"Cold Air Intake vs Short Ram Intake - Explained" blog reaction to Engineering Explained

Before I get into my reaction to Engineering Explained's good video and the comments below it, I've also done my own article about intake modifications
Weapon R Dragon Intake Review 
 :

Randy Knight, on Engineering Explained's video was talking about laminar or straight flowing air, vs. turbulent flow and entrance length. He has a good grasp on some of the issues facing intakes for sure!

I reply:
+Randy Knight Something to add to your considerations is the intake manifold after the throttle body. It does more to handle what you're worrying about than the intake ever does. Intake valves don't just take air in, they also lose air back into the intake manifold and that's a tough consideration for engineers that have handled these issues wrong in so many ways (It's very complex and many better and worse things have been tried). Try David Vizzard's book on porting an engine.

As I think on your comment again, I really believe that the intake manifold design is the most important for what you're thinking on and a short ram or cold air intake's only role in this is the temperature and volume of air.

The short ram's concept is to minimize the resistance to getting more air, but as it may be drawing hotter air than the cold air intake, hotter air is supposed to be less dense.

I think a short ram works for me so well, because I've done some mods going for colder air only to find ways to heat things up instead for the colder months as engine's are designed to waste fuel just to stay hotter during those times - that's a power killer. I've recorded my views on these points.

The other thing to consider is that the cold air intake has more metal to take on heat and help pre-heat the air as it comes into the engine. I combated this by adding piping from the front of the car to blow on this metal and cool it down. Depending on the cold air intake, it could take care of this on it's own.

Link to the video with the above conversation:

Cold Air Intake vs Short Ram Intake - Explained   by Engineering Explained

More after that reply:

In engineering explained's tests, he found that the short ram intake or SRI as he shortens it had more benefit between 2-3k RPM on his Integra and 4-5k RPM in 2nd gear for 3 runs averaged. He found a loss between 3-4k RPM. This may explain that my PCM is very smart on my Chevy Prizm as it usually switches gears just after 3k RPM even if I'm at WOT (Wide Open Throttle). The exception is when my family is in the car or I have a lot of tools in the car. Then it'll shift around 5,500 RPM and it'll have about the same wHP at shifting there as it would at 3k. If I do have a 3-4k power drop like Engineering explained did, it's explain why the PCM sticks with it through the losing period to get the 2nd gain rather than changing gears and having to climb back up to the power range available in higher RPM. This does assume that my PCM is infinitely wise in how it manages power as PCM or power control module implies. :) I found this written article much easier to extra data from than the videos themselves. Engineering Explained's Cold Air Intake vs Short Ram Intake - Explained.

I have zero data between 1 and 3 k RPM about patterns of power as my torque app announces peak power at an RPM rather than giving me a useable graph (it has graphing, I just don't find it helpful in my tests). It's easy to get a feel at different speeds and RPM where my power is at by simply letting off the gas at a given speed.

By AutoBravado

Schrodingers Box MAF diagnosis video reaction

Schrodingers Box part 1 reaction:

Anyone else catch that he introduced himself as MAF (Mass Air Flow sensor)? Nice Freudian Slip...not a true one, but the phrase has slowly changed to mean that something you're mind is working on came out. So cool. :)

Purposeful or not.
At 4:20, Matt (Schrodingers Box) is about to talk about IAC or the idle air control valve. While this is a bypass of air around the throttle valve, realize all the air that gets to this also has to go past the MAF. So, if you have a known expectation of your idle RPM and what your MAF could be, it could be a way with a scantool only to know if there is something wrong with your MAF. Just remember, this can be misleading as idle can be wrong for other issues like running rich. IAC will respond with more air than normal and RPM will usually be raised.

Matt's spoiler alert didn't ruin anything for me about his new tool. He had hinted at 7:20 about about another non scan tool test I was all smiles. :) I have this bad habit of reading comments before the video or as it runs, so I already new an oscilloscope was coming!

17:06 By now I'm very excited. I have successfully diagnosed two bad MAF sensors prior to this video. 1 was super easy. 2.3 to 33 g/s was normal for my car at idle. 93 g/s per second at idle and random spikes around that abnormal number as I pushed on the throttle? Okay. I knew what was wrong.

