Laying Into the 2017 Honda Civic Si

Well now that I’ve changed out the clutch on our test mule 10th Gen Civic Si I’m able to lay into it and see what this baby turbo with the 1.5L motor can really do. Thank you to ClutchMasters for providing us with a very strong clutch — it held up through all the abuse I just put this car through.

I am currently using KTuner on our test vehicle as this is the only software available to me that provides me with all the necessary control to really work on the innards of this ECU and dig deep into what this motor, turbo and ECU can do. Big thank you to them for providing the software we needed to get some serious testing under way.

Shut Up and Tell Me How She Did Already?

I have to say I am very pleased with the way this car not only drives, but makes power — it’s a VERY broad power curve and this is very noticeable when driving the car. She laid down over 255whp and 320wtq, and you can see the power curve is quite “fat”. This power was still made running quite an aggressive tune — but nowhere near any ECU or software limits.

However — for the sake of longevity I dialed the car back into the ~240-245whp and ~290-300wtq area for myself as I want the car not to just “make power” — which is something people tunnel vision on — but I also want it to be reliable. This car is our test mule and we have some more plans for it.

What About These Limits You Mentioned?

This was actually quite fun — in the ECU we’ve already raised all sorts of “limits” to allow us to make power (no throttle pullback, increasing boost targets, etc). However there’s always *something* lurking when you really push things. Which is exactly what I did — I went all out on the baby turbo to see what she could do, and sure enough, I clipped a very brutal boost “limp mode” type situation in the ECU that you can see killed power quite aggressively after 4500 rpm.

There’s two things we can discuss and analyze from this.

First — clearly the baby turbo can do LOTS of boost in the mid range — which continues to make a LOT of torque. As a result, our peak HP spot goes down in the powerband (and I drew in what a potential curve without the limits would look like given what I already know about the turbos capabilities after 5500 rpm). But as horsepower is just a function of torque — if you make enough torque you can make “more horsepower”. As you can see — we’re in the 270whp area! The side effect of this is you have to run the motor with a LOT more torque as your usable powerband for best acceleration actually goes down.

Which brings us to the second point — do you really want to be laying 340wtq into this motor? I think it’s very cool from a testing perspective to see what we can do — but may not be practical for day to day use or the longevity of the motor.




Introducing the 2017 Honda Civic Si

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.

The Baseline

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).

Well, let’s throw some bolt ons at the 9th gen Si and see how it compares to the 2017 Si? Solid is the 2017 Si again.


How about the bolt on 8th gen? Solid is the 2017 Si once again.

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.




Tested: PRL Motorsports CivicX RACE Downpipe

Well, after not getting any results worth talking about using my high octane fuel PRL has dubbed as my “secret sauce”, it was time to go back to low octane fuel and see what this downpipe could do — if anything. As much fun as it is to just push the motor and turbo to it’s full potential using the best stuff you can throw at it — testing on the average every day fuel most people will use is more realistic. And well — nothing gets more real than running this car on 87 octane, probably the lowest octane you can get in the USA (I’ve seen a few remote locations with 85 or 86 octane, but that’s really rare).

The results were pleasing.


I feel that I have to explain a little bit of the innards of the ECU here, so some of the results will make sense. For anyone installing the PRL downpipe and expecting some results with either the factory tune or one of the basemaps with their tuner of choice, you need to understand where some of the “gains” are coming from.

The CivicX ECU doesn’t use a standard turbo wastegate for boost control — it uses an electronic wastegate run by the ECU. This is more complex and actually very cool. Most “standard” boost control systems use a boost solenoid (mac valve or similar) and when you ask for, say, 20psi, it tries to target that immediately and let the turbo wind up as fast as it can.

This is not the case with the CivicX. Honda uses a “slope” or “ramp” style boost control. Essentially it knows “X” wastegate position means “Y” boost and will actually “ramp” or “spool” the turbo at a fixed rate to get there. This induces artificial turbo lag. I believe this is done in part to protect the CVT trans and possibly to protect the motor — as this little turbo has the potential to “wind up” (spool) VERY quickly if it’s unleashed.

So why is this distinction important? Advertising that anything will make “peak torque sooner” is actually not quite true. In repeatable and consistent tests peak torque is always the same spot as that is where the ECU finally lets the turbo reach it’s target boost. If we didn’t have this control in the ECU I can imagine peak torque being 2200-2500 rpm on this motor with this downpipe.

