For MY1993, Volvo introduced their famous 5 cylinder in the all-new 850. The whiteblock T5 engines that came in the P80s were easy to upgrade and there were strong manual transmission options available. Similar offerings came in the P2 generation for the T5 and R trims which made for impressive platforms to build upon. For stock power levels, the original equipment is adequate. But when adding power, there are some key areas we recommend you take into consideration.

Bolt-Ons

Intake

To start, we will address air flow. The Volvo 5 cylinders came with corrugated intake pipes. This is to reduce noise and turbulence past the MAF sensor. BUT the pipe reduces to a much smaller size restricting intake air flow. By increasing the air flow, more power is possible. And with a larger pipe, the turbo can spool faster for better throttle response. Most upgrades that fit the stock turbo will support flow to the turbo's limits. Many upgrade the stock airbox and MAF with either a 4” aluminum MAF housing or an Audi S4 MAF, both great choices for those with custom ECU maps wanting to add power to their R.

Exhaust

Along with intake air flow goes exhaust air flow. Back-pressure caused by small exhaust piping or restrictive catalytic converters can decrease horsepower. For turbo models, upgrading the downpipe can free up back pressure by increasing pipe diameter and reducing catalytic converter cell count. For race applications, back pressure can be further reduced by eliminating the catalytic converter. A cat-back can help as well by eliminating the restrictive rear muffler.

Intercooler & Charge Pipes

Even at stock power levels, the rubber couplers on P2 Volvos are susceptible to splitting. At the very least, upgrading the couplers to a silicone is necessary for reliable power. On the P2Rs, the intercooler system is diverted from a larger intercooler into a smaller one, restricting air flow. Even under stock power, we advise upgrading to allow your R to breathe. do88 offers a drop-in unit, while Snabb offers a giant front mount intercooler. Both will provide drastic improvements in intake air temperature over stock!

Injectors & Fuel Pump

The fueling system in the P2Rs was actually fairly robust. Many people will never have to upgrade. The stock “Green Giants” that came with your S60R/V70R flow enough fuel for almost 400bhp. That’s quite a bit. The stock fuel pump can match those numbers. For high horsepower builds, adequate fuel is necessary. Otherwise, you run the risk of causing serious internal issues such as burnt valves. If you wish to stick to 93 octane, larger injectors and fuel pumps are available as well as water-methanol injection systems preventing pre-ignition AKA ignition knock.

Spark

To go along with air and fuel delivery, ignition upgrades are welcomed. Using upgraded coil packs and racing spark plugs allows spark to be delivered on time.

Internal Upgrades

Shimming the Block

If the motor is ever to be opened, we highly recommend shimming. The shims we’re talking about are small pieces of metal put between the cylinder liners for reinforcement. Due to the large 83mm bore of the 2.5L engines, they are prone to cracking under stress - even being documented at stock power levels. A proper tune can aid this by ensuring cooler ignition temps, as well as water-meth injection.

Rods & Pistons

From the factory, P2Rs come with strong rods and pistons. It has been well documented that the stock internals can reliably make 400whp. For levels above that, forged rods and forged pistons are available. You would also need to start looking into block reinforcements such as sleeves allowing for higher boost.

In terms of availability, the P2R has some of the largest aftermarket support of any Volvo. This was intended to get you on your way to understanding what might be needed in upgrading your P2 or P2R. For those wishing to go past what is recommended in this blog, custom work may need to be performed and parts to be made. Whichever way you decide to go, know we are here to help, even offering a service where we build your motor. Don’t hesitate to email us with any questions!