M119 WOT fuel enrichment questions

[400Eric]

M119 full throttle fuel enrichment questions

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As I understand it, the power drop between the 92 500E and 93 500E was due to benz turning down the full throttle fuel enrichment and that under full throttle, there are no air/fuel ratio adjustments being made by the computer because it is in an "open loop" condition so it relies on the pre-programed factory settings. If all this is true, then if we put a very high flow exhaust and a nicer/colder ram air intake are we going to lean our cars out too much? Did this same "turning down" happen to the 93 400E but the power loss was negated by the increase in compression that the 4.2 received? (And why didn't the 5.0 get that increase?) Anybody have a favorite "chip"? I'm thinking about Jim F's chip... He is a good guy right? He wouldn't be selling something that didn't deliver right? I know alot of guys aren't keen on chips but I think it's because some of them don't add more air to go with the extra fuel the chip is adding. Is there anything else that can be done? (Please I want to keep my 2.24s.) We live in a day of 381 horsepower 14 second toyota pick-ups friends and we need to prepare ourselves! I don't own a 500E and I know I'm not worthy but please help and please let me hang out here because this site has the highest concentration of M119 performance info. Thanks to all that respond. Eric

[195910]

I do have a suggestion.

Since you already have an M119 equipped W124. Why not trade your 4.2L block With a 5.0L block ?
This would be a relatively affordable upgrade.

you will also need a 5.0L eeprom. which you are already buying, Or you could also trade the whole control unit with a 5.0L one.

If you could do the labour yourself. I think the whole upgrade can be done for about $1000.

regards

[400Eric]

Thanks for the response. It's funny you would suggest that because that is exactly what I plan on doing a little later to a 2nd 400E I have yet to obtain (but I will). I plan to turbo it and run it on natural gas or propane too. But first I want to escape Riverside permanently. (Scott says be proud of your locale but I can't be... I hate it here.) For now I just want to "turn up the wick" on this one a little. I'm looking for 30 more hp. and 30 more ft. #s of torque, 14.7 quarter mile time, 160 MPH top speed with no loss in current fuel economy. Regards Eric

[gsxr]

I don't know if you'll get 160mph top speed from a tweaked 400E, even with a rear-end swap (you'd need
to replace the silly 2.24 gears with 2.65, which would get you ~160mph at redline). Probably not enough
power, even with an extra 30hp, but I'm not sure. Cracking 150mph shouldn't be too hard though. There
is no reason to keep the 2.24... ditch it and get 2.65 instead, like the Euro 400E has. I'd avoid the 2.82
gears unless you're more concerned with off-idle power or drag racing, besides top speed would be ~150
with the 2.82's (remember, the 400E has smaller tires than the 500E).

That said, the only things you can easily do is free up the exhaust... replace the cats with high-flow, swap
the resonator (middle muffler) with a straight-through Y-pipe, and replace the rear muffler with something
that flows better. All that *might* free up 15hp or so. The chips are basically useless, regardless of what
JimF (or any other vendor) says. I tested chips at the dragstrip and dyno... they did zip, zilch, nada, nothing
for power gains. They may remove the top-speed limiter, or delete the cold-start upshift delay, but that's
about it. From my experience, there is not a lackof air flow on these engines. The 6.5L Brabus uses the
same airbox as the stock 4.2L, if that tells you anything. My high-volume airbox adds apparently zero
power as well, although the silver carbon-fiber looks neat-O. The other thing you can do is reduce weight,
the exhaust mods will drop some pounds,, and at the strip you can empty the trunk, have <1/4 tank fuel,
pull the back seat, etc.

[195910]

Dave.

Have you run a 500E with 2.82 rear Vs one with a 2.65 ?

I am interested to know the actual performance figures gains for the 2.82 . because I like the 2.65 more for city and high speed driving.

2.65 will get you a higher top speed. But will you loose 0-62.5 ?

regards

[gsxr]

Excellent question. I'm working on building a 2.65 limited-slip diff, so I can compare the difference between the
two ratios. I'm expecting about 0.1-0.2 seconds slower both 0-60 and 1/4-mile, but until I get the unit completed
and installed, we won't know for sure. I have tons of data with the 2.82, now I just need to get data from the
2.65 diff. A friend is doing the work for me and he hasn't had time to complete the project yet, which is why it's
taking soooooo long (sheesh, going on 2 years now, I think?). I'll bug him again though...