However, since the ECU is programmed for a STOCK downpipe, when you install an aftermarket downpipe (PRL’s in this case), the exhaust flows more freely and as a result the turbo will TRY to make more boost than the ECU wants and at potentially a little different “ramp” as the wastegate control in the ECU isn’t compensated for this new part.

So what did I find? When I tuned the car stock on 87 octane bone stock, I targetted 18.4psi and the boost level stayed very close to target boost. To try and give us 1:1 results at the same boost level, I actually had to target 17.5psi to get the same boost level I had before installing the downpipe. You can see this in the side by side comparison in the image to the left. I forgot to get this dyno comparison off the dyno computer before I left the shop, but keeping boost the same we saw 8-9whp on the top end and 10-20wtq gained. Keep in mind this is over our “stock tuned” 87 octane test — so we’d already worked on the timing map and fueling a bit as well. You’ll also note as we put load on the car before starting the pull — the turbo was already making almost 2psi more than before the downpipe — this will come into play later.

What does this mean to YOU? If you’re running the same tune with a freer flowing downpipe you will artificially increase the boost level a bit. This will have gains on lower octane fuel as you’re not at peak turbo performance on the stock downpipe on lower octane fuels. Just understand where those gains are coming from — it’s not all just the “tune” at this point. The ECU *will* try to normalize the boost control and bring it back down to the target as the pull goes on (as you can see it happening).

The Install

The PRL items, as always, are quality pieces. Very well done items and fitment on our car was like a glove. No rattles, no rubbing. If you don’t have a lift the install will be a bit more entertaining. On my lift it took about 2 hours to get the stock items off and this one installed. The studs in the turbo can be interesting — PRL broke theirs. I managed to get mine off without any breakage or stripping with the use of some magic lube.

Some pics, of course.

So What About The Toon?

Note: blue is HP, yellow is TORQUE, orange is BOOST.

So let’s try to give it a bit more boost and see what happens? Increased the boost level about 1psi (don’t want to go crazy with 87 octane) after adjusting the timing map and such — and the results were nice. 20whp and 30-32wtq gained.

Torque came in sooner too, right? Of course — if we didn’t have the “ramp” based boost control it would of come in even sooner, but we got maybe a 200-300 rpm improvement because the turbo just wants to GOOOO with the free flowing downpipe, even if the ecu doesn’t want to let it! Peak torque however — was still the same spot. This should never really change as long as the load & ramp rate of the pull is consistent (not all dynos can control this — and certainly load will vary on the street).

But hey, let’s try to give it a little bit more. In the dashed line we increased boost a bit more (with a few other changes), and as you can see the gains were marginal — a bit more torque, but top end HP actually suffered a bit. We’re now at the limits of the fuel and I was starting to see the knock limit approaching very rapidly — don’t want to run here long term at all for reliability’s sake. But hey, overall we still saw 5-8wtq more which amounted to 35-40wtq through the mid range and we still picked up 20wtq up top.

So if you want to run on readily available fuels and not go hunting for race gas or some sort of “secret sauce” (lol), then PRL has a great RACE downpipe. Expect to see diminishing returns in how much HP you can make with better fuel — on 93 expect maybe 8-10whp more with this downpipe. Of course more torque as well — if your clutch can take it.

Vs Bone Stone?

Don’t really need an explanation I think?

87 octane fuel.





Where can you get all these goodies? Right here, along with tunings and custom tuning!

Tuners vs Tooners

It has been a while since I’ve posted a good rant as I have been busy hitting the ground running in 2017. Kevin’s 9th gen Civic Si is alive and laying down some solid power with our MoTeC programming and we’ve done a lot of testing (lots in the background beyond the power/tuning figures I posted) on the new CivicX platform. We also have a project I’m really looking forward to coming into the shop soon — a certain yellow Chevelle we’re converting to fuel injection and building a MoTeC ECU for a twin turbo 76mm setup. More 9th and 8th gen Si’s coming in for MoTeC installs as well…

More on that stuff later as it progresses… on to the rant.

My Tuner Is Legit

You know we’ve all heard this one — but when they tag their tuner, no one’s ever heard of that one.

