The exhaust system in the 2000 Trans Am was modified by the previous owner with a Y pipe-back LoudMouth system, and boy is it loud. Last year I took the car to MadHatters in Columbus and they replaced the LM muffler with a Magnaflow. They gave me the previous muffler, which was noting more than a bulge in an otherwise hollow pipe to provide the appearance of a muffler, most likely to pass an inspection. The System had a lot of drone, specifically around the 1,500 to 2,200 RPM range which led me to shifting early or late to avoid the drone, which is absolutely no fun. The Magnaflow solved the drone issue but it still didn’t sound all that great, just loud.
Borla 14780 3″ Adjustable Cat-Back Exhaust System
This spring I purchased the Borla 14780 3″ Adjustable Cat-Back Exhaust System. I wanted dual rear tips and the ability to adjust the loudness with the various plates provided in the kit attracted me to it, and Borla makes a very good quality sounding exhaust system. The bolt pattern is 3 bolts similar to what header collectors and electric cutouts use, which got me thinking that an electric cutout could be bolted in. After a quick search, not only can it be done, folks have been doing it since the 90’s! After doing some research I purchased an electric cutout from DMH.
As pictured, the dual tips on the Borla system are just awesome. Sound wise, the car sounds perfect inside, no drone at all. When the windows are closed it does not matter if the cutout is open or not, you get about the same loudness inside the car. The biggest advantage to closing the cutout though is at the drive thru line. I see no benefit of having the system partially open, either it’s closed because I am trying to talk to someone or its open. Best part is the sound inside the car is now normal, maybe too normal as I then started to pickup sounds from the rear diff which leads me to the next post covering the work I did to rear axle.
The previous LoudMouth system also had dual tips and looked good, but these Borla tips are something else. I would love to know if the tips also help with the quality sound from the Borla system or if they are simply for show.
Electric Cutout for the Borla 14780 System
I ordered a cutout from DMH based on recommendations on the various 4th gen forums. I was going to get a cutout from Quick Time Performance QTP QTEC30B / QTEC30 but after talking with the guy from DMH, I decided it was worth buying locally (from Ohio) and a nice guy on the phone. When it arrived however, I was expecting the rectangular switch from the pictures on his website and description, instead I got the round 3/4″ momentary switch, exactly like what is in the QTP cutout. Lesson learned but the same day I ordered the DMH I ordered a plate on eBay to mount the rectangle switch in my ashtray based on measurements from DMH’s website. I called DMH and he said he would ship me the rectangle switch described on the website. After waiting 3 weeks, I decided to order another plate from ebay for the ashtray this time with the 3/4″ hole instead of the rectangular cutout. The seller on eBay rocks, he got the plate to me in 2 days both times! The correct switch from DMH never came. Truth be told, I prefer the round switch as it is a bit lower profile and has a clean look in the center console.
I think the DMH cutout is good quality, but my experience with not exactly getting what was pictured rubbed me the wrong way at the time, and never getting that replacement switch was irritating. I will likely get a Quick Time Performance cutout if it ever needed one again, or if I order from
DMH I will have 20 questions ready to make sure I am getting what I think I am getting.
Installing the Borla 14780 System
I can’t say I am an exhaust installation expert, but I have replaced a dozen exhaust systems over the years with various degrees of success as well as a failure or two. The Borla 14780 3″ Adjustable Cat-Back Exhaust System was the most straight forward and easiest I have ever installed, and this is a system with multiple pipes and hangers. I’ve had harder times installing just a muffler! I was able to loosely bolt the system together then slowly move connections here and there to get it to fit perfectly. When I say perfectly, I mean perfect, perfect clearance over the axle and through the special angle built into the car between the pan-hard bar and the pan-hard bar structure. They took good care on clearances, every pipe slid on snugly, I only had to massage the pipe that transitions to the factory Y pipe slightly to get it to slide on, but that should be expected since the previous system used a traditional U clamp.
Wiring for the electric cutout and switch in ashtray
Wiring for the electric cutout was rather straight forward. While I had the car apart I took the opportunity to also run backup camera wiring along with the cutout wiring. I added a very small hole in the rear spare tire well on the inside and fed the wires through and added my own mid-point weather pack connector to make it easy to connect/disconnect at the spare tire. If I need to switch out the cutout, I can switch to another brand and simply re-splice the wires to a weather pack connection under the car and plug it right in.
Wiring is straight forward, you need a power source to the switch, then the switch has its own wires that run to the back of the car where the cutout is positioned. I used the accessory ignition tap connection from the fuse box and ran the wire under the ash to the center console. It is a tight fit, I had to cut a little bit of the top GM tap wire to get it to fit the Velcro fuse box cover.
I located the switch in the ashtray. I do not smoke, converting the ashtray to something useful was a no brainer. The plate simply lays in the ashtray. I did not glue it or do anything permanent, someday if/when I want the car all original I can pull the switch and wiring and put the ashtray back in. Honestly though I think the next owner will also prefer the cutout switch over an ashtray.
The switch on the left is yet to be wired, but I am planning on adding something in the future that I will turn on/off. More on that next year.
Michelin Super Sport 245/40R18 tires
The previous owner, I believe in 2008 upgraded the wheels and tires on the Trans Am. The 18″ wheels are actually pretty cool, Halo HE834 18×8. I did some research and found they weigh 22lbs, which is comparable to anything I would buy today to replace them. Since they are in nearly perfect condition, I decided to keep the wheels and get new tires. After shopping around I decided on Michelin Pilot Super Sport 245/40R18 tires from Costco. These are summer tires only, which is fine as I do not plan on driving this car in weather when it’s below 40 degrees and never ever in snow. What a difference the tires made! I purchased the tires first before I started the suspension, brakes and exhaust work. Of the modifications made, this had the most dramatic improvement. The previous tires were on year 12 according to the date stamped on the rubber. Even though they had plenty of tread, they just didn’t feel right and now that I have new rubber on the car I know why. These Michelin tires stick to the road like no ones business. Maybe too sticky! With the previous tires I could do burnouts and side the rear easily, maybe too easily at times. These Michelins provide nothing but grip, now I have to really put some effort to get the wheels to chirp. If your tires easily slide and slip and its really easy to to burnouts, its time for new tires!
Next post I will cover the suspension work I did, including replacing the brake pads, rotors and replaced the shocks, springs, and bushings.