Exotic-metal55

Let`s talk solutions. I just started looking at the fuel system and been concerned with it for years now.. To many people adding way over 100 RWHP over stock and no fuel upgrades.. Don`t know of many car formats, where that can be done and live for long..

The ID of this hole is close to 6mm and I put a 6mm Exahust stud next to it for comparision.


First thing I buy is a new fuel filter.. Open the box and I see this little hole in the canister that an ant would have trouble crawling through, much less 650 crank hp.. If all the other line and pump openings are larger, then a larger flowing fuel filter could help some.. Do we need pumps , injectors or both?

Sathinas

Depends.

What duty cycle are the stock injectors running at stock and say, with an extra 100 horses? What fuel pressure will that pump run with stock power levels? How much flow at said pressure?

Can the fuel pump keep up with the pressure drop (and flow) if you're running an extra 100 horses, and the injectors happen to run at say, 95% duty cycle as opposed to say, 80% stock power?

Find out what injector size you have. Find the pressure and flow rating of the pump. Do some math based on those figures.

If they come up short, then go with an inline pump and bigger injectors. Larger ID lines might be necessary as well. Of course, a tune will be necessary, to tell the computer of the bigger injectors.

But to put it into perspective, a good tuner (actual tuner, tunes the hell out of FORDs), who's been around F1 in the past once told me that he was surprised to see 1/4 inch fule lines running to the motor on those F1 cars. For what it's worth...

Laptop battery is dying, I'll do some math for you to see how much fuel you can flow through that almost 1/4 inch opening at various pressures once I get my charger.

clkwork

http://www.pipeflowcalculations.com/...drop/index.htm

Jakpro1

Love this F1 Injector Vid.

Amazing!

Sathinas

PSI Gallons/Hr
30 504
35 546
40 588
45 630

Looks like you can easily flow more than enough fuel through a 1/4 inch line. Now, in order to go through that much fuel, you'd need injectors on the order of... well, 39746 cc/min injectors. 630Gallons * 3785cc/gallon = 2384809cc/hr / 60 minutes = 39746.82cc/min / 8 injectors = 4,968cc/minute.



So, I'm going to say the 1/4 inch line is more than plenty.

Now, how about a pump? Let's say that you decide to go with... 750cc/min injectors, you'll need a pump that can hold at least 45PSI at that rate:

750cc = 0.19812 Gallons
750cc injectors will flow 11.88 gallons per hour. Multiply that by 8, and we have 95 gallons per hour. That gives us 359 liters per hour. Wow... That's a lot, at 45PSI. Most people can get away with one 255lph HP pump.

So, in effect, at 100% duty cycle, a 750cc injector will make roughly 142HP (injector flow rate in lbs/hr / .50 = HP). This would yield you 1,136HP for all 8 injectors. But 100% duty cycle is not something that you want to run. 80% is more of an industry wide acceptable duty cycle. Even at that duty cycle, you're looking at 113.6HP per injector, or 908.8HP those 8 injectors can support.

Now that I've given you the math, find out what injector size the 55 has, and go from there to figure out if you need a bigger (more flow) pump or larger injectors or both.

Tech-Tune

Unfortunately its decision making time:

-For those who are done modding and simply want to address some top end leaning, your best bet is to upgrade the fuel pump and see if it resolves the top end fuel issue (chances are it will).

-For the enthusiast who knows he will continue modding, its time to upgrade the fuel pump, injectors, fuel filter, and some fuel lines.
Unfortunately this WILL require extensive tuning in order to get your car dialed back in again, and is a costly process.

Worth the wait

What about a KB boost-a-pump?
Very proven problem solver on other platforms and relatively inexspensive option. Of course if the problem is with the injectors, more fuel to the front of the car might not help.
Been researching this issue myself lately so I am very glad to see this thread!

Sathinas

I've heard the KB boost-a-pump is a very popular option for the Mustang guys. Apparently, it works well.

