So this just happened. Yup, it’s been a hectic couple months and through it all I’ve been waiting for our 2017 Si to arrive. We traded our 17 EX-T sedan test mule in for this one. I picked up the car with just 12 miles on it, fresh off the truck. The fit, feel and drive of this Si is way different from the EX-T Sedan, and even different to that of the previous generation Si’s — but that’s for another post.
After rolling 142 miles on the car between driving it home from the dealer and to the shop, I put it on the dyno for some baseline testing and a mild tune. Right off the bat I was not happy with the clutch — it’s the same setup (other than the flywheel) as the base model 1.5T vehicles and on a couple of street tests in 3rd gear I already noticed clutch slip between 2500 and 3000 rpm at WOT. Wonderful. More on that later.
First — the car came with a tank of 87 octane, not ideal for a sports model Civic, and we know these things will make more power on premium grade fuel (92-93 octane in our tests). I baselined it on 87 octane anyway. Solid is the Si, dashed is the EX-T. The upgrades on the Si clearly make more power than the base 1.5T — and at “only” ~17.8psi (yup, our car never hit advertised boost levels by Honda). 191whp and 208wtq. Not bad.
I ditched the 87 octane and got premium fuel in the car. I also sped the dyno up slightly as I was concerned with clutch slip (Dynapack allows you to control the acceleration rate of the motor — the “ramp rate”). The graph on the right shows what the Si makes on premium grade fuel (Si is solid again) vs our base EX-T. I noted no slip at this ramp rate, so I put the dyno back to the original speed and did another pull — and of course with the boost coming in sooner the car made more torque, and we hit some clutch slip (as you can see — chart on the left). So looks like on 92-93 octane we will see anywhere from 200-206whp and 210-220wtq (depending on your luck with the clutch). So right around advertised power at the crank, but to the tire… with more torque than advertised (actually).
How Does This Compare Vs The Previous Si?
I’ve been around long enough to watch the Internet explode with drama every time Honda releases a new generation of Civic. The subjective arguments of it “looks like blah blah” or blasting for Honda not doing this or that (only 205hp what?). I think we all need to settle down and just accept that Honda builds the Civic Si as a sporty econobox. That’s what they’ve always done, that is their target audience — and the cars seem to sell, so they can’t possibly be getting it all wrong?
So, here’s what they’ve done this time around. To the right — solid is the 2017 Si, bone stock. Dashed is a bone stock 9th gen Si. Wow, the 2017 Si makes a good 50-60 wheel torque and a good 40whp more than the last generation Si it’s replacing.
How about a stock 8th gen Si? It’s not even a comparison, it makes 100wtq more through the usable power range than the 8th gen Si and 75whp more (sure, only “30” hp peak — the K20 has always been high strong and peak HP doesn’t win you any races).
Clearly Honda got it all wrong? I don’t think so. I’ve owned and driven all the generations of these cars in every fashion — stock, bolt on, supercharged and turbocharged. While we did get rid of our 2013 Si, I still have our 2008 Si (a 900whp+ built car is hard to part with — a lot of upkeep but oh so much fun).
Let’s Throw a Mild Tune At It
With the clutch not wanting to hold even stock power on premium fuel, I didn’t want to get too crazy with the tune on the 2017 Si — yet. Hopefully 142 miles just isn’t enough break in on the clutch and it’ll improve with some drive time (already have a better clutch waiting as well). So just to be clear — I intentionally limited potential power gains and stayed under 230wtq to avoid damaging the obviously fresh clutch on the car. I actually detuned and lowered boost from 3000 to 4000 rpm. My goal was to fatten up the powerband and tune out the “pullback” even this sports model suffers from (throttle closures which also cause boost to get pulled back).
Mission accomplished. While keeping the mid range/low end relatively stock we were still able to net 50wtq and 40-45whp over stock through the curve (with about 20hp peak). This is a nice improvement in the way the car accelerates.
Is there more in it? From what we’ve seen on the base 1.5T which make over 240whp and 300wtq, absolutely. Stay tuned to see us squeeze the Si for all she’s got once it’s got a few more miles on it — only 24 hours old and I’m already putting her through the grinder.