Tuning with CIS - Page 2 - PeachParts Mercedes-Benz Forum

JayRash · #16 03-03-2009, 12:26 PM

i know timing is another ECU the way to work with it is to fool its temp based mapping and timing will be altered enough to feel the diff. i mean more timing than pulling the resistor could do alone

400Eric · #17 03-05-2009, 05:28 AM

I have an 88 M-103, an 89 M-103, and a 93 M-119. I believe the M-119 would benefit from this mod as well and stated so at the end of last year in post #39 of this thread: http://www.peachparts.com/shopforum/showthread.php?t=239201&page=3
In that post I stated, in part: "Also have done the Jim F "Cool Harness" mod but that had zero effect on my better runs cuz you've got to be at 80 degrees C or less to get a good time and the Jim F mod doesn't kick the fans on till well after that temperature. I guess a guy could run a higher value resistor to get the fans to keep the temp at 80C but I would rather run a second resistor at the other temp sensor to fool the ECU and EZL into thinking it's 80C all the time so that they will allow full "Party Time" mode all the time."
I think even 80c may be too high. There may be more to be gained by going for 40c or 60c. So today I picked up three 4 pin temp sensors at the local U-pull-it and I'm going back to the track this Sat. Since the sensor is grounded through it's wires and not it's case, I can just plug in a "dummy" sensor, wrap it in a bag, and leave it on top of the eng. Since the business end won't be submerged in water, it will automatically read lower---just what we want. And the gauge will be telling me what temp. the sensor is telling the EZL and LH ECU. I can move the sensor around a little to fine tune the final temp. I will report here, at that other thread, and on a new thread the results. Regards, Eric

JayRash · #18 03-05-2009, 05:43 AM

Eric,
Try and have the engine think its at 40c, on your car it will fool both injection and ignition together, but i suppose you will be running too rich. and thats what makes this modd better on the W124, since u can fool timing and injection seperatly.

Any way we tried this on a C36 and did give that car better response, thou i really didn't get to try that car enough to have more accurate data.
The limit was that it would start running too rich and thus loosing the gained performance way before reaching the timing limits.

any way just fit a variable resistor and look for that sweet spot.

looking forward to your update.

Opps, does the 400E control timing thru a similar EZL like w124s!!!! or is it like the C36 M104?? would be gr8 if its an ezl i guess.

400Eric · #19 03-05-2009, 07:29 PM

If you meant similar to the M-103 EZL then yes, it is. (All 3 of my Benzes are W-124s.) I'm not worried about going too rich as I've done breathing improvements that need to be compensated for anyway and both of the LH ECUs I'm running are 93s and therefore lack WOT fuel enrichment. If it gets too rich I can always up the temp. back to 60c or 80c. I saw an over 3 tenths improvement in the quarter mile just from dropping the eng. temp. from approx. 90c to 80c. I also have a traction problem at 80c that I don't have at 90c. (This is a non-ASR car.) Regards, Eric

JayRash · #20 03-06-2009, 01:45 AM

Quote:

Originally Posted by 400Eric

If you meant similar to the M-103 EZL then yes, it is. (All 3 of my Benzes are W-124s.) I'm not worried about going too rich as I've done breathing improvements that need to be compensated for anyway and both of the LH ECUs I'm running are 93s and therefore lack WOT fuel enrichment. If it gets too rich I can always up the temp. back to 60c or 80c. I saw an over 3 tenths improvement in the quarter mile just from dropping the eng. temp. from approx. 90c to 80c. I also have a traction problem at 80c that I don't have at 90c. (This is a non-ASR car.) Regards, Eric

Thanx for the proof that this somewhat free HP trick does work.

400Eric · #21 03-08-2009, 03:40 AM

Well what can I say--- the car needs bigger tires now.

14.72@95.51 vs. previous best of 14.959@93.81. (14.44@97.405 MPH vs. 14.593@96.219 corrected) This day was 9 degrees F. cooler so I corrected the times http://www.dragtimes.com/da-density-altitude-calculator.php?elevationcorrect=1696&et=14.72&mph=95.51&correctetmph=Correct+ET+and+MPH and as you can see, there still is a nice gain. The gain could have been even more but when I drop the temp below aprox. 70c the car makes so much low-end torque that I lose traction, have to feather the throttle, and wind up running 15s (if I'm lucky). I have a hard enough time hooking up at 80c! I'm not going to start a new M-119 based thread on this mod like I planned until I can upgrade my rims and tires so that the full benefit of this mod can be properly documented. (I'm going to wear out my current tires first). I am going to try to get a friend to scan the timeslip and post it. Regards, Eric

JayRash · #22 03-08-2009, 06:56 AM

so erric, i bet with no cats, the car should be close to abt 300 hp all in all. dunno just throwing a number here. but would be nice if you drop the temp more and dyno run the car.