Worth the wait

Very well, and not limited to Stangs. I have seen good results with the ricer set as well.
Should be simple to install as well, provide there is space in the general vicinity of the pump.
My understanding so far is that the fuel pump on the E55 is under the rear passenger seat. The filter/sender is on the other side. The filter/sender is one unit and needs to be replaced as one unit, with a cost of close to $800 from the stealer, or about half that from Rockauto. I have been having difficulty finding the fuelp pump, as a few have said it is part of the tank and not sold seperate.
Anybody have more info?

Exotic-metal55

Ok, just took a better look at the system, as I changed my fuel filter. Damn thing was original and full of black crap. 50K was on it and using the blow through test , it seemed to be at least 30% less restrictive..

The ID of the filter seems to be a restriction VS the lines and pump.. The ID was about 5mm and I machined it out to 6mm, so big flow change!!

We have and intake fuel pump that feeds the high pressure frame pump. This line going into frame pump is at least 1/2" but coming out it is 8.2mm OD..Filter is a simple inline, so most any will work.. Pump is also a inline and looks like most 80 plus PSI pumps will easilly replace this.. Good news~!

I am starting with my filter change and mod first.. Our filters are dated, so check your filters and get them changed... Moded engines will not like using a filter to the recomeneded filter change (80k or 4 years). I am going to change every 15K from here on out..

Below is a pic of the inline pump and filter. Note 1/2" line feeding into high pressure pump.

sneakyneon

Is the CL diffrent than the E55?
My car has 2 pumps in the tank and I have yet to see a outside filter?

sneakyneon

Answeared my own question, EPC show diffrent stuff for a CL than a E, bummer.

Exotic-metal55

Where is your filter?

cahiil55k

IIRC the E55 fuel filter and fuel sending unit are one piece. My tech said he needed to drop my tank when I inquired about getting a new filter for my lean condition. I found this thread a while back, so I'm going to see if the local stealer can tell me if the work was already done on my car.

https://mbworld.org/forums/w211-amg/...ding-unit.html

Exotic-metal55

Damn, that is a problem. To me , if we mod these cars to bring them near max fuel capacity, then the filter will have to be changed more frequent.. Changing them at 60-80K could mean a modded engine could be real lean.. I only had 50K and my filter was real , real dirty!

sneakyneon

Like stated above, But I dont belive you have to drop the tank, its has 2 collars under the seat, one as the 2 pumps the other has the sending unit and filter. I have not yet taken this all apart but should have more info in a few days.

I'm leaning to doing a complete fuel system.
Bosch 044 300gph 180.00
40 micron -8an filter 38.00
Fuel pressure regulator 110.00
Line 60.00
injectors cleaned 19/per injector

MBH motorsports

He is my take with fuel and these cars... If you can get your AFR dialed in to... say... 12-1 or optimal. Even if you've added 100whp or so over stock you should be good. If its able to maintain optimal AFR with all your mods your're good to go.

I know with the C32 and 55NA's those cars can run out of fuel. For example.. The C32 comes with the same injectors (IIRC) as the 55NA. Only 2 less. From what I've seen they get a bit tricky to tune in the higher RPM's when mated with big power mods.. Not because they run out of fuel pump, but because they run out of injector. Would a fuel system upgrade help that out? Maybe?

In my case, when I was building my SC C55. We toyed around with the idea of a fuel pump upgrade, then quickly tossed out the idea of a boost-a-pump. Knowing what we had seen with big powered C32's running the same injector as my C55. We opted to use a 55k injector. This make tuning that much easier because running out of fuel was no longer an issue. With the 55k injector being used on my C55 adding 130whp or so.. Fuel was never an issue. However I cant recall if I logged the duty cycle of the 55k injectors on my SC C55.

IMO, the 55k's have enough fuel to support basically all the mods that are available for the car. With E55's that make 520whp+ The AFR is still kind of easy to dial in. Even with Race fuel tuning (100 and 109 octanes) where I have seen upwards of 570whp+ on 55k's. There is enough fuel as a race fuel tune in most cases leans out the AFR.

