Time for a little work in process on the exhaust system. This is the last major item to fabricate before I start the electrical.
I probably have 50+ pics of various SLC exhaust setups. I had a few requirements for the exhaust and wanted to incorporate the following features into the system:
1)ODB2 emissions compliance with front and rear O2 sensors
2)EPA-ODB2 400 cell certified catalytic converters
3)Street Resonators - keeps the drone down
4)Optional Street Mufflers - keeps the volume down
5)304 Stainless - Long lasting
Here is a short video covering part 1 of the exhaust fabrication…
A few installs in particular caught my eye and decided to leverage some other builder’s approaches:
1)Fabricated down pipes like Ken Roberts
2)Position Catalytic Converters like Johan
3)Use Vibrant Ultra Quiet Resonators like Cam T
Here is an early design sketch of what I was thinking…the Spintech mufflers in the sketch are optional. I’ll add them after go cart if the car is too loud with just the resonators…
Then took the sketch and drew out to scale cardboard patterns of the assembly from the exhaust manifold flanges to the resonators. Due to the cylinder offset of the V8 engine, the passenger down tube is longer than the driver side. I wish the actual metal fabrication was this easy…
The 2D model was placed on the passenger side. At this point it looks like it fits OK but could be tight near the rear spark plug wire, knock sensor, and rear engine mount bolts…
Here are the exhaust components and where they were sourced:
Qty 2 Vibrant 3” Ultra Quiet Resonator PN 1142 - Amazon
Qty 2 GESI 3” 400 cell High Output catalytic converters - Verocious Motorsports
Qty 4 3” tight radius 304SS 90 degree elbows - Amazon
Qty 2 Stainless LS7 flanges - Tabzone
Next step was to cut the elbows connecting the resonator with the catalytic converter and the converter to the down tube. I used a 70 degree elbow on the pattern so wanted to start with that and see how the assembly would fit in the chassis.
I don’t have a tube cutting band saw so came up with a process by using a band clamp to precisely cut and angle off the elbows. By placing the clamp at 22% of the arc length, that leaves the balance of the tube after the cut to be 70 degrees. Pic of the elbow with the band clamp in place….
Used a Dremel tool and patiently ground along the band clamp to get a very precise cut. Both the resonators and the cats have slightly oversized tubing so the elbows slip into them and allows for some adjustability of the angle and length. This makes it much easier to fit up the exhaust assembly. Pic of the two elbows attached to the Resonator and cat…
Now to see if that part of the assembly fits in the chassis or requires adjustment. For the most part looks like the cat clears the rear engine mount plus leaves enough room for heat shielding for the rear spark plug wire, knock sensor, and shifter cables.
Pic of the passenger side resonator and tube clearing the spark plug wire and knock sensor. Will probably shorten up the resonator extension by .75” to provide a bit morel space…
Pic of the passenger side cat clearing the rear engine mount…
Fitting up the driver side has it’s own challenges. The driver side flange is about 1.5” closer to the rear of the engine than the passenger side. Also, down pipe from the flange needs to clear the LT4 liquid to oil cooler. Pic showing how close the cat pipe is to the flange…
Glamour shot of the resonators in place…
Next post will cover fitting up the down tubes.