Ok I see we are on the same page. I was just trying to clarify as not everyone that reads the boards has a deep understanging of the fuel system on this platform. I personally like the walbro pump over the sl55, it is capable of slightly higher volumes.
I'm still not sold in having to add an external regulator, as the fuel volume is regulated by fuel line diamater. The factory fuel line diamater is capible of flowing more liters per minute than this engine could ever use. Adding more pressure to increase volume is not a good idea, keep in mind that injectors are designed to operate at certain pressures, increasing those pressures only leads to bad things. A pump that is capable of maintaining 55ish psi is the most important thing, for this to happen a high volume pump is needed. Any extra fuel that is not used will be returned back to the tank via the filter. To summarize: First try a high volume, high pressure pump, if that doesn't solve the problem then increase injector size. Agreed?

 

Yes sir, we are on the same page.

I don't remember if the walbro was on the radar back when I had the SL55 installed. I know two other members had installed the SL55 before me with favorable results. My results showed an improvement but it did not fix the issue.

I considered the external regulator but came to the same conclusion as you. Especially since I was already taxing the stock injectors, adding more pressure was not ideal in my mind either.

I agree 100%.

 

May calcs show - at 6,000rpm sea level, 70F and 60% RH
Target AFR = 12.0
Injector values shown at 100% duty cycle.
Steve once reported our stock injectors are 450cc - I'm not sure if this is at 100 or 80% duty - I suspect 100.

SC Pulley........ Final MAP......... Fuel input per injector cc........ lb/hr/injector....... Snorkel Inlet Volume cfm
74.................. 13.7..................... 434................................... 41.4..................... 591
61.9................ 21.2..................... 550................................... 52.4..................... 748
65.................. 19.0..................... 516.................................... 49.1..................... 702
with a 178 crank pulley
Assumes no drop in SC performance - but there reportedly is.
65.................. 25.6..................... 616.................................... 58.7..................... 838

I think GG and Steve managed 22psi MAP with a similar stacked setup. GG noted lean issues and I'm pretty sure he simply solved it with the Fuel pump swap below.


Our Stock Fuel pump is the Pierburg - 7.XXXXX.XX.X ie: PENDING (will post when I find out)

The previously recommended Pierburg upgrade is the 7.00228.51.0
This pump is used on the
SL65 AMG 450kW M275.981
SL600 .....290kW M120.983 ........mfy 09.1995>08.2001
SL55 AMG 380kW M113.992 & 995 mfy 10.2001>>
S55 .AMG 265-368kW................mfy 08.2000>>
C55 .AMG 270kW 113.988..........mfy 02.2004>>
CL55 AMG 265kW 113.986..........mfy 09.1999>08.2002
CL55 AMG 368kW 113.991..........mfy 09.2002>>
E55 .AMG...................................mfy 10.2001>>

This data is avaialble via a 7.5MB download from http://www.armtek.ru/downloads/pg_.pdf
but you have to sift through the models - hence why I amalgamated above for convenience.

searching the forum many more walbro finding than pierburg's

 

In my signature there are two links regarding solutions for running lean. The first (181) was solved by adding the Pierburg pump. When I added a smaller SC pulley with the 181 (stacked) the Pierburg was no longer enough. At that point I added the 550CC injectors and was seeing plenty of fuel even at 23psi. Keep in mind, that's with stock fuel filter and fuel pressure.

- 181 Lean solution
- 185 or Stacked Equivalent Lean solution

 

There is lots of good info in this thread, someone should condense all the info and make it a sticky.

 

Great stuff.....lends cred to a "simple easily reversible upgrade setup...
65mm - 17psi - stock just makes it on AFR no retune necessary - within the capability of ECU
61.9/155 or 74/181 - ~18psi - upgrade to the 7.00228.51.0 and get a tune - ie: no need to change filter/reg.
65/181 or >19psi and you need to go with some 550cc injectors + fuel pump + tune but still keep your filter/reg. but your hitting 400-450 bhp and 300-350rwhp
HANG ON!!!!!

Apologies, if I have put any Walbro users off side.
good prices for a 7.00228.51.0 appreciated.
I found one in Aussie for AUD$375 here a little exxie for my taste tho.

 

This statement isn't accurate. There have been several here with 61.9mm pulleys that have removed them due to running lean even with the Pierburg pump.

 

Both the Pierburg and the Walbro flow about the same...The difference is the Walbro is less than half the price.

Anything above 16 psi should get bigger injectors. The stock injectors are maxed out with anything over 16, there is no room to tune after 16psi.

Correct sir, there is too much boost for the stock injectors to handle regardless of how much fuel you are giving them.

 

Also, the Walbro is noisier than the Pierburg and the Pierburg is noisier than the stock pump.

The Pierburg sounds as if you have the stereo on very faintly and forgot to turn it off.....seriously.

 

We don't even hear our Walbro....The straight exhaust may have something to do with that

 

Rob sent me a mail yesterday regarding the new map. He will ship it tomorrow with the leak tester. Next week I will do some test runs with the new map sensor , lets see if this solve my issue with the boost. I will also do a leak test and cross my fingers that Everything is airtight up to at least 1.8bar.

The only thing that could lead to low boost is that we have a leakage some where.

Will be back with logs and information

/Adam

 

If the car is running extra lean will the check engine light come on.

 

Not that I have experienced. I have seen some very lean conditions on the DashDAQ while trying to tune this car and have never set a code (besides excessive boost).

I won't chime in on the other stuff as my car hasn't run right in almost a year and I've tried most people's "winning combos".

 

ouch

a bit like starting the renos and 3 years latter wifey is still buggin you to get that bloody architrave painted!
speaking of renos - I wonder if Woody has swapped his passion for a paint brush.

 

I'm wondering if there's a better number to report/log than boost pressure since it's affected by so many things.
Intake and throttle losses, IC cleanliness, atmospheric prs, altitude, SC wear and obviously rpm

I believe there may be a g/sec fuel but that might only be a calc required value....????

 

I will do this in the next day or so. A 3rd gear pull is a little much for the traffic I have on the way home every day.



I installed an ultragauge and so far the timing is negative from -35 to -15. It gets closer to 0 and even went over a couple times with WOT/open loop, but stays in the low negatives most of the time. The LTFT is showing 7 after driving for a total 3 hours.

Is this saying anything? I am thinking I have a leaking injector or it isn't atomizing like it should.

 

Logged again today this time as Steve recommended.

93 degrees ambient, engine temp at 213 F, 93 octane

In manual mode while in 3rd at 2,000 RPM, the car downshifted as soon as I "stood on the throttle". I tried running the ultragauge while logging with zt-2 but the graphs were scrambled and it just didn't work. I unplugged the obdii port it the graphs were clean. I did another few runs without zeitronix and only the ultragauge and the timing starts out at -35 and slowly works its way up to about -4 before the upshift into 4th. LTFT is about 7 after the runs.


3rd gear pull

3rdgearpull_zpsb065b706.jpg


3rd gear pull shift into 4th

3rdgearpullshiftinto4th_zps604e6ee7.jpg

 

What should timing do and look like under ideal conditions?

 

Are you guys sponsored by petrol companies? much fuel must be used for all the testing. hope u all get it sorted.

 

I've reviewed this thread several times. There is a lot of great information here. I am moving toward installing the 62mm Karmen SC pulley (from Rudy), an SL55 high volume fuel pump, and larger 550cc injectors. The one piece of information I don't seem to find is where to get (what brand) are the recommended 550cc injectors. If they are OEM on a particular model Mercedes, I would like to know which model? Thanks for sharing your expertise . . .