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| Once the header is bolted in, the downpipe is easy to install if you have a lift so you can get a good angle. |
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| The rest bolts up in just a few minutes. Unlike a Subaru Impreza the FR-S is a pleasure to work on. |
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| This system has gotta make power! |
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| A look at the entire exhaust before we put the underbody shrouds back on. |
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| Back on the dyno, we definitely had results. Due to the car's wandering power nature, we installed, drove, dynoed and reinstalled and re tested the header three times to make sure we could show some sort of repeatable, consistent gain. |
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| Sigh, our car had dialed out about 9 hp since our last dyno sessions so we were back to a gain of around 7 hp over stock. Adding the header gave a consistent 4-6 hp gain with multiple pulls. This chart was something about typical. In areas with better fuel, the header seems to give more like 10-12 hp for most people. The good news if you can call it good is our power now doesn't seem to dip below 155 whp anymore. It seems like we went through a lot of work to only get 10-12 whp over stock. We feel that it is purely due to the poor quality of California gas as other people with access to 93 or E85 are getting around 200 whp with a similar level of mods. On our conservative dyno that would probably equate to around 190 whp. |
So we have been confounded in our attempts to make more NA power by the car's smarter than us ECU. Hopeful as more R&D is done and more is learned about the stock ECU we might be able to get consistent results. Currently it seems like Southern California's horrible 91 octane fuel does not get along with 12.5:1 compression, direct injection or not. We have never experienced a car that acts like this to date. As more is learned about the ECU you can bet that we will be back on the engine and reporting to you what it takes to get more power.
For those of you that live in areas with better fuel, the car responds well to simple mods and it is possible to get close to 200 whp with bolt ons.
With that in mind we will focus our attention on the rest of the car for a while and leave further power mods for later!
Sources
Want more Project FR-S? MotoIQ Project Scion FR-S
