I will be starting a series of blogs covering our 997 Turbo build process. I think I’ll label each blog a Stage, just like what we’re doing with our car. What is the first usual mod many enthusiast decide to swap on their car? Intake? Exhaust?
Well we started off with the exhaust, the OEM exhaust weights in roughly at 45 LBS!! Now that’s way too heavy. So what we did was we reach out to our good friends at Agency Power for a Titanium catback exhaust. Not only do they develop and create parts that look good, but they are also functional. Their Ti catback weights in at a whopping 21.25 LBS now that’s a little under half of what the OEM exhaust weights in. Not only are we getting a lighter exhaust but the performance gains along with it are huge. We got a quicker throttle response from the larger piping which is 60mm throughout the entire system help with unrestricting the turbochargers. This system also included Hi-Flow cats as well. My favorite part about this catback is the sound it makes, we all know when switching to a titanium exhaust the exhaust note changes dramatically and man car sounds just amazing…
We had Tomioka Racing design a Stainless Steel header for the 997 Turbo. Tomioka Racing sent us a header made of high quality SUS304 stainless steel (ss), with ported and matched flanges. When I first thought of the idea I was this is going to be a long process. Well I was completely wrong… the headers were pretty easy to install. It did take some hours but it was not difficult. Once we removed the exhaust we basically unbolted the OEM header from the turbo, and then took off the bolts holding it to the cylinder head. It was actually easier than doing a header install on a WRX/STI, at least in my opinion. With the added stainless steel headers from Tomioka Racing the spool time on the turbo was much faster due to the match porting that was done on the headers.
One of the biggest issues when running high boost on the 997 Turbo is from the diverter valve; the 996TT had the same problem as well. The stock valves use a rubber diaphragm which will leak boost at high rpms. The OEM BRVS (Boost Recirculation Valves) also deteriorates over time as well which can cause a boost leak. With our car we are planning on using every bit of boost the car can offer so we cannot allow a boost leak to happen. Once again Agency Power sent us a set of their BRVS to replace the OEM ones we had on the turbo. Each Valve was CNC machined from 6061 Aluminum, inside each base is an aluminum piston that has been 3D machined. The piston is hard anodized along included were o-rings that allowed an air tight seal as the piston moved up and down. These make a great OEM replacement for the OEM BRVS as to replace them only takes unbolting 3 allen head bolts from the OEM BRVS and replacing with the Agency Power BRVS.
*On the dyno we noticed quicker response getting into boost, it’s a must upgrade since I feel the stock boost is “mild”
So up next is getting the car tuned, we purchased a COBB AP which had included OTS maps. So it really was an easy install and we quickly got the car running after flashing in the stage 1 map. With the current mods on the car, the car gained a bit of power at 413whp 398tq. Not bad for a street car, we were really happy with the outcome.
One of the first things we actually notice when we first started the 997 Turbo project, was the OEM Engine mounts. They were designed to actually move back and forth which had a really bad side effect on the driver. It felt really weird off the line, during breaking, and shifting. We got in contact with Torque Solutions for a Semi Solid engine mount. Torque solutions designed there engine mount using lightweight 6061-T6 billet aluminum and polyurethane. This modification itself has a huge effect on everything, meaning the driver feels more of the car, and the car itself has improved 60ft times off the line, doesn’t move around as much. Most people would think these engine mounts would create more vibration like solid mounts in race cars, but Torque Solution has got it down to were it’s not as bad as Solid Mounts.
After installing the Agency Power BRVS, we decided to flash in a more aggressive map from COBB; we flashed the ap to stage 2. Stage 2 gave us some problems… not really bad problems but a problem. The over boost function stopped working in Sport Mode. Which made the car react really weird around 4K RPM? It would build boost, then stutter until over 4K RPM. After the initial test drive, we decided to apply a custom tune on our DynoPack, which got rid of the hesitation at 4K RPM. The final tune results ended in 566WHP 504TQ.
You can purchase these parts and/or find more info at these links below:
Torque Solution Engine Mounts
Agency Power Ti Cat Back and BRVS
Tomioka Racing Headers
Special thanks to our sponsors for supporting us:
AEM Electronics, Tomioka Racing, Ignition Project, Agency Power, Collinite Wax, LIQUI-MOLY, OS Giken