If you're looking to squeeze more life out of your Nissan, an sr20de t conversion is probably the most rewarding weekend project you can tackle. You've got the chassis, you've got the naturally aspirated motor, but let's be honest—it's missing that "pssh" sound and the shove in the back that only a turbo provides. Converting a DE to a "+T" setup is a rite of passage for many S-chassis and front-wheel-drive Nissan owners. It's often cheaper than buying a full SR20DET swap, and if you do it right, it can actually be a more responsive setup for the street.
The SR20 engine is a legend for a reason. It's sturdy, it loves to rev, and it handles boost surprisingly well even in its non-turbo form. However, you can't just bolt on a turbo and hope for the best without understanding what makes the DE different from its factory-turbocharged cousin.
The High Compression Reality
The biggest difference you'll encounter when starting an sr20de t conversion is the compression ratio. While a factory SR20DET usually sits around 8.5:1, your naturally aspirated DE is likely sitting at 9.5:1 or even 10.0:1.
In the old days of tuning, people thought high compression plus boost was a recipe for a blown motor. Today, we know better. High compression actually gives you better off-boost torque and faster spooling. The catch? Your tuning window is much smaller. You can't get away with "lazy" timing or poor fuel quality. You'll be running less boost than a DET to achieve the same power, but the car will feel much more alive when you're just cruising around town.
Gathering the Essential Hardware
You're going to need a pile of parts before you even think about cracking a wrench. Most people try to source factory SR20DET parts because they bolt right up. It's like Nissan left a trail of breadcrumbs for us.
The Turbo and Manifold
The easiest route is grabbing a T25 or T28 turbo from an S13 or S14 Silvia. These are small, reliable, and punchy. You'll also need the factory turbo manifold. It bolts directly to the DE head without any modification. If you're feeling fancy, you could go with a bottom-mount aftermarket manifold, but for a first-time conversion, the OEM cast manifolds are nearly indestructible and handle heat soak way better than cheap eBay stainless steel ones.
Oil and Water Lines
Your DE block isn't currently sending oil or coolant to a turbo, so you have to provide a path. You can buy braided line kits specifically for the sr20de t conversion. For the oil feed, most people use a T-fitting at the oil pressure sensor location. It's a bit of a tight squeeze near the block, but it's the most common way to get high-pressure oil to the turbo bearings.
The "Scary" Part: Tapping the Block
This is the part that makes most hobbyists nervous. Every turbo needs to drain its oil back into the engine, and the SR20DE doesn't have a hole for this. You have two choices:
- The Oil Pan Method: You can weld a bung onto the upper aluminum oil pan. It's a bit of work because you have to remove the pan (which involves a lot of RTV scraping), but it's the safest way.
- Drilling the Block: There is a specific flat spot on the back of the SR20 block where the factory turbo return sits. You can actually drill and tap this while the engine is in the car, provided you use plenty of grease on the drill bit to catch the metal shavings.
If you're not comfortable drilling into your engine block, stick to the oil pan method. Just make sure the return sits above the oil level so the oil can actually drain. If it backs up, your turbo will start smoking like a chimney.
Fueling the Fire
Your stock DE injectors are tiny. They're usually around 259cc, which is barely enough to keep the engine happy in its natural state. If you try to run boost on these, you'll lean out and melt a piston before you even get out of second gear.
You'll want at least the 370cc injectors from a stock DET, or better yet, some modern 550cc or 740cc injectors. Along with the injectors, you need a fuel pump that can keep up. A Walbro 255 is the "standard" choice here—it's cheap, it fits, and it's proven. Don't forget to grab a decent fuel pressure regulator if you're planning on pushing the limits, though for a basic setup, the stock one usually holds its own for a while.
Management and Tuning
You cannot run an sr20de t conversion on a stock DE computer. It doesn't understand what "boost" is. When the manifold sees positive pressure, the stock ECU gets confused, the timing stays too aggressive, and things go south quickly.
You have a few paths here: * The Budget Way: Find an ECU from a factory DET and a matching MAF (Mass Air Flow sensor). This works surprisingly well for basic setups, but you might run into issues with the idle air control valve or the distributor wiring depending on which year your engine is. * The "Nistune" Way: This is a daughterboard that gets soldered into your factory ECU. It turns it into a fully tunable unit. It's very popular in the Nissan community because it keeps all the factory "smarts" while letting you map for boost. * The Professional Way: A standalone ECU like a Haltech or Link. It's the most expensive option, but it offers engine protection features that can save your motor if a fuel pump dies or a hose pops off.
Keeping Things Cool
Heat is the enemy of any turbocharged car, but especially a converted one. The DE cooling system was designed for about 140-160 horsepower. Once you jump to 250 horsepower with an sr20de t conversion, that little single-core radiator isn't going to cut it.
Invest in a thick aluminum radiator and, more importantly, a good intercooler. Since you're starting with a higher compression ratio, your intake air temperatures (IATs) need to stay as low as possible to prevent detonation. A front-mount intercooler (FMIC) is the standard move. It might require a bit of bumper trimming, but the peace of mind is worth it.
Is the DE Internal Structure Strong Enough?
I get asked this all the time: "Will the rods hold?" Generally speaking, the SR20DE bottom end is good for about 300 to 350 wheel horsepower if the tune is clean. The main difference people worry about is the lack of oil squirters. Factory turbo blocks have little nozzles that spray oil onto the bottom of the pistons to keep them cool.
Does the DE need them? For a daily driver or a weekend canyon car, not really. If you're planning on doing 20-minute flat-out sessions on a road course in the middle of summer, you might run into heat-soak issues with the pistons. But for most of us, the lack of oil squirters isn't a dealbreaker. Just keep an eye on your oil temperatures and don't be afraid to install an external oil cooler.
Final Thoughts on the Build
Doing an sr20de t conversion is one of those projects that teaches you a lot about how engines actually work. It's not just about bolting on parts; it's about balancing fuel, air, and heat.
When you finally finish the plumbing, tighten the last T-bolt clamp on your intercooler piping, and turn the key, there's a massive sense of accomplishment. That first time the wastegate opens and the car hooks up, you'll realize why the SR20 is such a cult favorite. It's a resilient, punchy little motor that just wants to be boosted. Just take your time with the tap and die set, don't skimp on the fuel pump, and get a solid tune. Your Nissan will thank you with plenty of tire smoke and a much faster 0-60 time.