The better MAF I condemned I didn't do directly. On my car the MAF and IAT are in the same component. IAT was reading very accurately as compared to my "laser" thermometer of the intake that the IAT sat in....but when it got above 43 degrees C it would race hotter. The "hotter" the air the more the PCM believed it needed less fuel. The O2 sensor caught it and increased fuel trim.

I reference being excited by 17:06 as I realized my MAF is 100 to 200 degrees F hotter than the IAT? Well, since the IAT was getting off the more it got hotter after it's accurate range. of 43 degrees C...well hey, by it being in the same part I condemned my 2nd "MAF" ;)

By the way the 2nd way I had known to condemn a MAF (I'll go ahead and be more honest now, I condemned an IAT, it was just attached to it in the same part of a MAF, Lol) was achievable by DVOM, chart of known resistance representing what temperature and a laser thermometer.

I cross referenced my results via scan data and the laser thermometer as well. There's no way to get around that laser thermometer for this technique.

21:45 It seems to me that the way the MAF was intentionally designed was to appear to be a potentiometer. I think they avoided changing how PCM's reacted from the early VANE type MAF's and how they'd have to see a potentiometer.

So, analog MAF's appear to be engineered to me to prevent re-engineering PCMs. Sure the PCM needed the equipment to produce voltage and maintain constant temperature, but the change in V sure seems like a potentiometer.

by AutoBravado

For another article by AutoBravado discussing how I fried my MAF. The articles intention was to be about water decarbonization only, but I got into some related concepts as water decarbonization done wrong would get this sensitive sensor broken.

Milky Oil Cap? Reasons you should or shouldn't worry.

In case you haven't watched the video yet, milky sludge on an oil cap is simply an indication of water condensation in an engine. At the worst, it means you've blown through a head gasket and coolant has been ruining your engine for some time. Simply check your oil on the dipstick. If it's not milky too, then you're probably just having problems with living in a cold area, or your taking too short of trips for the water to boil off in your engine.

Despite no milkiness under my oil cap, and generally driving in a warm environment, this explains why there is a general brown tinge to all the parts inside of the engine in my 1999 Chevy Prizm. I should have been increasing my oil change interval.

I think I do a lot to prevent issues, always using quality synthetic motor oil like Mobil 1 or Castrol with Syntec. When these synthetic motor oils are the extended mileage type my oil looks pretty clean up to 5k to 5.5k miles, but when I get synthetic that doesn't have the "extended" design I only get about 4.4k miles out of the motor oil. (These synthetic motor oils are rated at 15k and 7k respective to my 5.5k and 4.4k mile synthetic motor oil change intervals.) I'm basing these decisions by how dark the oil gets.

It's all those short trips. I'm building up water, and therefore acids because of living in smaller towns since 2005. The metal of my engines in a Metropolis looked much better. You know, where I was usually driving at least 23 miles to work, and I bought much more used cars and it was a colder area too.

Short trips really are hard on cars. I never fully believed it, but "proof is in the pudding"! Just don't eat it! lol

I guess at 130k miles of having even my reduced "extended" synthetic motor oil change intervals, I should have stayed under 4k miles the whole time (car has 170k miles plus now).


Check out one of my other articles about synthetic motor oil. This article gives some answers to the questions. Why synthetic? How does it help with my cars miles per gallon?

by AutoBravado

Does Techron Concentrate Plus really work?

I know we can't go back, but I wonder if the Techron would have been effective at the soft carbon that hadn't baked on back at the beginning of the first video in this series? To be honest I don't think it's something ChrisFix or I will ever test.

To catch everyone up, ChrisFix is doing multiple fuel injector cleaner tests on a engine with some carbon build up. He has a bore camera so he can show evidence, rather than just listening to the engine or having a feel for his truck that can't be proven or shown on camera.

Think about it. Techron Concentrate Plus really doesn't look effective on the hard build up. For the price the Gumout did pretty similar work with a lot less cost on his earlier video. Plus, I see Gumout on sale at AutoZone...I don't know how often, but when on sale you can get almost 4 bottles of Gumout to the Techron at full price. Sure the Techron goes on sale too, but usually by not nearly as much.

On impulse before a 2,200 mile trip I did in my truck I ran Gumout Regane and the old Techron together. From other subscribers of ChrisFix's YouTube channel, I believe I actually got the PEA that techron used to show on the MSDS. The current MSDS for Techron doesn't show PEA anymore. That seems to be the cleaner of choice that actually has scientists finding data and publishing journals on it.

