Street Sleeper Part 13 - Helmholtz Resonator & New Exhaust Tip

In this episode I'm making some modifications to our DIY 3" turbo back exhaust. Thank you for watching!
Visit me on Facebook: / tomsturbogarage
Galant mod list: vr4.turbomirage...

[@minivanin]

Ive probably installed over 100 1/4 wave resonators. They always still amaze me when they work and my customers love em.

[@medleyscrapmetal9833]

minivanin

[@darrincarty2684]

Is there a good place to get diy math calculators for doing this? My BMW has a drone I need to nix.

[@BobWright1]

@minivanin I have a 5.3 GM V8 with drone between 1600 - 2000 RPM's. Can you recommend the best length 1/4 wave pipe to eliminate the drone? Also, does one pipe length get rid of the drone at all RPM's above? Thanks for any advice. BW

[@jxpatel]

You need to know the frequency of the wave you're trying to eliminate. Download a spectrum analyzer app onto your phone, drive around and figure out what the drone frequency is. Mine was 100-120hz between 1500-2000 RPM in a V8 TT BMW. I decided to attack the drone at the 110hz frequency to try to eliminate my range of 100-120. To figure out the length of pipe use this equation: 1200 / 110 / 4 * 12 Speed of sound / Frequency (to get wavelength) / 4 (to get 1/4 wavelength) * 12 (to get inches of pipe) 1200 is the speed of sound at 140f, its just slightly more than standard speed of sound in air at 1100fps, I just compensated for the increased exhaust gas temp. So my pipe needs to be about 32.7" long to attenuate the 110hz frequency that's annoying the piss out of me while cruising in the beast. Hope this helps!

[@gabrielkidder8112]

How many hertz does a 1/4 wave typically cancel out? Like a range 80hz to 120hz or is that too much to hope for.

[@JohnCasale]

You don't work your way up with hole saws, you start with the final size, so you retain your pilot hole in the center. Love your videos Tom! Didn't mean to come off as terse as it reads. Keep up the content!!

[@AF29007]

that's what I thought too lol

[@John-to2ki]

There’s a trick where you use your pilot saw in place of the drill on the bigger hole saw to hit center

[@MegaShowtime2012]

It's different if you pre smoke

[@ResNullium]

Just finished this series. My dad's first car was a used '94 7th Gen Galant Super Saloon, which he let me drive around and which I grew up with. It's been monkeyed with by a few owners and mechanics over the long years. It was even used as an undercover cop car for a short time (Dad was a cop). Now it's sitting on a parking spot outside collecting dust and rust. So I started looking for success stories of project cars and sick upgrades. Each video in your series is just amazing and really inspiring. And also very satisfying, coming from a family with no experience or skill with cars. I hope someday I get to experience these things with my old man's car. Thanks for the vids, Tom! Cheers from the Philippines.

[@quikgt]

I like how an exhaust tip can create so much emotion for us car guys-I also had to have a dual tip on my Colt turbo!

[@buaan]

My S2000 had a HKS hi power silent exhaust with a funny chamber on it, makes sense now as it sounded great at all speeds and loads. Thanks so much for sharing these, Tom. Love watching your vids

[@LasseHuhtala]

I appreciate your attention to detail. Most people would have just slapped an exhaust on there and lived with the drone. Kudos.

[@jwilliams703]

just put on a Helmholtz resonator on my turbo pt cruiser. it was just a 3 inch o2 housing down to a 3 inch dp and straight pipe. it was super loud. put in a 2.5inch 15in long Helmholtz and bam. much much better. still sounds straight piped but much less drone and a bit quieter all around. I think i just got real lucky on the size. didint do any math. Thanks for the idea man. works well. nice vr4 btw. havent seen one in a long time. very underrated car. 4g63 good engine.

[@Kadorja]

In my opinion exhaust is one of the hardest things to get right. Between my Mustang, Vette and Subie I've gone through probably a dozen different setups. You get one setup that sounds nice and end up adding headers or a cat delete and in comes the drone or trumpeting. Glad you enjoy it though and it definitely looks better with the dual tip.

