Hello! Welcome to today's introductory installment of "Make Forums Great Again," my feeble attempt to bring some sort of order to the disorganized chaos social media has brought upon this industry/hobby.

We begin with a look into the freshly-released 2017 Civic Si, which is a bit of a departure from Honda tradition both with turbocharging and the lack of any low cam/high cam switching we've all grown accustomed to over the last 25 years. While this is something relatively new to the brand and model, it's not so uncommon in the segment. Of course, the driveline is very similar to the existing EX-T/Sport models released last year, but this isn't "Car and Driver," and I'm not a professional journalist, so I'll spare you the buzzwords and simple explanations and get right to the findings.

I have gotten fairly well acquainted with the new Civic Si over the course of the last six days and 100 or so miles. The car was picked up from the dealer with a full tank of 87oct... So mod number one was to drain the tank and fill with 93oct. I estimate about 1.5gal of 87oct was still left at the bottom of the tank, then topped off with the highest quality "Sheetz" 93oct across the street from our shop. With 110miles on the clock, I decided to toss it on the DynaPack for some comparison testing. The run conditions were not exactly super ideal (93-94degF dyno room temps according to the DynaPack temp probe), but 'tis the season here in the Midatlantic. Runs were completed at as close to the same IAT/IAT2/ECT readings as possible.

I loaded the car up, input the test ratio (fourth gear for these tests), and performed some runs. Since I had been playing with the calibration on the street a few days prior (because I'm an impatient child), I decided to do a run with the reflash first. The calibration is essentially the stock Honda Civic Si mapping, with the exception of raised boost targets to 23.5psi. I didn't get a chance to do much more with it due to time constraints during the workday here (since every time the car is flashed, Knock Control resets and must relearn), so I expect some larger gains once I get a chance to pump a little more ignition timing into it over the factory setting. The results from the mild tweaking with KTuner showed 208hp / 260tq, with boost dropping from 23.5psi to 20psi up top.

After doing two runs with identical power and curve shape, I returned the ECU to the stock calibration and loaded it down enough to move Knock Control down a bit. The results were 184hp / 204tq. I think it has a little more left in it on the stock tune with less Knock Control value, based on the power figures some of my other tuner colleagues have tested at over the last few days as well.

Here's the comparison of the KTuner flash versus the stock calibration.


As you can see, the BIG gains are in the middle of the curve. Peak number differences were 56tq and 24hp, but as you can see, in certain areas gains of 40+hp were made.

For comparison let's see the 100% stock 10th Gen Civic Si versus the previous 9th Gen on this machine, completely stock as well (K24Z):


Aaaaaaand let's see the KTuner flashed 10th Gen versus a full bolt-on, RBC intake manifold swapped, KTuner-tuned 9th Gen:

On this one, the 9th makes a few more HP peak, but not much, and not for long.

Finally, here's the KTuner-flashed, 100% stock parts 10th Gen Civic Si versus a totally stock 8th Gen Civic Si (K20Z3):


While the 10th Gen Civic may lack displacement (get caught under about 2,000rpm at low to medium throttle, and you'll be wondering if you have enough power to evade the '98 Hyundai Elantra in the next lane), the tiny turbo and electric wastegate make for a wall of torque shortly after, especially with just a simple reflash. I have no doubt that some more tweaking to the calibration will reveal more power up top, and some simple breathing mods (I.E. ditching the GIANT cat, on race applications only, of course) would unlock a ton more fun.

I'll be adding to this post as I get more acquainted with the car in the near future, so check back periodically.

Thank you for reading!

P.S. For the love of all things holy, please ask your questions here, and not on Facetwattergram.

 

 

Awesome and well written,

 

Drob for president !

awesome to see some testing of these already and compares to the other generations.

 

Do you have any boost plots?

 

Posting just because it feels cool to log into my account. Good work sir.

 

Drob ftw. Thanks a lot for doing this and posting results here. Honda-tech ftw

 

So what is holding back the revs? Just the loss of efficiency?

 

Glorious!

 

very cool!!

 

Thank you for taking the time to publish this.

Very good to see.

:-)

 

Can't wait to see where this goes I hope you can bring back this place!

 

awesome dude. Thanks for posting it up and very good results with just a flash. I assume the turbo is pretty much maxed out but could possibly pull a little more power out with a better flowing exhaust/dp and intake? How big are the stock injectors?

 

A turbo swap away from more power.

Thanks for sharing, I know Wes was already on top of this.

 

Mind posting a few pictures from underneath? Curious as to the difficulty of working on these.

 

Torque gains are crazy with the reflash.

 

#MFGA

 

Good stuff man!

 

Wow nice!
@ drob if u get the New turbo type r u should test them too!

 

So ktuner is worth getting right now for my si?

 

Make HT great again.

 

Does this mean I'll be able to put lengths on this mustang guy that constantly drives around with slicks?

 

Wow! That is some improvement. Great post!

 

FUUUUUAAAAARK . . . a 6200 redline turbo honda. AKA alternative reality.
Anyway very nice post.Well writen.

 

Its awesome how much more jam it makes overall and the torque which is great especially for a daily driver. But man its weird seeing the rev limiter at 6000.