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p11 sr20de-t calculation K

Posted: Mon Mar 05, 2012 7:22 am
by JM
Hi,
i got p11, stock fresh sr20de, gti-r turbo, 370cc at 4 bars and stock p11 maf.

The calculation using 260cc stock and 427cc new makes something like 170K as new K, but the car runs very very lean with K so low. I changed the K to 210 to have 14.7 afr during cruising and it works ok for me. The car pulls ok. At 10-11psi it maxouts MAF and injectors both injectors and maf have their limits about 290hp. I can send a log anyway.. http://www.youtube.com/watch?v=fXUjEcUl ... re=channel

But tell me please why the K calculation is acting like that
thanks

Re: p11 sr20de-t calculation K

Posted: Mon Mar 05, 2012 7:59 am
by JM
attaching logs and bin. some pulls are downhill and some uphill, dont remember exactly:/

Re: p11 sr20de-t calculation K

Posted: Mon Mar 05, 2012 9:22 am
by Matt
K const calculation is quite basic. It takes 260/427 and multiplies it by the original K (287) to get 174

Suitable for most cars to get a decent starting figure but injection multiplier normally requires adjusting after this further to get the AFRs spot on, so where you have adjusted for 14.7:1 low-mid range is fine and then around 11.5 ish up top

Perhaps upgrade the MAF next, I wouldnt have expected injectors to max out just yet on that much boost. What duty cycle are they reaching?

Re: p11 sr20de-t calculation K

Posted: Mon Mar 05, 2012 9:41 am
by JM
over 100% while afr is 12.0 and maf voltage is 4.9v. fuel pressure 4bar, just checked. everything looks ok to me:) i just wanted to be sure about the K.. thanks

Re: p11 sr20de-t calculation K

Posted: Tue Mar 06, 2012 10:32 am
by Matt
No probs. I'm still used to injector size with 6 cyl RBs (dont need to be as big as with 4 cyl SRs)