[@kd7kmp]

The dual tip really does look better. I've really enjoyed watching your Street Sleeper series. It brings back LOTS of memories for me. My family had both a 1991 and 1992 Galant VR-4. The 1991 was given to my oldest sister who eventually sold it 😞. I did quite a few engine mods to my dad's 1992 (turbo, intercooler, injectors, etc) to up the ante under the hood. Unfortunately that car was given to my younger sister who let her ex-husband have it when they got divorced...double 😢😢. Like I said, lots of memories... The Galant VR-4 really was ahead of it's time and still looks great. You've just about inspired me to start looking for one of these myself to restore and modify into street sleeper status. Keep the great content coming!

[@jfv65]

i have seen these Helmholtz resonators on older rearwheel drive Peugeot cars. It was stock equipement on those cars. My own modern Toyota has them on the intake side. Simple small plastic closed spaces attached to the intake piping. Cool video!

[@TomsTurboGarage]

Thank you for watching everyone and I always appreciate your kind words and support! For more Helmholtz resonator exhaust info, a google search for that term and/or 1/4 wave resonator will get you images, equations and many first-hand reviews, mostly from car forums. Also, I do plan to add a hanger to the end of the pipe, I was just making sure I had the pipe length correct before doing so, forgot to mention that in the video. Have a good one! -Tom

[@supercoupe6288]

great idea Tom but " there's always a but " might want to install a hanger on the end of your Helmholtz resonator because once the weld breaks good bye Helmholtz resonator.

[@baloneyjusticecheezedog]

I really like this mod. I always though that the biggest problem with big exhaust system is everyone can hear the fact you worked on your car.

[@jtamxgsx]

Hey Tom! Do you recall the length of the resonator pipe you installed? I'm going to have a muffle shop install one for me in my 91 VR4. Cheers!!

[@SloppyMechanics]

this is cool! i have never seen anyone do this! i just recently started doing quiet exhaust and "loudvalve" for dumping and max power, so its boost/vac actuated cutout, nice and quiet and then open DP basically when you make boost, thanks for the videos tom! we just had our little guy 4 weeks ago and i feel the pain about garage time that you are always talking about lol

[@TomsTurboGarage]

Thank you for the kind words sir and congratulations to you!!! Oh yeah, having a bunch of kids is fun - but absolutely wrecks the garage time. :-D

[@coronapack]

hey! its sloppy mechanics!

[@ukmud6218]

I've worked with quite a few helmholes

[@SilveryFoxster]

Excellent video and very informative, I’ll be getting one of these Helmholtz resonators fitted 👍

[@tfrandomthings6602]

Thanks Tom, for sharing this idea to get ride of some exhaust drone! I had the exhaust done on our families Ford Expedition and it sounds great but the drone at 40/45mph is a bit much for the wife and kids.. After watching your video I took our SUV to the exhaust shop and had them add about a 2' long pipe to the side of each exhaust pipe to act as a helmholtz resonator. It did the trick, no more drone and the exhaust still sounds great! Thanks again!

[@JoeWrenches]

Nice work Tom! I love the way the resonator fits and the dual tip looks great!

[@TomsTurboGarage]

Thank you Joe! Hope you're having fun in sunny Florida, it's snowing here right now. :-/

[@JoeWrenches]

Yes! I had a great time at the track yesterday!

[@truthseeker8483]

That's a big spray booth! I have added more Hermoltz resonators to my intake and it made it quieter under load. Adding the conventional resonator to it was clever.

[@rabbon-ithegenesis7169]

You know you're getting old when you're trying to make you're exhaust quiet.😃 nice job by the way.

[@TomsTurboGarage]

Haha, very true! I didn't want it quieter though, just hate drone so dang much. :-D

[@myturkishlife1777]

I like the way you have paper towel on the bench to protect the tip and set up the exhaust on the floor with wooden blocks and use a bit of card to catch overspray 👍 it helps my OCD thankyou , you have a subscriber...

[@WilliamDye-willdye]

With AI-generated captions turned on, the exhaust sounds are identified as "[Music]". I agree with the AI. :-) Yeah, a "before" example woulda been good, but it was a "while you're in there" mod, so that's just the way it goes. It's still a good video.

