Understanding the Kelford 300+ HP Turbo Kit

The Kelford 300+ HP Turbo Kit has quickly become a benchmark for enthusiasts who want to unlock serious power from their engine without compromising daily drivability. Kelford Cams, a New Zealand–based company known for its precision camshafts and high-performance valvetrain components, has leveraged its engineering expertise to create a turbo system that delivers reliable, repeatable gains. This kit is not a generic “one-size-fits-all” solution—it is engineered with specific engine platforms in mind, ensuring proper fitment, oiling, and thermal management.

The core of the kit is a journal-bearing or ball-bearing turbocharger, selected to support over 300 horsepower at the wheels while maintaining quick spool characteristics. The included cast-iron or stainless-steel manifold is designed to resist cracking under high heat, and the wastegate, blow‑off valve, and downpipe are matched to the turbo’s flow range. Many kits also ship with silicone couplers, T‑bolt clamps, and a high‑flow air filter. Depending on the vehicle, an intercooler upgrade may be included or strongly recommended.

Expected Power Gains – Real‑World Numbers

The “300+ HP” name is not an arbitrary rating—it reflects the wheel‑horsepower target on a properly tuned engine running the kit with appropriate supporting modifications. On a typical 2.0‑liter four‑cylinder (such as a Subaru EJ20 or a Volkswagen EA888), the kit can deliver gains of 100–130 horsepower over stock, pushing peak output to 320–350 whp on pump gas. On larger-displacement engines (2.5‑liter or 3.0‑liter inline‑sixes), the same kit can often exceed 380 whp.

Torque increases are equally dramatic, often rising 80–120 lb‑ft, and the curve shifts earlier in the RPM range thanks to the optimized turbine housing. The result is a broad, flat torque plateau that makes the car pull hard from 3000 rpm all the way to redline. Keep in mind that actual gains depend on the baseline power of your engine, the quality of fuel, ambient conditions, and—most importantly—the calibration.

  • Typical horsepower increase: 100–130+ whp (depending on engine and tune)
  • Torque improvement: 80–120 lb‑ft with strong mid‑range punch
  • Throttle response: minimal lag; 80% of peak torque available by 3500 rpm
  • Comparison to similar kits: Kelford’s compressor map is tailored to avoid surge at low rpm and choke at high rpm, providing a wider usable powerband than many budget kits

Installation Considerations – What You Need to Know

Installing the Kelford 300+ HP Turbo Kit is a moderate‑to‑advanced job. While determined DIYers have completed it in a home garage, professional installation is recommended if you lack turbo‑system experience or access to a lift. The following sections outline the essential steps and common pitfalls.

Required Tools and Equipment

  • Basic hand tools: socket set (metric and SAE), wrench set, screwdrivers, pliers
  • Torque wrench (capable of up to 80 ft‑lb)
  • Jack stands or a vehicle lift
  • Fluid catch pans (engine oil, coolant)
  • Pry bars and gasket scrapers
  • Diagnostic tool or laptop with tuning software (for post‑install calibration)
  • New gaskets, o‑rings, and copper washers (may not be included in all kits)

Step‑by‑Step Installation Guide

Preparation is key. Disconnect the battery and allow the engine to cool completely. Drain engine oil and coolant to avoid spills. Remove the stock intake manifold, exhaust manifold, turbocharger (if present), and associated lines. Inspect all mounting surfaces for cracks or warping.

  1. Mount the new manifold and turbocharger: Use new gaskets and torque the manifold bolts to manufacturer specifications. Attach the turbocharger with the supplied hardware, ensuring the oil drain flange is horizontal or slightly angled to prevent oil pooling.
  2. Install oil feed and drain lines: Connect the oil feed line to the engine block (often via a T‑fitting near the oil pressure sensor) and to the turbo. The drain line must run downhill to the oil pan. Use new crush washers.
  3. Coolant lines: Some turbochargers require coolant circulation. Route the lines to the engine’s cooling system (often to the heater core hoses or a dedicated port). Purge air from the system after refilling.
  4. Exhaust system: Bolt the downpipe to the turbo and connect it to the existing cat‑back exhaust. A larger downpipe (3‑inch or 3.5‑inch) is recommended to reduce backpressure.
  5. Charge piping and intercooler: Run the boosted air pipe from the turbo compressor outlet to the intercooler core, then to the throttle body. Use silicone couplers and T‑bolt clamps. Consider a blow‑off valve or bypass valve if not already integrated.
  6. Intake and air filter: Mount the filter in a location that receives cool, clean air. Avoid placing it near the exhaust manifold or radiator.
  7. Reinstall components: Refill engine oil and coolant. Reconnect the battery and prime the oil system by cranking with the fuel pump relay or fuse removed for 10–15 seconds.
  8. Tuning: Do not drive the car without a proper tune. The Kelford kit will produce too much airflow for stock fuel and ignition maps. Use a dyno tune or an off‑the‑shelf calibration from a reputable tuner. Monitor fuel trims, boost levels, and knock retard on the first test drive.

Supporting Modifications – The Recipe for Success

A turbo kit alone does not guarantee 300+ horsepower. The engine, fuel system, and drivetrain must be capable of handling the increased airflow and torque. Kelford recommends the following upgrades to ensure the kit reaches its potential and operates safely:

Fuel System Upgrades

Stock fuel injectors and pumps are almost always inadequate. Upgrade to 550–750 cc/min injectors (or larger for E85) and a high‑flow in‑tank fuel pump (such as a Walbro 255 or 450 LPH unit). A fuel pressure regulator may also be necessary to maintain the correct pressure under boost.

