It's no secret that the 300ZX twin-turbo engine bay can be a nightmare to work on. The V-6 configuration, Nissan's placement of the turbos and its extensive piping and vacuum hoses make it tighter than a middle-row coach seat on a flight full of sumo wrestlers. Andy Turpin, however, has found the best way to remedy these underhood issues-swap in a RB-series Skyline engine. But he endured a long, harsh road to pull it all off and in the process has created a supremely serious sleeper.
Like many enthusiasts, Turpin started behind the wheel of a Civic, in his case a '93 DX. This pearl white Z's road to glory started roughly seven years ago. One month after Turpin graduated from high school, he sold his Civic in order to buy the Z off his older brother, Chad.
Turpin reports the first year of ownership was like playing hopscotch in a minefield. About three months after buying the Nissan, a few of the stock injectors died. And like many enthusiasts before him, this would be the moment of enlightenment that transforms an idle-on-the-sidelines enthusiast into a proper wrench-turning enthusiast. "Not knowing anything about cars," says Turpin, "I took it to the dealership for a diagnosis and $75 later they told me I had an injector going out, and handed me an estimate for over $1,000! Extremely scared of that large of a bill, and only being 18, I decided it was best if I learned how to start wrenching. After all, my father was an old gearhead, and obviously my brother was into the whole car thing. I learned how to do the injector replacement off of a Z website and jumped in."
In further stereotypical fashion this truly needed fix led to less urgent modifying. As always, it was baby steps at first. Turpin upgraded to "Stage 3" status. This first round consisted of a reprogrammed ECU, a GReddy SP exhaust and a mild boost up to 14 psi. The car ran great for about a month and then the stock clutch blew out, so he swapped it out.
After several trouble-free months, Turpin figured he had beaten back the curse so he decided it was time to make his first-ever dragstrip appearance. He made two mid-13-second runs, but he had failed to reverse the curse as the V-6 started showing some signs of rod-knock at the end of the second pass.
Again what seemed like a setback was pure opportunity for Turpin and after some serious wrenching the Z returned to road-going status with a built block, bigger injectors, bigger turbos and piggyback engine management. After break-in the car was making 475 whp and in 2005 it blasted an 11.5 at 118 mph at O'Reilly Raceway Park in Indianapolis.
In late 2005 he added a set of Jim Wolf Technology cams, aftermarket manifolds and home-ported heads. The Nissan went back on the dyno where it pumped 540 whp on 93-octane pump gas. In mid-June of 2006 it ran a best of 11.2 at 124 mph at Route 66 Raceway in Joliet, Illinois-and the two rode triumphantly off into the sunset, right? No. "Shortly after the quarter-mile hot laps another clutch took a crap and I was tired of pulling engines, transmissions and the like so I decided to halt the proceedings entirely for a few months," Turpin says. "I was debating on going to even bigger turbos and around January 2007, I finally decided I wanted to go RB26."
At the time there was no information about RB26/Z32 swaps. Plenty of guys had done it to older-generation Zs, as well as 240s, but not to the Z32. Undaunted, Turpin pressed on and ordered an RB26DETT and that's when his luck changed. "It was spotless," Turpin says, "and I even found a new OS Giken Triple Plate clutch behind the motor-all for free!"
Coaxing the RB, an inline-6, into an engine bay designed for a V-6 would be a true trailblazing experience. "Since I had discovered that the RB bellhousing would bolt on to the Z32 transmission without any modification, it made the motor mount process very simple," Turpin says. "I was able to utilize the stock 300ZX trans mount, driveshaft, sensors and shifter. After everything was in place I completely deloomed the RB26 wiring harness and removed all of the AWD electrical components and shortened the harness by about 4 inches."
When Turpin fired the RB to life for the first time he was running a single-turbo setup featuring a Precision Turbo GT4202 that produced 680 whp on C16 fuel. But there is more to this game than power numbers. "I decided that the GT42 was just too laggy for my tastes and began to search for something more suited to my goals. After a string of emails and phone calls, I was informed of a sponsorship offer by BorgWarner/Airwerks. I spoke with their lead Turbo Engineer, Kurt Henderson, many times and we finally made a decision on an S300 60mm turbo."
Directly after installing the new turbo, Turpin decided to make the switch to E85 due to its availability in central Illinois. Since he already had a rather large fuel system, featuring 1,000cc injectors, he needed to make zero changes to make E85 work. He took the car to Sound Performance in Chicago for the initial E85 tune and the RB belted out a solid 530 whp. After some trips to the dragstrip and some low-11 passes, with a best of 11.1 at 126 mph, Turpin figured there was more power to be had so he swapped to an Airwerks S300 66mm turbo. After fine-tuning the AEM EMS himself and setting the GReddy Profec S to 26 psi the Z dropped a 10.4 at 134 mph on its first pass, impressive considering the car has always run DOT-legal drag radials. "The Z is a solid 10-second sleeper running eco-friendly E85," Turpin says. "I have yet to dyno it, but I estimate the 134-mph trap speeds that the stock block is still holding right around 700 whp. I typically drive the Z to work on nice days without any hiccups. It drives just like a stock car until you don't want it to."
Among his favorite parts Turpin is quick to point to his Full-Race exhaust manifold. "This piece is a thing of beauty, almost worthy of framing rather than hanging off the engine," Turpin says. "I cannot speak highly enough about the quality of this piece." The Nissan's Mickey Thompson ET Street drag radials get kudos as well. "These tires grip unreal. Even with 700 whp on tap and 4:10 gears, the car hooks up without balking. I typically run through a set per year, they're worth every penny and they make the performance side of the sleeper look possible."
Turpin says he would eventually like to forge the bottom end and really shoot for some serious power-700 whp is not serious? He feels the stock RB26 has proved its strength for now and has satisfied his needs. We all know this sentiment will not last too long because committed enthusiasts like Turpin don't know the meaning of "enough."
Specifications & Details
'90 Nissan 300zx Twin Turbo
2.6-liter RB26DETT inline-6
Full-Race exhaust manifold, BorgWarner S366 turbo, Tial 44mm wastegates (2), TialSport BOV, Tomei Poncams Type A (260/252), Titan Motorsports 1,000cc injectors, Tomei 1.2mm head gasket, Precision FMIC, Custom 3" IC piping, custom 4" downpipe, GReddy SP after-cat exhaust, RB25 oil pan
Wheels, Tires And Brakes
5Zigen FN01R-C 17x8 (f) 17x9 (r), Mickey Thompson ET Street Radials
Powertrix HICAS Eliminator, SPL adjustable tension rods, Specialty Z subframe connectors
8-point rollcage (NHRA certified), Sparco Speed Seats, RCI 5-point racing harnesses, Sparco 350 steering wheel and hub, Auto Meter oil pressure gauge, Defi Link 2 and BF Series boost gauge, Optima Red Top Battery relocated to trunk
10.4 seconds at 134 mph
My parents, my brother Chad (sold me the car and helped with a lot of the custom fabrication), Geoff at Full-Race, Kurt from BorgWarner, Joe from DXD Racing, Eric from XS Engineering and Eric from Midwest Chassis & Performance, Vince from Sound Performance, Kyle Smith
AEM standalone EMS and UEGO wideband, GReddy Profec S Boost Controller, HKS Type-1 Turbo Timer