Knock Knock: Spark Map Tuning on the CHEAP! 

Protip: connect one hose to the exhaust and the other into your mouth so you can gauge the amount of uncombusted fuel in the exhaust.

Taking a risk to your own car to teach us about knock. Just like the video when you let your car overheat. It is amazing how far you go to teach us. Thanks man !

6:30 even tho this video is 3 years old. I feel so grateful this man is putting his engine at risk. Name one car RU-vidr who will purposefully make their engine knock so the kiddies can learn and understand. :( a true hero.

the real turbo yoda

super creative man. More dope content. You're gonna go so far Craig

Great video. I have home made knock ears too, one amplified with a mic and the hose variety. The problem is, with these damn BP engine, the natural internal noises are so severe, that at high load / rpm, hearing knock is very very difficult. Good tuners will pull the plugs to find signs of detonation on the porcelain (which is an art unto itself.) To help with hearing knock, I run my electric knock ears through a band filter (using Audition on my MacBook) and narrow it to roughly 5K - 10K HZ. It helps, but there is a lot of drivetrain noise at that frequency. Planning on doing a video on this, but haven't gotten around to it.

Loved the video. Some extra info for viewers: Low RPM high load = worst conditions for knock (for example, low rpm spooling turbos full boost by 2500 rpm) mid-High rpm high load = bad conditions for knock low rpm low load = mild conditions for knock tip in enrichment knock = mild conditions for knock High IAT related knock = bad conditions for knock, in turbo charged cars it can lead to preignition.

Very cool informative vid man👌🏼

I like your videos and I get that they're geared toward trying to explain everything in layman terms in a short period of time. However, this can easily present misrepresentations of what your talking about. As an example, your causes of detonation can be misconstrued. Fuel octane too low is NOT a cause of detonation. The ignition and fuel tables can be adjusted to accommodate low fuel octane. In order to keep things simple, detonation occurs when the air/fuel mixture combusts too early or too late in the combustion cycle. Octane itself refers to the stability of the fuel, basically a rating that tells you the fuel is more stable and is less likely to ignite uncontrollably. That said, it's not sensible to go hunting for 100 octane in regions where 100 octane is hard to find in order to control detonation (considering octane isn't really much of a reason for detonation but more like a factor)...I would advise anyone to just use a base ignition map and tune the VE tables if doing things on the road, up until the point you can put the car on the dyno. Also a little food for thought, there's no such thing as a knock free car...unless you're rotary; but most piston engines are knock limited. Ignition timing is VERY hard to do on the road without any sort of knock detection system; and even then you can't get it to it's optimum unless you can hold a certain load point and bring the value to its max torque threshold without the car knocking.

He seems not to understand the difference between pre-ignition and knock?

"At a certain point, the spark plug goes off and ignites that mixture and it pushes the piston back down, and that's what propels your car forward and allows you to smoke mustangs"... I wasn't expecting that last part and as a result I got a water bottle thrown at me by my roommate because I died laughing.

Greg why not install a knock sensor? you may have said this but I would think it would be more effective at picking it up at certain frequencies

I wonder how many exploded BPs this will lead to.

Detonation is actually a secondary, sharp pressure wave created when the fuel is over heated and pressurized. You are talking about preignition. Preignition can lead to detonation. Sorry not the same thing. Your channel is awesome though!

Another cause of knock is platinum and iridium spark plugs. Copper plugs will work better in any car the only downside is you have to check them and re-gap them every few months. But that only takes a few minutes and it's well worth it. Any modern engine with a knock sensor will pull a little bit more timing on platinum plugs than copper, especially at full throttle high rpm which is probably why it doesn't bother normal people only enthusiasts.

I have 2019 2.0T my first turbo car. Thanks for this info. This helped me understand more about my Ktuner gauges!

www.contactmagazine.com/Issue54/EngineBasics.html This is a really good read about det/pre-ignition if you've got the time

Best RU-vid Channel ever!!! Really hope you wil get more subs!! Deserve it!! Keep up the great work!

I was under the assumption (according to a wikipedia article) that there's a significant difference between pre-ignition and knock. Pre-ignition is much more harmful than knock, as all the fuel explodes before the spark goes off. Knock is when the fuel explodes more quickly and violently than it should, AFTER the spark goes off. Pre-ignition takes a lot more heat than knock takes. you have to have a REALLY bad tune or really bad fuel to get pre-ignition. it can also be caused by overheating pistons.

Without measuring in-cylinder pressure or at the very least utilizing a load-bearing dyno it's a guessing game trying to find MBT. If you don't know what MBT is, you shouldn't be adjusting your spark maps.

Great video, I also wanted to know what knock sounded like. I'm always getting 1 -2 knocks from a long drive.

A good place for sensing knock, is colse to the deck, where the heads bolt to the Block, right where the kaboom happens!!....

The barbed fitting on the pipe doesn't seem necessary. Just get pipe that the hose fits tight on and use a clamp or two.

They sell mechanics stethoscope at harbor freight for like 5 bucks. Just a heads up guys.

Your channel gets better and better. I know losing an engine is sad but I think it was necessary because it led you on new venture and lots of learning. Best wishes man.

