e55amgrocket

I drove my car a couple times on just the 550cc injectors with the 175 pulley and when we did the first pull my AFR never made it to 10. I maxed the stock injector duty cycle out on a 175 pulley. Any injectors that are bigger will need a tune to rescale the injectors.

cahiil55k

No rails or injectors here. I've been running my "stage 3" setup for almost 30K miles now (since early '09).

cij911

How are you guys accurately capturing IDC ? I was told the logging applications could not capture IDC....

GT-ER

IDC must be calculated from injector pulse width and engine rpm. You can measure IPW with any scanner that supports mercedes PID's, such as Autoenginuity.

pearlpower

yep, have yet to read where anyone blew a 'good' motor after installing the injectors/rail.

cij911

Sorry I was told that to measure IPW accurately you needed to do so at the injector or with the Star equipment (I believe it has to do with CAN ). Furthermore I was told that a 175mm pulley with stock exhaust and stock TB would see IDC less than 75%....So I am at a loss....I don't want to risk my motor, but I really don't want to spend an extra $1k on injectors if they are not needed....

GT-ER

The IPW is calculated by the ECU and there is only one value to read, no matter the scanner, if it can read IPW then it is accurate. I don't know about the oem injectors staying at 75% or less on a 175mm pulley with stock exhaust, but I doubt they will be maxed out either.

Firechaser

although I'm a few weeks away from my first E55...I'm very familiar w/ forced induction cars. If the duty cycles are reaching upwards but not 100%, another alternative to get more out of stock injectors would be to get a fuel pump that flows more GPH. Often high IDC's are seen and immediately people jump to bigger injectors when the root problem is the fuel pressures start to drop on the top end because the pump cant keep up. Just my .02

GT-ER

While this is true, it is not the case with the E55. Larger injectors will take car of the problem.

alextaylor29

I've been running stock injectors and fuel rail with no problem. See sig for video for proof. Just cruious though, how much are new injectors and can I get another remote Jerry tune with them installed or do all of these mods combined require a detailed dyno tune?

Happy to by the Injectors from EC, they're fantastic.

The video below is the only time I've really, "Booted" my E55 so this probablly helps.

My current tune is silky smoothe and I get 21 MPG as well!

GT-ER

Their injectors are $845 on their site which include the remote tune. I have them and my car drives like it did stock and it feels great to see my injector duty cycles below 80% instead of the 100% they were below.

novae500

but if you have a EC tune, retunes are free for life!

loungn14

This!

Its not a pump problem. We have a ton of data like GT-ER is showing that the injectors are going STATIC. Plus as you know, how many cars can you put in 100whp and not change injectors? Fuel pressure is fine with the car, as we run very high pressure as it is...

you need to seriously look at your setup. The knowledge that we have about the engines now is night and day to what we used to you. You are risking your engine...

This has been proven independant of the software on the car....the hardware cannot keep up...

cij911

^^ But a 175mm pulley is fine with stock injectors ? It would be great if we could have posts showing IDC with mods....

loungn14

I guess it depends on your definition of fine as well as your comfort level with the situation. Temps also play a role in this.

Personally, I suggest injectors on any car with a 172mm pulley and another mod like headers or tb.

cij911

OK great ....I wonder why we cannot seem to get consistent answers...It really should not be hard. At a certain point, the fuel system cannot keep up...

I guess I need to call you today and change my order....

Forrest Gump 9

I've always heard the same too, but recently I have heard other wise. A local member told me that Jerry is charging him $150-300 for retune.

Just to clarify, $150-300 for a retune is still very cheap in my book.

loungn14

custom dyno tuning is never free, and that hasn't changed since day 1.

Reflashes are....

hope that helps!

Forrest Gump 9

Gotcha, thank you for the clarification.

loungn14

what problems are you having with consistant answers?

Big pulley with headers and tb= injectors

175mm no tb or headers etc = no injectors

That help?

jmb614

But in order to get the file tuned correctly it requires either datalogging results or custom dyno tuning. If you want to take a chance with a box tune on a highly modified car be my guest.

GT-ER

That is EXACTLY what I told him via PM...lol.

GT-ER

Yeah, I had mine flashed a few times to get it near perfect but even on the first flash it was very safe. I just want it perfect ( I think one more flash will get it there ).

cij911

Yes, thanks !

AMG E Power

Ok I'm just trying to get a clear answer because I want my car to be safe as possible. I just purchased a set of ev14 550cc injectors and no fuelrail. My mod plans r only EC tune and a 172 pulley and headers. I'm not even doing headers for another year so i will only b with a tune and pulley for a while. Will these new injectors do there job in keeping my car running safe on the stock fuelrail ? Also what would b a fair labor rate for install ?
Thanks in advance