[400Eric]

I have been going through a lot of old threads trying to learn as much as I can and I keep coming across posts from you. I find you to be one sharp and helpful guy! As I said in the beginning of this thread, My concern isn't the ability to get adequate air into the engine (and out), it's getting adequate fuel in. If the 93 400E did fall victim to the same WOT fuel trimming that robbed the 93 and later 500E of some HP. and TQ., then I don't think adding more air is going to net me much of a power gain unless I add more fuel to go with it. (I'm thinking of exhaust and the headlight panel mod). Remember, if we go too lean, the eng. will detonate, the EZL/AKR will back the timing off, and there goes the power gain. I'm just trying to find the best way to add more fuel when in the "open loop" mode. I'm open to any other ideas. This car is my main driver so please, the back seat, the gears, and my current economy need to stay. (That's one of the reasons why I like this site so much....you guys are so hardcore!) I do a lot of 80 MPH freeway driving and I do believe the 2.24s help fuel economy in that mode. The goal is making the car quicker/faster in a daily driver/street configuration. (louder is OK.) I want to be ready for those 14 sec Toyota P/Us when ever and where ever I may encounter them. BTW, Car and Driver got 148 MPH out of a 93 400E and According to uncle Stu's Bible, The 92 and 93 400E are governed to 155 MPH and the 94 and later E420 is governed to 130 MPH. (Uncle Stu owns a 93 400E so he should know). I haven't had the proper chance to top mine out yet, all we've seen so far is 140 MPH before I had to let off due to conditions. Even my little M103 3.0 89 300E bone stock (later got the "resister removal" mod) 177 HP with 214,000 miles gave me 136 MPH. So 160 MPH doesn't seem like much of a leap from 148 MPH. If I'm off on anything here, please feel free to correct me. Again, Thanks to all who respond! Regards, Eric

[195910]

you are right. your 400E will do 155. it would be very hard to go above that though.

But then. those Toyota p/u can hardly go past 120 (becomes too dangerous above that) , so no need to worry. you probably would fly pass most stock evo's and wrx''s

[400Eric]

I know I don't need to worry about the Toyota P/U top speed. It's those high 14 second quarter mile times that I want to be able to top. The top speed is desired because you just never know when you are going to need it.

[OrangeHat]

I would re-evaluate turning the 400e into a faster car. Why not just upgrade to a 500e and use that as your upgrading base? One of my friends has one of those Toyota trucks.....yeah I bury him everytime he gets uppity no contest. It needs 380 hp just to think about moving, damn huge truck. Think about getting into a 500

-Mike

[400Eric]

But they are going to have to come down in price first. (Look what has happened to 6.9 values. My Dad sold his last year. He is so mad, he won't tell me how much he got. "I don't want to talk about it"). And even when I do get one, it will probably be a weekend only car. (It's too dear to be a daily driver.) I am also very afraid of the throttle by wire stuff that comes with ASR cars. It seems to be the source of a lot of problems and is one of the reasons I went out of my way to get a non ASR car (being able to hang the tail out is the other). As I stated earlier, I also want to get another 400E to do crazy things with. This 400E is my daily driver and with it's smaller eng. and taller gears, can actually pull down some decent fuel economy. What I want to do is make my daily driver able to hold it's own against the onslaught of quick cars from everywhere. Even Rav4s (with V-6s) are running 14.9s now. Who wants to be spanked by a Rav4? Lets be honest here, How many times have we found our selves pounding the steering wheel of our daily driver because some unworthy car just handed us our rear while we know in our heart of hearts that "If only I was in my Benz today I would've eaten his lunch/cleaned his clock/blew him so far into the weeds he'd need a compass to find his way out". What better daily driver could a 500E owner have than a mildly hopped-up 400E? I'm just looking to take a 15.2/15.3 car down to 14.7.
I have now done my headlight panel mod and exhaust work. Benzer III seems to like the changes but as Gerry V. would say, butt dynos are not a proper diagnostic tool. And I am still convinced that more power and torque are waiting for me if I turn up the WOT fuel a little. Please Benz brothers, what is the best way to do that? Regards, Eric

[OrangeHat]

500E's are about at their floor, if they get much cheaper they would be worth more in parts that. 500's aren't really drive by wire, they are the same as the later 300 and 420s. Your not going to make more power with the stock ECU, you need to look into megasquirt, or some other aftermarket fuel injection. If you could put something that resembles the later ME system on your car you could easily pick up a decent amount of HP. You don't just need more fuel, you need faster calcs, a more reactive system, better flow in and out. These cars already run rich as hell. Do a search for m119 upgrades there is a lot of info here.