[@TomsTurboGarage]

Haha, interesting about the captions! Thanks for checking it out William!

[@NoGrip]

'paint booth' hahah

[@TangoOne]

lol beat me too it

[@TomsTurboGarage]

Tee hee!

[@baloneyjusticecheezedog]

The amount of things you are doing on the floor of your shop or outside on the ground is surprisingly high. I can't imagine any of that is good for your back.. Maybe you should think about a roll around table project or two?

[@FatGuyBuilds]

hey there buddy. I just added a horse to the stable. 2017 mustang 5.0 with performance pack. when the wife finishes her masters in 2 years, i will ask to buy the miata again!! lol... keep up the fun.

[@Cobb]

Nice job, I liked the history lesson/explanation of why it works.

[@flyonbyya]

Jus wish I had 1/4 of the energy, talent, enthusiasm and drive to do all those cool azz projects... Gotta be amazed by the attention to detail and sense of correctness. I love the Buick grand national the best of all....super badazz ride

[@athotboy5050]

Love the videos Tom, good stuff. I find myself on KZbin quite a bit longer now with you, and Jafro uploading again.

[@paulwisdom5383]

Two of my favourite car channels after Mighty Car Mods. I also like South Main Autos channel for a more educative episode here and there.

[@tredfxman]

Very great work & lovely to see an old Mitsubishi Galant! 👍

[@estewar03]

Tom I love your videos, all of them. It's easy to tell you're a genuinely good guy. I know this because I've watched every upload for something like 8 or 9 years or so now. I don't usually comment these days but had to say that you're appreciated and keep up the hard work.

[@Sloppyjalopy123]

That's some cool science Tom, I wonder if it knocks any HP out? You should give us another v-box test to compare your new setup to the prior. Thanks for sharing your knowledge!

[@joegekko]

Wow! I was just wondering when we'd get another video!

[@DasSparschwein]

Hi! I studied Physics and built Helmholtz resonators for my recording room. It is really astonishing, that it actually works - and even the math is not too difficult. This video was really interesting :) Thanks!

[@ianc5265]

Maybe your the guy to ask.....I've been thinking about putting a Helmholtz resonator on my project car.....terrible drone @ 1900RPM. To counter this, do I just need the resonator tuned to a frequency of 1900Hz? I wasn't sure if this would cancel it out, or amplify.....

[@DasSparschwein]

Hi! Thats a good question. I think 1900Hz would be too high when your engine is at 1900RPM. It might be a multible of 1900Hz (e.g. 1/4th or 1/8th of 1900Hz). Drone is usually between 60-400Hz. I don't know how you could calculate the drone out of the engine RPM. A good way to measure it, would be an App, where you can see the frequency the mic records (FFT - e.g. SPLnFFT for iOS). Even better would be an external mic and a software like Room EQ Wizard. Then you can see exactly which frequencies need to be filtered out. Finding the drone frequencies is curcial for building the Helmholtz resonator. If you build one, you can vary how wide the opening of the tube is (I think its called cross sectional area A) and how long the tube will be (Length L). You need to adjust this according to the following formula: Drone frequency = speed of sound/(2*pi) * sqrt(A/(Volume of the cavity*L)) If you need help with calculating the right Length/Volume and cross sectional area, you can contact me anytime :)

[@ianc5265]

Thanks! So I used my phone (not ideal, but no better mic) and measured 155Hz @ 2100RPM. I believe I can calculate the theoretical frequency by knowing the exhaust pulses/rev of the engine...I get an answer of 140Hz that way....so which is right not sure, but maybe shoot for the middle? I've put that into a Google sheet to be able to tweak the Helmholtz resonator dimensions...I also tried to get the answer for a 1/4 wave resonator, mostly out of curiosity... If you can, have a look! docs.google.com/spreadsheets/d/1XvB_vQ-H3KeXHE1L8uB6_jwsMUdZELj72pHIfPPiicQ/edit?usp=sharing I think its correct, but not 100%....I'm still not sure if matching the frequency will cancel or amplify the pressure waves that pass over the Helmholtz resonator though....tricky!