Why didn't you just get a sensor? I know its suppose to be a cheap build but the sensor's ain't expensive.

Made this finally today. Definitely works

That's not detonation or pré-ignition. That's just too much advance.

You can get a cheap stethoscope. That works well. Play Doctor.

Which product do you have and what program is used?

Knock and det are not the same thing www.boefab.com/blogs/tech/72880323-knock-knock-ping

Do you think your spark map is pretty safe for a turbo 1.8 on 12psi no dyno near me

UK "regular" has octane rating of 95 RON and UK High octane is 98-99. Thx Greg for another excellent video, very helpful!

Pre ignition and detonation are NOT the same thing!!!!!!!!!!!!!!!

Harbor freight has em for under 20$ just not as long

Thank for the video, great Idea. For about the same price you can get a knock sensor off ebay, and a arduino board to read it, it is what I did for my dyno. I love your idea tho where you dont have to trust a sensor.

Did annyone ad a knock sensor to a miata engine and connected it to megasquirt?i want to ad one and want to know what the easyest way is

Jaja

So advance as far as possible without hearing knock? I can't do a second gear pull in my neighborhood, do I wear these things around town? Lol!

hey bro you look like donald trump lol keep it up, from spain

Very helpful for a lot of noobs... Great job

I’m having some spark knock right now and this vid helped alot! Thanks so much for the input! It all started a few days after I replaced spark plugs so maybe I should put better or even oem ones in! I’ll try some 93 first tho!

We have RON 98 en RON 102 here in the Netherlands .. The standard for normal cars is RON 95... I always put 98 in my Turbo Miata. Sometimes i will fuel up with RON 102 but not every gasstation has this and it's expensive! Awesome video man, keep it up :)

detonation is explosions AFTER the spark event when youre looking for a controlled burn instead.. pre ignition is what you explained where something ignites the fuel before the spark THESE ARE TWO DIFFERENT THINGS!!!!!!!! pre ignition can cause detonation, but again, these are two different things!!!!!!! man I think Im going to copy this so I dont have to type it out anymore

I second (third?) the request for a Megasquirt Bluetooth video. Also, something on MSDroid and/or Shadow Dash MS would be informative and useful. Keep up the good work.

seeing your diy headphones i was wondering would it work if you hooked a oscillioscope to the knock sensor and visually see the knock that way since the knock will create voltage spikes,the bigger the knock the bigger the spikes on scope?

Sitting here thinking about trading my truck for my brothers 04 Mach 1 stang, and after what Taylor said in his car list video about not trading down through passion, which is exactly what I would be doing, and you reminding me of my love for miatas and desire to turbo the $1500 Miata I was getting at one point, I think I'm gonna not do it. Besides insurance on that trash would be outrageous and I can't afford that shiz

Hi Greg, I being watching your videos since Day one. Sorry for my english, I'm from Uruguay. I have a 323 mazda and we are building everything forged. I love your videos man, keep them coming, I use allot of what I see in them in my cars. pd:whats the name of the song in the end? haha

Pre-ignition is completely different than detonation. I wont even explain it. Look it up.

once you go over the knock threshold, how far below it should you go to be safe? my setup is going to be using an adjustable trigger wheel because i have an nb and im using the stock ecu, and once i get fuel rich enough and things dialed in i want to go from 5 up towards 10 btdc as far as i can to get a little more power out of it despite using the stock ecu. and i guess how far away from knock is safe?

Very cool sir! i'll try these. Other question: Why is ignition advance above 3000rpm almost always constant?

This is how i did it about 15 years ago but i used the doctor listening device9cant remember what they are called) from HF lol. I hated that thing because it didn't isolate the noise and they were so uncomfortable. These earmuffs are a WAY better way to listen so you can hear it much better. Good video man!

Hey greg I have a question for you, I have a 2004 mx5 1.8 Vvt but im lookin to boost it and build a motor... my question to you is if I turbo it and then at a later date build with lower compression pistons will the engine still run even though ive changed the compression ratio? I know lower compression ratios means I can make more power but is there any additional mapping required once ive lowered the compression ratio to get it to run?

Currently in the process of getting my self a miata as a weekend/project car. Biggest thing I'm gonna do is turbocharge it. Being my daily is turbocharged, getting a project car to make fast will be fun as I won't have to keep my daily out of commission just to install a larger turbo.

All I want to say is really well done! You dont waffle, you are right to the point. I come from the classic car side and I own an MG TD that I keep in top mechanical order and the rubbish you hear spouted in the owners club litterature about ignition timing, it's what we call in the UK "Clod kicker wisdom" good term that isnt it! I have made stethoscope similar to yours many years ago and it works really well doesn't it? What I do is warm the engine thoroughly and accelerate the car (full throttle in third gear) up a moderate hill through 1000 rpm to 6000 rpm listening for knock and then repeat, advancing the ignition timing by turning the distributor body clockwise slightly. After doing this perhaps a dozen times you will eventually cause the engine to knock very slightly somewhere in the rev range. You know then you have reached the highest possible advance. It works on my RX8 brilliantly as well. Really well done!

