The saga of the Truck’s Exhaust
It has been a bit of a saga with the truck exhaust since shortly after installing the supercharger in fall of 2019. Within a couple weeks I decided that the factory exhaust was too restrictive but wasn’t willing (or able) to drop thousands of dollars on a “name brand” full exhaust. I decided to go with Speed Engineering Headers, x pipe, and full true dual exhaust. Off came the factory exhaust and on with the Speed Engineering:
It sounded decent at idle and light cruise, but it had an absolutely unbearable drone so within a week it came back off and the stock exhaust went back on. About a year later I found out the hard way that the supercharger’s intercooler reservoir design and tune were (are?) critically flawed. The reservoir slowly leaked antifreeze out of the cap and I never noticed until I floored the truck with a no longer functional intercooler on the interstate about 8 hours from home.
Edelbrock’s tune did not pull timing or enter limp mode for safety when it saw intake air temps skyrocket as a result of running out of coolant in the intercooler system. This caused detonation that knocked the #4 spark plug closed causing a hard misfire that had the check engine light blinking. Not knowing what happened and not wanting to pull over on the side of the interstate I limped the truck to the next exit and ultimately to a nearby Napa. Mark and I were fortunately able to buy tools, a set of spark plugs, coolant, and borrow a step ladder at the Napa and get the plugs swapped out. Unfortunately my decision to drive on the flashing check engine burned up the catalytic converters.
I reached out to Edelbrock as I was still (barely) within the 1 year warranty and the person I spoke to agreed to send me a replacement reservoir but disclosed his opinion that it was a flawed design that management refused to change and that I should replace it with another product. I decided to try swapping in the replacement. This one leaked far worse than the original so I set out to find a better option. This was during the peak of COVID related supply chain issues so I couldn’t get my hands on the options the Edelbrock tech suggested. I looked at everything aftermarket and OEM and discovered that a resevour for a Terminator Mustang was an almost perfect fit, while being much larger and having a cap that actually sealed!
With the intercooler system solved, it was time to fix the formally restrictive but now clogged and much more restrictive exhaust. I debated swapping the full Speed Engineering kit back on and seeing if I could have a muffler shop add a resonator or something but the tuner I decided to take the truck to suggested that it is the factory exhaust manifolds and Y pipe that are restrictive not the “cat back’ exhaust. So I decided to buy a Speed Engineering Y pipe, reinstalling the headers in front of it and keeping the factory “cat back” exhaust.
Unfortunately this second attempt of an exhaust was also bust. The joints all leaked even after swapping out the clamps for stepped clamps. This made for noxious fumes in the truck until I had the joints welded up by a shop it still leaked some which made the truck sound strange with the quiet “cat back” exhaust keeping overall noise down. Basically it sounded like it had a factory exhaust that had seen better days.
Additionally, as you can see above the 3.5″ Y pipe steps down twice to meet the factory “cat back”. After living with this exhaust setup for entirely too long I decided to buy a higher quality entirely new exhaust system. As I researched the products I thought would be best for what I want I found something out that I never knew. The trucks with the larger 6.2L engine got a 3.5″ exhaust while the trucks (like mine) with the 5.3L engine got a ~2.75″ exhaust. Suddenly the extra exhaust piece that came with the Speed Engineering Y pipe made perfect sense. It was for the trucks blessed with a larger exhaust.
Armed with that new knowledge I decided on a Borla touring “catback” with Texas Speed headers and Y pipe with high flow cats.