[@BassManBobBassCovers]

I've seen this used before, but i questioned how well it works. After seeing this here I am very inclined to try it myself.

[@TheMarcball]

I like the ventilation system in y'all's paintbooth... Thanks for the inspiration... Keep on trucking (from France) !

[@escape4wd]

Thanks for videoing this. I've wondered about doing this on my wrangler since it's got a pretty bad drone. Glad it worked out for you!

[@johnclark8052]

Tom I'm disappointed that you didn't play the sawzall song before cutting that tip off!

[@Kollida89]

Great video. Could you please add helmholz resonator to your video title or description so this video comes up in the search results. This video would have been really informative when I was researching helmholz resonators a few months back!

[@TomsTurboGarage]

Great idea, thank you!

[@MrDannyd9]

3:57 first time I have ever seen you make a silly mistake. You got rid of you pilot hole by stepping up in hole saw sizes. Seems like you ended up getting it done in the end though.

[@jellofuel]

Nothing wrong with a trusty cardboard box! In the end, this sounded great. Good job

[@bobandy3097]

Thanks for making this video. Been dealing with some drone on my Jeep and have been looking for solutions. You're awesome!

[@TomsTurboGarage]

You're welcome sir, glad I can help! I really wish I provided some more concrete info for folks, I had no idea this many people would be interested in the Helmholtz resonator.

[@bg147]

Yea, the smaller dual tip looks much better than the can-like one. Great idea to reduce the drone. As I try to tell the loud exhaust lovers, it isn't about the volume of the exhaust, it is more about the quality.

[@i_read_bad_reviews]

This was my first car , I always thought I was a bad ass . Saved all my money for underglow and it took so long to save up it was out of style by then .

[@charlieimpacto]

Great way to start the weekend! Thanks Tom!

[@beanvo9924]

The helmholtz resonator only works when the outlet is perpendicular to the pipe. Also that resonator you put on the helmholtz will make it less effective .

[@stuartw1667]

5:27... scared the crap out of me! As always, I'm jealous of your skill and your garage.

[@olderrol1968]

I love these kind of videos that leaves you with knowledge

[@Greenlightfilming]

Interesting modification. I wouldn't have ever thought it would make a huge difference like that. Must be why you see resonators configured that way on many OEM induction systems. Nice vid!!

[@tommylyeah]

I love this episode.

[@rtk4214]

We have the same paint booth, I finally feel validated in my choice.

[@TheMrmmkkpro]

Cool stuff, I'm building an exhaust for my 1990 ZR-1, and researching this subject. My stock exhaust is way too restrictive. Nice work. 👍👍🏁🏁

[@WraithDeath]

Can’t say I’ve ever seen a resonator setup like this before . All resonator setups I’ve ever had (including the current one on my S15) have all been through the actual exhaust system rather then hanging off the side

[@Nathan-rn8yg]

Them steps look dapper, good video Tom you biblical beast

[@bjornsama9649]

Let us know when you're ready to sell that thing. I, along with many other would love to pick it up.

[@edlingja1]

Super job, mate. This is such a great channel; always looking forwards to your little projects and teaching by doing.

[@eppyz]

Hilarious..."let's take this to the spray booth" ha ha 👍

[@RobertKohut]

Nice!! I think the newer Focus RS has one (or two) on their exhaust as well.

[@isca21]

surprised you didnt support the pipe to resonator, looks like with that length it might flex and crack

[@sneakeypete]

I find generally a proper mid muffler will do a lot for drone, at least on skylines. Of course space to fit one is a seperate problem...

[@johancronisk3405]

Looking good and fits like a glove. I learned something.

[@joelclear1578]

Love this setup Tom! Keep bringing us updates please!

[@ericsodt]

Any audio of before whine you corrected? Would be interesting to be able to hear the difference.

