PFC settings for S15 injectors.......

[USRB25S13]

I will be installing S15 injectors in my RB25 and I was wondering what changes need to be made to the injectors lag/accel time to get it to run.

[Guilt-Toy]

Work out how bigger the injectors are to a % range. Get a lend of a Wide band Oxygen sensor and set your injectors to run at %80 take it for a drive and see how the fuel mixtures are.

Look in Setting and then "INJECTOR" set the first values on all 6 injectors to %80 and see how it runs

[USRB25S13]

Well The good thing is I have a wide band on my car all the time. But as for the lag time is that going to stay the same?

[yogi000]

there is a ap engineering site that expresses the base fuel pressure and timings (lag...response...etc) for most of the nissan injectors.

side feed

http://www.ap-engineering.co.jp/el/inj_side.htm

top feed

http://www.ap-engineering.co.jp/el/inj_top.htm

Cheers

[knore]

Well ive done some research into this;

i think its;

370/480 = 29%

meaning the larger injectors will flow 29% more fuel at all rpm points than the standard injectors. So lean all maps out by say 25% then tune from there.

[32vspecII]

i think s15 injectors are 440

[Targa Tom]

i think s15 injectors are 440

...@ 2.55bar. Which is standard Nissan fuel pressure. Top feed for top feed and then they should be drop in replacement.

The only other base change to begin with is as per attached pdf.

Hope this helps,

TT

[SLY33]

knore your right, but youd be doing 480/370 x 100 to get 129%, meaning 29% more flow than the 370cc injectors.

i hope this is right as ive just done this for my 555cc's. 555/370 x100= 148%

so im getting ~50% more flow, i set all my injectors settings to 50, from 100.

car started and runs fine, tuning getting done monday.

[Targa Tom]

knore your right, but youd be doing 480/370 x 100 to get 129%, meaning 29% more flow than the 370cc injectors.

i hope this is right as ive just done this for my 555cc's.  555/370 x100= 148%

so im getting ~50% more flow, i set all my injectors settings to 50, from 100.

car started and runs fine, tuning getting done monday.

The Old ie 370/(new) 440 = .84 or 84% remember it is a correction from OEM to new.... you are telling the PFC to deliver less.

The lag is done by subtracting specs. eg new - old .73 - .64 = .09 lag

You might have to knock back your lower air flow voltages if its messy down low

Hope this gets you started...

You are doing stuff for pros or people who are responsible for their own actions... if you are not one of these, get someone who is!!

6 cylinder grenades are expensive

TT

[SLY33]

apologies, i just re-worked it out, i had it wrong~!

[knore]

The Old ie 370/(new) 440 = .84 or 84% remember it is a correction from OEM to new.... you are telling the PFC to deliver less.

The lag is done by subtracting specs. eg new - old .73 - .64 = .09 lag

You might have to knock back your lower air flow voltages if its messy down low

Hope this gets you started...

You are doing stuff for pros or people who are responsible for their own actions... if you are not one of these, get someone who is!!

6 cylinder grenades are expensive

TT

Cool so manual S15 injectors ARE 440cc?

Im going to be using s15 injectors on my RB25 with just an SAFC2 and SITC..

We worked out ill need to lean back about 18% across the board to get it running alright, then take it to the dyno for futher tuning.. is this right?

Also, seeing im adding a Z32AFM, im unsure as to how much but wont this lean across the board compared to the standard RB25AFM?

I need to work out how much the Z32 AFM will lean mixtures out compared to the standard rb25 afm..

440/370 = 18% richer - (amount the Z32AFM leans out) = ?

If you could help it would be great, i tried to work it out in the below thread

original thread is here: http://www.skylinesaustralia.com/forums/sh...&highlight=SITC