The results I could really feel came in about 1/2 through the trip. I filled up on gas pretty often and didn't get my tank low so math says that since I had double concentration between the two cleaners that it probably took half the trip for the solution to get pretty diluted.

I really wish I had a bore camera to see the before and after. I will say this though. It normally takes several thousand miles for my trucks oil to get some black in it. My oil was fresh before the trip and after it was as dirty as if I had driven more like 4000 miles. It's my only indicator that cleaning happened that's visual other than the experience of the engine really opening up, getting smoother, and sounding quiter.

To be fair, ChrisFix did a much better test than I did. I could show the results. When I ran Gumout Regane in my 1999 Chevy Prizm right after the water decarbonization article I wrote, I really didn't feel any difference. Since I had bought it as a buy one get one free, I figured why not put it in the truck? My MPG did improve throughout my journey. And the biggest changes were during the time that I still had a significant concentration left of the Gumout Regane and Techron Concentrate Plus.

Now remember, I felt quite the difference that I used to hear from friends all the time back in the day when I bought this Techron bottle. That was when it still had PEA. It's what convinced me to even put it in my truck. All my friends that thought it worked before have stopped buying it, and having seen the current MSDS myself, it doesn't have PEA. It makes me wonder if PEA has gotten more expensive. Seeing as Techron Concentrate Plus is one of the most expensive products on the shelf at my local store, I think they're just trying to make money on a reputation for PEA that used to be in the product. Well, even without bore scopes, all my friends have stopped buying it.

These videos get me to say a lot and I hope my personal experience may be of benefit to another. It's really too bad that I can only speak from how the engine sounded. I should have taken some screen shots at least from my Torque App before and after I did see a HP/torque bump, but I was also at lower elevation later in the trip, so having thicker atmosphere may have been the cause. Maybe that would have turned up some more evidence. I did see significant changes on my OBD II data during my trip. I haven't yet gone through many, many fuel receipts that I did MPG in a thorough way, but I'll be sure to report back with more detail.

Just for reference:
I was hauling a full load in a full sized truck bed on a 2004 Nissan Frontier XE with the V6 3.3 option with no supercharger. Also, when it was very cold out my engine seemed to ping some. My knock sensor went bad and it's on back order. I'm doing a knock sensor location mod once my parts from Bosch are no longer on back order so I'll be sure to report any MPG changes! Nissan put the knock sensor deep under the intakes so the proper job is a full days work, while the mod only takes 15-45 minutes. More to come. :)

Get more tips on how to improve your truck's or car's miles per gallon on my main website. Or watch my own video and reactions to a fuel additive. Lucas Upper Cylinder Lubricant:

by AutoBravado

Fuel Injectors and a audience inspired article from Scotty Kilmer's videos

Scotty Kilmer said he has a tool to see fuel trim per fuel injector. That's incredible and I think my ECU has maxed out adjustment if they still can't run even. Or the ECU is just not sensitive enough to get the fuel injector's timing any closer to being right.

I'm on my 3rd change of fuel injectors. This only covers a fraction of the times I had to pull the system a part because fuel leaks kept developing above the fuel injectors. With how my fuel injectors sit on my engine this gives an amazing opportunity for them to sit in fuel. I don't think they're designed to do that because they failed right and left until I got better at setting them up without leaks. Part of the posts that my fuel rail secure to are plastic and damaged so I think they were the cause of most of my frustration. It's easy to get the fuel rail to tight with this setup on my 1999 Chevy Prizm - same as a Toyota Corolla.

I developed an interesting problem towards, hopefully the end, of this project that has had me under my hood for hours at a time repeatedly for days and going into weeks.

At this point, I can do the job of changing them out or a certain faulty one out in 10-30 minutes. The 30 part was added just in case of pride, but I've really gotten much faster.

When the remanufacturer wanted me to switch fuel injector 1 and 2 I found myself to be very upset. Sure, I had misfires at every startup on cylinder no. 1 and sometimes I had a P0300 as well, but this was less of a misfire to do no flow, and more likely just incorrect flow.

When I switched 1 and 2 the problem would have disappeared without my laser thermometer.

Let me explain.

