Modifying a car, whether it be for better power, handling, reliability or even fuel economy, comes with compromises. Usually, if you increase one, you decrease the other. For example, better fuel economy might mean a smaller engine with less power. More power might mean less reliability, and vice versa...
...Or does it? Here's my take on how to increase power in a Volvo V70R without sacrificing reliability.
Stage 0 First
In my last article, I outlined how to go "Stage 0" with a Volvo V70R. This is crucial to do first before you start modding, because it'll ensure your car is at peak baseline performance prior to moving on to any sort of enhancements. With all of the stage 0 refreshes completed, you'll have a stable platform to build on. No sense adding power to a car that can't reliably handle it.
Upgrade 1: Intercooler
One of the best mods you can possibly do to a turbocharged car is upgrading the intercooler. FCP Euro offers an excellent kit from Snabb that will give you everything you need for your V70R. In the kit, you'll receive a 22" x 12" x 3" intercooler that supports up to 450bhp with a 2.5" inlet/outlet. It also has polished, lightweight aluminum piping that closely follows the stock piping setup for ease of installation. Also included are mounting brackets, hardware, 5mm thick silicone pieces, and a full set of instructions. One last bonus is the V-Band flange & Integrated MAP/IAT sensor. Really, you can't beat this kit.
Since I'm not going for crazy power on my V70R, this kit works perfectly for what I need. It's important to upgrade the intercooler when you're going for more power because it will significantly reduce intake air temps while increasing HP output and throttle response. You should see anywhere from a 20-40 bhp increase from this mod alone.
Upgrade 2: Intake and Mass Air Flow (MAF) Sensor
After you've given your V70R better cooling, you'll want to upgrade the intake and the MAF sensor. Once again, FCP Euro offers a great Snabb kit for this. There are a few MAF upgrade options, but I've found that the Bosch 3.25" ID "S4" MAF that comes with this particular kit is a good option for the V70Rs.
The importance of upgrading the intake shouldn't be overlooked. It will allow for better airflow to the turbo while simultaneously blocking engine heat. This should give you more power gains for a stock or modified V70R. The MAF upgrade will help your car manage the increased air flow from the new intake. You're looking at another 10-20 bhp increase here. It's important to note two things. 1) With this kit you'll also need the intake piping kit from Snabb, which can be found right here. This new intake will not fit with the stock intake pipe. 2) With the increased air flow, the new MAF, and advanced cooling from the intercooler, you MUST tune your car to account for these changes. The stock map on the ECU will not be able to handle the increased performance and may pull timing, make you run rich (or lean), or any number of other things which could lead to knock or catastrophic failure. The tune will be worth it. Let's explain that now.
Upgrade 3: Tune It, Be Happy
There's a few ways and places to do this. Two that come to mind are well renowned for their V70R tuning prowess: Hilton Tuning and Contrast Works. I personally went with Hilton Tuning as they are likely the most well known in the V70R community and have a ton of experience with it. Here's my reaction after slapping a Stage 2 tune on my V70R.
Long story short, the difference is noticeable. Before the tune, I was making 270 horsepower and 298 lb-ft of torque, and will update what those numbers are after we dyno it a second time, after the tune. I'm predicting a 30-40 bhp increase. As I said above, tuning the car after the intercooler and intake+MAF upgrade is a crucial step. It must be done at the same time. Hilton recommends a Stage 2.5 tune with those upgrades. All in, you're looking at anywhere from 50-75 bhp increases with these modifications up to this point; plenty of power without overwhelming the engine too severely.
Upgrade 4: New Exhaust
Ah yes, we've finally come to the best part - the exhaust. Throwing an exhaust on a car can turn it from a subdued gentleman's wagon into a snarling, 5-cylinder monster. The best part about exhaust mods on the V70R is there's no tuning required. I went with a custom, full turbo-back exhaust from 8 Eight Fab. FCP Euro offers a similar 3", high-flow cat downpipe that will open up the growl in the V70R's engine. Adding this, even with the stock exhaust still installed, will not only make the car sound better but give a 5-10 horsepower bump due to better air flow.
All in, with everything above, you'll likely get between 60-85 horsepower more from your V70R. Any further, and you'll need to look into forged internals, closing the deck, shimming or sleeving the block, and any number of extremely expensive upgrades to withstand the increase in power. With the ones we've outlined above, your V70R will come alive from a power stand point without stressing the engine. These are the safest mods you can do for good gains.