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Fresh Alloy.com Thread On 740 Nismo Lag Times Etc .

discopotato03

By discopotato03,
in Engines & Forced Induction

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discopotato03 Grand Master

discopotato03

Posted
Posted

Hi all , on my mind ATM so this was interesting to read even though it involved 740's and a PFC on an SR20 .

http://forums.freshalloy.com/showthread.php?t=164058

If this is true then the lag times of std 370's Nismo 555's and Nismo 740's should be 0.58 0.71 and 0.66 ms .

One claim is that the PFC correction should be +0.08 .

Also been asking around for fuel settings to temporarily run my RB25 with these 740's - so I cam get it home once the ported cammed head goes on , logical to fit the injectors while it's in bits .

Cheers A .

rtune Experienced

rtune

Posted
Posted

I have a set of 740s nismos yet to go in and I'm curious what the summary of the topic

is as well..

someone has evidence that the latency reported by the pfc faq and everywhere else is

actually better set to a different number?

discopotato03 Grand Master

discopotato03

Posted
  • Author
Posted (edited)

The guts of it was that the original poster was changing from Deuchworks 740's to tomei 740's and couldn't get his SR20 to idle over 12:1 AFR .

One person suggests that the latency/lag time for Nismo/Tomei 740's is 0.66 ms and he thought the correction was +0.07 or +0.06 for the PFC . Says his buddy has tuned 10 SRs with Nis 740s and no probs .

Another person suggests 555s are 0.71 and 740s 0.66 , std 370s are 0.58 so correction is 0.08 .

At the end the original poster removes his 740 Tomeis and tries 740 Nismos and they work fine .

You don't find out what the problem with the Tomeis is but I suspect that their were two versions of the 740 available in the US fro Zeds . I seem to remember reading ages ago that some screwy engine needed possibly peak and hold instead of saturated injectors so the problem could have been an electrical one .

My 740 Nismos came in boxes with SR RB VG on the label so should be the right ones .

Cheers A .

Edited by discopotato03

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