F1BHP

So which injectors do you go to next after the 550's

kponti

^^Good question

Hulk

Unless going to E85 very much doubt you will need more fueling.

Fastest no nos E55 10.50 @ 132mph

Fastest nos E55 10.39 @ 134mph

Both are on 550cc injectors

F1BHP

Does anybody know what the stock injectors are in the sl600 and when they need upgrading.

chawkins2001

550cc and looped rail is more than enough when you are approaching 500rwhp and above. 650cc is good to but once you go above 700cc, if they are not ID or equivalent high end squirtters, you will start to have drivability issues.

I was on 1000cc inj for e85, and drivability suffered.

T9ja

So, 172mm c/p, 84mm s/c pulley, kleemann headers, x-pipe will require a 550cc injectors? Another mods to worry about.

kponti

Are you saying each of those mods will require larger injectors or a combination of those mods will require larger injectors? I will agree with the latter but not the former

F1BHP

I am still trying to find out the details of my injectors for a 2010 sl600. I would like to know what the specs are as standard and secondly when I am doing my engine mods will I need to upgrade them and if so at what power level and what injectors would be a recommended upgrade?
For some reason i can't find this info on the forum and I am wandering if it is because the stock injectors are sufficient up to much higher power and boost levels therefore no upgrade is needed. I would be gratefully if anybody has any insight into the 5.5l v12

1ForcedBenz

The stock injectors in the 600's that I've sent out and had tested were 39lb. Pretty much after an aggressive tune and maxing out the breath of the stock turbos your about at the limit of the stockers. A 600 with 65 turbos bolted on it and tuned is max duty cycling the injectors for my experiences.

F1BHP

Thx. forcedbenz so what your saying is with an aggressive tune with intake mods but stock turbo I should be ok with stock injectors. Is this correct?

1ForcedBenz

Yeah, you'll be pushing them if you have down pipes, intake setup, and a stout tune. There's definitely power to be had by upgrading them even before you max them out. They tend to max out in the 2800-4000 rpms where the torque curve is at its peak. And FYI 39lb injectors are equivalent to approx 409 CC's incase you were wondering.

F1BHP

Ok so 409cc that is what I was looking for. I do have 3" downpipes, speedriven I/C and upgraded H/E and pump with Scorpion intakes, also trunk tank. I need to get an updated dyno tune from Eurocharged but by the sounds of I should do the 550cc injectors first. Does anybody know the part numbers and best place to buy the injectors that will work with the V12.

GregMB

Q1: How many miles are on your car?
Q2: Have you ever replaced the original fuel pump? (MBZ requires this to be changed at 60,000 miles)


Injectors are an important topic, but so is fuel pressure and flow. If you are running the original pump (and fuel filters) the pump is pushing against a clogged filter and creating lots of pressure but very LITTLE flow to those injectors.

If you go with larger injectors without confirming that you have adequate fuel volume from the pump to feed them, they will simply empty the fuel rails faster and you will still end up with a lean-running engine.

I know this is common-sense, but the E55 is not a new car anymore..... you can't assume that the fuel system is perfect, or that the previous owner did the required pump/filter services.

If there was a silver lining to the whole "E55 FUEL LEAK" issue.. it's that it forced a lot of guys to swap out pumps/filters that were in terrible shape and helped them find melted wiring harnesses too. Probably prevented a few blown motors as well.



-G

1ForcedBenz

There are quite a few options out there these days, any injectors that fit the 55k engine will fit the M275 engines. So pick the cc/lb injectors you want that are known fitment for the 55's and there ya go "IE 550cc EV14 injectors". The 55k injectors have the same install height and o rings. You should have all the info you need at this point to make a selection if and when you decide to swap em out.

T9ja

Combination of those mods. Also, adding a TB to the list.

uraberg

I'm with Greg. A lot of people will just throw injectors (or a looped rail) on the car, without having any idea what their fuel pressure during a run is.

In the case of a looped rail, if you suspect a significant pressure drop to cause #8 to go dangerously lean, that the proper solution is not a looped rail, but an increase of flow from the fuel pump. A rail may even things out a bit, but it is a band aid. (I know this has not been part of the discussion, but I'd like to draw some people in about the usefulness of a looped rail)

In the case of injectors, considering the price of this particular mod vs lets say long tube headers, it is actually a no brainer to add, if you're going to mod anyway, but it is completely pointless if your tired fuel pump and your clogged filter are unable to keep up.

The short answer is; There is no short answer. But replace injectors sometime after you've checked the fuel system, and before they become a necessity.

kponti

Fuel sending units and pumps replaced 30 to 40k miles ago

kponti

I do understand there is more to fuel than just injectors. Built enough cars to know that. I am not looking at this from a my circumstance only. This is theoretical with a dash of real world question.

So that being said.... Assuming brand new pumps and filters... At what power levels or what boost levels will the need for larger injectors present itself on the 5.4 supercharged AMG setups.

Hulk

Fuel pumps are very important and goes hand in hand with monitoring AFRs, hopefully if this whole inline filter works out the pumps will last much longer

boostedfe3

Hulk, I forgot to mention I also installed dual aem 320lph pumps at the same time when I installed the inline filter. Have not had a chance to monitor afr yet. Installing kleeman headers today.

kponti

While OT, I will love to see how that was done, if my pumps ever go again, I will be looking at this option with an inline filter. For now just the inline filter will suffice

Hulk

curious if the inline would work with the stock pumps

kponti

I believe Craig from BIP said yes to that. He already has that on his setup

Hulk

Craig had the aem pumps at one point so I don't know if he went back to stock or stayed with the aem again

kponti

11-13-2014 08:42 PM by chawkins2001
Yeah, I have dragbodys crank to repair, but you can get rid of the stock filter and add a inline. been on my setup for months with a return fuel line. runs and drives like stock.

Yesterday 09:17 AM by chawkins2001q
you dont need a return line, I just did it for my application.