DIY fake exhaust tone

[onobeka]

I have limited time to spend on this one, and I do things in a hurry. However, I’ve made some progress on the prototype. Two dog pots, stainless, aluminium baffle. The port was supposed to be welded on, as I do not have a TIG welder (yet) I burned thgough easily . For now it’s a plumbing pipe. Actually it’s better that way, I can tune it. It sounds decent/well given the sound is 8bit only and without a DAC. The speaker is nothing fancy, however it’s marine line.
Anyway I need to work on the samples more. My plan is to progress in parallel in every aspect: build/electronics/coding.
Now I need to make a good power supply for the Arduino.

Sponsored

 

[onobeka]

Here is another sample, revving from a 10k potentiometer . The rev part is very basic for now.
That is the volume I plan to run it, it can go higher.

 

[onobeka]

Hello again! I hope everybody is doing fine, it's been a while since I've last posted on the forum. It's been some busy (crazy) times for my family and me, since.

The project is not yet in the scrap bin. I've been changing quite a lot:
1) ESP32 instead of Arduino, dual core processing: one processes sound and one the handles the ELM327 communication;
2) Yes, RPM is read via an ELM327. I've been going through a few devices, until finally settled for the Vgate iCar Pro;
3) I've been searching for a lot of sound samples that were clean recordings without background noise - very difficult to find.

Issues I still have:
1) Tuning the sound - obviously;
2) Sorting out the delay in RPM reading from the ELM327 - it's not always present. Baud rate and protocol are already at maximum speed vs. stability;
3) Finding the right amplified that can deliver the output at higher rpm, right now there is a big imbalance between the idle sound and the revving sound, where the engine is completely outpowering the output.
4) The fact I could not yet let go of this project .

I am not running this setup while driving! It's still an experimental project that only runs in my yard.
Don't laugh on the name of the samples, as they suggest some really powerful and some exclusive vehicles . It's just what I could found in my searches.

 

[Dave1899]

The idle notes sound great.

 

[Zaph]

why not just get a simple bluetooth app and pick your engine.

 

[onobeka]

why not just get a simple bluetooth app and pick your engine.

First of all, I was not aware of it. Secondly, it's not the same thing, but not bad either. You gave me a good hint, as they seem to offer free sound samples, I will look a bit into those. Thank you!

 

[D Fresh]

While I still question the why of this and your sanity.

I do applaud you for sticking with it.

 

[got3fords]

When you have dialed in the design, sell it!

 

[onobeka]

Thanks guys for your support!

 

[JesseS]

The grids will upgrade. Don’t worry about it. They need to sustain all the solar panels you and me will have on the roofs anyway now or later. Will it be a zero sum game, maybe. Soon you’ll be able to sell electricity at your gate for EVs. I know many projects of that sort, and it’s a smart idea, less dumping in the networks, avoiding peaks, overfeeding a so-so network is also an issue not only drain overload.

Actually they already have a group and app for that, called Plug-Share. I have enough solar at home to run my house and charge a car, 9 months a year at least. California has already mandated all new homes must have solar, just like water, sewer, and grid hook ups. Now if they can only do something about the water......

 

[Zaph]

You know, if more 4 cylinder engine manufacturers would use crossplane firing orders, far fewer of us would be complaining about the sounds of our engines. Diesel, gas, doesn't matter.

This video, while it talks about the difference in older Yamaha R1 4 cylinder flat plane engines vs newer R1 crossplane motorcycle engines - applies to any engine. Take a look (timestamped) and understand how firing order affects sound.

It sure helps me understand how an old 650 ninja parallel twin I had sounded like a lawn mower (180 degree firing order) while my current Triumph Thruxton parallel twin sounds like a Ducati L twin. (270 degree firing order)

 

[Msfitoy]

I am looking to start a project to add a fake exhaust tone to my truck. I know … I can’t believe I am actually doing this as a purist gearhead myself, yet audis and maserattis have it too.

There is nothing I can do to my small diesel as it has a cat and a DPF with an aftermarket exhaust that would still be compliant in Europe.

I can buy off the shelf systems like Maxhaust that connect to the OBD port to read the RPM, yet I want to build one myself with an arduino, an amplifier and a ported box speaker enclosure.

I need a simple way to read RPM without CAN decoding or … to read the throttle, and I am looking for ideas.

The pedal is a potentiometer, I guess I can read the voltage or resistance, either would work. Any thoughts in this?

The fake noise will be outside, not inside.

These are done everyday for RC model tanks/trucks...

 

[onobeka]

These are done everyday for RC model tanks/trucks...

I know that! However, the NVH requirements are far off. This should sound as if the factory sound is as intended for a gear-head, which makes everything so complex. I want to tune a 4cyl barge to a pleasant small block v8 like sound. Anyway, I am learning a lot in this quest.

 

[Msfitoy]

Learn to code? ?

 

[onobeka]

Learn to code? ?

Coding is how I earn my living. However, coding an ESP32 is something new to me. Not that different from an Arduino yet tons of challenges. Yesterday, after a week of trying different things I’ve learned that a dacWrite in an ISR is very problematic .

Sponsored