In the previous installment of the DB2 build, Jason of Whitfield Racing finished up the Acura Integra turbo manifold and downpipe, catch can/overflow combo and airbox. Since then, Whitfield's been busy mapping out the cooling portion of the build. Obviously a front-mount intercooler is needed, but rather than just slapping a huge I/C in a hacked up front bumper, Whitfield took a step back to rethink the entire layout. The second-gen Integra wasn't blessed with a huge amount of airflow up front. The grille opening is long but slender, and though I was hoping we wouldn't have to cut out the front grille, I was much more concerned with fitting a good-sized intercooler and radiator in the tight space. A half-core radiator is what you'll typically find under the hood of a turbo DA/DB2, but with the space saved by Whitfield during the mock-up, it looks like we'll be able to fit a larger radiator that will have to be custom built—more on that in a future update. For now, we'll take a look at the intercooler and charge pipe mock-up, and a few of the supporting parts that will be used.
Due to the single, short grille opening in the front of the Acura Integra, most remove the grille completely, and trim the bumper to allow for the intercooler setup. Most reach for the biggest intercooler they can fit behind the bumper but you have to keep in mind that a radiator still needs to function behind that intercooler. It's a tough fit to stack everything properly, while avoiding with the turbo manifold. Whitfield suggested a universal unit that he could customize in order to tailor it to the car's front end. Vibrant offers a number of universal bar and plate design intercooler cores, and they shipped one out at Whitfield's request. Then, he began the tedious process of finding the best possible fit. Initially, the core was definitely too tall, so he took off a few inches, and fabricated a set of mounts using factory holes to allow the intercooler to sit perfectly behind the factory bumper. What's even better is that he was able to keep about 90 percent of the factory Acura Integra grille, while still leaving enough space between the intercooler and the Whitfield manifold for a good sized custom radiator, rather than a half core. To facilitate the custom "back door" setup and increase efficiency, Whitfield also fabricated a set of smooth, rounded end tanks that curve into the engine bay. By the time you're reading this project DB2 installment, all of those pieces will be welded and the mock-up portion complete. There's a little more space in front of the transmission side of the engine since the manifold sits on the opposite end, so a custom radiator will have to be offset, and will likely use a thicker, longer core for additional cooling.
Vanjen Clamping System
You've undoubtedly seen or heard of Vibrant's Vanjen clamps used on turbo builds of all types. Produced in 6061-T6 aluminum, the system consists of a quick-release clamp, hard anodized union sleeve, and a pair of aluminum weld fittings that have grooves engraved to accept O-rings for a tight seal. The fittings are welded to each of the pieces you'll be joining together, the union sleeve bridges them, and the quick-release clamp secures everything, incorporating a safety pin for added assurance. And while the fit is no doubt secure, it allows for some "play" to stay properly sealed while facing vibration and engine movement. There are a number of other clamping options that allow you to look beyond the old silicone sleeve and screw clamps, but the Vanjen clamps are one of the most affordable and able to withstand far more boost pressure than we'll ever see with this DB2 Acura Integra build, as well as heat resistance up to 400 degrees F.
Ever since their inception in 1997, Australian-based Turbosmart not only made a mark in the performance industry (both import and domestic), they've managed to climb to the top of the food chain with their parts being used by some of the fastest cars in the world. More recently, in 2007, Turbosmart USA was created to focus solely on the North American market, and you've seen their product on countless feature cars in Honda Tuning. Their Hyper-Gate 45 wastegate is an external, 45mm unit that's extremely compact yet still retains the flow characteristics of a much larger unit. Beyond the flexibility of its small frame, easy, ultra-quick spring changes are possible due to Turbosmart's unique locking collar design. Complementing the Hyper-Gate is a 50mm Race Port blow-off valve. Though it's the highest flowing blow-off valve from Turbosmart, it's substantially smaller (25 percent) and much lighter than the version that it replaced. In a busy engine bay like this we'll take all the extra space we can get. A rotating collar design allows for ease of installation and the Race Port relies on a quick-release V-band clamp. We just opened these up while I was at Whitfield Racing, and they'll be welded into place before the next installment.
Skunk2 Intake Manifold
Last year Skunk2 introduced their Ultra Race and Street intake manifolds for the B Series family and followed that up with a K Series version. After explaining that the car would see fairly mild boost in a street application, Skunk2 suggested their Ultra Street version manifold. It uses a 1.82L plenum volume and velocity stacks at the end of each long, 8.72-inch runner. A 74mm throttle body opening and a generous amount of material to port and customize gives users plenty of options. Though the manifold is intended for any B Series VTEC head, it's going to take some additional work to fit into a second-gen Integra chassis. Due to the runner length, it couldn't be coerced into place, so Whitfield removed the factory intake manifold studs, which granted enough space to set the manifold into place. At that point you can reinstall the OEM studs, or opt for longer bolts if you want to incorporate a thermal gasket. Another issue is the IACV will require a custom bracket in order to work alongside the rather bulky DA/DB2 master cylinder.
Skunk2 also supplied a 70mm Alpha Series throttle body that will receive a Vanjen aluminum weld fitting for a secure fit to the charge piping.
Next time around we'll take a look at the turbo that will be used, courtesy of Comp Turbo, we'll get the Turbosmart wastegate and blow-off valve welded and finish off the charge piping, as well as finalizing the welds on the intercooler and possibly getting a start on the valve cover/breather lines. Stay tuned, much more is in store for Project DB2.