Tuning with CIS - Page 12 - PeachParts Mercedes-Benz Forum

gsxr · #1 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 · #2 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 · #3 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 · #4 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 · #5 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

400Eric · #6 08-16-2011, 11:22 PM

Jay, what was the peak torque reading on your dyno sheet and at what RPM did it occur?
Regards, Eric

400Eric · #7 08-18-2011, 10:48 PM

Jay? Jay! Jay the Jayer where are you?

JayRash · #8 08-19-2011, 06:16 AM

Eric im back,

Ok the i gave u was with the fuel trick on as well as timing. so car was rich. and between 2000 rpm and 4000rpm the graph for torque is clearly not smooth.
numbers for that run were exactly:
pw at eng: 145.2 KW ( 197.5hp) @5950 rpm
pw at wheels: 112 kw ( 152.3hp) @5950 rpm

Tqat eng : 250nm @ 5200 RPM

RBYCC · #9 08-19-2011, 09:36 AM

Quote:

Originally Posted by JayRash

Eric im back,

Ok the i gave u was with the fuel trick on as well as timing. so car was rich. and between 2000 rpm and 4000rpm the graph for torque is clearly not smooth.
numbers for that run were exactly:
pw at eng: 145.2 KW ( 197.5hp) @5950 rpm
pw at wheels: 112 kw ( 152.3hp) @5950 rpm

Tqat eng : 250nm @ 5200 RPM

Jay

Falls in line with my baseline dyno pulls for my M103-12V USA spec motor.
Stock engine tuned to factory spec with stock cat and exhaust
135.9 RWP @ 5500RPM published 177HP
145.3 Wtorque @ 4500RPM published 188 torque
My torque band seems lower then yours !.

Your Euro spec should be about 10HP/Torque at the wheels higher.

Ed A.

JayRash · #10 08-19-2011, 12:02 PM

Quote:

Originally Posted by RBYCC

Jay

Falls in line with my baseline dyno pulls for my M103-12V USA spec motor.
Stock engine tuned to factory spec with stock cat and exhaust
135.9 RWP @ 5500RPM published 177HP
145.3 Wtorque @ 4500RPM published 188 torque
My torque band seems lower then yours !.

Your Euro spec should be about 10HP/Torque at the wheels higher.

Ed A.

i know ed that my M103 seems running a lower total tq number than stock which was rated at 260+nm at 4500. this leads me to think that the cam timing must have been set with retard at some point. which in it self brings up other questions. usually retading a single cam engine will lead to shifting of the power range up wards in the rpm range, thus maybe the trick has little effect on top end maybe a few hps 5 at best. the rest must have come from the retard. and any better low end i felt could be very much due to the increased timing by the trick when warm. its another reason y my M103 had no knock with the trick. Eric will report with time what he finds on his car.

400Eric · #11 08-19-2011, 06:22 AM

Thanks Jay!

What would that torque figure translate into in "foot pounds" of torque?
Regards, Eric

JayRash · #12 08-19-2011, 06:34 AM

185 lb

400Eric · #13 08-19-2011, 07:24 AM

Thanks Jay.

I have no doubt that this mod works when the engine is operating at elevated temperatures, I saw it first hand with Benzer3. That's why I'm leaving the resistor hooked up so that I'll see the benefit in daily driving.

I do however need to come up with a way of advancing the timing when the engine is at around 80C. Anybody have any ideas? The one that I have come up with is to move the vacuum line the feeds the vacuum signal to the EZL to a different source, one that still maintains a little vacuum even when under WOT conditions. We used to call such a vacuum source a ported vacuum source vs. a manifold vacuum source. (But I may have that backwards though.) This would fool the EZL into thinking that the engine is under a semi part throttle condition and thus is in need of more ignition lead. Obviously, I would need to proceed with this plan slowly, gingerly, and carefully and it would have to be just a little vacuum being supplied, not a lot cause we are only after a little more ignition advance, not a lot. I'll test and monitor the different vacuum ports on the engine with my vacuum gauge under varying conditions to see which port will serve this goal best. I'm thinking the one that sucks the fuel vapors out of the charcoal canister may be a front runner for this job.