Not to say that automatically implies the said person isn’t a magician at their trade. But the reality and years in this business has made me a skeptic. I’ve been sent plenty of datalogs to review where the owner thought the car “drove fine” where in reality it was not even remotely close and was improved on significantly. It just exemplifies the ignorance when it comes to what a “properly tuned car” is. And really, the average enthusiast/car owner/racer shouldn’t really have to care or worry about it — it is in fact not their job to set the ECU up properly. They are paying for it to be done right.


I feel like a broken record on this one point, as this argument comes up a lot. Tuning isn’t just about power. YOU CAN ALWAYS MAKE MORE POWER. Either with better parts, better fuel, or running the motor harder (the “tune”). In some of those scenarios you’re in a situation where you are going to trade off “more power” for reliability. And a dyno is a tool — it was not invented so we can go around racing the dyno sheets and arguing about “making power”. It’s a tool designed to let the operator run tests and make CONSCIOUS DECISIONS about how they are going to CHOSE to run a motor — and this will vary depending on the venue the car is used in.

The “basics” of tuning an engine, any engine, is mostly the same from platform to platform, car to car. Fuel injection is fuel injection, whether it’s port or direct — there are some differences, obviously, but the concepts of fueling & ignition timing (then throw in cam timing) do not really vary from engine to engine. If you can tune one engine on one platform, you can tune another engine on another platform.

Can’t Be That Hard Then?

So where does the complexity arise? The ECU’s themselves. This is where the platforms start to vary and the actual work, experience & knowledge start to come in to play. The way Honda does things in the ECU is different from how Ford does it which is different from how Subaru does it which is different from how Toyota does it which is different from how Chevy does it, on and on. I work on a large variety of platforms, the ECU’s can be wildly different.

This is where someone that is only familiar with one way of doing something because that is the only platform they work on (or mostly work on and see something else very rarely) will stumble and produce results which are not the best.


You can literally spend weeks if not months figuring out how to setup a calibration (the “tune” file) properly to get the ECU to do what you want it to do not only repeatedly, but safely.

So what have we done to figure out what strategies to employee to run the motors with the factory ECU’s? Well — either I work closely with a friend/customer that has a certain platform or we have purchased and own (or have owned) our own cars to test on. This way I have a car readily available to not only test parts on — but to test different strategies on and figure out what the ECU is actually doing with the input in the exposed tables in the software and whether the results are good or bad and something underlying in the ECU needs to be changed.

This is a hefty investment in not just resources — but time. And largely this investment isn’t appreciated or is under appreciated as no one is really aware of what has gone in to get a certain platform to where it is today.


I’m going to be very blunt here — there’s a million of these guys. Anyone with a $150 laptop, some free software and a base file or two can pass off as a “tuner”. This doesn’t just apply to the Honda market — I’ve watched it grow and repeat in the Subaru, Ford, Chevy and even some stand alone ECU markets. I’m sure it happens on anything that you can “tune”.

So what actually happens? It’s very simple — on most solutions it’s virtually impossible to protect your work. So after a car has been tuned and is out in the “wild”, either the owner takes it to a dyno day or the car is sold and the next owner takes it to someone… and something as basic as this happens: plug into the ECU/device and click “Download”.

Done, you’ve pulled the calibration (“tune”) off the device or the ECU, and from there on they can claim it is there’s.

You are now a legit tuner and I’m sure the car(s) the calibrations are being recycled on even drive alright.

Who’s going to know it wasn’t your work, right?

Guess what, I know. Anyone that’s developed a calibration from scratch on any platform will know when their work has been ripped off and recycled.

Some are doing it so flagrantly that literally the whole calibration is 99% identical to what was ripped off the device/ECU. Not even changing any notes or comments. They have absolutely no clue what they are looking at but making a buck off someone that is oblivious to what is actually happening is just easy money. Hey it drives fine and the owner of the car is happy, so screw it?

Then there is the other crowd — they are pulling/ripping the maps, and then analyze them to figure out what you did and they duplicate it in their own calibrations. This is known as “R&D” (read & duplicate). They understand the basics, but when it comes to the platform, really have no idea what they are looking for beyond just that — the basics (fuel/timing). As long as they can duplicate it to get the results, they are happy and their customers are oblivious.

In both situations I’ve watched the tooners and their “fans” defend them tooth and nail. In situations where I absolutely know this “map hijacking” is happening. They will, of course, deny it til they are blue in the face. Can’t admit to it, ruins their credibility right? Lol, what credibility?

Really, it is flattering, I guess?