You described pre-ignition not detonation. Detonation occurs when ALL the fuel spontaneously combusts when the piston is right around TDC and is responsible for bent con rods, holes in the top of the piston and bent cranks.

lol go e85 won't have to worry about it.

Dude, Love your content. I've been following your channel for a long time and found your videos very helpful. I have just MS my miata when you started the series. But I've been stuck setting up the "Closed Loop Idle" (CLI) on my miata. Do you run your cars in "Open Loop"? I know you don't Run AC and you probably don't need to use CLI but living in the Caribbean no AC is not negotiable for me. If you do run CLI or know how to set it up. Please do a video to help a Noob with it. I've searched High and Low and no body seems to know how to Really do this properly. Not even miataturbo.net. So I know I can't be alone in this CLI setup mess. Also I would like to know what Tips you have on using Tuner Studio's "AutoTune". Thanks for the content (and discounts for parts. I've used a couple of them :D)

I love the fact you are BMX'r and tune shit up! FBM, Premium, what's next!

Tuning my stock 10:1 VVT motor was a pain, It pinged so easy. I spent way too much time dialing it in. Sigh.

I've been told that the oil pressure gauge acts like a knock sensor, dropping as knock occurs. How true is this? If true how much will it move? Is it sudden or slight?

Timing (no pun intended) couldn't be more perfect for this video, I just made some det cans using the hearing aid and cutting/extending the mic method. It's been raining in Norcal, so I haven't had the chance to test it out yet.

Laughed hard at this! Another option is to get a bosch knock sensor and an adapter cable from efi express. It costs 50 bucks or so. Add your headphones and laptop.

It's the flintstones

What is sequential spark?

Pre ignition and knock is not the same thing

I haven't taken control of my ignition timing on my MS vehicle yet because the IAC control is somehow based on the ignition timing in the factory tuning. once I can get around that, it's on!

have you ever set up the knock sensors to be actually useful? I've been trying to set the knock sensors to be useful on the MS3 but no one really has done much work in this area that I can find.

how much timing should be pulled for boost? Will stock timing be safe for a turbo on an originally na car?

Does the color on the map let you kn when your running rich or lean? I am starting to tune but i haven't found anything about the colors or anything on the map tune. Thanks.

+TheCarPassionChannel this is probably the coolest video I've watched this year.

You make sample easier to catch ..brilliant way to make me understand.

What if I get 102 octane? Is it bad or good for the car? Or isn't it even worth paying extra for it?

whrs ma channel goin rite now.. lol u real tho cus aluminum has great surface hydrogen bond for energy absorbtion whilst heat disipation from its low density construction tension

I wanna smoke Mustangs! But, stuff keeps breaking on my miata and it's taking forever to turbo!

Would there be a way of determining a pre-detonation event based on a few logged parameters? Say, a random boost spike, a random AFR dip (leaning out) or a logged spark advance jump?

What flex fuel sensor do you recommend running with Megasquirt? I will be boosting my '93 Miata with a Garrett GT2560R, and want to use e85. I'm almost done with the DIY Megasquirt kit. I believe you are currently using a GM sensor on one of your cars? I prefer to use a part that has been track tested. Please advise. Your videos have been very informative and recently subscribed.

Do you know how the stock knock sensory on the miata works with Megasquirt? Is it reliable?

Interesting

Hey would a too far ignition advance cause a random misfire ? I cleared the code and started running premium and I didn't get another misfire and the care feels better

Thanks for sharing! Knock on high rpm and high load shouldn’t feel like losing a bunch of power in the “knock zone”?

please google pre-ignition vs detonation, they are not the thing. I would love to see this video redone with a more accurate explanation.

Hey Greg, is that your actual spark map for broke and boosted?

Thanks for the explanation of why alcohol has a higher octane therefore higher boost levels can be chanced.

Don't try this with a rotary

I'm very novice with cars, but you explain everything super simple. The best car channel I've seen! And I've seen a lot...

I see you got a new google pixel

I instantly hit the like button when you said "allows you to smoke Mustangs."

Imagine what the world would be like if Greg uploaded every day. Oh the possibilities!

Thanks Greg for the informative video. The forums say megasquirt isn't that good with knock control, what do you think?

haha those are hilarious never seen anyone with those made before. seem to work well though. another cool informative video

"and that's what propels your car forward and allows you to smoke mustangs"

how we destroy mustangs....lol

detonation is the combination of heat, high rpm and high torque.

If you're over 500HP, there isn't enough time to realize which rpm and pressure it was, as it knocked.... This works only for small N/A's

Hey Greg. Question for you. When boosting the Miata would I still need an FMU even if I use 450 cc rx7 injectors ? I am trying to run a gt3076r.

LO F'n L!

You should've showed how to make the det-cans in this vid.

Hey Greg, love the videos! One thing that I would clarify is that knock actually happens after the spark plug fires- what you are describing is pre ignition and can be a lot worse than knock

Best video showing real world use of a detonation hearing device, so many other video never showing these devices in use. You even go as far as to show normal running and actual pre ignition. Really a great video thank you