Can M104 HFM boost? - PeachParts Mercedes-Benz Forum

taint · #1 04-26-2010, 02:09 PM

Hi everyone just wanted to know if anyone out there is running a turbo or supercharger setup, on the stock M104 HFM ecu setup, and if so how much boost can the HFM system handle before a piggybank/aftermarket ecu is needed or required. I have just started turbocharging my car so i'm tryin to figure out my options, not looking to run more then 6psi at the moment nor do I plan on lowering the compression. Any useful advise would be welcome.

RBYCC · #2 04-26-2010, 02:20 PM

Quote:

Originally Posted by taint

Hi everyone just wanted to know if anyone out there is running a turbo or supercharger setup, on the stock M104 HFM ecu setup, and if so how much boost can the HFM system handle before a piggybank/aftermarket ecu is needed or required. I have just started turbocharging my car so i'm tryin to figure out my options, not looking to run more then 6psi at the moment nor do I plan on lowering the compression. Any useful advise would be welcome.

The question is not how much boost can the HFM handle, but can it handle the boost by consistently and with safe reliability changing the AFR...

Typically the range needed for a boosted engine usually requires a signal or base line from a wideband O2 sensor.

You may consider the installation of a water/methanol injection system which would give you a bit of a safety factor against detonation.

taint · #3 04-26-2010, 02:52 PM

Quote:

Originally Posted by RBYCC

The question is not how much boost can the HFM handle, but can it handle the boost by consistently and with safe reliability changing the AFR...

Typically the range needed for a boosted engine usually requires a signal or base line from a wideband O2 sensor.

You may consider the installation of a water/methanol injection system which would give you a bit of a safety factor against detonation.

hi thanks for the reply. So the answer is no I cant run the turbo safely with the stock ecu. when you say a water/methanol setup as in the Aquamist system? wouldn't fitting bigger injectors work just as well or an extra injector thats triggered on boost work (man if my car was cis i would have just used the cold start injector as fuel enricher).

JayRash · #4 04-26-2010, 02:58 PM

PM "Turbo E320" he is your best bet on knowing what u should do to boost an M104 HFM.

good luck, and i have to say, u will love it as long as you get the tune right, and it will live but dont go overboard with boost and making HP.
a low boost setup will make you 350HP safe and usable for many 1000s miles ...
oh and this is the best forum around for booosting mercs.

Turbo E320 · #5 04-26-2010, 03:28 PM

On a completely stock HFM-SFI M104 with a turbo setup the car will fall on it's face as soon as it reaches 2-3psi which is the MAF sensor's(and subsequently the fuel map's) limits. Solution? Use a rising rate fuel pressure regulator from BEGI if you don't want to mess with the electronics or an AEM F/IC-6 if you do.

The BEGI will be the easiest to install with slight custom fuel line work(very easy to do if you read up on it). It is quite accurate for a non electronic device and once you get it set for a target AFR of say 11.5-11.7:1(recommended) then it will alway stay really close to those values no matter what the boost is. Problem is you can't use aftermarket injectors unless you implement a cheap Apexi SAFC(super easy to wire in) to turn them down during regular driving.

The AEM F/IC is the eletronic solution and probably the most proven for the HFM-SFI motors(as I do not run a BEGI, I only set it up for another E320 owner). It's also the cheapest option surprisingly. So far I have set it up on my e320, a clk430 and a c230 kompressor and utilized all the features. My e320 had some ignition problems initially but it came down to a bad connection on my part and improper grounds. It can modify the fuel, timing retard, MAF, O2 sensors and any other 0-5v or 0-1v sensor. The maps are huge 17x21 setups and make tuning incredibly precise. A word from experience...DO NOT GET SMALL INJECTORS! Small injectors cost me my motor when I turned the boost up to 15psi. After a month they started to crap out from all the heat they were making and I didn't know. I caught it too late and came out with 5 cracked pistons. Would have never happened, had I got at least 440cc injectors(I had 310cc's with a 5 bar fuel pressure regulator). Surprisingly it was a relatively cheap fix as only the block had to be re-honed and I got pistons out of another e320 but still....Small injectors blow.

Here is my E320 a few days after I installed the F/IC. Took me less than 4 hours total of street tuning to get it dialed in and I never touched the tune again. This was with small 2.25" intercooler piping(you need at least 2.5") and a 2.5" exhaust(you need a 3") so the lag was terrible to nearly 3000 rpm. Then it flipped the switch and took off

.

http://www.youtube.com/watch?v=SHJfTVeXNAk

Here is the CLK430

http://www.youtube.com/watch?v=qjeig5k4GE4

taint · #6 04-26-2010, 04:04 PM

@jayrash thanks for info.

@turbo e320 you sir are a lifesaver. thanks for that bit of information i like the idea of the rising fuel regulator, and that is the root i'm going to take for now. I have made megasquirt ecu for car but am for waiting for to get wideband O2 sensor, but i was after a solution that i can fit in the next few days that will allow me to drive the car with the turbo for afew months till I change over to the megasquirt setup when I fit back the manual gearbox. Oh by the way nice car I think I have read almost all the stuff you have posted about your build it's one of the reasons I'm turbocharging my car and not to mention to be faster then a friend of mine, who I fitted a c36 engine into to his 190e.

edit: do you know where i can pickup a BEGI FMU that delivers to the United Kingdom

taint · #7 04-26-2010, 05:09 PM

okay just had a thought anyone know what the fuel pressure is for the stock e320 fuel pump. I was thinking if I replace the standard fuel regulator with one from a porsche that works at 4bar (i'm assuming the stock one works at 3bar) will that not give me the same result a fitting the BEGI unit. I know it will still be a 1:1 ratio but in theory I will have a higher fuel pressure and be getting more fuel as the boost rises.