Cool thing is that on a g-tech i clocked 1/4 mile in 14sec @102mph. but that was before i upped the boost and installed the meth kit.
Last time i timed my car 0 to 100 mph it clocked 12.1 sec

400Eric · #23 03-08-2009, 07:30 AM

I figure I'm at 305hp even with the stock cats. Remember, I'm running a uncorrected 14.72 vs. the corrected 15.3 Car and Driver got from a stock 93 like mine back in 93 and it is rated at 275hp stock. And I'm still running those rotten 2.24 gears in the back! The commonly accepted rule of thumb is 10hp for every .10th reduction in ET. That should equate to a three tenths reduction and I'm already at twice that. Regards, Eric

JayRash · #24 03-08-2009, 07:33 AM

impressive man, btw u think cams from the e500 would fit on your engine and still give you some more power?

400Eric · #25 03-08-2009, 07:52 AM

Only the intake cam is different I think and yeah, it would probably gain me a bit but I'm not going to bother with it cause my long term plans involve swapping in a whole 5.0 eng. from a S class--- there really is nothing unique about the 5.0 in the 500E/E500 you know. GSXR and I have already talked about swapping S-class 5.0s in place of our 4.2s at that thread I linked earlier in this thread. But you know, I'd like to turbo one of my I-6s like you have done too! Regards, Eric

JayRash · #26 03-08-2009, 08:43 AM

ERIC,
If you ask me, i would never turbo charge another of my cars again

its just too much trouble, maybe its cause my car has so many miles on it, but every time i stressed my car out on a long run i would be thinking if somethin has went bad with the engine.

yesterday i took my car on 100mile trip in hot temps, and thou the car never overheated nor did it ping once it developed a small miss fire on idle and the breather is smoking more than usuall. now my plugs are way over due for a change and since i have no oil cooler on the m103 it could be cooked oil. any way tomorrow ill compression test the car, if anythin is off, ill be rebuilding the engine.

not that i dont love the way it delivers the power, its just that maybe my car has too much miles on it to take all this abuse. :/

gsxr · #27 03-08-2009, 11:24 AM

Quote:

Originally Posted by 400Eric

I have an 88 M-103, an 89 M-103, and a 93 M-119. I believe the M-119 would benefit from this mod as well and stated so at the end of last year in post #39 of this thread: http://www.peachparts.com/shopforum/showthread.php?t=239201&page=3
So today I picked up three 4 pin temp sensors at the local U-pull-it and I'm going back to the track this Sat. Since the sensor is grounded through it's wires and not it's case, I can just plug in a "dummy" sensor, wrap it in a bag, and leave it on top of the eng. Since the business end won't be submerged in water, it will automatically read lower---just what we want. And the gauge will be telling me what temp. the sensor is telling the EZL and LH ECU.

Eric, that's a great idea, adding a "dummy" coolant temp sensor that's loose under the hood. One catch - the dash gauge reads from a totally different sensor. So you will never know what the "dummy" sensor is reading, without a digital scanner connected (which will show you the live data from the dummy sensor). That's good though, this way you know the exact engine temp based on the dash gauge.

Regardless, it should still work pretty well - and your tests back that up. I was going to try this myself, with a resistor pack, but I like your idea better since it's easier! Now I just need a 4-pin sensor...

gsxr · #28 03-08-2009, 11:30 AM

Quote:

Originally Posted by 400Eric

...when I drop the temp below aprox. 70c the car makes so much low-end torque that I lose traction, have to feather the throttle, and wind up running 15s (if I'm lucky). I have a hard enough time hooking up at 80c!

Eric, assuming you have stock wheels & tires mounted, what tire pressure were you running at the dragstrip? With traction problems, I would try lowering the pressure down to the low 20's (I wouldn't go below 20psi (cool/warm) on street tires though). That may help you hook it up. You may also need to start doing a burnout prior to launch, just in front of the waterbox (or are you already doing that?). You generally want to stay out of the waterbox with street tires since the tread will pick up some water and carry it up to the starting line.

pentoman · #29 03-08-2009, 01:28 PM

Quote:

Originally Posted by JayRash

As soon as i find it my self man, if it is the link to the post where the values for the 7 position switch are listed!!!

anyway here they are as i have them on my phone

just dont ask y

:

7. -No resistor = no retard
1. -1.4Kohm resistor = 2 degree retard
2. -1.3Kohm resistor = 4 degree retard
3. -750 ohm resistor = 6 degree retard (standard in US car)
4(S)-470 ohm resistor = 8 degree retard
5. -220 ohm resistor = 10 degree retard
6(N)-0 ohm resistor = 12 degree retard

Jay
These can't be right - the order should be either x,x,x,x,N,x,S -- N should be in the middle and S at the extreme end, if you look at the switch.

pentoman · #30 03-08-2009, 01:31 PM

Quote:

Originally Posted by 400Eric

--- there really is nothing unique about the 5.0 in the 500E/E500 you know.

Not true, I believe Porsche or whoever fitted a a different injection system compared to the S class engine they started with (I believe it was LH instead of L which included hot wire intake air mass sensor?). It officially has 21 lbft more of torque from memory.