Exotic-metal55

Wanted to do live road test VS dyno and make sure I was under real time load.. It is 90 deg and the DA near 3000 ft these days, so in cold weather fuel demand will be higher..

I filled up with gas (23 gallons) to help get traction but no help.. Pulled out of station and rolled into it at 30 mph and spun like crazy. Saw pressure pressure drop 10PSI and I let out of it.. Then did two rolls from 45mph (bottom of second) ,, Pressure looked to hold, then at 5K is dropped like a rock to 65-68 PSI. As most of you know, a 2-3 psi drop is bad but this much is a serious problem..

I suggest anyone with most the bolt ons, check fuel PSI ASAP and do what you need to do to keep your motor safe.. This test took less that 20 minutes to hook up gauge and do a couple quick driving test..


This is just a fuel gauge taped to the wiper test.. Don`t laugh, it works well.. Idle and cruise pressure shows to be 78.5 ish on this gauge..




I am going to ADD a Bosch inline 44 pump to replace my stock inline pump and then re-test pressure..

shardul

iTrader: (1)

nice work, thanks for sharing valuable info!

bassn_07

Nice Brooke and thanks for sharing the results!

I also see the same conditions but never had anything to really compare it to. I would really like to see what a stock E55 does, I bet we'll still see a slight drop.

Exotic-metal55

Thanks Shardul. We will check yours and Hadilaw car next..


I would assume our pumps (although different) are rated pretty close in flow capacity. No need on us working on injectors, until we can hold solid stable PSI.. Good news is, that a pump may fix all our fuel issues up to our mods HP range.. I have an extra 8% fuel added into my tune above 5K and when I hold 78-80 psi, going to be filthy rich! So, will have to re-tune to level out the A/F again.

bassn_07

The good news is that tuning should be much easier with a steady supply of fuel. The bad news for me is that so far there isn't an easy fix for my platform. Man, you would think a supporting vendor would get involved and try to help resolve this issue. It seems obvious to me that this now a problem for few and soon to be problem for many.

I now have 55k on my motor and I think it's time to replace my pump and filters. I know of a member that was having some severe fuel issues and after replacing most of his fuel system he no longer starved for fuel. At this time this might be my best alternative until someone gets a boost-a-pump to work in our cars.

Ghostrider

There has been some discussion and I would start with a Kenne Bell Boost-a-Pump. From my research, it may not be the fuel pump but the voltage feeding the pump that decreases, especially at WOT. As the voltage decreases so does the flow of the pump

Forrest Gump 9

That's very nice to know. Btw, what is the stocker flow rate at? Wonder if there are some easy drop in upgrade (Porsche 911 turbo?).

bassn_07

This makes sense and that's why I'm curious to know what a stock E55 would look like. Like I mentioned in my first post, I wouldn't be surprised if we see the same drop in fuel pressure. Is it just coincidental that we all see the same drop in pressure with varying mods?

Sneakyneon tried a single Kenne Bell boost-a-pump and since we have to pumps it didn't work properly. I also contacted Corey from Kleeman and his only recommendation was to switch to SLR injectors. I would much rather fix the drop in PSI's through the pump if possible like others have mentioned.

Exotic-metal55

Based on my past tune days, I feel I have had fuel issues for a while. It seems getting the top 500 rpm rich enough, has been challenging. Even with stock manifolds. It really showed with the change to the 185mm..

I feel this bosch 44 pump will take care of the pressdure but not sure if it will operate at the 80psi we need for our injectors... Anyone know if the 44 will show 80 psi at the rail???? Specs listed below..

If the e55 was two external pumps, then one should be a low pressure pump and the other a hiogh pressure? If so, why not just put two pumps in thier place. Simulair to what sneakyneon did? An easy test/fix may be to just add another inline pump after your stock pumps.. The integrated filter is still a problem..

I should be able to change my pump in about 15 minutes, once I have all the parts.. Then I will post results..


Bosch 044 Fuel Pump Specs:
Bosch Part Number: 0 580 254 044
Minimum Current: 12 Volts
Operating Pressure: 72.5 PSI (5 Bar)
Minimum Flow @ Outlet: 80 GPH (300 LPH)
Fuel Pump Location: In-Line
High Temperature Reduction: 8 GPH (30 LPH)
Weight: 1030 Grams (2.27 Pounds)

Fuel Pump Connections:
Inlet: M18 x 1.5
Outlet: M12 x 1.5
Electrical: Positive M6 / Negative M5
$219.99

Ghostrider

But that makes me wonder if it wouldn't take two b-a-p's because I'm sure they are both running off of the same voltage source.

What did sneakyneon do to his fuel system?

vietjdmboi

i have used the bosch 044 pump on hondas plenty of times and they are good to 150psi. 80psi is no problem for it.

bassn_07

Yeah, that's what Sneaky was possibly thinking of doing....running two boost-a-pumps. I'll be speaking to my tech later this week and I'll bring this up and get his thoughts. He knows the 55's like the back of his hand.

Sneakyneon is working on a huge project that is very involved. I'm sure the end result will be nothing short of stellar. I'll let him chime in and explain his project.

broke1

If voltage drop at the pump is a problem,instead of spending a bunch of money on a BAP(crap IMO),use a hotwire kit for the fuel pump.You could even make your own taking power off the back of the alt(the highest voltage spot u can pickup from)Running 10awg wire from the back of the alt to the fuel pump positive wiring will cure any problem with voltage to the pump if there is a problem to start with.

