300SEL Twin Turbo Project. - PeachParts Mercedes-Benz Forum

osama · #1 03-02-2011, 07:16 PM

Hello everyone..

first of all.. Im sorry, because i did not document the setup and installation of the project. but its a KIT so you didn't miss much

I got the Mosselman Twin Turbo KIT from Jay, Thank you Jay

Installed it, took us a bit of time, had to make new downpipes as the old ones were old

plus on the W126 there is like a bridge connecting the chassis together, this had to be taken off if we were to use the old downpipes.

now its back on.. don't really know what exactly its for, im sure it has to do with handling.

Results?? AMAZING, the car is way much more powerful and i get 0.45bar on the boost gauge.

things that could have gone wrong, but thankfully didn't:

Temp, very cool always below 80. (although the inter cooler gets very hot, and the pipes to the inter cooler gets very hot too, strange?!)

AFR, well i need your help on this one to decide if there if a problem or not.
when i first start the car, its 12 then slowly goes up to 14~14.7
upon acceleration and under boost, its always under 14
some times when revved hard get down to 11 and 10

But, sometime after stopping the engine for 10 minutes and starting again, and also when driving down hill (using only gravity at speeds lower than Five (5)KMPH and slight pressure on the brakes it reads 18 and 19 , , it immediately goes back to normal ~14 when i accelerate..

So do you think i have a problem here?

Oil Pressure, Seems fine to me, but something is bothering me and this doesn't happen all the time.. on idle, the pressure drops below 1. once even to 0. a slight pressure on the accelerator pedal will instantly make the pressure go back up to 2. What do you think?

Now to the things that did go wrong.

The Gear Box.. now its not as smooth as it was, same problem jay was facing, harshly shifts when accelerating slowly even hard back shifts from 3rd to second , but on full throttle strangely smooooooth shifts. i did not try 3rd and 4th gears yet. Jay you said you solved the prob. but you didn't say how in your thread when you installed the kit

Ignition.. (Maybe?)
on high RPM and under boost, i heard some noise, something like a small bill ringing fast, and my mechanic told me its a valve sound.. dunno im not sure. but could it be the timing?

I have 2 knobs to adjust the EZL timing, one next to the ECU inside the car (in the passenger feet compartment) and one under the hood. i dont remember now what they are set for, will check and report back. but i need as much info as possible about this..

Is there any recommended OIL brand or a specification that i should be looking for?

Guys im really sorry i don't have any video or pics now.. but i promise you i will detail everything either with a pic or with a vid tomorrow. we were to excited to get the car on the road that none of us, my friends and i, even thought about holding the cam corder and document everything.

We Appreciate any help or comments.. we are no experts, hardly even beginners.. all our knowledge is derived from Forum(s)... mainly this forum, and some book reading.

I Promise you next time the post will be shorter

JayRash · #2 03-03-2011, 03:21 AM

Man that ball sound bouncing at high revs is knock watch out man set the ezl knob to N and try again. Did u use the cupor head gasket! Afr is fine and it should read lean on light or no throttle.

Also for oil press issue did u use a restrictor on the line feeding the turbos? Don't open more boost before u know u have no knock. If there remains knock then u might have to retard the cam shaft, as I have heard the sprocket on the M103 can be used in 2 positions; stock and retarded by some 3deg which should be enough to drop ur dynamic compression a little releasing more top end power.

osama · #3 03-03-2011, 05:57 AM

i did not use the copper head gasket yet, id didn't open the engine head.

yes i used the oil restrictor, maybe we need to restrict more?

i'll set the ezl to N or 7, correct?

i will take photos and hopefully some videos and update here within a couple of hours.

nick.ged · #4 03-03-2011, 11:02 AM

top mount intercooler was the mosselmans achiles heel.

fit a front mount, you will get more reliablity and more power.

cooler intake temps will lead to less pre ignition.

JayRash · #5 03-03-2011, 12:13 PM

True very true but for .5 boost it should do fine if the air duct is connected. But a front mount can't hurt and the 126 should have the room for one.

osama · #6 03-03-2011, 02:00 PM

Fabrication of new air pipes is not an easy choice for me..
i advanced both EZL knobs to 7. then we noticed that the car is not idling very well, although AFR readings were in the OK margin, i disconnected the O2 sensor (not the afr one, the original one) and it turned out i was running a bit rich.. retuned it again with the sensor disconnected and its now idling well with even better AFR Readings.

and the oil pressure issue seems to be fading away on its own. or at least im hoping so.

but What about the gearbox?

its really shifting hard, i removed the hose from the gearbox to the intake manifold, and the car shifts on WOT.

when cruising around it shifts hard,, but upon hard acceleration it shifts almost too smooth to be normal.

