Cali 617 Test Pipe - PeachParts Mercedes-Benz Forum

mach4 · #1 07-22-2012, 10:17 PM

The OM617 engine in my 380SL has a California version of the engine rather than the federal. I've decided to build a test pipe to temporarily eliminate the trap-cat, also commonly called a trap-oxidizer as that was what was originally installed in the vehicle. The jig is being built with a junk yard trap-cat, so I will always have the original one available to reinstall once the testing is complete.

This wonderful technological device does seven things really well - it increases emissions, increases fuel usage, decreases power, reduces turbo performance, takes up a huge amount of space, forces the use of an expensive, special CA-only starter and reduces visible soot so the car appears to run cleaner.

To build a test pipe requires a stable jig that maintains the absolute relative position of the exhaust outlet and the turbo inlet, such that when the test pipe is installed in the vehicle it will fit properly.

The best solution is to cut the flanges off a clogged trap-cat and weld the new pipe to those.

Here is a picture of the trap-cat mounted in the newly fabricated jig.

To build this I fabricated a couple of plates that matched the turbo inlet and the exhaust outlet bolt pattern. I then bolted these firmly to the trap-cat and using sturdy angle iron welded up a simple yet sturdy jig to hold the trap-cat.

Once I had that done, I could cut the flanges off the trap-cat and prepare for fitting the connector pipe. My original intent was to cut the flanges with the trap-cat in the jig, but there just wasn't enough room to maneuver the cut off saw.

I'm not exactly sure what I'm going to use for pipe, but it will probably be just a 2" 180 degree piece of exhaust material that when cut, will provide me with the two 90 degree fittings I'll need and the straight pipe to join them.

The one tricky thing is the turbo inlet which is a rectangular shape so that will take a bit of fabrication and fitting.

More to follow...

Diesel911 · #2 07-22-2012, 10:50 PM

I think there is 2 of our Members who have made thier own Test Pipes. They both have threads and could be consulted concerning materials.

280EZRider · #3 07-23-2012, 12:19 AM

I have a feeling your testing will go on indefinitely, as there is much information to be gathered. Of course, there is always the option of going next door to a neighboring state where you know someone, registering the car there, and having done with it.

Sometimes this detuning junk just mysteriously disappears without any explanation!

mach4 · #4 07-23-2012, 12:30 AM

Quote:

Originally Posted by Diesel911

I think there is 2 of our Members who have made thier own Test Pipes. They both have threads and could be consulted concerning materials.

I've seen the finished products but not the methods, which is why I decided to post a howto on the way I approached the problem.

sixto · #5 07-23-2012, 01:39 AM

Your jig doesn't simulate the EGR supply port

Wouldn't it be more practical in the long haul to swap in a non-trap manifold and turbo? Much as there is to love about that California air cleaner notwithstanding.

Sixto
87 300D^2

mach4 · #6 07-23-2012, 01:58 AM

Quote:

Originally Posted by sixto

Your jig doesn't simulate the EGR supply port

Wouldn't it be more practical in the long haul to swap in a non-trap manifold and turbo?

I'm using a virtual EGR port...for testing purposes. It's kind of hard to see, but it's there.

I was thinking that the 78-9 SD intake/exhaust might give me a cleaner look, but there was some speculation that the lower positioning of the turbo might provide some interference with the fender wells in my tighter engine compartment (380SL). Going that route would entail swapping out the turbo line, the intake and exhaust manifolds, turbo, U-tube, and some form of air cleaner setup.

For the time being, I think that this will be clean enough... for testing purposes only. If I score a better system, it's not that tough to swap in.

DeliveryValve · #7 07-23-2012, 02:11 AM

This fella did a similar project. He built his jig on his metal bench. At least you can move yours around more easily.

http://www.peachparts.com/shopforum/diesel-discussion/314680-cat-ox-delete-pics-my-85-300d-mini-intro.html

.

mach4 · #8 07-23-2012, 02:22 AM

Quote:

Originally Posted by DeliveryValve

This fella did a similar project. He built his jig on his metal bench. At least you can move your around more easily.

Somehow I missed that thread. Thanks. I like his tube.

I wanted to do something that could be used over and over. Maybe even in the tool rental program. I have another trap-cat that I'll probably make up another unit using its flanges.

Jeremy5848 · #9 07-23-2012, 02:31 AM

Nicely done. I had a test pipe made for my '85 300D-T. It was a one-off and made for me by a professional welder/machinist so it was expensive but at the time it was my only option. With a jig you'll be able to make as many as you have customers for.

You might try selling test pipes on an exchange basis. Customer sends in his trap and you immediately ship out a test pipe so that the customer's car isn't down more than a couple of days. Option: charge a deposit, refundable when the customer sends you his trap, after installing the test pipe. Either way, you'll always have a trap from which to cut flanges for the next test pipe.

Pay attention to Sixto's comment. You may be able to get along with a virtual EGR port but some folks may need a real one, depending on the smog inspectors in their state.

Good luck with your new job!

Jeremy

DeliveryValve · #10 07-23-2012, 02:32 AM

Quote:

Originally Posted by mach4

Somehow I missed that thread. Thanks. I like his tube.

I wanted to do something that could be used over and over. Maybe even in the tool rental program. I have another trap-cat that I'll probably make up another unit using its flanges.

That's a great idea. All someone needs to do is take it to a capable exhaust shop to cut off the flanges and weld in the new pipe to the flanges bolted in place on the jig.

.

mach4 · #11 07-23-2012, 11:55 AM

Quote:

Originally Posted by Jeremy5848

Pay attention to Sixto's comment. You may be able to get along with a virtual EGR port but some folks may need a real one, depending on the smog inspectors in their state.

It would be easy enough to add. I'll probably go ahead and include it - most likely as a bolt-on addition to the jig. Positioning isn't 100% critical since it attaches with somewhat of a flex hose.

eatont9999 · #12 07-23-2012, 12:46 PM

I feel sorry for you guys in Kali. It seems the citizens there are always getting bent over one way or the other. In TX there is no emissions inspection for Diesel vehicles so I am lucky. I can't wait for parts to be made so I can delete my EGR.

charmalu · #13 07-23-2012, 12:57 PM

You do have your yearly or bi-yearly vehicle inspections, and have to have a sticker on the windshield. at least we don`t have that one here in Kali bend over land. Just the smog checks every other yr on gassers and on Diesels newer than 98.

You are right, we do get the shaft here in Kali land in many other ways. what starts here, polutes the rest of the country.

Charlie