S15 Sr20det Injector Details Please .

[benl1981]

Any upadate on the latency for the S15 injectors? Is -0.06 the setting everyone else is still using?

Getting my tune tomorrow.

[Dale FZ1]

"Everybody else" still seems to be Birnie and myself.

I haven't changed any of the corrections, and it's still running just fine.

In the absence of information from any of the experts regarding what latency or lag time actually is, it seems that it is not a critical figure. The correction for flow rates, is.

[Birnie]

hah, yeah that's right Dale !

.....although Ben has joined the club too

Just check my settings as i forgot all about it since being tuned by The Hitman,

He has em setup as 72.0 % and +0.10 Latency?? Go figure.

As far as the 72% goes, i guess his full tune would be applied to that setting so i wouldn't advise using that as a temporary figure to get to the tuners......stick with the 82.5..it's a proven working setting, then let the tuner do whatever they want.

PS...The Hitman RULZ !

[STATUS]

Any upadate on the latency for the S15 injectors? Is -0.06 the setting everyone else is still using?

Getting my tune tomorrow.

444cc and 0.5 as i posted only a page ago

[benl1981]

I used the below and put in +0.06 as calculated. Also used the 82.5%. Tune done at MRC Castle Hill. Got a nice 247.4rwkw (18psi peak trailing back to 16psi).

Tough to test in the wet though. Spins from 4000up.

Good tune at a reasonable price.

Thanks Birnie and Dale.

How do I configure larger injectors?

Configuring larger injectors into the PowerFC is quiet simple and takes only a few moments. You need to know the following information before you can continue

Current injector size

Current injector latency

New injector Size

New injector Lag time

Injector Size and Latency (standard units)

Unit Size Latency

RB26 444cc/min 0.772msec

RB25 370cc/min 0.528msec

SR20 (Jap Spec Manual) 448cc/min 0.584msec

Nismo 480cc 480cc/min 1.100msec

Rx7 550cc 550cc/min 0.730msec

Aftermarket New Units 600cc/min 0.810msec

To work out new INJECTOR correction and latency;

Old SIZE / New Size = Correction

New Latency - Old Latency = Latency Correction

John plans to install 600cc injectors into his RB26 VL Turbo. The following figure's are used;

444 / 600 = 0.74 * 100 = 74.0%

0.81 - 0.77 = +0.04 msec

So he would enter 74% for correction and 0.04 as new latency

Once you have switched to larger injectors you should still check your AFR's with a wideband to ensure they are safe and acceptable.

For a list of common OEM injectors and their settings try here;

Injector Chart - Side Feed OEM

Injector Chart - Top Feed OEM

[stolen_s15]

Well I just purchased 6 of these things and will be getting them installed/tuned in the next month or so.

What duty cycle were yours on at that power level ben?

[benl1981]

i forgot to ask. When I plug the Hand controller in again (and when it's dry ) Ill do a few 2nd gear to redline pulls and check the peak.

He didn't say that they were close to maxing out but I reckon they wouldnt have much left.

Edited January 21, 2008 by benl1981

[STATUS]

i forgot to ask. When I plug the Hand controller in again (and when it's dry ) Ill do a few 2nd gear to redline pulls and check the peak.

He didn't say that they were close to maxing out but I reckon they wouldnt have much left.

best to check duty in higher gears. 2nd doesnt have enough load.

[benl1981]

Yeah I know, but I dont think Ill be able to check even 3rd gear above 5000rpm on the street.

[STATUS]

Yeah I know, but I dont think Ill be able to check even 3rd gear above 5000rpm on the street.

why? is it playing up?

[benl1981]

hahah. No it's just that im soft and prefer to keep my licence. Might be able to get a 3rd gear run sometime.

[discopotato03]

I thought I'd crunch some numbers about RB25DET injectors and larger direct fit replacements to put y'all in the picture .

Std - 370cc , S15 T manual - 450cc , Nizmo 555 and 740cc .

If you divide the std 370 by 450 555 and 740 you get 0.82 , 0.66 , 0.50 .

So I guess this means the S15 Terracotta coloured ones are ~ 18% larger , 555's are 33% larger , 740's are 50% larger .

I ended up buying new Nismo 555's from a member here which I reckon would be fine for my power requirements using PULP , trouble is if you ever decide to use high ethanol fuel blends such as E85 (if it becomes readily available) you need injectors approx 33% larger than you would with PULP to maintain chemically correct AFR's for E85 .

Where that leaves me is line ball (555's vs 370's and PULP vs E85) so in hindsight if I knew then what I know now I would have bought Nismo 740cc injectors .

Nismoid uses/used 740cc Nismo's I believe in an RB25 and had no issues at idle or light loads - on PULP ?

Cheers A .