Cylinders 2 and 3 fire one after another just like 1 and 4 fire one after the other. Basically, switching two injectors got rid of a misfire as each cylinder firing order set has a lean and rich injector. The O2 sensor sees the pulse on exhaust of each group of time of cylinders next to each other in firing order and everything looks on target. Virtually no fuel trim, except at idle, but I'm sure that's a separate issue.

I believed that my original set of fuel injectors were actually much more efficient because the leaking fuel injector actually caused the rest of the engine to run lean.

When they sent me a set of fuel injectors that ran perfectly even all the laser temps were the same per cylinder and fuel mileage was down from 43 to 35....or way worse if you include that over some days all but one failed on the first set, but that's a bigger more frustrating story....

So, with how long winded I am, I only could ask Scotty Kilmer one tiny bit of all this on the live event, but what I'm going to do before I install yet a 3rd set of injectors is widen the spark plug gap on the two cylinders that are getting more fuel.

You see, I learned from my ACE studying today that the spark line can indicate a problem in a cylinder. The shorter the spark line, the shorter the secondary resistance should be, however, when spark is normal, it can also be a way to detect a greater fuel to air mixtures.

More fuel equals less resistance to spark. So, I'm thinking of checking if I can change my richer cylinders 3 and 4 to .046 spark plug gap instead of .044. This would raise resistance, get a longer burning of the richer fuel, and I'd LOVE to see the car's miles per gallon results on that!

All I could fit in to ask Scotty Kilmer on the live event today on YouTube was if I should keep plugging on with my current ones, I mean, I have better MPG because the O2 is seeing stoichemetric...yet it's due to a bit of a trick ;) lol. He guessed right away what I didn't have space to say that they were remanufactured and that they'll never be perfect unless I want to buy new ones...

To check out my question from this mornings live event check here: Scotty Kilmer Live Event He does this about weekly, except that his older son had a wedding so this was the first event in a few weeks.

....this is very tempting as my system is pretty stable and I have another miles per gallon experiment to run. :) If you want to check out the conversation that lead to the making of this article go to Scotty Kilmer's video on Gasoline and Your Car

12/21 update:
I've been running the 3rd set of warrantied injectors for about a week now. I was able to put my spark plug gap back to stock 0.044 inches. The trick with increasing the spark plug gap where I had hotter cylinders due to more fuel did help. I almost got the temperatures even. The engine wasn't actually running even of course, but it was a lot better. So that's a trick that can help you get through a leaking injector...though in my case that fuel injector was less leaking and more just over spraying...I think ;).

10/11/2015
A year later, and now I'm making videos. See some knowledge I talk about here presented in video format!

by AutoBravado

Decarbonziing Your Engine with Water with Ericthecarguy

I was like a child again after I did this to my 1999 Chevy Prizm with all the jumping up and down I did as I told my neighbor, and then my wife, and then the internet. I had just taken care of my fuel injectors - at least one was very leaky, but that cylinder was still 5-7 degrees hotter than the other cylinders. For a bit I was thinking and growling, did I spend too little? I actually diagnosed that the fuel injector was bad, right? Of course I did!

I watched a bunch of YouTube videos about different engine clean up chemicals while I considered removing my engine's cylinder head. I read a lot of MSDS on those cleaners and found which ones did more cleaning by their ingredients. (Note: Ericthecarguy's review on Gumout Regane? Had more PEA or what actually does the cleaning, about 2-3 times as much as The Scotty Kilmer review on Gumout Multi-System fuel cleaner...though that also protects you from Ethanol. It turns out that some cleaners have quite approximate values for the cleaner with a range of percentage.)

I digress. I tried a spray water bottle. Knowing how I fried my MAF not waiting to run it for long enough after cleaning it with MAF cleaner, I didn't want to spray the water in pre-maf.

I also didn't want a CEL over my MAF not being involved. So I finally opted to use a tube that takes blow by gases to my intake right before the throttle. (For more about MAF go to Schrodingers Box MAF diagnosis reaction blog)

For 10-15 minutes I sprayed water in there (engine was already warmed up to a normal operating temperature), when the engine started to struggle a little, I kept the RPM up a bit until it cleared.

When I was done, the temperature on all the cylinders were the same! No more super carbon on one from the leaky injector!