A Bosch 044 will not flow well at 80psi.There are specs out there online.Grand National guys have found this out years ago,044's have higher psi volume drop starting around 75#.

I wouldnt think the e55's pumps would be a low pressure and high pressure,id think theyd both be high pressure pumps.

Zod

Some cool FYI on what your talking about but on the new AMG V8 bi turbo engine

http://www.mercedes-amg.com/#/157v8
go to the direct fuel injection bit and you will see talk of 2 pumps
1 low
1 high

Exotic-metal55

Ok, then what pump do you use, that will alolow for 80psi from the regulator but still have a strong LPH? The pumps that work at 80 psi plus, all drop off on the LPH flow?


Ok, then what pump do you use, that will alolow for 80psi from the regulator but still have a strong LPH? The pumps that work at 80 psi plus, all drop off on the LPH flow? I was wishing that the 44 pump was under rated and would hold the 80 psi, especially since it is feed by and intank pump already..

SterlingE55

Just a thought. It would be just as easy to test voltage and amperage to the pump. If someone is bored they could throw on a data logger and grab fuel pressure, voltage to pump, rpm, % open throttle, mph and some more.

KIWI KEN

I have used Bosch 044 motorsport pumps many times and have found them to be very reliable but very noisy.

The one thing that effects fuel pump pressure and volume delivery is applied voltage which you can see from the bosch charts.

If you use data logging you will notice that fuel pump pressure will vary with battery voltage fluctuations and can cause the engine to lean out.
A constant voltage power supply to the fuel pump will fix this.

cpais

That seems to me to be a ridiculous amount of fuel pressure at idle. I assume that this is on a 55 engine. Do you know what the factory fuel pressure is suppose to be at idle. I am used to seeing numbers around 40 psi. Why would this car be so high?

Tony the Tuner

Nice work Brooke, you would want to stay around the 73psi mark under heavy load, while doing these runs are you checking your injector duty cycle? If the injectors are open they will also cause your pressure to drop along with voltage don't forget to take all these measures under consideration.

Not sure if the Bosch 044 will hold up to what you need but look into Areomotive inline pump. They are loud but it they will get the job done.

Hope that helps some

Exotic-metal55

Most modern perfoamnce engines have been going with much higher pressure over the alst 10 years.. Increase in MPG and performance are a few.. The 55 motor factory set fuel pressure is 78-80psi.. That is normal and stock..


Tony thanks for the input.. Below is a picture of the stock CL55 inline fuel pump and filter next to it.. The high volume low pressure intank pump feeds this inline pump.. Pretty much a stock race car set up from AMG but just to small now.. This pump is very, very small in size and just a guess but the Bosch 44 is 2.5 times larger, heavier and I am guessing would have to help a lot.. Just ordered one, as it is easy to sell if it does not work..

The Areomotive is a damn nice pump and has Russian race horse flow specs! I just don`t like noise .. If the Bosch does not work or hold 80psi, then larger injectors are going in,, as I do not want to mess with the intank pump either..I have no idea what it limits are either..

98aggie

Exotic-metal55

Thanks Kurt! I cant wait to get that bad ***** on my ride ASAP!

sneakyneon

I'm not at all surprised by this findings, this what I saw on the dyno with my car.

The stock voltage at idle is 13.5-14.0 This is not out of a book but straight from my multimeter. I would not assume that the voltage would drop at higher RPM unless there is a wot cut out for the alt. (I doubt it).

I tried a single 40 amp BOP and it would blow the fuse every time, I tried it on one pump and both with same results. I sent it back to kenne bell and they could find nothing wrong with it

If going to a 044 pump I would think it’s going to need to be before the regulator so the regulator can do its job.
On the E55 this is near impossible with the pumps and regulator in tank.
My solution was way over the top; with 2 bosch 044 pumps modified rail and aftermarket regulator and return line. I have been working on mine for what seems forever but I should have it button up tomorrow (fingers crossed) I'm sure there going to be a whole slew of complications but I'll start a thread with pics and photos.

The bosch are known to be good to around 600 whp but I have no idea of what the pressure is unregulated.

Exotic-metal55

By searching my STAR manual, I found some interesting info.. Not sure how or if this applies to other 55`s but should help.. It seems the Cl55 may have a BAP built in already..

Sneakyneon, glad you mentioned about the regualtor being in the tank, as I just found my is external under the tank.. Not sure how that will affect or control pressure from my high pressure pump now, as it will be rated at 72.5 psi, unless it is regulated somehow. Not sure how though..

Here is a pic. of the CL55 external tank regulator. I guess that may be easy to change and just increase pressure some???


Here is the info on the voltage control unit to maintain a constant 5bar.. Well no if you add to much power..hehe




Here is the sensor that controls pump voltage. I would say this is a built in boost a pump, in a sense.. Hope it regulates the bosch 44 from its 72.5 rated psi.

Exotic-metal55

Anyone figure out yet if the E55 has a ECU controlled fuel pressure control unit? How about a fuel pressure sensor? This would be an important fact to figure out how the stock pumps work.. Why would they both be high pressure?

If the pressure is dropping and fuel pumps are hard to change, then add another high pressure pump inline but figure out how the pumps work..

My pump should be here next week and my trunk tank too. Lot of test coming up!