But what stems from this is having to wade through oceans of bullshit.

So How’s This Happen?

Not only is the ease in which maps (“tunes”) can be pulled, but the tactics they use, are really disgusting. I’ve witnessed maps get pulled off cars on dyno days where the car was just there for a baseline and the laptop had no reason to be near the vehicle. A certain customer of mine had his VTEC Killer tune ripped off his laptop via a remote “support” session (lol?). One even had a map ripped from him under pretenses of “making the tune better”, which when comparing the “changed” calibration (99.9% identical to what he had to start with anyway…) was leaning the car out to something ridiculous like 13.88 A/F under WOT — so in reality he actually paid someone $50 to rip the map to use as their own. Yes this actually happened — I was dumbfounded when I was told about the situation (I was down in SoCal on a trip and he swung by to have his car retuned in person for the S/C he was having a friend’s shop install on his car while I was in town).

In fact, the most common ways the maps find their way into the hands of tooners is under pretenses of “making more power”. It’s disgusting and I can only hope people do their research and understand that very little in tuning is about just making power and getting a number.

It really is a vicious cycle — I’ve personally witnessed this happen over the 10 years in the Honda market. As the 8th gen Civics and 9th gen Civics got older more and more tooners were popping up out of the woods offering “tunes”. They were absolutely nowhere to be found when the platform was in it’s infancy and just starting out. And they are still nowhere to be found in any of the circles that are trying to advance the platform in one way or another.

Some of the names I even recognized from customers who had paid me to tune their own personal vehicles — are now proclaimed legit tuners. Gee I wonder where they got their maps?

I’m sure recycling cooking cutter bolt on and light F/I (basic s/c and such) maps is one hell of a market. I’m sure it is a hell of a lot easier and much less of an investment than having to devote countless hours/days/months of your time to actually developing the platform, arguing with the company developing the tuning software to get improvements added and figuring out what’s what.

Oh well, back to the grind I go, I guess.

Project Civic X — Bone Stock on High Octane

Just days after tuning the Civic EX-T bone stock on 87 octane I’ve managed to get the tank low enough for some high octane testing — still completely stock. Wasn’t an easy task running the tank low when it gets 40mpg on the highway!

But here goes… the results are FANTASTIC!

High Octane Vs 87 Octane

This doesn’t take a whole lot of explanation — we picked up as much as 60 ft.lbs. of torque more on the high octane fuel — and almost as much as 40-50whp more through the curve.

How’s this stack up against completely stock? Here you go — something like 80-90 ft.lbs. of torque more over stock.


Versus 8th and 9th Gen Si

Since we were having a bit of fun comparing the results of the Civic X vs the previous generation Si — might as well keep going!

Versus a bolt on 8th gen.


Versus a bolt on (RBC swap) 9th gen.




I could of actually made more power (especially more torque) on the Civic X on the high octane fuel — but I was cut off at the knees by the software currently available to tune these cars. So take these results as “software” limited. It is very early in the life of these cars and once we get more ECU development for the platform a lot more potential will be unlocked.

And keep in mind — this is still BONE STOCK. Time will tell what a few bolt ons will do (especially a downpipe).

Project Civic X Begins

Ever since the announcement that the new generation of Civic was going to be turbo we have all been anxiously waiting to see what Honda had in store for us. Turns out it’s a 1.5L turbo engine which the factory reports is “only” 174 HP and 162 ft-lb of torque. And this engine is also being released in the Si — with some cosmetic upgrades, transmission upgrades (limited slip — we’ll get to that later) and *maybe* a slight turbo upgrade.

The announcement of the 1.5L was met with a lot of criticism, as the aftermarket and enthusiasts are used to B18 and K20 style engines dominating in the four cylinder market making absurd power figures (1k+ hp). Hell, I like making that kind of power too and support quite a few people in their endeavors to chase big power goals in the Honda scene. But we need to step back and look at the actual market segment that these cars sell to — even the Si to a big extent.

So just take a deep breath…. and imagine you’re an average Civic buyer. What do you want? If I had to take a wild guess from years and years working with customers tweaking their rides — and you certainly have the folks throwing superchargers and turbo kits on the cars — the vast majority (by a huge margin) just want a peppy economical car. So where do most stop? Just simple bolt on modifications.

