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.com/vr4_mods.html
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
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.
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!!
@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
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!
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
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.
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!
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!
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.
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
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.
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.
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.
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
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!
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...
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.
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.
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.
Is there a difference between using a resonator for the cavity or a bigger pipe at that section as I’ve seen in some videos? I really want to do it, but I want to make sure I get it right. Thanks for the video and I love the car. 😍
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
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.
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?
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!
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!
Can you provide a link to the calculations you used? I'm guessing it's based on frequencies; how did you measure the frequency you were looking to eliminate?
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.
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.
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?
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 .
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.
Hi Tom. I have gvr4 950/1000. Its currently not running and needs a radiator. I cant seem to find a stock radiator without an auto trans cooler built in. Is there a difference in radiators from auto and manual? Thanks
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!
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.....
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 :)
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!
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!
I've been wanting to do a Helmholtz mod on my 1990 TT 300ZX dual exhaust for over 8 years but there just isn't enough data out there. My Current exhaust is polished SS from the turbo's back with HFC's, Sebring Tuning 12" resonators in the X pipe and twin tipped Sebring Tuning mufflers. The little data I have found from Synapse Engineering is that I need to try to place the extra tubing as far forward in the exhaust system as possible. But it's the length of that supplemental piping that has me confused. And if I fit stubby SS resonators (same size as you used), how will that affect the length of that tubing?
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
