FoundSoul

iTrader: (5)

That's what I had thought too originally, but I had based the 230cc off the FAQ... so I can do some digging, but which is it?

Here's the DIY Turbo FAQ entry on it:

Taken from https://www.miataturbo.net/diy-turbo-discussion-14/diy-faq-all-your-answers-one-big-post-4288/

Braineack

iTrader: (62)

those numbers have been verified from a number of sources.

now if jerry can only solve my issue.

devin mac

iTrader: (2)

have you noticed much of a difference with MAT only, CLT only, or averaged?

seems to me that if your intake temps are 50, and the coolant is 190, averaging them would put you in a spot where nobody's happy... i'm just supposing, though.

Braineack

iTrader: (62)

no its clt only, i think i want to try averaging them.

devin mac

iTrader: (2)

yeah, i was thinking about that the other day, when mentioned that i fired the car up with 43* CLT and 60* intake, but then later couldn't fire it with similar CLT and 40* intake.

richyvrlimited

iTrader: (1)

i've read that FAQ a lot and never noticed it quoted different numbers than what I'm used to.... hrm

ah well always happy to be proved wrong

FoundSoul

iTrader: (5)

Don't know if I can magically solve anything-- but I'll surely try and help

Firstly I don't know that i'd average IAT and CLT for this-- the engine temp is much more critical for this calculation. If you're averaging the two, and IAT is at 50 while CLT is at 190, you need a tiny little PW to start the car, but you're getting a much bigger one because the averaged in IAT reading in bringing the temp used to calculate cranking PW way down to a much lower temp, where a much higher PW is commanded, instantly soaking your plugs and flooding you out.

That would be my theory anyways...

FoundSoul

iTrader: (5)

Me too-- much better to be proved wrong, learn something from it and be better off the next time than hardheaded about it and dumb forever right?

I had always used the 205cc value before on the 1.6 and 230cc on the 1.8, probably just forum misinformation which is all too common, and manufacturers really don't make this type of info the easiest to come by alot of the time. This is actually part (not all) of the reason why the AFR number used to set REQ_FUEL when scaling to different injector sizes on the MSPNP MM9093 and MM9495 isn't 14.7-- I had to account after the fact for the true injector sizes so it would scale properly for you guys. It won't change anything though as long as it's consistent.

Braineack

iTrader: (62)

i guess ill try lowering the PWs a tad more and turning off the priming pulses.

Braineack

iTrader: (62)

that seemed to have worked. i drove home and parked and waited untill 100* playing with my ait based corrections and PWs some more got it to start everytime from 80* to 108*

hopefully it will do the same tomorrow at 190* CLT and 50* intake.

Atlanta93LE

iTrader: (5)

So...what 1.6L injector size did you use to rescale the diyautotune cold start pw values?

FoundSoul

iTrader: (5)

Actual injector sizes will apply for this as it was tuned with the actual factory injectors in the car, so 230cc for the 90-93, and 265cc for the 94-95.

FoundSoul

iTrader: (5)

Glad to hear it looks like you've made some progress Scott--

Atlanta93LE

iTrader: (5)

Thanks very much! Exactly the info I was looking for.

Braineack

iTrader: (62)

they also use 13.7 as the afr multipler, however, iirc.

cjernigan

iTrader: (13)

Anyone know why DIYs cranking/prime table counts down until it reaches 40F then it jumps up again and then continues counting down versus counting down the entire time?
This might just be an error of me not having MT setup to read their MSQ but I don't think that the values themselves would change because of that.

Jerry, what kind of AIT related air density have you used on turbo cars? Just curious if you have a table to share.

neogenesis2004

iTrader: (12)

It never got below 40* in Atlanta, so they couldn't tune below that.

devin mac

iTrader: (2)

i ended up cutting the DIY cranking values down, by multiplying them by 75%, and so far so good. only tested in 50* temps so far, though. tomorrow morning i should get a solid 40* startup try, so i'll see how it works tomorrow morning. optimistic, though.

cjernigan

iTrader: (13)

hahahhaha That's right, makes sense, i didn't think about that.

devin mac

iTrader: (2)

heh, i had the same thought as you, cj. then the "oh yeah... atlanta... 40deg..." thought hit me, too.