How much power do bolt ons pick up on a naturally aspirated Civic? Not a ton. How much do bolt ons pick up on a factory turbo car? Well from having done quite a few factory turbo cars on another platforms (Mazda, Subaru, Mitsubishi) I can say it’s a lot more than an N/A Civic, regardless if it’s a 2.0 or 2.4 motor in the N/A Civic.

Dyno Disclaimer

Before I get to the cream — I have to do this as this is just a never ending battle. “Bro your dyno reads high”, blah blah. Right, sure. Magically reads high for just one specific car and not a single one of the other ones we’ve baselined completely stock and are either right on the money or slightly lower than the average power figures we see elsewhere. I personally won’t claim a dyno reads “high” until it’s consistently high, over and over, across multiple platforms (you know who you are).

Bone Stock, Not a Single Mod

This little guy showed up today, fresh from the dealer (they even delivered it!). I drove it around and got some grub to get a feel for the car — it certainly felt peppier than a stock 9th gen Si.

It went on the dyno, bone stock, no mods. Just a Hondata FlashPro to get some testing under way… and a bit of tuning. A whopping 196 miles on the car.


What did she make stock? 181 wheel horsepower and 188 wheel torque. Wait… what? Yes I was a little surprised, I expected 160-170 area. This is also on 87 octane… not the best fuel. Of course I wanted to see if there was more in it. I proceeded to frantically smash on my laptop keyboard and I managed to pound out 192whp and 235wtq out of a completely stock 2017 6MT Civic EX-T on 87 octane.

I really can’t hate on these results. The “hp” is decent and the torque is fantastic — and this was only peak. Through areas of the curve we got as much as 55wtq and 30-35whp over stock. Not bad at all — for just a tune.

Comparing To The 9th Gen Si

This is going to go quick and easy. I’m not going to say a whole lot as the graphs speak for them selves.

First, a completely stock 2015 Civic Si and the stock 2017 Civic EX-T.

Then to the left, a fully bolted on (even RBC swap) 2015 Civic Si and a stock tuned 2017 Civic EX-T.

To put the picture in words: even stock the Civic EX-T makes more power through the whole power curve over the 9th gen. Almost as much as 80wtq more than the 9th gen Si. This makes for some great get up and go.

Comparing To The 8th Gen Si

Same idea here…

A completely stock 8th gen Civic Si and the stock 2017 Civic EX-T.

And then a fully bolt on 8th gen Civic Si (your typical quality bolt ons — nice 3.5″ CAI, Skunk2 RH, 3″ exhaust, etc) and the stock tuned 2017 Civic EX-T.

Historically the K20 has never been big on torque (well, until you slap a good turbo kit on it — but this isn’t what we’re comparing and that’s a whole other discussion). Almost 110wtq through most of the low end.

What Next?

Well as you see these results for the Civic EX-T were on 87 octane. Next up is some tuning on a higher octane fuel — 92 octane. Then possibly either 100 octane or some ethanol!

We also have some additional bolt ons coming soon for more and more testing…

The car definitely needs a limited slip! Maybe we’ll be able to snag one from the Si that is coming out?

What about a turbo upgrade? Yup, already doing some scheming here too.

And of course, we have our renowned  FlashPro + Tune combo offer you can take advantage of. For $800, it’s the best money you can spend on your car. I’ll make sure your Civic X is dialed in to suit your mods, your needs and the fuel you are using — and make sure it continues to run smooth and reliable for a long time to come. And as Hondata adds more features I’ll make sure your calibrations stay tweaked and up to date with the latest and greatest in the software — something I’ve been proud to do for customers on all the platforms we support.


What About Dat Short Ram Intake Doe?

Back to Honda today…

If there is one question on the interwebs that bugs the crap out of me, it’s definitely “What intake should I buy?”. Really? Come on! In this day and age Google knows that answer. So I’m not going to talk about what intake you SHOULD buy, but what intake you SHOULD NOT buy.

Short Ram Intakes Suck

Now I do realize this is a bit of a generalization as there are some exceptions (namely SRI’s designed to point at fresh air and are directed completely away from any heat sources).

Generally the SRI style intakes commonly found on the 8th and 9th gen platforms all point the filter/inlet at the back of the engine bay. This is just plain dumb. Some people will argue that the intakes do “make power” and the manufacturers claim absurd (and unrealistic) “gains” from this style of intake.

