cpu set at 640x480?

No idea what you're talking about. How do I check?

Joe Perez 01-10-2009 03:20 PM

That ain't the problem.

A normal 12x12 table gets rendered at 635x407. The ones he posted are 1024x651, including the whitespace. However it appears that they're being upscaled post-capture, due to the uneven stroke width (and antialiasing) of the text.

Pat, how are you doing these screencaps?

y8s 01-10-2009 03:34 PM

that's a lot of advance for 500 and 1000 rpm columns. does the MS use that table for idle? cuz if so, you're idling way advanced. and based on your AFRs, very rich. that lower left corner should be all 10-14 degrees and 14:1 AFRish.

Joe Perez 01-10-2009 03:41 PM


Originally Posted by y8s (Post 351579)
that's a lot of advance for 500 and 1000 rpm columns. does the MS use that table for idle?

Yeah, it does.

I think he discussed this earlier (or possibly in another thread) where he's deliberately running a lot of spark advance, and a super-rich mixture, in idle. He was tuning for max vacuum at idle, and that's the setup that achieved it.

Braineack 01-10-2009 03:57 PM


Originally Posted by patsmx5 (Post 351559)
No idea what you're talking about. How do I check?

I'm talking screen resolution, your screen captures are always insanely enormous.

patsmx5 01-10-2009 03:59 PM

I was using what brain said to do: Alt and then print screen. That copys JUST the window that's on top so to speak, rather than the entire screen. Then pasting it in MS Paint. Then making dragging it bigger so it's easier to read and doesn't leave a huge white space of nothing. Is there a better way to do this I assume?

As for the idle advance, I do that because I like how it runs. It's quieter, cooling fans run less and less chance of overheating at idle, more edgy. I get 23-24 kpa total map at idle when fully warmed up. And as Mr. Perez noted, I run these idle cells rather rich too because I don't have a working IAC valve, so when it's 20 or 30 *F out, it idles well.

Braineack 01-10-2009 04:07 PM

Select the corner little box on the edge of the white box (will turn into a double sided diagonal arrow) and shrink it down so it crops around the pasted image :P

patsmx5 01-10-2009 04:25 PM


Originally Posted by Braineack (Post 351592)
Select the corner little box on the edge of the white box (will turn into a double sided diagonal arrow) and shrink it down so it crops around the pasted image :P

Sweet! Didn't know you could do that. :noob:

So whatcha think of my AFR table now? Look more better?

y8s 01-10-2009 04:38 PM

it does look better. but there's no reason to run richer than about 13.5 below .001 psi.

patsmx5 01-10-2009 04:45 PM


Originally Posted by y8s (Post 351604)
it does look better. but there's no reason to run richer than about 13.5 below .001 psi.

Really? What brings you to say this? Most agree 12.5-13.0 is the best AFR for max power. Or is there another reason to run leaner than this seeing how it's boosted? Perhaps helps with spoolup? I'm curious as I've seen a few AFR tables that do run in the 13's up to a few PSI of boost, though that doesn't seem 'right' to me.

y8s 01-10-2009 05:19 PM

thought maximum N/A power/torque was at 13.2ish... but i'm only saying up to 100kpa, not a few psi of boost. I forget what mine is incidentally :)

edit: just looked and I'm a little leaner than I suggest. I probably could use some AFR updating, but I'll probably still aim for around 13:1 and no richer at 100kpa.

but it's too cold to go outside.

patsmx5 01-10-2009 05:33 PM


Originally Posted by y8s (Post 351620)
thought maximum N/A power/torque was at 13.2ish... but i'm only saying up to 100kpa, not a few psi of boost. I forget what mine is incidentally :)


To quote Abe in another post:


Originally Posted by AbeFM (Post 351614)
You can run a LOT leaner at 101. Unless you're NA and trying to make big power. Otherwise I'd run 15.5:1 at 100 kpa.

I think you can rescale, maybe that's only MS-II.

You're not the only one running 13's at atmospheric pressure. And I even see some running 13's up to a few PSI of boost.


As for 13.2 being the number, where did you get that? It's not too far off base from 12.5-13 that I've always heard. Just seems a bit too lean.

y8s 01-10-2009 07:24 PM

abe's nuts running 15s at 100kpa! Though Ben does run that lean up to about 80 kpa (Ben?) I seem to remember.

a google search turns up the 13.2 number various places.

patsmx5 01-10-2009 07:45 PM


Originally Posted by y8s (Post 351664)
abe's nuts running 15s at 100kpa! Though Ben does run that lean up to about 80 kpa (Ben?) I seem to remember.

a google search turns up the 13.2 number various places.

10% rich of stoichiometric. Reading up...

spoolin2bars 01-10-2009 08:15 PM

at steady cruising speed with very low throttle/high vacuum you should be at 14.5-14.9afr. as you near boost afr should be in the 13 afr range, a few psi of boost 12's, and full boost 100% throttle, i tune for 11.6-11.8 afr. only time i run 12.0-12.3 afr under full boost is at the track (drag racing). and i switch back as soon as i leave. your right about switching to 12.0-12.5 as you come into boost. 11.0 is way too rich at that point.


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