RBYCC · #7 03-03-2011, 02:38 PM

Quote:

Originally Posted by osama

Fabrication of new air pipes is not an easy choice for me..
i advanced both EZL knobs to 7. then we noticed that the car is not idling very well, although AFR readings were in the OK margin, i disconnected the O2 sensor (not the afr one, the original one) and it turned out i was running a bit rich.. retuned it again with the sensor disconnected and its now idling well with even better AFR Readings.

and the oil pressure issue seems to be fading away on its own. or at least im hoping so.

but What about the gearbox?

its really shifting hard, i removed the hose from the gearbox to the intake manifold, and the car shifts on WOT.

when cruising around it shifts hard,, but upon hard acceleration it shifts almost too smooth to be normal.

The Mosselman piggy back control always ran a bit rich at low speeds.

As far as the hard shifting you may want to adjust your linkage as the M103 is all mechanical using a Bowden cable and is adjustable for shift points.

http://w124performance.com/service/W126/w126CD1/program/Engine/103/30-300.pdf

JayRash · #8 03-03-2011, 06:00 PM

Don't mess with one for the injection only the on in fender man

JayRash · #9 03-03-2011, 06:04 PM

For the gear box there is a diagram on my thread provided by rbycc I think on how to install the hose. Also adjust the gearbox modulator to firm up the shift at full thort or else u cook the box oki. When I'm home I'll email the diagram. Any ways

osama · #10 03-03-2011, 06:04 PM

Quote:

Originally Posted by JayRash

Don't mess with one for the injection only the on in fender man

you mean the EZL knob??

tbomachines · #11 03-03-2011, 06:38 PM

If your trans is anything like the diesels (it is), shift harshness is controlled by a vacuum modulator on the passenger side of the trans. On the diesel section there are tons and tons of vacuum tuning for transmission. The Bowden cable just adjusts the shift points around--while important to tune (since it stretches over the years) it shouldn't affect the firmness of your shifts. As far as the knocking you really gotta be careful...install a FMIC if you can afford one. The heat you feel off of the IC and piping is actually a good thing, means its doing its job transferring heat outside of the system, but top mount intercoolers have almost never been as efficient as front mount. Cool the intake air down a bit more and it will help with the knocking.

RBYCC · #12 03-04-2011, 12:32 PM

Quote:

Originally Posted by tbomachines

Cool the intake air down a bit more and it will help with the knocking.

Inexpensive and easy to install a water/meth injection that will spray the intake air under boost to lower the charge temp.

osama · #13 03-06-2011, 08:13 PM

Sorry for the late reply, but i lost my internet connection for the last couple of days..

many things happened, some good some bad.

the good thing is, after providing vacuum for the transmission modulator using this diagram

The transmission is shifting much better, almost as it did before the turbo. But i have a question here, doesn't the 12mm orifice effect the boost? doesn't it count as a leak?

to fix that, i think its time to adjust the modulator, anyone knows some tips here?

The bad news is, i lost the Power.

We removed the exhaust manifold to do some welding on a small crack.. both manifolds.. and installed everything the way it was. now the power is gone.

its very annoying because nothing had changed. just welded the manifold!!

i checked for leaks, nothing. the boost gauge is reading 0.45 @3KRPM, yet the previously strong but now weak power surge from the turbo kicks in @ 4.2~KRPM
(this situation also existed before the addition of the vacuum hoses to the modulator.)

there is something that i don't fully understand, now since the turbos boost 0.45 bar ~ 6psi , does this mean that each turbo is boosting 6 psi or each is boosting 6?

i changed the EZL Knob to 7 and the knock is gone. don't hear it anymore even @ 6.5KRPM

another question.. what oil should i use? 10-40 or 20-50?

We feel we are almost there, only if we can reduce the turbo lag to 2.5KRPM , how can we do that, any tips ??

Dearlove · #14 03-06-2011, 10:21 PM

are you now pinging when you're on boost?? because if you've got that rattling sound you'll have no power... and soon no engine

are you using good fuel? as in 98 ron?

osama · #15 03-07-2011, 03:40 AM

Quote:

Originally Posted by Dearlove

are you now pinging when you're on boost?? because if you've got that rattling sound you'll have no power... and soon no engine

are you using good fuel? as in 98 ron?

I don't hear the pinging sound anymore, actually no noise of any kind.. and yes im using 98 ron.

what else could it be?