The actual FACT is these style of intakes breath hot air from the back of the engine bay — fresh air rarely, if ever, makes it to the intake and it’s pulling very hot air from an area of the engine bay where the exhaust manifold is emanating a generous amount of heat. Hot air does not make power — in fact it creates a scenario that is unsafe for optimal engine operation and you have to “dial the tune back”, something I’ll address in a bit.

The Snorkel Mod

This is a fun mod — I’ve seen this a lot and some places claim to do this to try and create “conditions similar to the street when the car is moving”. So at the heart of it they know these intakes breath hot air. This is just a cop out to “make numbers” — gotta get a print out to race the dyno sheet online, right? I don’t care about “numbers”, if my dyno generated absolutely no numbers and just a power curve I could still do my job. We sell tunes, not numbers. Let that sink in.

So what do they do? They point the IMG_0953intake out of the engine bay to artificially reduce intake air temps (“IATs”). Sorry to break it for you — this doesn’t mimic actual road driving even remotely. I actually see IATs dramatically increase in “normal” driving conditions — as high as 40-60 degrees over ambient with these style intakes.

So let’s use the tool at our disposal — the dyno — to get empirical data on how the engine is affected by changing the position of this style SRI.

The Test

vs_stockThe car in question is a 2013 Civic Si w/ said SRI, catted Full Race DP, RBC swap and stock exhaust. The change over a completely stock car looks like so. Overall not a bad gain, and as always, the RBC sacrifices mid range over the stock intake manifold.

Now that we have done the “tuning” to extract power, let’s see how intake vs_in_engineplacement affects power. We turn the SRI back into the engine — but leave the hood open, and do a subsequent pull (making sure engine conditions are at steady state — meaning we don’t have a heat soaked car with a high ECT, we make sure we start at the same temps as a high ECT will cost power as well and render our test meaningless). The chart to the left demonstrates this change — all we did was lay the intake back in the engine bay — and we lost on average 10-12whp and 10-14wtq! Really?? What???? WHY IS THIS??

shut_hoodBut it gets better, what happens we if shut the hood? Whoops — looks like we lost another 5-8whp and 5-6wtq just full_vs_shuthoodshutting the hood over our previous pull. The left chart demonstrates how much we lost overall — as much as 20whp! No way, right? Yes way!

Why Does This Happen?

This is actually quite simple — when you tune a car, particularly on the dyno, you are tuning in as close to steady state conditions as possible. You do this so when you make changes in the ECU (“Tune”) you can verify your changes have some sort of impact on the way the motor runs. Whether this is good or bad. You also have to make conscious decisions on how you want to leave the motor running long term — these should be intelligent decisions as they will dictateiat not only long term reliability but how well the motor runs in dynamic conditions which the ECU does have to account for.

So why the power loss? Quite simply, Intake Air Temps went up and the motor got warmer air as conditions changed. The read outs to the right indicate what the intake air temp (IAT) was on each pull. As the IAT went up, we had a respective drop in power. Will this drop in power continue to get worse as IAT climbs further? Absolutely.

In fact, as IAT climbs, the motor will run hotter and less “stable” (to put it in simple terms), which will create situations in which the motor can “knock” or “detonate” — which is an unsafe condition where your combustion event is no longer in a safe and controlled burn and will destroy your motor if left running in this state. The ECU allows us to account for this timing_reductionbehavior — by reducing time and/or adding fuel. An example of this is in the table to the left. Does reducing timing hurt power? Absolutely. Is it necessary? When the motor could potentially see unsafe running conditions — absolutely. You want to protect the motor as much as you want to make power.

Tuning Tool

Now back to those dyno “numbers”. A dyno, any dyno, is a tool. You can take your car to 15 dynos and get 15 completely different “numbers”. You can always “make more power” when you stick a car on the dyno and make changes in steady state conditions — especially if you disable any of the dynamic compensations the ECU will apply to protect the motor. Factor in strap down variances (particularly on roller style dynos) and your numbers will potentially be all over the place from day to day, dyno to dyno, etc.

I use the dyno as the tool it was meant to be. Making power is awesome — fun even, but at the root of it, the correct PARTS will make power, and will potentially make better power in fluid day to day conditions as well. The tools at my disafr.pnposal will let me find where the motor runs best, runs safest, and how it responds to the changes I make.  Tests like finding out what AFR the motor runs best at — and what AFR it actually starts to lose power (from either running too hot, or “choking” on the fuel). Yes the plot to the right is an N/A 9th gen, the AFR it loves to run at might surprise you — it definitely isn’t 13.88.

