- Fast Intentions Twin Turbo Kit
- Fuel Return
- VitTuned MoTeC M150 ECU & Firmware
- 92 octane Pump Gas Fuel
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.
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.
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 intake 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 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 placement 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??
But it gets better, what happens we if shut the hood? Whoops — looks like we lost another 5-8whp and 5-6wtq just shutting the hood over our previous pull. The left chart demonstrates how much we lost overall — as much as 20whp! No way, right? Yes way!
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 dictate 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 behavior — 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.
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 disposal 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.
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.
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 Subaru 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.
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.
We’re using a Dynapack — so obviously it’s going to read super high 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.
I was able to install all the intake parts without even removing the car off the dyno. 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 day 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 amount sooner, resulting in more torque a lot sooner in the curve. The gains over completely stock are on the chart to the left.
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!).
But 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 setup. 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 levels — 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 happens 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…
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?).
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. 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 demonstrate 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.
Because I made X amount of power or I made Y amount more power than Joe Bob Smith!
Now that I have your attention, it’s time to get serious.
This blog has been a bit quiet since I’ve been busying moving into the new shop, getting the new 4WD dyno setup operational and all that MoTeC development (more on that another day… you guys following our FB, YouTube & Instagram have probably seen some of it)!
What I wanted to discuss and address today is a small scope of what “tuning” is and what role “making power” plays into it — with some practical examples.
A lot of people bring their car in or buy a tune and want to make more power. I have to break it to you — this is the lowest form of tuning. A trained monkey can run a car on a dyno, smash on their laptop and make the dyno graph go up. None of this is any indication the actual calibration (“tune”) was done properly or any intelligent decisions were made.
That’s the biggest part of it — using the dyno (or datalogs, or street, however you’re doing the tune) as a TOOL to make intelligent decisions about how you are going to leave a motor running long term.
Today’s example is brought to you buy a 2013 Civic Si w/ just a Takeda intake. The vehicle runs quiet enough that you can very easily distinguish any scary situations (knock especially) and isn’t so radical that pushing the motor a bit too much will cause damage from a few test pulls (the Honda community has long been spoiled by very strong motors that take abuse for a long time before going BOOM).
Something I’ve iterated to people over and over — parts make power. The tune wraps it all up and an intelligent tune will leave the car running SAFE and reliable for a long time. Can a tune make power? You bet. Will a tune make power? Sure. Will the tune make power SAFELY? Um…
I love having our Dynapack at my disposal — I can make minute changes in the tune and see the difference. So let’s take a look at a practical example of making power safely.
All the fueling and VTC were already tuned up to this point and we’re in the “sweet spot” here. On this initial graph we also found a power curve (for the sake of a concise discussion we’re just sticking to the top end of the power curve) that’s what we can call “clean” — dyno says the curve is clean, ECU is reporting no knock, and your senses are telling you all is OK. This is the solid curve in the next two graphs and we’ll call it our “baseline“. So let’s try a minuscule change — 1 degree more ignition timing. Hm.. looks like we found 2-3 more hp (dashed curves). But wait… it also knocked on this pull, not only via the knock detection in the ECU — but your ears hear it too. But it’s making power — sure not a lot, but it’s making power!
Well, let’s go the other direction — let’s try 1 degree less. Interesting — now we’re making 2-3 hp less (as much as 4hp less) than our “baseline”. So if we factor in the “gains” we saw in the previous test, that means we’re now down about 5-6hp on “max power”. Hm… how about we go back to our “baseline” and give it a short cooldown (as the engine got a little heat soaked during tuning — this is normal and expected during a session). We’ll compare this pull to our “1 degree less than baseline” pull which arguably for most people is “safe” (more on that later…). and what do we see now? Well crap, we’re down like 6-8hp in some areas. This is a lot of power N/A, especially for a car with just an intake!!! Right? RIGHT?
This is were some intelligence and decision making comes in. Effectively what we’ve found with just those three pulls is the knock limit, actual audible knock and a spot just under the knock limit. We’ve also proven that you can absolutely make power while knocking, or at the knock limit, and a small cooldown will make a few more HP.
Keep in mind this is all done in a controlled environment — our conditions have not changed during the session. We’re not seeing varying loads or acceleration rates (someone doing a hard pull getting onto the freeway or down the straight on a road course…). We’re definitely not seeing extreme weather swings (super cold to super hot). What makes “best power” and is “clean” on a dyno today, may be beating the motor up tomorrow… what about if it gets to triple digits outside and the intake is pulling charge temps into the 140*F? Does this change how the motor runs? Does this impact how the tune should “adjust” or “adapt” to these conditions? Absolutely — in fact I have yet to see a single ECU that doesn’t let you build in compensations to ensure the engine runs safe in all conditions. Does this affect the power the motor makes? Absolutely, you can see radical swings in power!
