Best injector dead time for 1991 Miata

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Best injector dead time for 1991 Miata

Postby quixotic » Mon Nov 12, 2012 12:30 pm

Sorry. Tried to upload the datalog and wound up with two posts.
Last edited by quixotic on Mon Nov 12, 2012 12:51 pm, edited 1 time in total.
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Best injector dead time for 1991 Miata

Postby quixotic » Mon Nov 12, 2012 12:32 pm

evan n0v.msl
Any suggestions?

On the base map that came with my MSPNP2, the injector dead time is set at 1.3 ms. But with that, my afr’s are quite low (eg, 11.5 at warm idle). On the miata.net forum, I’ve been advised to re-set the injector dead time down to 0.8 ms. I’ve also been advised that 0.8 ms is way too low (which also makes sense, since I had to richen up my idle, because it was so chunky).

I’ve been compensating either way by adjusting the VE table and/or using the autotune feature, but in point of fact, even after reading books by Banish and Cramer and Hartman, I still only have the vaguest idea of what I'm doing.

I should also note that this is just a daily driver, naturally aspirated with the usual intake and exhaust modifications.

Evan
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Re: Best injector dead time for 1991 Miata

Postby techsalvager » Mon Nov 12, 2012 7:47 pm

I have yet to see a tune file from you after and before changes here and on miata.net
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Re: Best injector dead time for 1991 Miata

Postby Matt Cramer » Tue Nov 13, 2012 6:17 am

Dead time is not what you should use as a primary tuning tool - it should be set so that you have the same AFR with several different injector staging settings, and left alone after that.
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Re: Best injector dead time for 1991 Miata

Postby nextproject » Tue Nov 13, 2012 2:23 pm

Hey matt, in regards to my tuning (posted here a couple threads away as well as on MR2OC) should i attempt lowering my dead time? what would you regard as a good starting point? lowering from 1ms to, say, .99ms? and then switch back and forth between 2 squirts and 4? and continue lowering it until the AFRs dont change much when switching between the two?
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