latency

[curbcheck]

i got an email from deatschworks with info on my injectors. they sent it to me in ms. what is it in uS? is it 1200 uS ?
here is the email:

Hello

Below is the latency for our 550cc Nissan side feed injectors. 7v-17v in 1v increments, measured in ms




4.1
2.9
2.3
2.0
1.7
1.6
1.4
1.3
1.2
1.1
1.1

[TM_S13]

I think so... not sure though...

[Matt]

Nissan does its latency calcs @ 12V and then adjusts accordingly based on voltage change

so pick 1.6 ms * 1000 = 1600uS that you put in for the latency

[curbcheck]

Nissan does its latency calcs @ 12V and then adjusts accordingly based on voltage change

so pick 1.6 ms * 1000 = 1600uS that you put in for the latency

1600uS is way to high. I cant even get it to idle with that high of a latency. 800uS is the highest i can go with latency before it starts idling in the 10's. is there an equation i need to apply to the 1600uS before i input it into the tune that i am missing?

I've read that DW injectors are just reworked oem injectors to flow more and that you should use the stock settings for latency, 720uS

I also read that you are supposed to use this equation to get the proper latency for larger injectors
(latency in dec/ injector cc = x/ new injector cc) ( - latency / 2 + latency)= new latency
(72/270 = x/550) =146.6
146.6 -72= 74.6 / 2 =37.3 + 72= 109.3dec x10= 1093uS

then i also read that you take the suggested latency for your injector and divide in half. 1.6x1000/2= 800uS

and, why does nistune say that oem ka injectors are 275cc? I always thought ka injectors where 270cc.

[Matt]

Latency values normally come from the manufacturer

I agree those values are too high... especially the 4.1!

There is no calculation or formula. It is specific on the application

For 550CC I would expect about 800uS would be about right

We got provided with the CC and put that in the address file. Sometimes information out there varies but this one is minor CC change so wouldnt be too concerned about it

[Eric]

I found that most DW sidefeeds seem to have a latency of approx. 0.84 ms @ 14V

I have read somewhere that you have to multiply the numbers you get from DW with 0.64 to get the correct latency figures.
Seems to be correct in this case also...