[@stevebarnette]

Love your videos, Tom, but I have to ask a question. Why not put the resonator inline with the exhaust flow? Seems like that would have close to identical effects with less weight. Regardless, very cool science mixed with your car. I installed a block off kit on the intake to my 997 C2S to increase intake sound which was reduced by a Hemholtz. It sounded great, but now the exhaust is loud enough you can't hear the intake growl as much. If you ever want a chance to get some more channel content, I have a turbo S2000 in my garage that we could finish in about a day's worth of twiddling around. It's mostly wiring in widebandto the AEM Infinity, gauges, and sensors. Electrical has turned out to be my Achilles heel! Think about it. Later, dude!

[@keloduma]

I've a dual exhaust setup. Does that mean I'll need two?

[@scoobygms210]

The dual tip looks way better sir good work

[@martyhandley4456]

Its cool that you noticed a difference, would have been really cool for a before and after both from the rear and in the cabin comparision so we could also see the difference......might be a mod some others would consider with some comparision vid, awesome videos, loved the shop tour, really nice shop, cool cars and projects, cant wait for more

[@shredder8910]

Great video again Tom! Keep up the great work and solid entertainment for your viewers!

[@lucaspamplonica]

Hi Tom!! Great video! Just wanted to tell you that I think that your seatbelt seats too high in the B pillar, you need to lower it in order to work properly in case of an accident, where it will stop your left shoulder from moving inmediatly! Cheers

[@drewdavis239]

The resintor will absord the 1/4 wave. Makes it less efficent

[@gimmethecarkeys]

Twin tip looks wayyyyyyy better!

[@mikec1096]

looks good, seems to sound good. i was just a little worried about hot exhaust gasses blowing on your shock and tire. I would have taken one more step to have a turn down pipe so that hot exhuast wasnt blowing back onto the car after leaving the resonator. I know from personal experience I boiled a brake line that was a foot away from a custom exhaust pipe exit. I don't want to be critical , b/c it looks great. thanks tom.

[@pgtmr2713]

The end is capped, exhaust doesn't come out of the resonator.

[@mikec1096]

I was not sure about this as he did not show the end of the resonator in the video. If it is capped, then it is not an issue. Thank you for your response. edit, he did mention the cap 4:25. Thanks.

[@nbowling10trio]

Too cool, good you were able to kill the drone. The Fam definitely going to appreciate it too.

[@timohietala9895]

You should take the galant for detailing at sarah-n-tuned :)

[@doctahwhoopass285]

The good ol' Gran Turismo 4 exhaust.

[@dsmmike95]

That drone sound for some reason the only way I could get my cranky nephew's to got to sleep when they where baby's and little. 5-10min drive and out like a light.

[@BIGSMOKE-bl2lq]

dsmmike95 same with my kid put her in my car out like a light was awesome

[@user-kk4hv4mq7c]

You guys hypnotized the kids into sleep hahaha

[@iMann_iFail]

Tom, I'm surprised you didn't put some kind of hanger on the resonator or reinforced strap at the join.. Seems like a simple mod to do, I've been suffering from that horrible droney noise for a while now, it'll be good to not have a headache after a roadtrip xD

[@snoopy5736]

I was thinking I wanted to add one on my Buick Riviera supercharged, the only thing I would do different is add an exhaust cutout at the end of the Helmholtz resonator.

[@gnarkill32]

Looks like a pant antler. Nice!

[@mushfiqchoudhury537]

I've watched all your videos and can't get enough!!

[@TomsTurboGarage]

Mushfiq Choudhury Thank you sir!

[@MustangManV8]

Garage looks great Tom!

[@finlay230]

Lovley job 👌

[@morejelloplease]

Sounds like there's a little drone around 1000 rpms but as long as it's gone in the cruising rpm range!

[@paul9813]

Drill a little hole in the bottom of the resonator so condensate has somewhere to go, it probably won't get nearly as hot as the rest of the exhaust to evaporate it off

[@richardwilliams9815]

Hey Tom, just recently picked up a 92 vr4. Got some goodies waiting to be installed. Going for 390/400whp. Was wondering how your 3 bolt rear end is holding up as I know you are past 400whp. People are telling me it will snap around 350whp. Thanks in advance.

[@SamOnsite16]

Good content man 👍. Honestly I don't care what others say ,most important is it works and looks good too 💯.

