In late 2003, we suffered the fate of a torrential rainfall that put our beloved shop under four feet of water ( Flood). It almost wiped us out entirely. Without flood insurance, we were forced with the decision weather to open our doors again. Several customer cars were destroyed as well as our shop RX-7 and GSX.
After dealing with the respective auto insurance companies to help with the loss of the cars, we somehow managed to scrape together enough finances (begging, borrowing, begging some more...) to reopen at a new and larger location. Awesome! Wait a minute…we had a new shop, but no shop car.
With our recent trip to Japan for the 2003 Tokyo Auto Salon fresh in our minds, we knew which car was going to be the “Hot Ticket”. We decided to roll with the all new 2003 Nissan 350Z. It was amazing how the Japanese took to the platform and we wanted to follow in suit.
In September of 2003 we decided to concentrate on the VQ35DE bottom end. With less than 1000 miles on the Z, we “yanked” the engine. We have boost in our blood. NA would just not be enough. It had to be force fed. At the time there were only a handful of manufacturers in the world building the vital engine parts for high boost. Most in Japan were focused on tuning the engine for normal aspiration. From the mother land, we could get high compression forged pistons, ECU flashing, and screaming cams, but we wanted to boost the crap out of the VQ35. That required severe duty low compression pistons and big burly connecting rods. Unfortunately, they did not exist. We knew of only 2 US companies prototyping the engine internals.
CP Pistons informed us that they would have 5 sets ready before the end of 2003. We were on the list. Our pistons arrived from CP in January of 2004. Then the Crower "Pro Billet" prototype rods followed soon after. Finding the bearings for the bottom end was a ridiculous challenge. We got the last set just before an international back order from Nissan was issued.
Tried and true, custom made ARP fasteners were called on to hold the VQ cylinder heads and main caps in place. With up to 25 psi of extra air in the cylinders, it needs to be held together with authority. Thanks ARP
The boost duty VQ35 was blueprinted and assembled by Bob “The Builder” Cossaboom, in house at Car V2. With his extensive experience with high horsepower Honda engines, the all aluminum VQ would be similar territory. He was enamored by the cylinder head design and wanted to see how they would perform untouched. So, we left them as-is. At the time, there were only a handful of boost built VQ engines. Some have proven the VQ35DE to be a very robust under boost. The stock block was considered to handle cylinder pressure around the 25 PSI level with the proper internals. That was plenty for us.
Greddy was one of the first to release a twin turbo kit for the 350Z and we were first in line. The 18g Mitsubishi based turbos would be able to provide enough forced air for our lofty 600+ wheel horsepower goal. Because the 350z was still so fresh on the scene, there were many unchecked boxes on our build sheet. We needed engine management, fuel delivery, and clutch to hold our planned power.
We tooled around in our force fed Z, breaking in the boost duty engine with the Greddy recommended 6psi and the Emanage orchestrating fuel and ignition timing. In this trim, we managed just over 400 whp and 400 tq. O.K., we did a little fuel tweak and wicked up the boost to 9psi for those numbers.
Right around that time, the car was taken by the industry and parts were starting to fly off the shelves. Having plenty of experience with RPS clutches on MKIV supras over the years, we decided on their stage 3 clutch/pressure plate/synergy flywheel. It was rated just about where we needed it to hold the gut wrenching torque.
With the help of our colleagues Altered Atmosphere Motorsports (AAM) and Turbo XS (TXS), our fuel delivery and engine management prayers were answered. We were one of the first to receive the AAM return fuel solution and race duty swirl tank fuel system. This system eliminates the OE in-tank fuel pressure regulator to provide reliable boost induced fuel needs. With hungry 750cc RC engineering injectors clamped tightly in the AAM billet fuel rails, one fuel pump simply won’t get the job done. A Walbro GSS342 HP in-tank pump feeds the AAM swirl tank. From there, a race duty BOSCH external fuel pump sends the fuel to the engine. Just what the doctor ordered.
The AAM team helped again when we discovered an exhaust “bottle neck” in the design of the Greddy waste gate placement. For up to around 14 psi, it wasn’t an issue, which is more than enough for most users. Once we dialed the pressure to 18 pounds, the gremlins appeared. The way Greddy has the exhaust recirculation path entering back into the stream at a 90 degree angle, caused a very strange boost response. The two exhaust flows were fighting each other. To eliminate this issue, we completely replaced the turbocharger outlets with full 3” down pipes and relocated the waste gates. The waste gates now have atmospheric outlets and command attention under full load. Imagine a jet flying by you at about the head level. Problem solved!
The TXS UTEC fuel management system is very unique. It’s a “plug and play” parallel computer that takes over all functions of fuel and ignition timing while allowing the factory computer to remain happy in control of all other functions. With newer technology and drive-by-wire throttle control of the VQ35, keeping the OE ecu in place in a necessity. The UTEC can provide control for up to 1000cc fuel injectors and 45 psi, so it fit the bill for us. We begged and begged and bribed the guys at TXS until one showed up at our door step.