The last time we met on these pages (et 2/07) I boasted that some forged connecting rods were next on the list for Project Jetta. Well, do we have a story for you! It has love, romance, drama; all the things you expect from a rush job. Rest assured, you'll not be disappointed.
Since 3/07 my life took a different path. I shed my Sergeant stripes and picked up a Warrant Officer bar at Fort Rucker, AL where I've been attending flight school. The goal is to become a Blackhawk pilot in the Utah National Guard and I moved down here with the intention of buying a Suzuki GSX-R750 to ride while bumming rides on rainy days. All the while, Project Jetta would be tucked snugly in my garage at home, gathering handlebar marks from my daughter's bicycle until I returned a pilot. That idea lasted three months until I started to get the "itch." So after graduating SERE school, I decided I needed my car, but not until I'd finished the engine work I originally set out to accomplish.
So I called my friend Cameron Brewster, owner of Thirty 20 Motoring, to have him throw in a new set of forged rods from Integrated Engineering. Following our previous GT32 turbo upgrade, this would give the motor the internal strength to push us closer to 400whp.
As we worked out the details over the phone, we decided a ball-bearing turbo might be a nice addition, and while the GT32 was a great turbo, it was hard to maintain boost between shifts, having a touch more lag than I liked. Therefore, we decided that with only 2500 miles on the GT32, it was time to swap to a GT3076R.
The problem was, I only had a 10-day period to finish the car and drive it from Utah to Alabama. That gave us five days to get the car built and on the road. Cameron was confident it was achievable, provided the parts arrived on time.
Since I last visited Thirty 20, the company had outgrown its modest shop and planned to relocate to a larger one. After a tour of the new shop, Tim Semple introduced me to what used to be my car, minus half the motor.
New Rods
In less than two days the Thirty 20 crew had managed to tear down the motor. The first job recommended by Cameron was to change the connecting rods in order to keep the motor in one piece under the increased boost pressure and power load we were aiming for. So a set of forged-steel, H-beam connecting rods were sourced from Integrated Engineering. These rods are computer designed, then two-piece forged from 4340 Chromoly. After being machined to exacting tolerances, they're inspected and Magnafluxed to check for potential flaws. Integrated Engineering offers specialty applications for most VW/Audi applications, including the rods used here, which were designed to work with the factory Mahle pistons. These pistons have been tested up to 700hp, so retaining them is a good way to save some money.
Placed alongside the new rods by Integrated Engineering, it was easy to understand how the stock 1.8T rods could be the motor's weak point. Not only are the new rods made from a more durable material, they're thicker and forged into an H-beam to increase the beating they can take. The new rods were then fitted onto the stock crank without a hitch.
With the head removed, we checked Thirty 20's original custom exhaust manifold and downpipe for cracks in the welds, but found everything was as good as the day it was fabricated.
Bigger Turbo
Having the head removed eased the installation by giving us the opportunity to mount the new GT3076R turbo out of the engine bay, rather than trying to squeeze it behind the head in the engine bay. It also gave us a better opportunity to see the size of the turbo in comparison to the head. The rest of day was spent refitting coolant lines for the new water-cooled turbo.
Once the head was refitted to the block, Cameron returned to work on the welder, ensuring the new turbo would get a 4" mounting flange due to the size of the anti-surging compressor housing.