440cc/3bar injectors potential

[Rocco]

the same old good rule of thumb for 5cyl operation here is that the injector rating of ccpm at 3bar is *broadly* a good guide for the max power when running at 4bar - as long as you remember that yields a slightly optimistic result.

320cc ==> 320bhp
360cc ==> 360bhp
440cc ==> 440bhp

Thats just an accident of how the numbers work on the 5cyl

it seems a "nice" easy rule for our 5 cylinders using 4bar FPR

thanks Paul¡

soo seeing this ....with 90%DC could be normal 430hp?

[Billman]

Answer from Bosch on the question from a German forum

[Billman]

Answer from Bosch on the question from a German forum

According to this rule of thumb none of the chip tuned rs2 should make more than 350-360.....however real world experience shows otherwise.

I think Rocco got his answer from Paul a above.

[prj]

Injectors are not hp.
Never forget that anything that allows you to run more timing will allow you to have more power.

But most tuned RS2 setup cars do not make much over 360hp, even if dyno shows otherwise
Anyway, can argue back and forth all day. RS2 turbo is usually enough to max out RS2 injectors at 4 bar pressure, and RS2 turbo does not flow enough for 400hp on stock CR and straight pump.

[Ross]

What is considered the best injector for the 400-420hp range? I'm looking at the Bosch '558 Ford Racing 440cc but can't find a decent set... seems to have impedance @ 14.5 Ohm and 4-hole spray pattern as per RS2. The Bosch '968 'Green Giant' Volvo S70 injector is rated at 450cc but 12 Ohm... same spray pattern too; still a good match or could this cause problems?

My RS2 injectors are at 375hp, not sure of the exact duty cycle but gfrom Mihnea's comments and general consensus I think that's as much as they will safely deliver.

[prj]

Volvo injector is 415cc @ 3 bar. It won't flow more than ~410hp assuming pump gas. Most sites advertise them wrong.
150 558's are NLA.

[Ross]

Not according to this link?

http://www.fiveomotorsport.com/produ.../?p=0280155968

415cc will be fine though, i need ~400 with a little head room.

[Thuppu]

What is considered the best injector for the 400-420hp range? I'm looking at the Bosch '558 Ford Racing 440cc but can't find a decent set... seems to have impedance @ 14.5 Ohm and 4-hole spray pattern as per RS2.

I bought mine from here: http://speed-autoteile.fi/index.php?...&product_id=58 You can always ask if Teppo ship to other countries.

[karlblues2]

Ok. This is timely! I have just received my GT3071R (0.63 AR) turbo kit from 034motorsport and 5 x 42lb ""High Impedence"" Green tops.

What is the difference between the high and low impedence values and is the 42lb equal to the 440ccm used in their chip tuning kits?
I currently have an MD147 and 386ccm RS2 oem injectors fitted and a 4bar FPR.

I will be using the MTM copy chips from Brams old setup
Are the injectors correct??
Cheers in advance
Karl
Oz

[prj]

Not according to this link?

Most sites advertise them wrong.

is the 42lb equal to the 440ccm used in their chip tuning kits?

There is more to an injector than flow. You also need to know latency to tune correctly.

I currently have an MD147 and 386ccm RS2 oem injectors fitted and a 4bar FPR.

RS2 injectors are ~360cc at 3 bar, not 386.

I will be using the MTM copy chips from Brams old setup
Are the injectors correct??

No one knows, that's why you don't do silly stuff like copying chips on higher power setups.
Could be ok, could run pig rich and not make any power, could run too lean and blow up your motor.

3071R with 0.63A/R on stock head might have some surging issues as well in higher gears, so needs careful mapping.

Get your car custom mapped, 400+ hp is not baby power anymore on these engines, things can go wrong easily.

[S2central.net]

You can get refurbished proper 440cc (150 558) injectors from some sources - but I would advise you only do so with an ASNU flowbench report on them.

Dmitri and I have been looking at the Volvo 415cc injectors as an alternative (150 968) - these seem to be broadly called the 'green giant' and are often advertised as a 440cc/42lb injector incorrectly.

We are hunting down the latency information on these Volvo injectors at the moment... Long story short I even had to learn a wee tiny bit about ME7 in this process. There are other suitable looking injectors around, but they cannot be used blindly as the latency/lag characteristic varies widely sometimes. That and there is a fuel pressure related aspect to it as well.

100% agreed with Dmitri that custom mapping is the only way to safely go with anything other than factory injectors.

[Rocco]

it´s crazy to think about use ramdom chips in $$$$ engine projects ¡¡

[Billman]

What is this injector latency? Why do you need it?

-ok found it- knew it with other term

You need it on motronic because you adjust fueling by changing inj dc.

[prj]

Wrong.
You need it on any ECU to have correct fuelling, especially at low pulsewidths, where dead time can even exceed ipw.
Basic tuning 101.

And what's this???

You need it on motronic because you adjust fueling by changing inj dc.

Technically on every ECU you adjust fuelling by changing IDC.
On Motronic all fuelling is target lambda and it calculates IDC or more correctly IPW to get you there.

[prj]

And why it is so important in tuning?

In a mass-flow system if you have the wrong Injector offset (TVUB), your target lambda table will look messed up. It will not be correct... if your offset is too low, then on low IPW's your lambda table will be way leaner than actual.
If you only adjust injector constant, you will either overfuel down low or you will underfuel up top.
And now if you screw up your target lambda map, so actual does not match requested, when you change your injectors you have to start over again... not to mention huge problems with closed loop correction.
When you tune correctly, changing injectors will only mean changing latency and injector constant, and not touching the target lambda table at all.
Most Motronic tunes request 18 AFR, because people don't know how to scale to injectors .

Now, let's go to speed density systems with WBO2 feedback.
In a speed density system you do not know engine VE. So you use WBO2 feedback to tune engine VE.
Now, if you don't have injector offset set correctly, your injector offset gets coded into your VE table. That means when you change to other injectors, that have sufficiently different offset, you will have to re-tune VE table, or your ECU will get target lambda wrong.

This is VERY general. I am not talking specifically about VEMS or Motronic, but about Speed-density and Mass-flow.
Every system has their own name for injector offset/latency, but I have not seen a proper system without it.

EDIT:
Good article on injector latency:

http://www.injectordynamics.com/GMDATA.html

This is also why DEKA's suck. minipw = 1.5ms.