[@elliotcarter3016]

Tom, How did you determine the length and diameter of the resonator section? I've been looking for a way to tame the drone on my '95 Mustang Project.

[@rhkips]

Diameter is variable, within reason. In theory, diameter is equal to surface area of the emitter, but in the case of exhaust, it's a restricted system so just keep it close to exhaust diameter. Length is easy; it's just a 1/4 wavelength enclosure. Wavelength = Speed of Sound / Frequency, then divide the number you get by four. Whatever units of length you use for Speed of Sound will be the units of length in your wavelength.

[@marcelpursche5339]

Adding to the previous comment: To measure the drone frequency you can record your exhaust sound(when the drone is audible) with a standard microphone or your phone if you don't have one handy. You can then load the soundfile in the free software "Audacity". The software has a frequency analysis feature which creates a nice plot of frequencies and their amplitude(i.e. loudness). You want to look for highest spikes in the plot to get your drone frequency.

[@colormesarge]

God damn real ass answers. Thank you both and OP for the question.

[@insiditious6203]

Does that reduce air flow/ scavenging (power)? I read a bit online but couldn’t find a clear answer.. most I found was that it may create a lower pressure than outside and cause gasses to rush that space as opposed to getting sucked out the butt end 😝.. but fr tho, tryna find the best performance set up without sacrificing ur ears and sanity is hard

[@themechanic6117]

I always wanted to try that on my exhaust. With the headers on drone was horrible.

[@Heath3250]

Silly question, but why didn't you just add the resonator in the existing exhaust piping just upstream from where this branched off? Still waiting on you to sell me the Miata btw :)

[@NoGrip]

ARE THEY 6UL'S WITH SLICKS! what are they from/ for?

[@typedrew]

No Grip his Miata

[@shaneduncan2996]

great video tom!

[@roderickconstantino5354]

Wouldn’t using a packed resonator on the Helmholtz defeat the purpose of the Helmholtz? Don’t you need those sound wave to be unchanged so when it bounces back it puts it out of phase

[@BIGSMOKE-bl2lq]

My civic has 1 on the intake at least thats what I think it is taking away that nice doch vtec induction noise

[@GIZZMOTORSPORTS]

Did it make it any quieter at WOT? I have a single 3” already with 2 inline resonators and a muffler on my 2.0, crazy loud from 7000-9400rpm

[@kevinisousa9733]

Hey man can you share the literature you used to calculate the Helmholtz resonator? I'm trying to design a exhaust system for Formula SAE but we have a lack of knowledge about it.

[@e46silverbullet62]

@2:15 i didnt know stubby ends had plenty of meat to work with lol anyway keep up the quality content!

[@Dnasty1]

Can these be used to give the exhaust note a higher pitch?

[@bassgitter3929]

Hey, thanks for the run down on the Helmholtz. I was wondering how you calculated pipe size, length, and cavity size/volume. To further explain: I just installed a new muffler with stubby down exhaust on my inline 6 cylinder 4.0L and I'm noticing a drone at 1750-2250rpm (ish), in the 90-105hz range. It's only 60ish decibels so not overbearing, but if I could get an explanation of how to calculate a Helmholtz style branch resonator and quiet the drone down it would be great!

[@JC7119]

I'm surprised you didn't get a Varex Muffler for true dual mode exhaust.

[@KevinBuckham1]

First good review of an exhaust Helmholtz resonator that I've seen. Back in 2003-2004 I was trying different exhausts on the Talon trying to get rid of the resonance. At the time I was playing with different length round glasspack mufflers inline with the pipe but they all didn't work that well. I did look at Helmholtz resonators then bit the trials were getting expensive. I gave up and used an RS*R exhaust which has zero resonance but is quite restrictive. This makes me want to try it out again. Do you mind sharing the dimensions you used?

[@SteveRand]

How does one work their way up with holesaws?? =-o

[@JustKyzuuh]

Hey Tom, I see 6UL's and konigs along the wall, what wheels are you running now on the mx5?

[@TheForcedinductn]

Love that DSM sound, and I don't even own one :(