Tuning with CIS - Page 14 - PeachParts Mercedes-Benz Forum

JayRash · #**196** 08-14-2011, 07:10 AM

I dunno Man, on my M103 i ran at abt 1.6 max. the car always felt better with the resistor. To the point that when i changed the harness and as such removed the trick my sister noted that the car had lost some low down pull. any way all i can say is that i dynoed my car and engine power was rated on the Bosch dyno at 205 or something close to that at the flywheel.

the reason i fit a variable resistor is because u might need to make several changes. BTW i do believe certain EZLs have already more timing in them. depending on the make year.

JayRash · #**197** 08-14-2011, 07:16 AM

do try the 2200 thou
it might do just fine

oldsinner111 · #**198** 08-14-2011, 08:35 AM

Pardon me with a 1.5 k on my m104 I get knock,so I run a 1k.I want to try 1.3k as soon as I find one.The rattel (not really a knock) is on light pedal.

JayRash · #**199** 08-14-2011, 08:45 AM

M103 runs 9.2 comp vers 10 in M104. M103 has no cam advance in mid rpm range thus runs lower dynamic compression in that range. Thats y in M103 u can go more with timing. but also do keep in mind that ezl and M104 ecu are already mapped differently and as such we cant even comp the 2.

As i told u Nate , knock will be on part loads in mid range. its the cam advance that gets us there.

400Eric · #**200** 08-14-2011, 10:19 AM

An increase in low end torque is what I was/am after with this mod but the 60' times don't reflect a gain there. Our best 60' this time was a 2.572 even though Benzer1 has gotten some 2.4xs on previous dates. It just seems like the timing advance hasn't been increased enough if any at all to make a significant enough difference to show up on the time slips. I guess I need to advance it enough to hear some pinging and then back it a bit back off from that to know where I should be, then take it back to the track. I don't think I'm being unreasonable to expect a 2.3x 60" from the increase in low end torque that a generous amount of timing advance should be netting me.
Regards, Eric

400Eric · #**201** 08-14-2011, 12:23 PM

Hey Jay, is it possible that this mod only comes into play under part throttle conditions? Cause there was really no difference under full throttle but the part throttle did seem to be a bit stronger. It makes sense if you think about it. I mean if you were MB would you want high loads being put on the engine while it is still cold?

As to why this mod gained me fairly well with my 400E, that could be because it was also netting me a gain in fuel as well which was needed at that point because I was still running the non-enrichment ECU. In other words, it may have only been the increase in fuel that gave me most, if not all of my gain instead of both an increase in advance AND fuel like we originally thought. Maybe the only way to know for sure is to put an adjustable timing light on the subject car while the engine is fully loaded under WOT on a chassis dyno. I dunno. I do know though that I just hate tanking at the track and having to explain to people that not all of my chit is slow, just some of it! I just don't wanna give up though cause I just know there is a little more left in Benzer1! I'm not yet ready to admit defeat!

Jay, please review for us all of the mods you had done when you got that 205 number on the dyno. My goal for Benzer1 has been 200 hp 210 tq but to be honest, I would really like to see 205 hp 220 tq even if that seems a bit unreasonable. This day and age, with 300 hp common place, 205 is BARELY adequate so we need to pump up these M103s as much as possible! (No, I don't want to turbo this one because of the over 235,000 miles. How many miles were on Dima when you first turboed her?)
Regards, Eric

JayRash · #**202** 08-14-2011, 12:47 PM

Eric, on my M103 i did the mod, only timing one as the fuel one only made it run worse. I had no cats. the ezl was set to 1 and i guess that was it. but i know for a fact that the car gained power because it was a pig with with the modd in off. i dunno man mine is a swiss 1992 W124 so maybe the ecu was really detuned i dunno but still i was faster than any M103 i ever raced and top end pull was good all the way to 6600RPM

http://www.youtube.com/watch?v=ovEuGp0DsVI

400Eric · #**203** 08-14-2011, 01:24 PM

Jay, please read the post again, I was adding more questions while you were posting.

I figured you were sleeping by now!

We also need to hear from the crazy Idahoan too!
Regards, Eric

JayRash · #**204** 08-14-2011, 01:31 PM

No im not sleeping its 8:30 pm here now and u know hardly sleep

, but 220 lbft is way out of the quest. but 200 hp is reachable. when i turboed the m103 it had some 360000km just like u have i guess 230+kmiles

JayRash · #**205** 08-14-2011, 01:35 PM

oh i did change the head gasket a couple of times on my 300 so maybe the cam timing was slightly retarded after that. but i doubt it would make that big a diff. the car had good pull as ever.

gsxr · #**206** 08-14-2011, 07:40 PM

Methinks you're trying to get blood from a stone here Eric.

