E300TD turbo boost tweaking, possible? - Page 2 - PeachParts Mercedes-Benz Forum

KarTek · #16 08-30-2009, 10:16 PM

OK, here's an update from my observations this afternoon:

The angle of the wastegate in the relaxed condition is similar to the one shown in the picture. Actually, the wastegate arm is angled slightly more toward the outlet clamp. (Longer adjustment position on the rod).

As for the operation of the vacuum wastegate, prior to starting, the actuator is relaxed and the wastegate is open. After starting, the wastegate closes and remains closed unless the ECU senses an overboost condition at which time, it vents the vacuum on the control circuit and allows the wastegate to open.

Exhaust pressure also aids in opening the wastegate rather than closing it tighter.

Hope this rambling explanation helps.

Olivier · #17 08-31-2009, 03:54 AM

Thank you Evan,
I'll see whats happening today with it. I was wondering if I could find a spring that fit the lengh of the rod to slightly make it harder to open the wastegate, this would create more pressure? No?
Olivier
The important question I forgot to ask, if the arm pass a certain angle toward the clamp, would that open the valve the other way like a swinging door or the valve will sit and shut tight the more the arm is put toward the clamp?
Thank you.
Olivier

KarTek · #18 08-31-2009, 05:37 AM

In this case, the wastegate has a spring that's trying to open it all the time, unlike a pressure type where the spring is trying to close it all the time. You would need a tension type spring working in opposition to the existing built-in spring in order to make the wastegate close tighter.

On a side note, I have read somewhere here that shortening the rod (adjusting the nuts) to bring the control arm into a more parallel position with the exhaust clamp can help increase or stabilize boost.

Finally, to answer your last question, the control arm moves AWAY from the clamp to close. The valve inside the housing stops against the casting to seal like a regular household door rather than swinging through.

You can see it in this picture:

Olivier · #19 08-31-2009, 07:29 AM

Quote:

Originally Posted by KarTek

On a side note, I have read somewhere here that shortening the rod (adjusting the nuts) to bring the control arm into a more parallel position with the exhaust clamp can help increase or stabilize boost.

Thank you Evan,
This is what I did yesterday, I move it a wee more paralel and I thought it was better, then put it back the other way around 5mm pass the original as I thought what I did was wrong. Defenitly the car was more sluggish this morning. I need to put it back again on the paralel side then.
Its not a too bad job to do, the worse is removing the engine mount heat shield, especially with a hot engine. Ouach!
Olivier

Olivier · #20 08-31-2009, 09:52 AM

It look like its a fine tweaking. I put it back a little further from where I did it the first time and the car seems better but not like the first time, need to go under again the put it back another mm or so...
Tomorrow will tell

Olivier · #21 08-31-2009, 01:34 PM

Finally, got it.
I put it back like the first time, about 5mm ot the width of a nut away from the clamp, as Evan says, paralel.
The car is more responsive on first and feel better.
Don't know why it work as it should be the opposite, but it does to me anyway.
Thank you all.
All the best.
Olivier

ingmar55555 · #22 09-01-2009, 05:57 AM

Oliver,

Are you sure by perfoming this tweak that the max. turbo pressure is not exceeded, since at a certain moment max. pressure is reached and wastegate needs to be open ? Issume by adjusting this nut you determine the opening of the wastegate.

Cheers,
Ingmar

Olivier · #23 09-01-2009, 07:43 AM

To tell you the truth I have no clue. All I know is that it worked for me. What I think is that the valve might be slightly open ( as you screw the nuts away from the clamp) but there is still plenty of pressure to boost but it take longer for the electronic to realise or reach the max pressure so the boost might stay longer? But again, I need to be honest, I haven't got a clue.
Next I might look for a spring, that will fit on the rod, this will certainly increase the pressure as the valve will be slightly delayed to open fully.
How's your car?

ingmar55555 · #24 09-02-2009, 09:46 AM

Car runs fine on the home-brewed WVO, last weekend I had a problem...lost the turbo-power, drove home the last 15 km felt less than a 200D

. Appeared to be the main filter that had lasted for 13.000 km that was the cause, after changing the filter I got back my rocket

Not too bad I reackon, my 207 stopped after 2000 Km when changing the fuel.

Before the winter I at least want to check the strainer in the tank, and probably the fuel line change it from 10 to 12 mm, also the heat exchanger will be fitted under the bonnet.

Together with this conversion I willl also change some of the old "gardena-style" fuel lines together with putting in some helicoils for the intake manifold bolds. In the past I think someone torgued them too much

. Might as well change the glow-plugs as well, just preventative.

But first coming friday I willl change my condensor to get the airco working again. Visited a indy/forum member 2 weeks ago and discovered that this was the cause for the malfunctioning.

Cheers,

Ingmar