Turbos

Ensure proper sealing when installing the turbos on your N54.

Kit includes:

• 16 - ASA M7x39 studs
• 16 - Flange nuts
• All required gaskets and o-rings
• Water pump install hardware
• Replacement vacuum hose
• T-bolt clamps

Helpful hints:

For complete installation instructions, refer to Haynes Service Manual (T#193950).

Both downpipes must be removed to remove either front or rear turbo. Tie rod end may need to be separated from knuckle for clearance. Steering rack may also need to be rotated away from subframe for access. Valve cover heat shield will need to loosened and pushed upward to get clearance for turbo manifold removal.

If studs back out of cylinder head and nuts are seized to studs, replace studs. Thread studs in to head by hand to prevent cross threading. When installing the new studs in the cylinder head, use a high temperature loctite in the cylinder head side, and copper anti-seize on the nut side.

To make more room for access to the front turbo, remove the rubber line running in front of the subframe that attaches to the back of the map thermostat and remove the clip. Cut off the OEM clamp and replace it with a new hose clamp as well.

Complete removal of the water pump is not required. Detach the water pump from the side of the block and push it out of the way to make more room for access to the front turbo. If water pump is unbolted from the block, the aluminum bolts must be replaced.

Torque specs:
Bracket to cylinder head: 9Nm
Coolant supply line to crankcase: 9Nm
Coolant return line to crankcase: 8Nm
Coolant return line to turbo: 8Nm
Coolant supply line to supply line: 8Nm
Exhaust manifold heat shield: 8Nm
Oil supply line to crankcase: 20Nm
Oil pressure line to turbo: 8Nm
Oil return line to crankcase: 8Nm
Oil return line to turbo: 8Nm
Turbo manifold to head: 20Nm

Vargas Stage 1 N55 turbo upgrade is good up to 425whp with proper tuning and high grade fuel. Vargas N55 turbo is an all-new turbo specially made for Vargas. They build it with a billet compressor wheel of their own design and a stock turbine. It will accept all of the stock water and oil lines and the original diverter valve (upgraded DV is recommended). This kit is a direct bolt-on replacement for the original turbo and necessary if you want to start making big power from the N55.

The stock plastic diverter valve and chargepipe is the weakest point for boost leaks (the plastic cracks). Vargas Turbo recommends upgrading it to a stronger DV design. The aluminum DV designs will hold up to just about any boost level currently available.

Vargas Turbo Technologies has been in business since 1979, offering rebuilt and re-engineered turbo solutions. For the BMW market, they identified a need for both cost-effective turbo replacements and proven turbo upgrades. It's recommended that the rest of the system be upgraded to handle your tuning goals. The final Vargas rebuilt turbos are better than the factory rebuilds and at a lower cost!

Oil Recommendation - modern engine oil is formulated for emissions and to be environmentally friendly. The additives in current oil lowers the oil's ability to withstand high temperatures and stresses, lowering its shear strength and its lubricating properties. Vargas recommends oils with high ZDDP (zinc and phosphorus) content that will better protect and cool the turbo bearings. Examples of high-zinc oils are Red Line Race, Red Line Euro, Motul 300V Racing, Joe Gibbs Racing, Valvoline VR-1 oil, and most Diesel-spec oils that you can buy off-the-shelf. Some oils, especially the Race type, will need more frequent oil changes and may be harmful to catalytic converters.

WHP rating: 425. This rating is used to compare various stage of Vargas turbo kits. There is no advertised horsepower gain with this kit as it depends on your other mods and tuning. The rating is provided as a reference to use in your tuning planning. Custom tuning is recommended to match thIS turbo to your existing mods and upgrades.

Turbo maintenance has become part of our daily lives here. Our Service department does several turbo overhauls, wastegate adjustments, carbon cleaning, and upgrades every week. For the DIY owner, however, having a complete overhaul kit takes some of the stress out of 135/535 turbo replacement and this kit includes all of the basic items. It's highly likely N54 turbos will have to be replaced before 100,000 miles. Signs of a failing turbo are high oil consumption and blue smoke from exhaust (not from a leak or failing CCV system) because the internal oil seals are no longer retaining oil. Without critical lubrication and cooling effects from oil, the turbo shafts and bearings are usually the first to wear and that requires a complete rebuild. You might also see increased turbo lag or failure to hold boost, which is usually a sign of a failing wastegate or some other internal issue. With any internal problems the turbos need to be replaced. 

This package uses new (not rebuilt) Mitsubishi turbochargers (the original supplier to BMW). These are essentially direct replacement turbos but we went straight to the manufacturer instead of going through BMW. They are the same as the factory turbos but without a BMW logo so you save yourself a few hundred dollars. It includes everything that needs replacement during a 135 or 535 N54 twin turbo overhaul -

• Front and rear new OEM Mitsubishi turbos (the original supplier of BMW turbos)
• 1 gallon of Genuine BMW coolant
• ​16 - ASA M7x39 studs
• 16 - Flange nuts
• All required gaskets and o-rings
• Water pump install hardware
• Replacement vacuum hose
• T-bolt clamps

These are brand-new turbos so a core charge does not apply.