Turbo E320 · #8 04-27-2010, 12:09 AM

The fuel pressure is static all Mercedes I can think off. Once it hits the max(55psi) it stays there. Tuning by sticking in a different static fpr is impossible. Stock fuel pressure(55psi) and injectors(210cc) with the BEGI FMU can take 6-8psi before your putting too much pressure on them. After that you will want to upgrade to bigger injectors(like 440's) and an AFC to adjust your short and long term fuel trims back to stock when not boosting.

EDIT: You don't have to use the BEGI FMU. Just use a good brand name rising rate fuel regulator.

KotoWong · #9 04-27-2010, 01:11 AM

Thx for your help Mr Turbo E320. I have a C36 5 speed manual and going to turbo with a pair of Mosselman manifold. I will also follow the BEGI root at 5-6psi.

TurboECab · #10 04-27-2010, 02:41 AM

Quote:

Originally Posted by taint

okay just had a thought anyone know what the fuel pressure is for the stock e320 fuel pump. I was thinking if I replace the standard fuel regulator with one from a porsche that works at 4bar (i'm assuming the stock one works at 3bar) will that not give me the same result a fitting the BEGI unit. I know it will still be a 1:1 ratio but in theory I will have a higher fuel pressure and be getting more fuel as the boost rises.

I would go a step furthur and recommend the Porsche Turbo blue sleeve fuel pump found on 944 turbo's This pump will supply fuel up to 600rwhp. Some thing I overlooked also was the factory 5/16 fuel line. Despite all the talk on the net about it being okay a 3/8 supply line is better...MUCH MUCH BETTER ask me how i know?

c280nz · #11 04-27-2010, 03:53 AM

i wouldnt run any more than 5 psi on a rising rate fuel pressure regulator, and that is including a front mount air/air intercooler,
try and run some sort of cold air box aswell, as hot air is a power killer, you want it as cool as possible before the plenum and before the turbo.
the rate that the fuel pressure rises is important to, i cant remember the reccomended rate, is it something like 10:1 turboe320?,
so it raises fuel pressure 10psi for each 1psi rise in boost.

and yea a bigger fuel pump wont be a bad thing, i run a bosch 910 and it fitted in the factory location without too much modification.

taint · #12 04-27-2010, 04:35 PM

thanx for the info guys its priceless,

now i like the idea of the porsche fuel pump they are pretty cheap, but since i have a few merc pumps lyin around i could add an extra pump to the double pump setup on the car now and make it a triple.

just wondering if i have 11.5:1 RFPR then it would add 11.5psi every 1psi so if our pumps run at 55psi all the time that means if i'm running 6psi of boost then the fuel pressure would be 124psi (6x11.5)+55) which is crazy high by any standard. So would i not be better with a 7:1 RFPR as this will give me 97psi at full boost.

Turbo E320 · #13 04-27-2010, 11:57 PM

Quote:

Originally Posted by taint

thanx for the info guys its priceless,

now i like the idea of the porsche fuel pump they are pretty cheap, but since i have a few merc pumps lyin around i could add an extra pump to the double pump setup on the car now and make it a triple.

just wondering if i have 11.5:1 RFPR then it would add 11.5psi every 1psi so if our pumps run at 55psi all the time that means if i'm running 6psi of boost then the fuel pressure would be 124psi (6x11.5)+55) which is crazy high by any standard. So would i not be better with a 7:1 RFPR as this will give me 97psi at full boost.

7:1 would probably run the car too lean. Most boost referenced rrfpr's have adjustable ratios, like the BEGI. That is what makes using them so easy and accurate. BEGI themselves ship to the UK. You need the 2025 model. http://www.bellengineering.net/product_info.php?cPath=7_76&products_id=4

The pumps don't run 55psi. The fpr limits the fuel pressure to 55psi. The pumps are on full blast and could push over 100psi if setup that way. When you start upgrading the fuel system while using a mechanical tuning method like the BEGI you need to get an additional electronic device to readjust the car's fueling during off-boost driving.

taint · #14 04-29-2010, 06:04 PM

thanks for advise mate. I have decided to stop being lazy and just use megasquirt as a piggybank I will have it handle the fueling side of things and keep the stock ecu setup for the spark and idle. Instead of getting the RFPR I ordered a wideband O2 sensor should get here in 3 weeks or sooner i hope. Viva la aftermarket

taint · #15 05-26-2010, 05:04 PM

got another question for yah. okay i have gotten my megasquirt working the car naturally i have the wastegates fully open until i get some injectors (need to wrok out which ones to get). Now my question is what how many bars does the fuel pressure run at on the m104 3.2l and 3.6l cause i was looking at the fuel injector part numbers on the 2.8l, 3.2l and 3.6l m104 (yes i have access to all three) and noticed they all have the same 205cc/min injectors which works out fine for the 2.8l since at 55psi the injectors are good for about 198bhp at about a 75% percent duty cycle, now the same injectors are on the 3.2l and 3.6l which make 220bhp and 275bhp respectivily so does that mean the other two engines run a higher fuel pressure ratio and if so what is it.