pugguy2001

I searched some forums and found some good info but it seems to be for the M111 engine and the SLK32 car. How much differnt is it for the M271 engine? Is it as easy as to tap into a tee vacuum line?

Buellwinkle

Just T into a vacuum line near the throttle body.

infected

I believe there was a thread a while back where it was a step by step write up on how to tap into the Vacuum line. He used an Autometer guage that only went up to 15psi and it was mounted on his A-pillar. Try searching it up.

pugguy2001

before or after the throtle body. do i have to remove the engine cover

rlee02135

someone should write up a DIY on this.

pugguy2001

I second that.

white_w203

i have been planning to do this for some time now. this actually brought it back to my attention

levelr123g

I wrote one awhile back, but it was poted on mbklasse.com which appears to be down for some time now.

rlee02135

no, just got to mbklasse.com/forums

pugguy2001

I know i checked it out, it was very helpfull, but your engine is a m111. Has anybody done this for the M271. I cant find a tee to tie into like the M111 has. Has anyone come up with a pillar with the gauge pods in them for our cars. I've been searching and search but no one has a custom replacement. You think with our cars being supercharged there would have been one out along time ago?

levelr123g

I realize that I had a different engine, but the hooup will be the same!

infected

Anyway you can pull the write up back up?

Moviela

A word of caution from someone who has blown a motor by relying on an inexpensive boost gauge. They are not very accurate. They can be as much as 30% away from the true reading. I found that you had to spend around $ 250.00 for an accurate gauge, and pay a test lab about $100. to certify it. That is a little pricey if the gauge is just for show. For show any gauge will be fine, but if you are watching the boost gauge to avoid excessive intake pressure, you really need an accurate gauge.

I had an Audi, and I connected a valve on the dash to the waste gate so I could dial in the power from the c0ckpit. The cheap VDO gauge said I had 4 lbs boost, when I actually had 11. The valves and pistons did not play well together. I had to take a bus home.

white_w203

whoa....aren't defi gauges around that price?

pugguy2001

Is the throtle body on these cars just after the air intake. Is it somewhere in the red area I circled? If so now I just need to tee into a vacuum line?

arell

The boost gauge should be tapped before the oneway valve going to the EGR solenoid which is hidden under the head cover

pugguy2001

Where is the head cover? Can you point it out from this picture.

arell

remove the silver 'Mercedes-Benz' cover. Remove the two bolts below it.
Now you will see the ignition coil packs and a solenoid valve aside. There is a check valve from the solenoid going to the manifold. This is where you will want to 'T' your gauge into.

pugguy2001

Is this what you are talking about? Which side do I tee into, the side by the fire wall or the side towards the front of the car?
Once I removed the Mercedes-Benz cover the coil packs are right there. I didnt remove 2 bolts below it?

arell

yeap that is the solenoid. Further down (not shown in your pic) you will find a check valve. The further end of the check valve (not the end going to this solenoid) is where you Tee off. BTW, blanking off the EGR bleed from the supercharger gave better low end torque. I tried it on the dyno. This I think is due to the engine getting more boost by not allowing some air to the catalytic converter. I have been trying to tune the ECU with Dastek Unichip piggyback system.

arell

BTW, no bolts, my bad!

pugguy2001

Hey thanks Arell, so far so good. I can follow what you are saying. I will take another picture further down to locate the check vavle.
Where is this EGR bleed. When you say blank it you me plug the end.
Thanks for great instructions, so far.

arell

That gold colored actuator where the two lines after the solenoid leads to, above and slightly in front of the header. On the EGR you can see one ~1/2" hose going to the intercooler piping. I inserted an aluminium rod inside that hose to block it off.

pugguy2001

Ok I think you are talking about this 1/2 hose. Is there a way to just cap it of where the hose is connected. If I put a rod inside the hose it will block it off and also make it look as if there was no messing around with it? I like that idea better.
Ok next I followed the hoses from the egr selonoid to the right and towards the front and I see there is a tee with one coming from the egr seloniod, one going into the supercharger and one i dont know where it goes. Then on the other side of the supercharger there is a tube coming out of the supercharger but then it hooks into a thin white tube?
So far I think I am still with you. Your insrtuctions are great!

arell

Yeap I inserted a rod inside so it can't be seen from the outside. BTW, the boost gauge tee off is now clearly marked in the following picture: