Helmholtz or Quarter Wave - S2000 Exhaust Drone
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- Опубліковано 14 жов 2024
- This has been very time consuming and a huge learning curve.
We've tackle drone many times in the past, but not this low down on a 4 Cylinder.
Most of the time it's been around 4-5K rpms and has been easier to tune out.
We've put a lot of hours into this testing and I hope it gives you some ideas too.
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This testing was so satisfying to watch.
I really love the passion this crew has for all cars. Need to get my prelude down there for some better intercooler pipes! Need that TLC, believe me it does
This was really something to behold. I've never done 1/4 wave resonators like you've done here, but rather Helmholtz resonator canisters that were attached to the rear of the exhaust the same way and I was blown away with how well they work...
Exactly! My drone is gone now.
One can’t help but admire your dedication and determination to make it the best. Thanks for sharing my friend.👍🏽👍🏽👍🏽
Very interesting testing. I appreciate all the time you guys spend testing things out.
this kind of dedication is motivating
Sometimes you have to figure it out hands on. 👍🏻
We appreciate your work
It's just like tuning a trumpet or any other brass instrument for that matter. The finest movements of the tuning slides make a huge difference, so much that I used to tune my trumpet before every performance to account for differences in the air, altitude, temperature, etc.
The dedication of time you have invested into this project is exceptional. 10 years ago i wouldnt have even begun to understand why... today the idea of subtle superiority over stock ...leaving people scratching their heads, and a piece of unique craftsmanship is just so appealing.
Going from my 510 being the ONLY car of its type at any track day auto-x, or meet... to an s2k that i love - while still wanting to own something that isnt "off the shelf"... Its by your efforts that i hope to make that a reality. Eagerly awaiting the end product.
Thanks for the comment. I think over the years I’ve become more picky. Or maybe it’s more of wanting perfection.
I’m 95% happy with the results. It’s still close to 1/3 of the factory weight and has a great sound. But while tuning out the drone at 1900-2000 rpm’s it has brought a slight drone around 1400rpms. It’s no way close to original testing, but it still bothers me.
Stay tuned as there’s more coming. I have a completely new idea I’m going to try and I’m pretty sure it will be the answer.
@@LHTPerformance Following up here for this new idea. Has the video been released?
Yes. Went with the plan of a two loop. It’s great now. ua-cam.com/video/sP4YUPYj4mo/v-deo.htmlsi=mmxU9NXQwjfJMZk-
What a great job ! Thank you for sharing !
Love it man! I'll have to drive down to get one of these from you when you get the last details nailed down!
Thanks you for your efforts, It has been my experience on many cars there is always the best possible solution with compromises that is. You either have a quiet well made exhaust system, a not so quiet with low drone, and a loud system with lot's of drone. You just got to find the one for your taste.
I always wondered about drone removal ever since I've seen the exhaust on the S2000. This video helps if i ever need to eliminate drone in the future. Thanks LHT!
Now we understand it more. Also the plunger method is so much faster. Thanks for the comment.
Very interesting. Time consuming, but satisfying process with desired results.
Excellent tuning! love the attention to detail! the temperature of the exhaust gas makes a difference
Hey that's kinda same extra anti drone exhaust chamber as I got..but I have it in the end muffler called no drone muffler. I got it from a Dutch exhaust maker, not trying to make an advertisment here!
I chanced my 3inch skunk2 mega power rr end muffler for the one I have now and while cruising it's pretty quiet but when opening vtec and turbo(b18c) it screams almost as loud as the skunk2.
In short, I'm very happy with this kind of exhaust with a extra room for the drone. Ofcourse it's not as detailed and engineered as this LHT one.
Awesome Channel John❤👍🏻🇱🇺
Amazing experiment! Love the plunger idea
So entertaining to watch. Thank you for taking us along. Can you make the next video tonight and upload tonight too haha jk. Cant wait
John you are a mastermind brother! Nerd stuff ❤
Wow. Pretty impressive. Well done!
Very cool what you guys did here 👌🏻😎
🙏
I love how nerdy this is!
Thanks. Those that are picky, understand the time involved
I wish i worked with you john, i would love to learn things like this, ive been a fan since i worked with mcclesky
Great! Can't wait till this becomes more common and well understood. I personally can't stand drone so stock exhaust it is for me. I have zero tolerance for drone.
Time to change the shop name to OCD Performance!😂 Seriously though we all love it and your dedication to perfection. The insert to slide into the open end to quickly find the spot the ideal spot was absolutely genius!🤓
I think were you guys were struggling was the material properties affecting resonance though, the vinyl clear tube and PVC have to have been dampening compared to thin wall titanium? I would think more than volume it is wavelength that cancels the resonance so your adjustable insert into the open ended pipe makes the shortest work of dialing in length.
For measuring the volume (I think you came to the conclusion it was somewhat irrelevant) I am surprised you didn't simply use a measuring pitcher to get the exact volume of the PVC then easily match the titanium tubing volume, but again an irrelevant step as the slide does the job ideally.
For me personally I wan't bone stock OEM quiet exhaust and all out performance so am putting in a 3" Stainless Bros boost actuated dump valve in the downpipe, it is supposed to open at 5PSI (wish it was 10PSI) I will be doing an easy version of what you have done and tune it by pin holes in the boost supply line which should bleed off pressure incrementally to open at the desired PSI... or I will simply buy a bag of springs and experiment tune the actuator resistance it has to overcome to open.
Thanks for the response. Yes, we certainly learned a lot from it all.
We have use the boost activated valve a lot and really like them. They do rattle a little but it’s not too awful. You can change the actuator to change the boost opening point. Or an inline boost controller.
Thanks for watching and engaging 👍🏻
@@LHTPerformance Wow thanks for the info on the valve! I know you guys love stainless bros BUT I have to ask is this the one that had a rattle???😵or some other brand? Do you have a source for those actuators? It appears to be specific and I didn't see anything from stainless bros when I bought it. Inline bleed valve, as in ball and spring oldschool valve?
Thank you John! Also can't wait for "uncle Ray" to get featured
@@lcq4blackstar This one is from stainless bros. They only rattle at certain rpm’s. Not too bad.
great work
the problem with measuring DB like that is that it is a relative, not absolute measurement. I think the important thing you are looking for (at least with that type of measurement) is the difference between the peak of the problem frequency compared to what is around it. At the beginning, the main profile of the noise was much further away from the tip of the peak. Based on a DB number of 110, I have to assume you are measuring Peak DB as compared to a ref volume established as zero noise. What you really want is DB Gain from Mean (Average) measured across all frequencies up to the max amplitude of the loudest frequency. It seemed like Intuitively you guys were recognizing that along the way, but I just wanted to add some more detail. Measuring sound in an absolute way is difficult.
It’s an interesting science for sure. The more we experiment, the more we learn. I once talked to a sound engineer from Mercedes at the SEMA show that explained how difficult tuning an exhaust was. Of course they have more restrictions but still have to please everyone.
that's really cool
Very informative. I Learned about Helmholtz resonators at SPC. In Acoustics and Psychoacoustics class. Need to know information when it comes to mixing music in recording studios.
It’s very interesting and I’m sure way more technical than our crude way. It’s also amazing how much length and diameter effect the sound wave
What about the dampening affect of the material?
that was extremely informative on how much trial and error is required to make that work the way you would want, i appresate it as i plan on doing the same, also are those mugen or replica wheels ? if so which ones are they ? thanks
Thanks. The wheels are from MITA. A very good replica wheel that’s forged and allows large brake options and no hub rings like the Mugen MF10s
I wish you’d have purchased aPVC cutter. That was painful to watch. Good call on the piston hack. Increment it if you use it again.
It didn’t go large enough for the larger diameter pipe. It cuts pretty easy. We know how to do it the next time. lol.
This is great but you need to tune it at operating temperature vs cold temp. It makes a significant change in volume because it’s relative to the speed of sound which changes as a result of temperature.
I’m also curious to see if you do the same volume water trick but use the original canister method.
You also want to tune the exhaust relative to your cruising rpm. Drive at different RPMs and you’ll see your frequency change. Higher RPM = higher frequency.
The exhaust sounds amazing at every RPM except the 1600-1900rpm. It’s much better now, I’d say it’s 95% right. Most wouldn’t care and be completely OK with it. I’m just picky and want things perfect.
You might have better results if you put the quarter wave resonator after the other resonator which could be where the 65hz drone is coming from.
