June 2019
Just a small upgrade. I put Whiteline poly bushings in the front lower control arm inner bushing spot. These are the bushings where the control arm mounts to the frame. A few years ago I put in the radius rod rear bushings so it made sense to finish the poly upgrade. The photos show the arms ready to reinstall and then installed on the car. I cleaned up the arms and gave them a shot of cast iron look paint.
And a bit later in the month a bit bigger upgrade, a FAST 102 LSXR intake manifold for the engine. I ported it a bit before installing it. The install was without issue. I did remove the plastic EVAP lines and replaced them with rubber vacuum line for a cleaner more well fitting appearance. I also got tired of the LS2 throttle body causing codes so I replaced it with an AC Delco LS3 throttle body. This stock throttle body seems to make the engine run better than even the ported LS2 throttle body I had.
July 2019
After the addition of the FAST 102 LSXR I had rather outgrown the Predator etunes I had been running so I had the car dyno tuned. It came out reading 379 rwhp. It drives great. Below is a link to Youtube for a video of the car on the dyno.
https://www.youtube.com/watch?v=98vH5flPRqE
February 2020
Next up will be a set of Kooks stepped headers and cats. These are headers that have 1.75 primaries that step up to 1.875 about 10 inches along and then into a 3 inch collector. The cats are entirely 3 inch piping through high flow cats. I got a great deal on some very lightly used Kooks stepped headers, the good ones that aren't even made anymore. The headers are also JetHot coated.
The headers arrived. They have a few nicks and scrapes from having been installed and uninstalled once but otherwise look great. If I can get a few warmer days I'll get them installed. They came along with the necessary O2 sensor extensions.
And here they are installed.
While it doesn't sound a lot different, here is a clip of the sound. This is Kooks stepped headers, Kooks high flow cats and a Magnaflow catback.
https://www.youtube.com/watch?v=ipLXhl3ExfQ
March 2020
Next up are some 1.8 ratio rockers to get me a little more lift out of the stock cam. The LS2 cam has 5.25 lift, with the new rockers lift will be .556. The new rockers will require heavier valve springs.
The rockers, springs and valve cover spacers (required for these rockers) have all arrived. I installed Comp Cams Pro Magnum 1.8 ratio steel roller rockers, Lunati dual springs and Comp Cams Magnum chromoly push rods. Along the way I also installed some orange Dragon Fire spark plug wires mostly for looks (they are orange!) but they are 8.5 mm and seem to work just fine.
Here the GTO is on the dyno after a touch up to the tune following the header and rocker install:
https://www.youtube.com/watch?v=UiMhpvjcZFU
The output increased though not as much as I'd hoped, but dyno numbers are just a number. I can tell I've improved the output in the midrange and top end.
RWHP: 388
RWTQ: 390