carlossousa99

Hi..

I need information about the C43 fuel pump. the current one doesn’t have what it need to run the car in a half mile race, the fuel pump fail to supply the enough fuel and the car enter in protection mode.

I need to upgrade, Any Suggestion?

The car is tune and have downpipe.

munis

Who tuned your car?

carlossousa99

the car is tune by LWS Tuning

MatthewJ

Not aware of any FP upgrade just yet.
Are you running ethanol blend? Looked into meth?
BMS did some 1/2 mile runs with their C43 without too much problem but it was on just tune, no DP and i think it had meth kit.

carlossousa99

The car is running on VP Fuel and at the moment is doing 149 @ 1/2 Mile Runs.. that is much better that some c63 tune with BMS and DME that they were doing 152 @ 1/2 Mile Runs.. If I Solve the fuel problem we estimate that the car will more that 152 with the stock turbos..

Hrd_workin

Yes that would be nice if someone knows of an upgraded high flow fuel pump.

evoi19

would a c63 FP work or maybe one from an AMG GT? I haven't seen an aftermarket FP yet but you can always go custom.

Star4life

yep this is the problem with our cars tuned. the minute you get above like 98 octane, the fuel pump runs out of room at around 111 mph. but varys depending on conditions. no solution i have heard of yet.

carlossousa99

Hi to all..
I upgrade the fuel pump.. I install a C63s fuel pump, the car performs much better and you can feel more power. now the tuner will upgrade the engine map. Looking to test the car in the ½ mile race in march

Matthew Cohen

Was this a straight bolt on/bolt off job with the c63s fuel pump? Or were other mods required? Besides an ecu tune ofc. Why does the fuel pump run out of juice with fuels above 98 octane? What's the etiology of that issue? Curious as to why it wouldnt run out with 93 octane.

Would it be because 98 being harder to burn than 93, can be compressed further and therefore used in higher quantities to make more power under more boost?

Star4life

did you replace the HPFP? if so, was it a direct bolt on? Are you sure the rating is higher than the c43 fuel pump? it only has 2L/4 cylinders to supply fuel for vs 3L/6 cylinders on the 43. The c63 has 2 HPFP where as the 43 only has 1 HPFP suppling all the cylinders.

this is only an issue when running a tune which uses more fuel than the stock HPFP can keep up with. You could use any octane on stock tune and keep up just fine.

Hrd_workin

yes I would definitely like to know details as well please.
local tuner here was talking about running E85 with the upgraded turbos but not sure how that would be better than a high grade race fuel.
Both are dense and can compress more under boost but assume the car would run worse on E85 when not under boost.
Did find Ron Davis Racing to be able to make a high performance heat exchanger and radiator though to combat the heat soak issue. 😁

carlossousa99

The fuel pump is a direct fit, the new pump is handling up to 6.5 bar.. the pump code is A2054708501 C63s Couple. The stock pump goes between 3.5 to 5 bar. The only thing is you must use your old pump sender level sensor.

carlossousa99

Hi..
This is a Screenshot of the pump pressure doing a run with ½ a tank. using the EasyDiag 2.0 diagnostic tool

AhEmGee

is it a straight swap? this would be a great upgrade as the Standard C43 pump cannot fuel well on mapped cars on long pulls , as you said.

Petje

Does the EasyDiag read much data?

like boost pressure etc?

I noticed some sort of “cut off” when full throttle, can this be the FP ?

also noticed that it’s much more when the PE is open?!

Star4life

this is a LPFP not HPFP. i dont see this as the bottle neck. The HPFP is the bottle neck to the system. Did you change this one too?

Cosworth2000

I would source a c63 fuel pump.

Jeffrey Jaquez

Hi Carlos, I replace my fuel pump today everything fit good how you say, unfortunately in my car a long pull the the fuel pressure drop dramatically, my question is the 63 pump have 3 hose the 43 2 hose what you do the 3 hose ? Thanks

Star4life

We are just trying to figure out where to connect the other end of the angled piece!

Salco45

Is there a HPFP available for our engine? Would the one from c63s fit?

carlossousa99

Hi.. The tank of the C63 and C43 are the same As far as I understand .. If you do a long pull with very low fuel it will present that problem... the c63 has a different level the reserve in the tank..

The 3 hose of the C63 pump is a Mystery form me, I let you know If I find the answer ..

mo11

I don’t know much about the fuel systems for these cars. However, is it possible that these return lines are just connected to a Y-connector to a single line as this video (1:55) shows? The video is for the E, and CLS. But, would it be the same in principle?

allanyeung99

I recently got my C400 tuned by DME, and couple of months driving, I was in manual mode, going around 80mphs and all the sudden I heard like a backfire and the car kinda lost power but was driving fine. Check engine came on and was able to pull up a code P008700, said that the fuel pressure was low. I took it to my friends shop and he said the pumps are running fine. So I was thinking maybe it was the fuel that I put in it, I use premium as always but that time it was at a different gas station. Haven't came on since, anyone got an idea or maybe just a hiccup?

Star4life

how did you install it then? You said you have it working? Did you just leave it disconnected?

The c63 tank is different than the c43 tank. I am thinking this may be an extra suction point on the c63 tank. if the c43 doesnt have it, its possible we wouldnt need it in our application.