Is there anyway to lower the required Turbo RPM for the stock everything OM603? I was looking into performance intakes, but I guess the only real thing I want to accomplish is hearing the sound of the Turbo spool up and whistle. Any recommendations? Performance intakes?

Give up on hearing it, and adjust the ALDA a bit for more off the line power.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

A good Air-To-Air-Aftercooler and pipes will sometimes make the turbo sing. It's a pretty small turbo to get much sound out of though.

__________________

Gone to the dark side

- Jeff

I have an 1983 300SD that I bought an after market K&N style performance intake and it sings awesomely at a little after takeoff. I was hoping that there would be something like that for the OM603 Turbos.

Let clear this up, a small K&N filter on the end of a cheap tube is NOT a performance intake.

If you can hear the tubo its got problems. Without an intercooler you should not be able to hear it over the sound of the engine's intake.

Thanks for clearing it up then. Does this mean my 617 is weaker than it should be?

No its running fine but if your turbo is whistling you either have sealing problems around the inlet or your filter is inadequate.

Whats wrong with the stock setup anyway? the stock filter is pretty big....Unless you have an intercool why change it?

__________________
1981 300SD 512k OM603

I took off the stock because I simply thought that it was better sounding and that I don't have to worry about those damn rubber mounts that break every week. Plus I do get a bit more off the line performance. When I first got it, I switched the stock and the aftermarket and it would not whistle with the stock, then would whistle with the aftermarket. I just thought it's less weight and sounds cool and supposedly "gets more MPG" due to better respiration.

The mounts break becasue your engine is vibrating too much. Look up "rack damper". Putting a piece of radiator hose between the valve cover and filter housing will also help stop the mounts from breaking.

Thats not possible. There is no throttle so between idle and flooring the throttle there is no change in airflow. The stock air filter system can flow 450cfm, even after the engine is modded to burn all the fuel the stock injection pump can flow the engine will not hit 450cfm. The better performance is a psychological affect of the louder intake, you think its faster because its making more noise. Do some 0-60mph tests with both filters then none at all and you'll find the times to be almost identical.

It gets slightly beter economy becasue its taking in hot air from the engine bay. Hot air is thinner which means less air is being pumped through the engine.

Hot air gives worse mileage, it is less dense and provides less oxygen to the mixture.

K&N filters claim better fuel mileage and better power because some manufacturers' filters restrict flow enough to hurt mileage and power.

The real affect is that most people are replacing an old clogged filter with a new K&N filter and get more flow just as they would with a new factory filter.

K&N filters are okay, but a lot of hassle for a daily, and IMO not as good a filter (especially if not oiled properly). They also tend to get some oil in the intake, not an issue for those of us without MAF sensors (started in '96 on MB diesels).

Biggest thing is (as mentioned) it is getting hot air from behind the radiator, which being less dense affords less power.

__________________

Gone to the dark side

- Jeff

Not if you want an air filter that actually filters well, the gauze in a K&N does no filtering. The oil is what catches, not filters, the dirt.

Would you trust a filter you can see through on your engine? Thats why it flows so well.


Read through these sites.
http://home.stny.rr.com/jbplock/ISO5011/SPICER.htm
http://www.bobistheoilguy.com/airfilter/airtest3.htm
http://forums.roadfly.com/forums/porsche/porsche_944_924_968/4959457-1.html
http://forums.roadfly.com/forums/porsche/porsche_944_924_968/4948180-1.html

So let me get this straight. I should go back to conventional Air Filters? It's really rather embarrassing, but it looks like I put my money in the wrong place.

Yes, even if its a Fram on the end of a tube like mine (see attached picture), conventional air filters are far better than any K&N.

K&N's market is based on hype and myth, as are most scams.

Attached Thumbnails

 

yes, it is and yes you did.
Hey, BTW, I have a K&N round filter for sale...

__________________
1984 300D

Well I'm on way to replace it back to my old filter that I thought was worse....

In that picture though....through what I've read here...we go back to the filter absorbing engine heat?