Intake/Exhaust Modifications

[RichardLSU]

After reading through this forum for several hours today I've decided that instead of keep replacing the broken intake bracket which makes a horrible rattle sound over and over again I think I would just like to remove it all, buy a 240D oil separator and a cone filter to stick on the front of my turbo. If I could find a piece of angled tubing to separate the turbo from the filter that would be a bonus. Is it really that simple? I've got a K&N filter on my car right now but I've been scared from buying another one...

From what I understand removing the stock setup and replacing it with a cone filter will help the turbo spool faster? Also I've read that putting a free-flowing exhaust system will help it spool faster too. I was thinking about just taking off my old exhaust which is riddled with holes and having a muffler shop just fab up a 3" exhaust strait from the turbo out the back of the car.

Anyways, any input from anyone who's done this before??

[MTUpower]

Check the diesel performance section- I did many of those same things to my 84 wagon. You can find a proper paper cone filter instead of oiled cotton/gauze.

[RichardLSU]

Has it worked for you? I've been reading horror stories and plenty dismissing them...

[tbomachines]

Well the intake is already a true cold air intake. Much of the debate revolves around K&N filters (see thread that is active now) and it is generally agreed on this forum that the oil-fabric filters are not as effective as a good ol' paper filter as MTU said. Exhaust can decrease spool time marginally, but IIRC the biggest bottleneck on the exhaust side is the turbo itself, so straight piping it or widening the diameter won't do TOO much. If you're looking for more power, generally the best way to start is with fuel mods (ALDA removal, etc.). You'll find a lot of good reading in the diesel performance section at the top of the diesel board index page.

[ConnClark]

On a 300SD a performance muffler does help some because its not a straight through muffler. I threw a cherry bomb on my SD and boost did come up sooner.

Edit:
Richard,

I noticed you have an 85 SD. The intake on that is near optimal.

[MTUpower]

Originally Posted by ConnClark

The intake on that is near optimal.

Removing the muffler helped my car and it's not really loud as some claim. Now the intake is mechanically near optimal, but it sure is ugly and those pesky rattles and rubber mounts just do not go together.

[panZZer]

Someone in the parts section has an 85 cali aircleaner for sale right now--They are like mini Semi truck filters and are the best---but the elements are around $51.00
Some people could modify a 76 w115 300d aircleaner -add another aperture -and enlarge the outlet to turbo elbow tube and also have a good aircleaner that route too, Those elements are about 3/4 the surface area of the 85 Ca one and much less expensive.

[ConnClark]

Okay,

An 85 Cali air cleaner has some advantages (other than cost of the filter). I do think the flex tube that feeds the turbo on it could be replaced with something smoother to lessen the turbulence fed into the compressor though.

[RichardLSU]

Well I'm working on it right now. I've pieced together an intake tube with a 90 degree angle right off the turbo, another peice with vacuum line ports and then fitted it to a cone style filter. Its all 3" in diameter. I've got a Kobalt air/water separator for an air compressor to use as my oil separator. 13 bucks at Lowes! 5/8" line coming from the valve cover into the separator, then 3/8" line draining into the return line and another 3/8" line to return air into the intake. I'm in the whole separator for about 25 bucks. The intake and filter I'm in for about 50 dollars. We'll see how it sounds when I start it up.

I also got some diesel purge to run on my injectors, hopefully to quiet a little of that nailing sound. Its really not all that bad but I figured a little injection cleaning wouldn't hurt.

I'm replacing the alternator a the same time while I've got it all jacked up and am currently waiting for a ride back to the hardware store for a 22 or 23mm socket to get the pully off the front of the old alternator.

I'm pumped to see how this turns out and I'm taking pictures.

[RichardLSU]

Originally Posted by ConnClark

On a 300SD a performance muffler does help some because its not a straight through muffler. I threw a cherry bomb on my SD and boost did come up sooner.

Edit:
Richard,

I noticed you have an 85 SD. The intake on that is near optimal.

I noticed the pipe coming out of the back of the turbo just heads strait down and out the back of the car. My exhaust is pitted and full of holes and needs replacing anyways, which is why I'm looking into having one made. Probably cheaper that way than trying to source, buy, ship a new one for my car.

Performance is not only the reason I want to change my intake setup. I've busted 3, yes, count them 3 intake housing brackets and I think having a small filter right off the turbo looks a hell of a lot better when I pop the hood. I like seeing that turbo sitting there . I would find a nice stainless steel or aluminum housing, I hate the chrome, but this is all temporary for a few years until I start working on the super-turbo version of this engine. I'm collecting a nice pile of parts for when I have the time.

[Diesel911]

This is what I did with washable Fram filter that unlike the K&N types needs no oil or special washing fluid. I got all the ABS Plumbing at the local Lowe's Home Improvement Store.
The filter is can be a little hard to find. I bought the only one they had at Walmart and the other I ordered on the internet. I have one on the Mercedes and other one on my Volvo Diesel.
Washable Air Filter and Intake Mod , With Larger Breather
Washable Air Filter and Intake Mod , With Larger Breather

In the below thread towards the end is a similar intake but it has a larger non-washable Paper element Fram Filter; if you think there is room for that.
Also in that thread is another thread I did testing the Hot Air Intake. In actual fact the only time hot air builds up under the Hood is when you idle. Ounce you start moving that temp drops quickly to nearly the outside temp; even in City traffic.
But, that is with no sort of Belly Pan under the Chassis.
any real benefit to a K+N filter

[Gillig]

Originally Posted by RichardLSU

I think having a small filter right off the turbo looks a hell of a lot better when I pop the hood.

Thats half the problem.

You'd be better off with something decent like this: http://www.peachparts.com/shopforum/attachments/diesel-discussion/84716-any-real-benefit-k-n-filter-8037a.jpg

[Diesel911]

Originally Posted by Gillig

Thats half the problem.

You'd be better off with something decent like this: http://www.peachparts.com/shopforum/attachment.php?attachmentid=84716

On mine the AC Hose prevents using a larger filter.

[RichardLSU]

Originally Posted by Gillig

Thats half the problem.

You'd be better off with something decent like this: http://www.peachparts.com/shopforum/attachment.php?attachmentid=84716

Let me rephrase that. Having a stand alone air filter on the end of the intake pipe looks better than that large, heavy air cleaner assembly that was previously attached to the side of my engine above the turbo.

And that picture is pretty close to what I put on there.

I kind of resent the comment about my work being a hack-job, but I'll let the pictures speak for themselves when I get them posted. You'll notice no duct tape or evidence of presidential procedure.

The whole setup seems to work very well. Once I finished I drove it to work (about a 30 min drive) and I noticed the boost coming on early, around 1900rpm like I'd read. The revs at 60mph dropped about 500rpm and my accelleration seems to be better, probably because I have boost from 1900-3000rpm instead of 2500-3000.

My oil separator works very well and my oil pressure has increased at idle from right around 2 bars right up to 3. It dropped a little below 3 sitting at a stoplight a couple times.

Yes, I plan on rebuilding the injectors. On Thursday it goes into the shop to get the valves adjusted again. Its been about 30k since I had them done last, I'm hoping that will make it run a little smoother.

[RichardLSU]

Also, if anybody is interested the bolt on the front of the alternator pulley is 22mm. Might save somebody a second trip to the hardware store like I had to take!