In the S-chassis world, the SR20DET has become the de facto engine swap for anyone looking to add more power to their 240SX without breaking the bank. The swap is simple, effective and offers plenty of opportunity for further power upgrades.
The average SR swap with intake and exhaust puts out around 200 whp, which isn’t bad at all, but the hype and excitement wears off after a couple of months. All of a sudden, you’ll be left wanting more, as is the case with the owner of the S14 in this article.
He wanted to add more power without affecting the reliability that he’s been used to day in and day out with his pretty basic SR20 setup. Other than a Power Enterprise air filter and a GReddy Ti-C exhaust mated to a Megan downpipe, the S14 SR20 was all stock.
There are countless mod paths that can be taken here to extract more power, but we find too many people focus on upgrading the turbo or adding cams before addressing the single most important concern: engine management. That new turbo may give you a great seat-of-the-pants feeling, but in reality, it’s not being used to all of its potential without a proper tune — especially when you’re still running the stock 370cc fuel injectors. That’s downright dangerous.
To combat the problem, we’ve seen people upgrade their MAFs to 300ZX units and add some 550cc injectors that should theoretically increase airflow and fuel by the same amount. A less common option is an old Super AFC that alters airflow signals to the ECU, all in hopes of trying to save some bucks while still making more power.
We’re here to tell you that we’ve tried it all, and nothing compares to a programmable EMS, not even the mail-in ROM chip tuning. If you want to drive your car hard, then get a proper EMS; in the long run, you’ll be saving yourself lots of money and headaches. Make the initial investment up front, and you’ll never regret it later.
That’s why the first thing we did was install AEM’s newest EMS Series 2. The original EMS was highly successful, and the Series 2 brings all of the same great options found in the original but with many new refinements, such as user-adjustabile knock-sensor frequency, 12-channel injector and 8-channel ignition outputs, 1MB of internal data logging (versus 512KB on the Series 1), the ability to adjust four camshafts for continuous variable cam control, and much more. At its core, the AEM EMS still allows full fuel, timing and ignition control, plus electronic boost, traction and launch control. The list goes on and on — simply put, if you want to be able to fully tune your engine, then the EMS Series 2 is the way to go.
To help maximize the new features on the Series 2 EMS, AEM has also released its AEMTuner software. Perhaps the biggest addition to the program is the Support Pane feature that not only explains what an item is, but provides info on how the item works with live links in the text. It’s like having a teacher guide you through functions of the system inside the software. For example, if you don’t know what Knock1 volts means or how to set it up, the Support Pane will provide all the necessary information. It’s an invaluable feature for novice and even professional tuners.
Other nifty new features include calibration comparison. Now it’s much easier to compare two different maps within the program. Conflict detection has been added to help eliminate assigning multiple outputs to the same item that can cause timely delays during tuning. There’s a lot more to this software that would take this entire article to write about, but thankfully AEM has made a great video explaining the AEMTuner at youtube.com/watch?v=bkGrq8ACyR8.
Since the AEM is a plug-and-play setup, it only took 30 minutes to install and get running. The longest part of the job was adding the MAP and AIT sensor so we wouldn’t have to run the OE MAF setup. Having a MAP-based metering system allows for better tuning options for most tuners — that means running a few extra wires to the EMS, but it’s smooth sailing after that.
The fuel injectors were the next area that needed to be addressed. As mentioned before, the stock SR20 injectors flow a dismal 370cc, not enough if you plan to raise the boost past the stock 7 psi. DeatschWerks supplied us with a set of its 550cc injectors that are a plug-and-play option — no changing the fuel rail or wiring, just pull out the old ones and throw the DeatschWerks in. You can rest assured that the DeatschWerks injectors will flow as advertised since every injector is flow matched within 1 to 2 percent accuracy before it’s shipped (a flow report is included to verify the numbers). Even the flow pattern is specifically designed for excellent atomization that ensures proper combustion.
We thought long and hard about a turbo upgrade, which was originally the plan, but even with his upgraded ARC side-mount intercooler, it wouldn’t be enough to provide a cool charge for the engine. Instead of spending the money on a turbo, an HKS Type-S front-mount intercooler kit was purchased. This way when a bigger turbo does find its way into the setup, it will have all the proper cooling it needs. Even though a cheaper eBay special intercooler setup could have been had for much less, the HKS intercooler was chosen because it has actually been tested and designed specifically for the S14 SR20DET, not just based on its size and dimension.
With the choice to switch over to a MAP-based system, the stock OE intake and MAF sensor were ditched and replaced by an HKS suction kit, which has wider-diameter metal piping and an easy-breathing HKS mushroom filter. We’ll admit this piece was also added because of the amazing sound it emits. If you’re into hearing the whooshing sound of the turbo, then the HKS suction kit does an outstanding job of amplifying it.
With all the parts buttoned up, we loaded a base map into AEMTuner and made some quick adjustments for the 550cc injectors to be able to drive the car to the tuner. However, after some slow and steady laps around the neighborhood, we realized the engine temperatures were a bit higher than we wanted, especially since we were just cruising around. A day later, we had a Mishimoto aluminum radiator in our hands. With three rows of cooling, the Mishimoto rad cools much more efficiently than its stock counterpart, which, with most front-mount intercooler setups, is a must due to the reduced amount of incoming air it sees. We thought about upgrading the fans as well, but have never had a problem with the stock mechanical fan, so we passed on it.
An EMS is only as good as its tuner and there was no way we were going to mess with tuning the engine ourselves, so we headed up to our local tuning guru Sasha Anis of SG-Motorsport. With the S14 loaded onto the dyno, Sasha began to adjust all the necessary parameters to add more power while keeping it within safe margins. We had dyno’d the car previously in its stock form and it put down 188 whp and 186 ft-lbs of torque. After tuning and boost being raised from 7 psi to 11 psi, our SR20DET netted 239 whp and 245 torque. That’s a significant increase considering how low the boost was that we were running. It goes to show that having a proper EMS like the Series 2 and the adequate bolt-ons can go a long way. Even though 239 whp isn’t neck-snapping fast, it’s now much more responsive with boost coming on quicker and smoother. In case you’re wondering why we didn’t push more boost out of the stock turbo, we want to ensure it’s reliable for the track and the tiny Nissan T28 turbo doesn’t like to be pushed much higher than 12–13 psi for long periods.
If the decision comes to upgrade the turbo, the supporting mods are now in place. All we’ll need to do is install a bigger turbo and get a retune, and we should be able to extract 300–350 whp with ease out of this setup. The owner says he’s enjoying the car right now at its current power level, but we know all too well that it wont last for long.
Engine Management System Series 2
Type-S Front-mount Intercooler System & Suction Intake Kit
AEM Series 2 Engine Tuning