So ask yourself, where SHOULD you leave the motor running? Should you leave it right at the knock limit simply because it didn’t knock in the datalog and your ears didn’t hear any (not every car will be quiet enough for you to hear detonation…). Or is a safe point going to be somewhere that might be what we consider “leaving a lot on the table”?
Hell I only showed the difference two degrees makes… and this may not even be the “safe” spot to leave the car at long term. What if it’s 3-4 degrees of timing under absolutely max power? How much are we “leaving on the table”? Is this necessary to ensure the motor is safe for what the owner of the car is going to be doing?
My job as a reputable tuner is to leave the car running safe for years to come — in all the elements and any conditions. So I know what I would do, and I know exactly why I do what I do.
This brings up an interesting point — people get blinded so much by peak power figures on a dyno sheet that they forget what tuning is for. A dyno is a tool and not there so you can race your dyno sheet — it’s a tool to get a job done. You can always “make more power” when loading a car on the dyno, any dyno. Only an incompetent tuner will leave a car running on the knock limit. But hey, if they do — a little while later it was just “bad fuel” that got you, right?
There’s a difference between a proper and correct tune — and “making power”. You’re not uncovering Egypt’s secrets by “making power”. So sad, right?
I love this topic — it’s probably one of the most common online aside from people racing their dyno sheets online and arguing about “bro that’s low you should be making X power”. LOL.
Although there IS a point where it’s too rich — all motors have a “sweet spot” they like to run in as far as fueling under full load (depending on fuel). Here’s an example that shows the motor run at 12.2 AFR, 12.8 AFR and 13.5 AFR (roughly). Note the torque curves on the left… almost identical. Fuel curves on the right graph. The timing map remained the same on all 3 pulls, as did VTC. Only variable changed was fueling used. On the orange plot (13.5 afr) we had some light ping — which again did not affect power output.
So what fueling would you run?
James had us install the Jackson Racing supercharger kit on his BRZ last summer, and now he’s gone for more power and the upgrade to the C38 supercharger that Jackson just released. I had the unique opportunity to do a nice comparison between both units on the standard “low boost” pulley before upgrading the C38 blower to the “high boost” pulley.
This test was done on 92 octane fuel. Our dyno baselines a stock FT86 at 148-150whp (not the typical 170 you see elsewhere).
So after swapping over the C38 blower onto the car, dropping in the 900cc port injectors (you’re going to need an upgraded port injector for the high boost pulley), this is what we got. Solid lines are the C38 blower w/ the standard pulley, dashed lines are the C30 blower w/ the standard pulley.
The results were exactly as expected — the low end was basically a wash (slightly lower with the C38 blower — it made the same or a little less pressure ratio, aka “boost”), but the efficiency of the C38 compressor started to shine on the top end, and we had a decent power pick up on the top end over the C30 blower.
On goes the high boost pulley. Internet experts quiver in fear as we swap on this pulley. The world is going to come to a grinding halt with the uber boost levels this pulley makes and is apparently going to make it impossible to run the motor safely at such “extreme” boost levels. Imminent danger to manifold — obviously.
Well I’m going to have to let the experts down on this one… but this “high boost” pulley is perfectly safe to run on pump gas (91, 92 or 93 octane). We actually picked up a solid amount of power through basically the whole curve — as much as 25whp over the low boost pulley @ 7000 rpm — making just shy of 290whp. And yes, it’s perfectly safe to drive. You don’t “need” a built motor to run this power level — or E85 to make it “safe” (but we’ll get to that later..).
And to compare it to stock….. lots more power everywhere. So what do I think? I think our Internet Experts need to do less “blah blah” on their keyboards, and more work in the shop. And I think if you’re looking for a centrifugal setup, this is the way to go — the nice C38 blower with the high boost pulley. I would just skip the standard “low boost” pulley. There is nothing “scary” about this power level and it’s not particularly hard to tune it to be reliable in the hands of a competent tuner — our 290hp is 1.9x more power over a stock FT86, so on a higher reading dyno that baselines an FT86 in the ~170 area, you should be seeing 320hp, or so.
And the info graphic on the boost levels with the blowers. Blue graph is the C30 blower with the standard pulley. Orange is the C38 blower with the standard pulley. Grey is the C38 blower with the high boost pulley.
Now the awaited E85 update… or in this case, E65 as I only got 10 gallons of E85 into the tank, and it blended with the remaining ~3 gallons of 92 octane. The results are fantastic — the car makes 2.3 times more power than stock, and well over 200whp more than stock at rev limit. The graph to the right are the gains over 92 octane. Graph to the left are the gains over a stock FR-S/BRZ.
With the extra 20% ethanol a full E85 blend would bring, we’d probably pick up another 6-10hp on our dyno. On the more high in the clouds style dynos, this setup is “400hp” 😉