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.

 

 

 

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.

Prologue

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!

http://vittuned.com/2016-civicx-1-5t-3-downpipe-front-pipe-combo-pre-order.html

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.

 

 

Thoughts?

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).

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.

 

I’m The Best Tooner In The World!

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.

What is Tuning?

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).

Making Power

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) t1_morehat’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!1_less

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 1_less_finalgive 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?

Wrong.

Decisions. Decisions. Decisions.

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.

The Dyno Phenomena

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?

Bro You’re Running Rich!

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.

Yes, 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 (dependingfueling 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?

Trolls Go Round And Round

What appears to be the one absolute and unsurprising fact in this industry — someone is always out to try to take a bite out of you. Or try to get their friends to come after you so they are not seen as participating. What is surprising (or maybe amusing?) is how they like to come at you at times. It would be a much more entertaining read if they had some understanding about the things they were frantically smashing into their keyboards. Unfortunately — it’s quite clear they have little to no experience in anything but slinging mud. I cannot help but just shake my head and go back to helping my customers paying for my time.

Fortunately, I had the time and opportunity to bring up a few examples — had a 2014 Civic Si on the dyno to tune and it turned out to be a chance to touch base on the results of tuning a stock 9th gen Civic as I still get asked about it a lot.

Oh That VTC Mapping Is Such Shit!

This one really gets me. When someone doesn’t understand why something in a tune was done the way it was — it’s clearly shit. Their first reaction is to grab their pitchforks and torches when it should be to pause and analyse why something was done the way it was.  I see this attitude frequently and can only wonder if someone like this would ever take any advice or constructive criticism thatuned_vtct could help? If something is truly “shit”, lay out why in intelligent fashion — and no, not just a dyno sheet or 3hp. Or switching gears on the dyno and claiming you made power with your “tune” when all you’ve done is introduce another variable that just made any use of the baseline invalid. We’ve made 6hp on some 9th gens just by letting it sit and cool off . Not even the best troll attempt I’ve seen — but cute, I guess?

A truly good example is a tuned VTC map — particularly the low cam (non-VTEC). Low cam was tuned to determine the best cam advance, and then high cam was tuned to determine the best cam advance. Finally the transition was optimized to provide the best curve possible when going into VTEC during a full throttle pull. Optimal power at 5000 rpm out of VTEC was with 5* VTC — however it was 35* VTC in VTEC at 5000 rpm for optimal power. So what happens when VTEC engages and you have such a large VTC transition? The VTC system is still at 5* and the motor makes less than optimal power until the cam has a chance to move to 35* VTC. As a result the transition was optimized by a very short and quick snap from 8* at 4900 rpm to 32* at 5000 rpm while VTEC is still off — a very smooth transition when at WOT and no loss of power is seen or felt. If you don’t see this difference on tvtec_diphe dyno — time to replace your piece of shit roller (hah, I just went there).

What does this look like on the dyno? The graph at the left illustrates this. Solid lines are horsepower and torque with the VTEC “pre-phasing” trick done, dashed lines are without. Pretty obvious torque dip at VTEC, right?

Wait, if this is so good, why are you telling everyone about it? Because this is not a secret. When the K series first came out Hondata pioneered this trick and published it publicly for EVERYONE to use. The irony here is — very few use it, and even less understand why. It’s a better idea to just go on the Internet and make it obvious you’ve done like two Honda K series vehicles and now you’re an expert? More like wet behind the ears.

Hold on, it gets better… you know even *Honda* uses this trick now? Juhonda_vtcst look closely at the stock Honda 9th gen tune. For the two seconds it takes to see it — it’s not tough. They didn’t use this on the RSX’s or the 8th gens — and their use of it is very subtle on the 9th gen.

I’ll be Mr. Nice Guy — to the right is the stock 9th gen VTC map. Note the values at 5000 rpm at full throttle — they go back up slightly in anticipation of the VTEC crossover (which is 25 at 5000 rpm in VTEC on the stock Honda tune) — the only difference is they didn’t use a 4900 RPM break point as they really don’t care if the car loses 4hp across 500 rpm worth of power from running 7-9 degrees too much VTC (I guess they haven’t met the experts on the internet yet?). Yes, Honda intentionally mapped the motor this way — there is absolutley no reason to bring the VTC back up in an area it naturally wants to taper down to keep making power on the low cam.

Shocking, I know.

I Did Such And Such And Made More Power

LOL.

Let me repeat.

LOL.

Tuning is about so much more than making power. I have customers with 150k+ miles on their turbo vehicles. I also have a dyno at the shop readily at my disposal. I know what makes power — in fact I use the dyno not only for tuning customer’s vehicles and builds at the shop, but as an R&D tool and apply what I discover into our eTunes to help deliver reliable cars for customers around the world.

Part of tuning is making decisions and judgement calls that will ultimately determine a setup is reliable long term — or not. In varying conditions year round — that the tune has to take into consideration and adjust for. This is why people go to reputable and experienced tuners, instead of a random guy offering you tunes for $50? Right? Maybe I’m wrong, what do I know?

So About That Stock 9th Gen?

I’ve posted several comparisons of stock 9th gens. I always answer — yes there are benefits, it will make a bit more power, and the power will be more consistent.

Here is the simple and visual example of this. The engine coolant temps (ECT) where 185-188 degrees F and intake air temps were 59-60 degress F on the stock tune baselines. Yes, I made sure these were consistent to avoid any extra variables when doing the comparison — if you’re paying someone 60 bucks for 3 baseline pulls I can tell you with absolute certainty they are not paying attention and simply don’t care. Yes it does matter — I’ve had customers datalog their baselines and in some situations there’s not even a dyno fan on the car — I’ve seen 20-30 degree difference in ECT (180 and 210…) and even a 30-40 degree swing in air temps between pulls. If someone thinks it “doesn’t matter” — they should not claim to be any kind of EFI tuning specialist.

Astock_comparisonnyway… stock pulls. Three pulls with consistent conditions. Left graph is torque, right graph is horsepower. Quite the difference on the top end right? 10-12 HP swing in some spots. Yes, the stock Honda tune is very inconsistent in it’s power delivery — and no it is not the “knock control” as some would make you believe. The simple answer is just this: emissions.

Ncomparisonow four (yes four) pulls with consistent conditions — 185-188 degree ECT and 68-70 degree IAT. A negligible .5-1.2hp swing. Virtually nothing. This is on a dyno that is accurate to .1hp (no, a roller dyno does not nearly have this kind of accuracy — having a wheel/tire on the car can cause a 2-4hp swing).

finalAnd as every tuner in the world loves to do and not tell everyone… we overlay the highest “tuned” graph with the lowest “baseline” graph. This behavior should come as no surprise — as a ton of “tuners” make a living off nothing more than the way their dyno reads (big numbers sell tunes and that means you’re the best right? Hm… I’ve got some graphs I can post… no, I probably shouldn’t go there).

final_bestWhat’s it look like if you overlay the best “tuned” and the best “baseline”? Pretty good gains still.

And now I’ve run out of thinks to rant about…