Quick question: I know there's debate on whether to do the fuel pump or injectors first, but am I right in assuming that if I replace both the pump with an SL55 pump *and* the injectors with ones capable of 550cc+ that i'll have enough fuel capacity to support almost any combination of the common mods?


Thanks!

 

Yes, but upgrading the injectors will require scaling them which can be difficult and time consuming for a tuner. If you change to a SL55 pump, change the filter to an unregulated one and add a adjustable fuel pressure regulator.

 

Ok, thanks! So I'm figuring on an SL55 pump (like this one) and a Hengst filter (0024772701)

So now I need to figure out pressure regulation.

What sort of fuel pressure do I need to run to get sufficient fuel through the stock injectors?

 

Hi ThinkRob
I have a SL55 pump, oem fuelfilter, 665 cc/3,8 bar/55,1 psi/92 % duty cycle.
No problem at all. ( BUT i have a AutronicSM4 thats controls the fuel )
I think you will bee fine on oem fuelfilter and SL55 pump and 550 cc fuel injectors.
Dont use a adjustable fuel pressure regulator. You dont need it. Oem fuel filter is 3,8 bar/55,1 psi
If it is time concuming for the Tuner. Change tuner. They dont know what there doing

Regards Göran

 

Correct me if I'm wrong.....but you are running a SLK32 and not an SRT6 ?? There are a few differences between the two OEM fuel systems. SRT6 has a fuel filter with a built in regulator....SLK32 does not.

 

Yes.

The stock fuel pump will exceed it's capacity before the stock injectors go static.

Also, more info here:
Ultimate Fuel Rail

 

regulator is on the rail not the filter. both cars

 

The regulator is built into the Fuel Filter on the SRT6.

 

The fuel pressure regulator was most definitely built into the fuel filter on my 2003 SLK32 AMG. The only thing on the rail was a pulsation damper.

 

I knew the SRT was also at the filter but I read here previously somehwere that the SLK32 was diffrent and near the fuel rail connector. Probably one of Steve's posts. LOL

 

There is no differences between SLK32 and SRT6. Same same, but different look.
Same fuel system. Built in regualtor in the fuel filter. 3.8 bar/55.1 psi

 

Are you thinking of any specific mods?

 

I'm already running an Evosport crank pulley and a custom dual CAI intake setup, along with a larger-capacity heat exchanger + CM30.

I've got a conservative tune from Eurocharged on there now, but since I'm well in the safe range, AFR-wise I may have them make it more aggressive.

I'm planning on (eventually) running stacked with a 65MM or smaller SC pulley and, after that, Needswings custom manifolds (both of which I've been told will definitely require more fuel.)