-Choked to Death-

We install Kennedy Diesel's 3.5" exhaust on our project suburban

They build them; we make them work. For us, that's the general theme when it comes to cars. Detroit does a good job of making something that can satisfy the everyday motorist, but only the re-engineering of a gearhead can yield a product that turns more than just a set of wheels.

Case in point: Our 1996 6.5TD suburban. The exhaust system is so restrictive in places that it actually proves to be not just a detriment to performance, but to efficiency as well. The combination 2.75" and 3" system is kinked so badly at the downpipe that there is nearly no cross sectional area at points. There's a clearance fit for some AC lines downstream that again cuts area in half, plus a soot trap (CAT) which has no business being on a 3/4 ton diesel. All in all, it looks like General Motors designed the exhaust for 6.5TD equipped trucks on a Friday.

Enter John Kennedy of Kennedy Diesel. He sells a fully mandrel bent 3/3.5" exhaust system with no kinks for people who want more than just transportation from point A to point B.

If you live in an area of the country where diesel emissions for your GVWR rating don't require the catalytic converter, we recommend depositing it in the nearest trash can. It's an impedance to power and efficiency, and with a properly fueled and timed 6.5TD you shouldn't be making too many hydrocarbons or NOx emissions.

We chose to start by cutting off the old exhaust with our trusty sawzall. We cut up to where the downpipe ended in front of the AC lines, and then we unclamped the downpipe and removed it.

You can see here the difference between the old downpipe and the new one.

The kit comes with extra length in transition section and the tailpipe, so some trimming is required. This is to allow for a custom fit since there are a few cross member variations among the difference cab and chassis configurations. We trimmed the tailpipe with a 45 and 90 degree combination like what was on the factory tailpipe.

The kit comes with the wrap around style connectors, but we prefer the sealing that a c-clamp provides.

After one trip to our local NAPA, we had all the clamps we needed.

The kit comes with some loose instructions and a CAD drawing of the system as it is put together. The first section of pipe after the 3-3.5" transition has a raise in it, and we found that it was necessary to install it backward to clear the rear most of the three cross members on the suburban. A pickup may be different, and like most "one size fits all" setups, there's some tailoring needed.

We flipped this section around to where the pipe raises in front of the torsion bar cross member.	We trimmed nearly 15" off of this section where it transitions from 3" to 3.5".

To replace the fifty-five gallon drum muffler, we have a louvered style unit that flows straight through the center of the canister. It's actually more of a silencer than a muffler. One has the option, and we chose to point the louvers backwards for maximum sound. We're told that it doesn't matter which way the muffler faces. The power is just about the same, and one should choose based on the sound desired.

The new muffler flows straight through. We installed it so that the louvers were facing backwards.	The new muffler clears the bottom the frame rails nicely, and takes up much less space than the old OE unit.

It's been about a year now, and we are thoroughly pleased with the new exhaust. The best part truly is the sound. It's deep and throaty, and the turbo is easily heard. It's music to the ears. There was a slight power increase, but we know that this new free flowing system will help keep the EGTs in line, and that helps engine cooling during those long pulls.