from old school to new - Page 4 - PeachParts Mercedes-Benz Forum

RBYCC · #46 07-24-2011, 08:28 AM

Quote:

Originally Posted by JayRash

if that is really the case then every merc can benefit from an adjustable fuel regulator. that would be the easy way to deal with this. it will cost u a few mpgs. but if u can gian up to 20 hp trust me its worth it.

Jay

I don't think an adjustable FPR would change anything.
It's not the amount of fuel that is delivered, it's what the ECU believes should be delivered.
The 14.7 AFR is the optimum/efficent burn ratio.
Good for economy/environment but not performance.

On Osama's Turbo thread note that on a dyno we starting enriching at 10PSI atmosphere ( not boost ) as power gains were indicated pre boost with additional enrichment.

Ed A.

oldsinner111 · #47 07-24-2011, 08:31 AM

Still confused on what to ask for?

400Eric · #48 07-24-2011, 08:39 AM

The actual resistance values will have to come from Jay because, again, I have zero HFM experience. (I think he shared them earlier in this thread though.)
Regards, Eric

oldsinner111 · #49 07-24-2011, 08:42 AM

I'm confused with the K.Like 400K to 1500K.What is HFM I assume my fuel injection?Why so different that earlier model w140.

JayRash · #50 07-24-2011, 10:08 AM

Ed I know the ecu will try and adjust but all ecus have a tiny margin of correction after which u gain control. Do our hfm cars always run in closed loop! I doubt they do. Even if Afr is steady at wot. It's a tried and tested way of flowing a little more fuel on turbo cars. It's easy to try with no fpr, a restrictor in the return line should work for testing.

Man as for the resistor value just get a variable one they are available in any hardware electronics outlet. Get one with a range up to say 3kohm. That's 3000 ohms. And start out a measured (by ohm meter ) value of 400 and then keep going up. I think on ur engine u can run a 1kohm safely.

oldsinner111 · #51 07-24-2011, 10:54 AM

Thans for clearing up resistor.

400Eric · #52 07-25-2011, 03:21 AM

Quote:

Originally Posted by oldsinner111

What is HFM I assume my fuel injection?Why so different that earlier model w140.

It's just the newer engine management. It's called "progress". I think it's short for "Hot Film Management". I don't think there is anything inherently wrong with the system, it's just that, like all MBs after 92, there is no WOT fuel enrichment. So, unless you have an AMG tweaked ECU, your WOT AFRs aren't as rich as they need to be. LHs were just as bad after 92. The difference is, since there were LHs prior to the enrichment cutoff, one can substitute an older LH ECU to get WOT fuel enrichment into a newer LH equipped car. That's not an option for HFM equipped cars because HFM didn't even come out on MBs until 93 which was after the cutoff. (W124 M104s got it that year.) So there are no older pre- cutoff HFM ECUs to use.
Regards, Eric

oldsinner111 · #53 07-25-2011, 10:06 AM

what is the timing set for 99 m104? tdc?before tdc? going to advance 6 degrees and leave it alone.Can't find variable resistor.Using Data for tuning with CIS.I use to set all my cars advance 6 degrees,when they had distributers

JayRash · #54 07-25-2011, 10:34 AM

man the go buy a fixed value resistors a few of each: 400ohm ; 750ohm, 1000 ohm (1k) and 1.2k or anything close to those values. and just start trying
i have them by the hundreds here they r cheap .

oldsinner111 · #55 07-25-2011, 10:53 AM

I'm guessing My car is timed at before top dead center 6 degrees.

oldsinner111 · #56 07-25-2011, 02:33 PM

wow guys I used a 1.2k resistor I burnt rubber past my neighbors house.

JayRash · #57 07-25-2011, 05:35 PM

so guys ( Dave, Eric), those who have said before that the free hp trick is a worthless thing. give it a try guys.it can be worth it.

so it makes more power

i know. first time i learnt abt this trick was on a 201 2.5-16 evo1 the car had one resistor for fuel and another for timing and it was wired to 2 switch in the dashboard. with them off the car was fair quick, with them on it was mental. i am yet to see a car gain as much as that 2.5 did. it seems the internals in that car need an agressive tune. but i would swear it was making abt 250hp. hell the owner of that 2.5 had a c36 as well brand new back then and the 2.5 up to 170km/h was always pulling on the 36.

My m103 also was fairly quick with a similar trick thou i never used to enrich the fuel, didnt feel it made any usable power unless i was mixing alc in the tank and then had to flow more fuel.

any way i wanna see eric give this a try since he goes to the strip.

oldsinner111 · #58 07-25-2011, 06:06 PM

I burnt rubber 400feet.Its a monster.who said 6 cylinders were slow.

400Eric · #59 07-26-2011, 08:14 AM

Quote:

Originally Posted by JayRash

so guys ( Dave, Eric), those who have said before that the free hp trick is a worthless thing. give it a try guys.it can be worth it.

Jay, I never said that it is worthless, I was one of the ones arguing that it does work! My 400E loves the ETC trick, but my 300E, inexplicably, doesn't. I have already freely admitted on my dragstrip thread that it may very well have been because of something that I did wrong or didn't do right. Also, Benzer 1 is proving to be kind of an odd duck anyways as I try to hop him up. He does love the "24 81" resistor removal mod though as does my 88 300E "Benzer 2".

Quote:

Originally Posted by JayRash

any way i wanna see eric give this a try since he goes to the strip.

Yes, I agree, more testing is needed and I do believe that with enough trial and error, I would be able to figure out the right combo. You've got to remember that, even though my 89 is only a little older than your 92, they are in fact fairly different animals because of the fairly major changes that occurred in 90. (My 89 is still "KE 3" while your 92 is "KE 5".) There were a fair amount of differences between the two so I'm afraid that I may not be able to just copy what you did on yours. Heck, just look at the number of pins on the ECU. Your ECU has about 30% more pins than my ECU does! Not all CIS-E cars are the same. My 2 300Es don't even have IAT sensors! (The addition of an IAT sensor was one of the several changes that occurred in 90.)
Regards, Eric

oldsinner111 · #60 07-26-2011, 02:04 PM

modified intake I don't drive in rain aways.