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).
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?
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.
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?