I've heard of the SLR injector having more holes in the nozzles.. However I haven't heard of this offering a benefit to run of the mill 55k's Most likely because it just hasn't been tested to much.

At the shop Ive seen Boost-A-Pumps used on supercharger kits. I cant recall if any of the kits that come with a BAP also come with injectors. We all know injectors are not cheap, so a BAP might be a cheaper alternative. Thus making aftermarket SC kits more affordable to the average guy.

For instance the 2010 SC'ed Camaro make big HP with the use of a BAP, and a stock fuel system. However other cars or Supercharger makers come with injectors from Z06's or something like that. Pending if its a GM app.

IMO, until an aftermarket blower upgrage comes out for the 55k, I dont think there is a need for fuel system upgrades as of yet. Maybe a fuel cooler, but I don't know much about those. I've heard about evaporation issues, but thats Greek to me.

Jakpro1

Lol, I have been staring at that part since you posted and was wondering if I have been missing something all these years.

Totally agree with everything you have posted Exotic. Someone was working on boost a pump. Wonder how that turned out.

cahiil55k

I might have misunderstood my tech about dropping the tank but I hope you are right for all of our sake. Best of luck to all who venture into upgrading their fuel systems.

sneakyneon

I have to disagree, My car make ok afrs but lacks pressure. I was on the dyno with another 55 with similar mods and using the same tuner I was missing right around 70-80 hp. I'm not sure were else 70hp could go?

MBH motorsports

Its cool if you disagree... Its more about solving issues. I would think if you were making "ok AFR's" but were lacking pressure. than for sure I would look into the fuel system. I would also think, If the fuel system was working as it should and tuned with a perfectly functioning fuel system, you would be where you need to be. If it is a case of a parts crapping out, do you replace the part with a new one? Or look for an upgrade?

Maybe as these cars are starting to age a bit, we might be seeing some taxing of some stock components in the fuel system of big modded cars. I know we have an SL55 in the shop that has the whole trunk taken apart with the guts of the gas tank also taken apart. This is a 500whp+ SL

Exotic-metal55

I don`t know all your car`s (RWHP, mods and miles on engine) details but it sounds like you may have mechanical issue. Weak pump, clogged fuel filter, etc etc.. The drop you mentioned (25PSI) is HUGE!!! That sound slike more than all your parts working perfect and then just make to much HP for the fuel..

I will be running fuel pressure checks on my car under WOT loads and see how pressure holds up.. I think my issue was my original fuel filter (not being changed) and the amount of sirt that came out of it, when I reversed flowed it..

Plan to cut it open this week and look deeper.. The new filter is 20% opened up, so I can X that off my list now.. Based on our listedinjector flow capacity, duty cycles are over 80% on cars making 550 plus RWHP.. Plus or minus 15 hp and depends on you dyno as well.. In other words, if you have good headers, TB, 180mm pulley and tune , you are at risk.. Does not mean you will blow but means you are at risk.. Also means that you are stressing the injectors and they could fail much sooner..

Since I have an intank pump and inline pump, fuel pressure increase is easy on my format.. Based on injector numbers , I would feel better going up to 48lbs injectors at this level of mods.

sneakyneon

195mm pulley
85mm TB
"so-so" headers
tune
3 inch exh no cats
Some port work
all the other supporting mods

I might be at risk....

Exotic-metal55

I would start with the filter, based off of what I have seen in the last day.. Our fuel lines are 6MM ID and the filter Id was about 5MM, so if any dirt is in your filter and if it is 5mm ID, then you are hurting flow a lot! I feel the system on my car, if clean and working should pump fuel for 600 RWHP all day long.. After I test pressure, I am going to just put injectors in and get back to adding HP!.. Oh yeah, and get rid of this launch TCU MGT.

Luke_M

What would be the major challenge for a tuner tuning a car with bigger injectors vs a car with normal injectors? Just a new learning curve?