In our last edition of Project SE-R Revisited, we got our car running again with a turbo kit in place. The base Turbonetics turbo kit produced gobs of power, making the car a terror on the street, even with a paltry 10-psi of boost.
Getting the car boosted was one part of our story; in this installment, we're going to probe the limit of what can be done with bolt-ons to a stock SR20DE.
As we have said many times in this series, it's a little-known fact the SR20DE was designed from a clean sheet of paper as a factory turbo engine and is one of the strongest four-cylinder compact car engines you can buy. How tough is the stock SR? We'll find out. We're going to add some additional bolt-ons to enhance our turbo kit, turn up the wick on the dyno and see what she will do.
To ensure we have enough exhaust flow for our heavy breathing turbo engine, we constructed a custom 3-inch diameter, stainless-steel exhaust system using mufflers and components from Magnaflow. Since no 3-inch system was made for this car, we had to build our own. We used a Magnaflow polished 304 stainless 3-inch ID straight-through perforated core muffler and pre-silencer for maximum flow. Despite the large pipe diameter and straight-through design, the Magnaflow mufflers were relatively quiet. Their polished exterior and polished 4-inch diameter tip dressed up the look of our car as well.
We also obtained an assortment of 3-inch 304 stainless mandrel bends and stainless hangers so we could construct a rust-free, all-stainless system. We wanted to keep a cat in the car so we would not be considered gross emitters of pollutants. We also used a Magnaflow 3-inch inlet and outlet high-flow cat, making it quickly detachable from our exhaust system with Turbonetics V-Band quick-release clamps. When we go to the track, we loosen two bolts to drop the cat and either run uncorked or put in a 3-inch bypass pipe.
Wayne Zotti, owner of Speedway Muffler, and Mike Saiki of Motivational Engineering, fabricated our Magnaflow system. They cut sections out of the mandrel bends and tacked them in place with a MIG welder before seam-welding the parts with a TIG welder using stainless welding rods to match our stainless tubing. If you live in the Gardena, Calif., area and need a properly made mandrel-bent system, Speedway does good quality work.
With Magnaflow components, we were able to have our own custom system built with better quality than any system currently available for this car for a reasonable price.
To help get the good stuff into the engine and the bad stuff out, we installed a set of JWT's S3 camshafts. The S3 is a mild street grind designed to use the stock valve springs. JWT uses sophisticated computer modeling and harmonic analysis to develop a lobe profile that both maximizes the area under the lift curve and ensures valve train stability at high rpm.
With a fairly short duration and high lift, we figured these cams would be fine for a turbo engine. The S3s are ground on new billets with a great deal of precision. Finger follower valvetrains with hydraulic lash adjusters like what the SR20 is equipped with need to control camshaft base circle run out to several 10-thousandths of an inch to avoid problems with rough idle and low cranking compression. Too much run out causes the lash adjuster to pump up, holding the valves slightly off the seat and causing problems. JWT takes great pains to ensure this precision in the grinding of its camshafts.
A turbo lives and dies in the power wars by the amount of boost pressure the engine is force-fed, and, for us to up the ante, we needed a boost controller.