2013 Scion FR-S: Forced Induction
June 28, 2013
You think you're frustrated about the lack of forced induction on our Project FR-S? Believe me, you're not alone. I won't get into the excruciating nitty gritty specifics as to why it's taking so long, but I'd like to address some of the "but there are so many kits available!" refrains.
We live in the land of 91 octane. The FR-S has a 12.5:1 compression ratio engine. This combination means low boost. Also, what this car needs is punch down low and through the midrange. Sure, a bump in peak power would be nice but not if it comes at the expense of what the car actually needs, power delivery-wise.
Consequently, for a turbo kit, there's no sense using a turbo capable of supporting 400 horsepower, since you're simply giving up boost response to meet a power number you can't reach. It's wasted headroom. Yet the various turbo kits I found all use a 400-hp (or more!) turbo. And when the kit vendors have released a dyno chart (a best-case run, probably) for their kits, they generally reach their peak of 5-7 psi at about 4,000 rpm. It's just not the power delivery we're looking for in a dual-purpose car, a sentiment I suspect other owners would agree with.
Furthermore, I don't want mushroom air filters that draw underhood air, or methanol injection or cheap knockoff turbos or other such forced induction kludges, and neither should you.
That's not to say there hasn't been progress. If all goes according to plan in the coming weeks, we'll have some updates to share with you regarding a set of lungs for Project FR-S.
Jason Kavanagh, Engineering Editor