Personally I never want to own a car thats not a daily driver. There are plenty of cars in museums already, and DD doesn't mean anything its all about maintanence. I have a friend with a 1970 6.3 and he has 140k on the clock and it wins where ever it goes and he drives it there. He has put 80k on his 1937 Rolls Royce Phantom III, and it still looks damn good.

[gsxr]

Like OrangeHat said, there really is no easy way to pick up measureable power. It's also not a true throttle by wire,
it's a hybrid... still a mechanical linkage, but you don't get full power without the copmuter's say-so. I love ASR, and
it's easy to add an 'ASR Off' switch if desired. If you wanted mostly mechanical, you'd need the early M119.96x engine
with KE injection from the 90-92 R129.

Anyway, to get the high 14's like you want, first thing is that silly 2.24 axle ratio needs to go. A 2.65 will make a big
difference, and it wil sacrifice VERY little in fuel economy. Shoot, my 500 gets 20-22mpg on the freeway, what are
you getting on the 400E? Otherwise, it's the same stuff I mentioned before... open up the exhaust, and consider
some intake work (porting, port matching) but that's an awful lot of effort for minimal HP gains. I wish there was a
magic trick to extract another 30hp, but AFAIK... there isn't.

BTW, my earlier comments about emptying the trunk & removing the seats, etc was not meant as daily driver mode,
that was at trick to use at the dragstrip to drop a couple of tenths if needed.

[OrangeHat]

Listen to gsxr, after reading most of his posts (and there are a few) he has tried almost everything to get a little more out of the 500. He just posted a bit a little while ago about different LH modules, you could try putting a 500 LH box in your car if you have a CAN system in there, that might net you some HP, but your MPG would go down, but thats enrichment for you. Internal benz parts are about as good as they get durablity wise, but they are all so damn heavy that the motors will never get the MPG of a cheaper penny pinching v8.

Now I am an idiot, and I believe in things like high flow jet hotted exhaust, big bore/stroke m119, 722.6 conversions, etc etc, but unless you want to eat ramen and throw cubic $$$ at it then I would say just get a 500, a 1997 C36, or a C43 and live with the worse econ. I looked at all the options and at the end of the day I would rather drive a 500E than a C36 or C43 or w210 or w211 (except a 63....) if you don't want the worse MPG get a later model with the enrichment pulled. Having a v8 and talking about fuel econ is like a battle ready budda action figure, it just doesn't make any sense. Not to be a buzz kill but if there was a way to make more power cheap with a m119, someone here would have done it already. The best thing I have come up with is don't work on the motor, do a rear gear and a 722.6 transplant.

http://www.msefi.com/index.php

Read the above site, its your best cheapest bet, stand alone EFI. They might have a way to control cam phasers now which would make life amazing.


-Mike

[gsxr]

Mike, you bring up an excellent point that I had forgotten about. While achieving better MPG is obviously a
good thing, sometimes the numbers can be deceiving. You HAVE to do the math and translate the MPG into
dollars per year (or month, or whatever) based upon your personal driving habits. If you put a ton of miles
on your car every year (say, 15-20kmi, or more) then a few extra MPG could mean a lot of dough. But if not,
the MPG difference could translate into a much, much smaller dent in your wallet. I created a simple MPG
calculator in Excel, download the attached file and play with the numbers.

Another option is to do what I do... have a second car that gets good MPG, and rack up most of the miles
on that car. Mine happens to be a 300D diesel, so I still get to drive a W124, but enjoy about 50% better
MPG than the E500 (roughly 27mpg average vs 17mpg average). And since the 500 gets driven less, the
insurance is also significantly lower than if it was rated as your daily driver. All things to factor in to your
decision making process.

I'd still love a 722.6 transplant, but to date, I don't know of a single 124 anywhere in the world that has
received such a swap. I'm told that besides the electronic hassles, there may be physical fitment problems,
the 722.6 may be large enough to not fit neatly into the 124 tranny tunnel.