I bet Steve Mould could help you guys. He is into pipes, sound, and mazes. No wonder the starters don’t last very long on these cars.😊
They usually last around 15 years of normal use. I’m sure I’ve shaved a couple of years off mine. lol.
just rebuilt my original 94 GSR Denso starter contacts a couple weeks ago. Last time I rebuilt it was nearly 20 years ago. Had trouble getting those solenoid contacts to touch on cold mornings.
@@LHTPerformance Yeah mine flawless for 22 years. Thanks for sharing your tuning. You sure are creative!
10db reduction is an insane amount. Every 3db is perceived as twice the volume by the human ear.
To cancel 80 hz you need a 1/4 wave length, that is 107,5 cm, and that is big length so lets cut that to 1/8, 53,7 cms that you may split in 3 parts and insert the small hole at the first 1/3 of that 53,7 pipe. (diameter 5 cm). In mm is 10 x those. Closed at both sides, a "H" shape.
Do you frequently use other peoples spreadsheets and information without giving them credit?
The answer is no. I try to credit folks as I like to share findings. The spread sheet was from someone I talked to on IG but couldn’t find name when I posted the video
LHT exhaust funnels in the store soon 🤣
lol. I’m thinking a beer mug
All that testing and you didn't show cruising down the road before/after with the sound meter?
Because it didn’t work. I didn’t want to waste any more time testing something that was a fail. Check out the twinloop exhaust testing we did. That one works.
The pvc muffles more than thin wall
I know you don’t like obnoxious loud cars, but would you consider this car in the louder side or closer to stock?
We’re not talking about just loud. Drone is a very deepTone typically in one portion of the rpm. It’s very annoying and sounds like a bass speaker over powering the exhaust sound.
On a side note, I’d rather have a quiet fast car over a slow car loud.
Science 🎉
Nice
Any way you have a link for that helmholtz resonator calculator spreadsheet?
@@CoryBan777 I will see if I can find it. A follower sent it. However, it didn’t work. lol.
@@LHTPerformance lol ahh well, don't worry about that then.
I need to get my S2000 down to you for some LHT TLC
We’ll treat like our own 🙏
So I wonder, how much is drone affected when comparing the material and it's static frequency? I.e, titanium, 304 stainless, aluminum... I'm not scientist, I don't know what I'm talking about lol
Material doesn’t really change the drone. The sound is coming from the tail pipe. The PVC didn’t sound any different from the flexible tube or the titanium.
LTH....I think your calculations might have been wrong because your speed of sound is wrong. In other videos I've seen of people doing this, the thing they struggled with the most was calculating the speed of sound at the temperature of the exhaust (not ambient air temp). There was no good way for them to get an accurate exhaust temp. Maybe try installing an exhaust temp sensor in the pipe. The re-run your calculations.
There has to be something we did wrong. The chamber almost sounded louder and deeper. Now the quarter wave is doing a huge difference and is packaged neatly. I will get some sound clips on the next video. It’s on the back burner right now as we’re busy. I will share anything we find. Thanks for the comment
I like the detail in this video, but I think you’re going about it wrong. You need to think vibration dampening and frequency. So short side pipe stuffed with steel wool or the foam in exhaust mufflers.
Titanium will resonate differently than PVC.
App name?
Who does this ?
Hello, sent you a message on your website in regards to your NSX package. Are you still responding to emails?
Yes. Esther is here 10 to 3 pm. If you don’t get a response message me on IG please
@@LHTPerformance will do thank you!!
The Hotrod collander😂
lol. It just handle a little better.
I could definitely tell the difference listening to this in a car with good speaking, the drone was hurting my hear though
I’m glad it translates over. It’s was interesting that reducing just a couple of db in the 65 hz made a big difference. I don’t mind sound, just not drone.
Need the name of the app
I don’t remember. We downloaded a bunch until he found that one. I’ll check with George
Thanks. Can't seem to find it. I've tried different ones but they seem to be confusing compared to what you have used in this video.
Also wanted to compare the DB & HZ on my 8th civic as I'm also experiencing an annoying drone starting from around 2k RPM up to about 3k.
@@LHTPerformanceYou there sir
1st one, did I get a free turbo kit?🤣
Is it just me who think these guys are remarkable 🥲
Thanks my friend 🙏
Vtec yooo
for me is your Y catback because i change my catback exhausthon my delsol and she have the drone to, so maybe look that way ;)
Not sure if you watched the whole thing. But we fixed the drone.