In Conclusion

It’s easy to hit the plus key on your keyboard and keep on pumping timing into the motor to “make power”. It’s all fun and gains til it melts a piston or throws a rod and the oil pump “failing” gets blamed for the motor going out. We’ll be having none of that here — a lot more to tuning than “making power”, sorry.


2016 Subaru WRX DIT Platform Tuning & Parts Testing

What a boring title… but I’ve got nothing catchy for the title as I gaze at my monitor through allergy induced tears and catching up on the “where’s my toon bro” emails after a crazy week that involved 3 days of parts testing & tuning at the shop that pulled me away from my normal routine at the desktop computer. Yes there was a joke in there, I know my humor doesn’t translate well on the interwebs at times so can I at least get a “Haha” before someone calls me an asshole?

But down to business! We have ECUTek as our tuning software for all SubaruIMG_0744 platforms, and this week our victim was the VitTuned 2016 Subaru WRX. Love them or hate them — I don’t care, I enjoy working on a variety of platforms and Subaru is no different. I want to give PRL Motorsports a big shout out for supplying me with a full array of bolt ons to test on our car. This was also a great opportunity to break in the new AWD Dynapack setup at the shop.

The parts we’ll be using.

  • PRL Motorsports TGV Deletes & EGR Delete
  • PRL Motorsports Intake Kit & Charge Pipe Upgrade
  • PRL Motorsports J Pipe
  • PRL Motorsports Front Pipe
  • PRL Motorsports Front Mount Intercooler
  • STM Exhaust

I broke up the testing into 3 parts. First I did the car completely stock — just tuned it. Next I installed the intake upgrades (less the intercooler) and retuned. Finally I installed the full turbo-back exhaust setup and the front mount intercooler (you’ll see why…).

All these tests were performed on our Oregon 92 octane. No extra ethanol blending at all.

Part 1 – Stock Tuned

We’re using a Dynapack — so obviously it’s going to read super highstock_tuned_vs_stock and we’re going to be seeing rated crank numbers at the hubs… right? LOL, right… Not on this Dynapack. With an AM (Advance Multiplier) of .88 we had a baseline of about 210whp. After spending some time retuning the car I got it up to 240whp and 265wtq. Not a bad gain at all for a stock car. I spent time mapping the dual cam timing system and found that the stock settings were pretty much spot on with the stock car. Most of the extra power was found in cleaning up the boost curve and raising boost targets — a little bit in the timing map, but not a whole lot as the motor was definitely a bit touchy on the pump gas.

Part 2 – Intake Side

I was able to install all the intake parts without even removing the car off the dIMG_0751IMG_0752yno. On went the intake & charge pipe upgrade for the stock top mount. On went on the TGV deletes & EGR delete. The TGV’s were a very quick swap — each side came out in seconds (no trouble with the driver’s side getting stuck anywhere when removing it). The intake fit like a glove as well. I was able to hop back in the car and retune it again. It was a bit hotter this dastock_tuned_vs_tgv_intakey and I was seeing 10-15* higher charge temps than when the car was tuned completely stock — however we saw a solid gain over our “stock tuned” baseline (to the right). It was pleasant to see that boost came in a considerable astock_vs_tgv_intakemount sooner, resulting in more torque a lot sooner in the curve. The gains over completely stock are on the chart to the left.


Part 3 – Exhaust (and FMIC)

The car came off the dyno and went on to the lift for some surgery. I started with the full exhaust setup. One look and I knew the stock J pipe was going to require some luck — those damn studs and nuts love to strip or come out as one piece. Luck was definitely on my side, two of them came out with no problem and the other two were saved by our tap kit and one Honda nut (haha!). Seems Subaru just loves their seized hardware — only other car this bad is the shop 370Z (good luck removing those cats!).

IMG_0755IMG_0756IMG_0757But once the stock exhaust components were off — all the PRL parts went on smoothly. The items were well crafted and up to the quality I’ve come to expect coming from PRL. The STM exhaust bolted without much fuss at all as well.

Finally I put took the bumper off and fitted the PRL front mount intercooler IMG_0758IMG_0759setup. Having done quite a few PRL turbo kit installs (we run two of their kits on our shop S2000 & FR-S even!) the intercooler for the WRX is just as beautiful as the ones they provide for all their other kits. The bypass valve is relocated to the passenger side of the bumper — which is a nice location as it makes servicing or replacing it easier in the future.

