PeachParts Mercedes-Benz Forum - View Single Post - Basic question: Can performance be increased in a 300D & 300SDL??

rcounts · #6 09-20-2009, 11:27 PM

Quote:

Originally Posted by 82-300TD

The stock exhaust can have the cat removed, but the muffler is already a straight through free flowing design. Increasing size has no power or economy benefit.

Well, unless you're talking about a Cali car with a trap-ox, there isn't a catalytic converter (or anything like it) to remove. There is a resonator ahead of the muffler. Numerous people have reported noticeable performance increases by removing both the resonator AND the muffler. I personally have not done this yet - have you 82-300TD? I've heard others say the stock muffler is a straight-through design, but I've heard just as many people say that it isn't, so I don't think you can say that all of them are.

At any rate. a diesel will perform at its max potential with NO exhaust installed whatsoever. Therefore the closer you can get to that (while still remaining civilized about it) the better. Therefore the most wide-open exhaust you can install will help with performance. I intend to upsize mine to 3" pipe all the way from the turbo flange back. It may not yield a huge performance increase, but it sure can't hurt.

Quote:

Originally Posted by 82-300TD

...A cone filter that is too small for the engine, doesn't filter well and sucks in hot engine bay air is a major downgrade, not an upgrade. I have yet to see a single person measure intake restriction with the stock filter system then a hot air intake.

I'm not talking about restriction from the filter. I'm talking about the air having to make a 90* turn (downwards) into the opening in the bottom of the air cleaner, followed by another immediate 90* turn (towards the front of the car) coming out of the bottom of the air cleaner, followed by a 180* turn through the U-tube (from moving towards the front of the car to moving towards the back of the car) before entering the turbo inlet. Air has mass, and twisting and turning through that labarynth to get from the inlet pipe above the headlight to the turbo inlet can't result in the best possible flow.

I'm also NOT talking about a small cone filter exposed to hot underhood air. Read what I said again. I am talking about a LARGE cannister filter - like around 8" in diameter and 10" long. I am also talking about installing a partition between the inner wheel well arch and the radiator support - to effectively isolate the entire area behind the headlight all the way from the radiator support to the wheel well. This would form a large cold-air "box" that is isolated from the rest of the engine compartment. The cannister filter would be installed inside this box effectively making it a large cold-air intake chamber.

The only opening through the partition would be a hole where the intake tube between the cannister filter and the turbo inlet passes through the partition panel.

With the size and style of filter I'm considering, the filter area will be in the neighborhood of 250 square inches - not even counting the pleats in the filter media (8 x pi x 10). This is pretty much exactly the same area as the stock filter (13 x pi x 6), but with an intake path that is a single smooth, gradual 90* curve - instead of all the sharp twists and turns of the stock intake path.

And no, I don't have a $50k flow bench to test it on, but it is logical that the straighter intake path would be a benefit, all other things being equal.

Seems like it would be worth trying to me.