Anybody have any thoughts on any of this? There's a mid-90s Nissan Maxima that runs consistent 15.9s (my 15.9s are NOT consistent) at the track that I want to be able to spank!
Regards, Eric

RBYCC · #14 08-19-2011, 09:48 AM

Quote:

Originally Posted by 400Eric

Thanks Jay.

I have no doubt that this mod works when the engine is operating at elevated temperatures, I saw it first hand with Benzer3. That's why I'm leaving the resistor hooked up so that I'll see the benefit in daily driving.

I do however need to come up with a way of advancing the timing when the engine is at around 80C. Anybody have any ideas? The one that I have come up with is to move the vacuum line the feeds the vacuum signal to the EZL to a different source, one that still maintains a little vacuum even when under WOT conditions. We used to call such a vacuum source a ported vacuum source vs. a manifold vacuum source. (But I may have that backwards though.) This would fool the EZL into thinking that the engine is under a semi part throttle condition and thus is in need of more ignition lead. Obviously, I would need to proceed with this plan slowly, gingerly, and carefully and it would have to be just a little vacuum being supplied, not a lot cause we are only after a little more ignition advance, not a lot. I'll test and monitor the different vacuum ports on the engine with my vacuum gauge under varying conditions to see which port will serve this goal best. I'm thinking the one that sucks the fuel vapors out of the charcoal canister may be a front runner for this job.

Anybody have any thoughts on any of this? There's an older Nissan Maxima that runs consistent 15.9s (my 15.9s are NOT consistent) at the track that I want to be able to spank!
Regards, Eric

Eric

I would think the manifold vacuum would give a more linear smoother signal to the EZL.
The ported may cause low RPM problem as the signal is a bit more choppy.

Anybody fool around with a one inch spacer between the throttle body and the manifold.
I know it works on LS2 Chevy engines as I installed one on my C6 vette.
On other engines it is not so effective...
It's typical a machined aluminum plate with a helix bore...theory is a larger charge of air that is sped up by the helix bore...doesn't increase volume so will not lean out.

Ed A.

400Eric · #15 08-21-2011, 12:59 AM

Quote:

Originally Posted by 400Eric

I have no doubt that this mod works when the engine is operating at elevated temperatures, I saw it first hand with Benzer3. That's why I'm leaving the resistor hooked up so that I'll see the benefit in daily driving.

I do however need to come up with a way of advancing the timing when the engine is at around 80C. Anybody have any ideas? The one that I have come up with is to move the vacuum line the feeds the vacuum signal to the EZL to a different source, one that still maintains a little vacuum even when under WOT conditions. We used to call such a vacuum source a ported vacuum source vs. a manifold vacuum source. (But I may have that backwards though.) This would fool the EZL into thinking that the engine is under a semi part throttle condition and thus is in need of more ignition lead. Obviously, I would need to proceed with this plan slowly, gingerly, and carefully and it would have to be just a little vacuum being supplied, not a lot cause we are only after a little more ignition advance, not a lot. I'll test and monitor the different vacuum ports on the engine with my vacuum gauge under varying conditions to see which port will serve this goal best. I'm thinking the one that sucks the fuel vapors out of the charcoal canister may be a front runner for this job.

Anybody have any thoughts on any of this? There's a mid-90s Nissan Maxima that runs consistent 15.9s (my 15.9s are NOT consistent) at the track that I want to be able to spank!
Regards, Eric

Dave, you never weighed in on the above post.
Also, the difference in the amount of power robbed by automatics vs. the amount of power robbed by manuals is greater than you think. It's a known fact that some automatics rob as much as 45 horsepower! The power loss range for automatics is 18-22% while the power loss range for manuals is 15-18%. I think our 722.3 autos are at least in the 20% range. Did you know these old dinosaur 722.3s have over a thousand moving parts? Supposedly the 5 spd auto that replaced it has only about half that many moving parts. These old trannys aren't the lightest things around either. Lots of reciprocating weight!

Ed, thanks for the informative post. As I understand it, another mark against the inertia type dynos is that turbo cars don't really build full boost on them because they don't fully properly load the engine like it is loaded in the real world. Do you agree with that?

Jay, you said your chassis dyno is a Bosch dyno. Is that an eddy current load type dyno or inertia type dyno?
Regards, Eric