Now I had wanted to test the FMIC all by itself towards the end… but I’ll get to why I installed it while the car was already on the lift (other than it’s a royal pain to take AWD cars on and off the dyno, hah!) a bit later.

The car went back on the dyno, and now that I had all the exhaust components done I wanted to see what this little turbo could really do — and I found some annoying ECU related nuances along the way. No big deal, something for the engineers at ECUTek to dig into in the ECU code — have to make sure their day isn’t boring either.

Once I was comfortable with how the motor was behaving with the new mods (checking all the cam phasing as well), I wanted to see what kind of power I could get out of our car by going “all in” on the boost levels — let’s see what the turbo can do.

Given we have a roughly 2.7 bar manifold pressure sensor on the vehicle stock, I wanted to get up to those boost fbo_all_in_vs_intakeslevels — and I did. The graph to the right demonstrates what happens when I target right up to the clipping limit of the map sensor and then taper boost down (as the turbo can’t hold this boost level anyway). The torque is fantastic — even with a conservative timing map in the peak torque area. 330whp and 365wtq on 92 octane — not bad. But you’re going to ask me about that torque dip at 4400 rpm — and you’d be right to! At first I thought it had something to do with the fuel system (pump not keeping up, DI pressures dropping) — but nope, everything is rock solid. After a few days of street testing since these dyno tests were done I can repeatedly duplicate this issue — it happens anytime boost pressure get up to the 2.6 bar absolute or higher area. In the datalogs you’ll see the AFR on the factory sensor read 12.4-12.6 (not that scary right? on the dyno tail sniffer it was 13.4-13.8, so a bit more concerning…), and it appears the ECU is applying some sort of torque limit or power reduction via fueling (seen this behavior on other ECU’s). I’ve been on the horn with ECUTek and we definitely have some digging to do.

So calling this our “all in” pull, let’s see what happfbo_all_in_vs_safeens when we run a more conservative tune? Calling this our “safe” full bolt on run, you can see that dialing down the boost levels the torque level gets flatter and the ECU behavior going through that area isn’t pronounced (in fact power gets a bit better). One of those “tuning” battles… is fighting what the stock ECU wants you to do, even if that’s not what you want to do. How I would love me some MoTeC right now…

But bafbo_safe_vs_intakesck to the point, gains with the “safe” bolt on tune versus just intake side mods? Pretty good power pick up.

fbo_safe_vs_stockHow about versus completely stock? Mmm, even better. Hard to hate factory forced induction when you see these kind of gains with just bolt on parts and tuning.

That Intercooler!

This is where the pretty graphs come in! After spending two days tuning against the climbing charge temps with the factory hot mount, I was ready for the FMIC upgrade. Having owned and tuned other platforms with top mount intercoolers and run them at the track, the heat soak is brutal (even at the drag strip — we’d see staging temps of 50-60 degrees Celsius on a good pass).


With the PRL FMIC and even more boost our charge temps actually continued to DROP after the pull started — and the temps started lower to begin with. With the factory hot mount temps would just climb every pull. Does this have an impact on power? Absolutely. There shouldn’t even be any argument here.

Now I’m ready for some rest and my weekend — and the car is begging for E85 (next week?).

MAF Tooning

I just wanted to briefly touch upon this point as a little birdie mentioned that some have claimed the PRL Intake has a “whack” or “terrible” MAF curve. I’ve found this to be absolutely false. I found a very clean MAF curve when tuning this  intake, stock I/C or their FMIC.mafvoltage I’ve been tuning MAF for something like 14-15 years, it’s actually a break to tune a MAF vehicle — it’s quite easy compared to some of the other projects we tackle.


But what about your fuel trims you ask? Here we have a nifty graph that not only includes the fuel trims from a 45 minute drive, but a nice mean line to fueltrimsdemonstrate the average of all the data sampled across the whole datalog. Note how the mean stays very close to zero — our long term has a 2% drift in a couple of areas and our short term is overall  +/- 4% from the mean with one spot that drift ab it towards 6 with some blips in the 8% region. Not exactly bad for a MAF curve that literally came off the dyno and I drove the car home. One minor tweak and she’ll be tight around +/-5%. That’s pretty damn good for an aftermarket intake.