Sure it wasn't a dyno, but I used my Torque App - which calculates everything accurately if you have give it the right values (weight of the car plus me for example). I went from 109 to 114 wheel horse power!

The engine was so SMOOTH. I checked my oil after this, it was due, for my car at 5,500 miles, but I had to change it 500 miles early because of all the crap I knocked out of the engine. So I recommend doing this before an oil change because of the filth and because there was probably some water in the oil after this.

My water bottle was filled just above the 21 oz. fill line and afterward I couldn't even tell how much water I had used because it looked like it was in about the same spot.

After the test drive, I rechecked the cylinder temperatures (or as close as I could get to them on my metal intake*) and all the cylinders were still the same temperature.

My car didn't complain about any knock that I know of, but that cylinder was hot enough that it may have been getting ignition a little early so my timing was retarded, or possibly I just stopped that cylinder from putting out extra power over the other cylinders.

Final consequence: I could hear my engine wasn't quite even in spark. I rechecked the gap on my iridium spark plugs and steamy water had changed their gap. This may not always happen, it only threw one spark plug gap off.

I've made my own video now too!



Check out my latest article about fuel injector cleaners and another YouTube channel that's really putting it to the test! Does Techron Concentrate Plus really work? Or another upgrade entirely that really smoothed out my engine: grounding wire upgrades.

*my metal intake has air in between each tube so I didn't feel the need to take off my exhaust shield and check engine temperatures there

by AutoBravado

Beating the P0420/P0430 Catalytic Converter below efficiency

If you have trouble understanding this article, better understand the role of Upstream O2 Senors first.

Try cleaning first, but find the cause to prevent it again!

If the catalytic converter is dirty I can see how cleaning it would work. Try a gallon of lacquer thinner in a 10 to 12 gallon tank. P0420 comes with just 5% below correct efficiency threshold. If it was broken, it definitely would not work. (Melted or broken up.) Also, remember, if your catalytic converter went bad, be sure to look for any leaking fuel injectors, check timing and spark, as these problems make catalytic converters go bad. (To test fuel injectors requires some advanced equipment.)

My point about trying to clean a catalytic converter, is that it just has some carbon build up on it keeping combustion gasses from getting the catalyzing metals, then cleaning it off will work. If enough of these metals are eroded away off of the ceramic honey comb, no amount of cleaning will make it work. If the catalytic converter doesn't have to be cut out of the car, then it may be practical to unbolt it and leave it in a thick concentration of dawn detergent over night, rinse it off, reinstall it and it may work again. This is a more aggressive and more effective way, but if your car is really old, my guess is that it just needs replacing.

Back to the analysis, has it really gone bad?

On a live data scan you can see the stoichiometric up and down from lean to rich on traditional O2 sensors. Seeing that on bank 1 sensor 1 or bank 2 sensor 1 - O2 sensors that are prior to the catalytic converter you're fine. If you see that same, or nearly the same wave form on sensor 2 for bank 1 or 2, then you should have a bad catalytic converter (saying this to cover V6/V8 cars with two engine banks, just apply the information to to a 4 cylinder or inline 4, (L4) engine without the bank 2 information. The sensor 2's on bank 1 or 2 are after the catalytic converter. Bank 1 catalytic converter below efficiency is a P0420, and a P0430 is a the same problem on bank 2.

I had an exhaust leak prior to my cat (a nickname for catalytic converters). When I replaced my cat I was lucky that I did indeed need it.The new cat almost stopped the wave form on the sensors behind the cat. You see, as outside air burps into your exhaust via the venturi effect (move gases down a pipe at high speeds will pull outside air in through a hole) it'll cool the exhaust gasses, and make your catalytic converter cooler for a moment, and burn less of the unburnt combustion gasses. A human can see the difference but the car figures exhaust leaks as a bad cat.The rear O2 sensors should be pretty steady. They can stay steady rich or lean and you've beat the P0420 and/or P0430.

They can go from lean to rich at times. My car's cat lives super lean, by my O2 sensors estimation. If I'm accelerating for a while onto the freeway or the exhaust isn't warmed up yet, then that sensor will go rich. Some rear O2 sensors will see rich all of the time. That's how usual catalytic converters/rear O2 sensor relationships are.

by AutoBravado

Related content:
Catalytic Converter and Horse Power, Why More HP?