Intercooling

The included intercooler (if provided) is sized for the kit’s power target. If not included, an upgraded front‑mount intercooler with a core volume of 600–800 cubic inches is recommended to keep intake air temperatures under control. Charge air temperatures above 140°F significantly reduce density and increase knock risk.

Exhaust System

A free‑flowing exhaust is critical. A 3‑inch downpipe and cat‑back system (with or without a high‑flow catalytic converter) will reduce backpressure and allow the turbo to spool more quickly. Avoid restrictive mufflers that create excessive obstruction.

Engine Internals (Optional but Advised)

While the Kelford kit is designed to work with stock internals at the 300–350 whp level, forged pistons and rods, along with upgraded head studs and a metal head gasket, provide an extra safety margin. If you plan to run high‑boost or E85, internal upgrades are strongly recommended to prevent rod bending or ring land failure.

Driving Experience and Performance Metrics

Once the kit is installed and tuned, the difference is immediate. The turbo spools noticeably earlier than many comparable kits—often reaching 10–12 psi by 3200 rpm on a 2.0‑liter engine. This results in strong, linear acceleration that feels more like a larger naturally aspirated engine than a traditional laggy turbo setup.

0–60 mph and Quarter‑Mile Times

In a car that weighs 3000–3300 lbs, the Kelford 300+ HP kit can drop 0–60 times by 1.5–2.0 seconds compared to stock. For example, a Subaru WRX that runs 5.8–6.0 seconds stock can dip into the 4.5–4.8 second range after installation. Quarter‑mile times typically improve by 1.5–2.5 seconds, with trap speeds increasing by 8–12 mph. These numbers assume proper traction and a good launch.

Street Manners and Daily Drivability

Unlike aggressive big‑turbo swaps that sacrifice low‑end response, the Kelford kit retains excellent part‑throttle behavior. The turbocharger is sized to provide boost without overspinning at lower RPM, so you can cruise in traffic without surging. When you put your foot down, the power comes on smoothly—no violent sudden surge, just a steady push that builds as rpm climbs.

Maintenance and Longevity

To keep the Kelford turbo kit performing reliably, regular maintenance is more critical than with a stock system. The turbo’s bearings and seals are sensitive to oil quality and temperature.

Oil Change Intervals

Use a high‑quality synthetic oil (5W‑30 or 5W‑40 depending on climate) and change it every 3000–5000 miles. Many enthusiasts opt for a shorter interval (3000 miles) when track driving or using E85. Always run the engine at idle for 30–60 seconds before shutdown to allow the turbo to cool and prevent oil coking.

Boost Control and Wastegate Inspection

Periodically check the wastegate actuator arm and e‑clip to ensure it hasn’t loosened. Boost creep can occur if the wastegate hole is too small for the turbo’s flow. If you notice boost exceeding your target by 2 psi or more, consider a larger wastegate or porting.

Cooling System Maintenance

Increased power generates more heat. Upgrade your radiator to a high‑capacity (all‑aluminum) unit and consider an oil cooler if you do frequent track sessions. Monitor coolant temperatures; if they exceed 220°F under sustained boost, add a larger fan or water‑methanol injection.

Tuning and Calibration – The Make‑or‑Break Step

The Kelford 300+ HP kit will only deliver its promised gains with correct tuning. Whether you use a standalone ECU (like a Link, Haltech, or MoTeC) or a piggyback device (such as a Cobb AccessPORT or ECUtek), the calibration must address fuel enrichment under boost, ignition timing maps, boost target, and knock detection.

Many Kelford dealers provide base maps for common platforms (Subaru EJ, BMW N54, Nissan RB, etc.). These maps are a starting point—you must still verify the tuning on your specific car. A dyno session with a professional tuner is the safest route. They will adjust ignition advance and air‑fuel ratios to stay within safe limits. Expect to pay $400–$800 for a custom dyno tune depending on your region and the complexity of the ECU.

For those who prefer a more plug‑and‑play option, Kelford partners with several tuning shops that offer remote calibration services. You can download a file, flash it, and then data‑log to ensure everything is safe. However, remote tuning cannot account for every variation in fuel quality or atmospheric conditions, so on‑road data logging remains essential.

Common Tuning Pitfalls

  • Ignoring knock feedback: Never ignore knock sensor activity. Pull timing immediately if you see repeat knock events.
  • Incorrect boost reference: Ensure the wastegate pressure line is connected to a clean boost source (intake manifold or compressor housing).
  • Fuel pressure drop: If your fuel pump isn’t flowing enough volume at high boost, you’ll see lean conditions. Install a fuel pressure gauge to verify.
  • Overly conservative timing: While being safe is good, leaving too much timing on the table will rob power. Let the tuner optimize for your fuel.

Conclusion

The Kelford 300+ HP Turbo Kit offers a well‑engineered path to serious power gains without the headaches of a custom fab build. With proper installation, supporting modifications, and a professional tune, you can expect 300–380 wheel horsepower, strong mid‑range torque, and a responsive driving experience that still works on the street. The kit’s reliability is directly tied to maintenance and tuning—skip either, and you risk damage. But if you treat it with respect, the Kelford turbo kit can transform your car into a formidable performer, whether you’re chasing lap times, street pulls, or just a big grin every time you hit boost.

For more information on the specific components included in the kit, visit Kelford Cams’ official website. If you are new to turbocharging, consider reading our guide on turbo sizing basics to understand compressor maps. Additionally, forums like NASIOC or E90Post have extensive build threads where you can see real‑world dyno results and installation tips for specific platforms.