AFAIK there is nothing you can really do to increase timing, at best you can try to make the computer not pull any timing, i.e. just have the max allowed by the factory map. Otherwise, you'll need a full standalone fuel system (Megasquirt, etc) and tune it via laptop where you can dial in whatever you want for both fuel and ignition.

I think you will have a very, very hard time getting anywhere near 200hp from a normally aspirated M103 with stock engine management. It just doesn't flow enough air, no matter how much fuel & spark you feed it. You aren't going to "tune" another 20-25hp gain with the stock long block and no forced induction or NOS. Sure, a custom camshaft might bump the top end, but at the cost of low-end torque (further hurting your 60' times).

Remotemark just had a twin turbo kit installed on his 88 300CE (M103) and it made 140rwhp stock (~170hp at crank, pretty close to factory ratings)... with around 6psi boost it was ~210rwhp (~250hp at crank). Based on that you should only need 3psi boost to achieve your goal!

The only thing besides making more power, is to modify the torque converter to allow a higher stall speed, which should improve your launch a bit; along with using the lightest wheel/tire combo you can find (the CLK forged wheels with lightweight rubber like Conti), somewhere in the 35-lb range (or better) for wheel+tire combined at each corner. Oh, and dumping weight.

You already know what I'm gonna say, ditch the 300E's and focus on the 400's, blah blah blah. Or stick a C36 engine + computers in the 300E, or at least an E320 motor. The M104 makes more than the power you want in bone stock form. The 400 can be tweaked to nearly 300hp without much trouble. It just isn't worth the time & effort to mess with a 177hp M103 unless it's forced induction. No ROI.

duxthe1 · #**207** 08-14-2011, 08:27 PM

GSXR makes some good points. Before hanging my turbo, I think I had one of the best breathing N/A 103s around. I doubt it would have hit your target numbers. Despite all of the breathing mods I had done, it still had to breathe through a stock set of manifolds. I just don't think they are up to the task in N/A form. What I'd really like to see is a nice tuned length header on a 103 engine. The only problem then is that you would shortly be at the limits of the intake manifold. You can go a little bigger on the T/B but runner diameter isn't easily changed.

A nice tuned header, an extrude honed intake, a well prepped head... I believe could make some very respectable numbers. The economics of making that happen though preclude most from ever attempting it. For similar or less cash, one can get boost.

400Eric · #**208** 08-15-2011, 03:33 AM

Dave brings up an interesting point that actually also occurred to me right after I turned off my computer right after making my last post. This mod may actually only prevent the pulling of timing when the engine is warm, not add it when the engine is cool. This might also explain why the dummy ECT sensor worked so well on Benzer3 while not helping Benzer1 one bit. When I did the trick to Benzer3, he was warm/hot but when I did it to Benzer1 he was no higher than 80C.

Dave, when I said we need to hear from you on this topic, I meant that we need to hear your thoughts on how to make this work not that it won't work.

Regards, Eric

JayRash · #**209** 08-15-2011, 04:12 AM

When i say it will advance timing, i mean it will only access whats there in the ezl in the first place. the best u can hope for is the timing u get when engine temp at 60C'.

ok went back to my dyno sheet and the numbers it posts are: 151hp @ the wheels @5900RPM
198Hp on the flywheel. so not the 200+hp i hoped for. but i swear that my car improved and became on of the sweetest M103s i have ever driven. I used to race M104 320 W124s and atleast till up to 110mph i would be either on par or slightly ahead..

who knows y my car was that quick. maybe it was just being in good shape and as dave said staying at good timing.

400Eric · #**210** 08-15-2011, 04:50 AM

Well I know that Benzer1 is stronger than the average 3.0L M103 W124. The quickest E/T for one that I have ever seen in a magazine is Car & Driver's CORRECTED 16.3 which is completely eclipsed by Benzer1's UNCORRECTED 15.950, so I at least know that I haven't made things worse nor is Benzer1 a poor example.

I'd just like to be able to consistently run 15s, not just run them once in a while.

I'm going to do as much as I can with Benzer1 while the weather is still hot, as it is a complete waste of time trying to get good E/Ts out of Benzer3 when it is hot anyways. But once we get back into a cooler time of year, I'm going to go back to work on my M119s. I'm also going to try to finish my 90 Volvo too.
Regards, Eric