1966 C10 Exhaust Resnonance issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

njc1230 · 12-15-2018, 11:50 PM

Hi guys, hoping ya'll mind might have some answers to this conundrum. My 1966 C10(short wheelbase) has a 350 Chevy(w/headers) and 700r4 swap and I just took it out for a test drive after finishing a 2.25" exhaust system. Above 1800 rpm, or so, the exhaust is tolerable, but when it drops below 1800 rpm it develops an unbearable resonance. Could barely talk to my dad in the seat next too me, and it quite literally started to give the both of us a headache. I'm using 2 chamber mufflers included with a Speedway Motors kit I ordered a few months ago and I'm less than confident that the mufflers are quality. When I got the truck it had this horrendous 2" exhaust system with glass packs that made it loud, but had no resonance. However, I've seen people put in more restrictive mufflers and have no resonance issues either. Do I need to go back to glasspacks or a less restrictive muffler, or can I go to a quieter muffler?

The kit:
https://www.speedwaymotors.com/DIY-U...-4,284231.html

**cwcarpenter98** · 12-16-2018, 12:06 AM

I run a Black Widow Exhaust Venom 250 with my 283, and I absolutely love it. I have the stock ish looking pipes (2 inch) for the whole way except for the muffler that is a 2.5 inch. I love the sound it makes when I floor it, and even better is that it does not seem to drone at all. Black Widow sells mufflers that are louder than the Venom 250, but for me, I like the quite sound in the cab at cruising speed, and when I floor it, she wakes up and gets loud. I have not heard what it sounds like outside of the truck when I floor it, but my friends say its pretty loud. Hope that all makes sense

vin63 · 12-16-2018, 10:09 AM

Where/location did you mount the muffler (under the cab, under bed, etc.)?

Indian113 · 12-16-2018, 10:52 AM

Do you have a X or H pipe built into your exhaust? I put a H pipe in mine and lost the drone.

**Chevy Fleetside** · 12-16-2018, 11:18 AM

When the exhaust was put in my truck, the exhaust guy put in two resonators. I am running 2 1/2" exhaust with Flow master 40's. At first it was really quiet but now sounds real nice. Not to loud and not to quiet. I also had a cross over pipe installed. This is with a Big Block.

njc1230 · 12-16-2018, 03:47 PM

Hi guys, thanks for all the responses. With the short wheelbase, the mufflers are underneath the cab, and theres nothing in the exhaust system other than the mufflers. No x pipe, h pipe, resonators, etc. I found these mufflers from Walker on Summit called "SoundFX" that are supposedly really quiet and Im considering putting those in. Yes, they wouldnt be the best for performance, but its already plenty fast for me.

https://www.summitracing.com/parts/wlk-17808/

vin63 · 12-16-2018, 04:55 PM

Before spending money on another set of mufflers, try moving the mufflers as far back as possible under the bed (out from under the cab).

bigmoe · 12-16-2018, 05:00 PM

A buddy told me a lot of newer exhaust systems have weights clamped to them to decrease drone. Might be worth investigating.

Edit* If you google 10199232 you can see a pic of a dampner GM used in the 90's.

**PGSigns** · 12-17-2018, 08:07 AM

Put a H pipe in it. Made a world of difference in mine.
Jimmy

**jayoldschool** · 12-17-2018, 10:19 AM

Quote:

Originally Posted by njc1230

Hi guys, thanks for all the responses. With the short wheelbase, the mufflers are underneath the cab, and theres nothing in the exhaust system other than the mufflers. No x pipe, h pipe, resonators, etc. I found these mufflers from Walker on Summit called "SoundFX" that are supposedly really quiet and Im considering putting those in. Yes, they wouldnt be the best for performance, but its already plenty fast for me.

https://www.summitracing.com/parts/wlk-17808/

The muffler location and the dumps are 100% the problem. Mufflers need to go under the bed, and the exhaust needs to exit behind the rear wheels. Your problems will immediately disappear.

**mongocanfly** · 12-17-2018, 11:55 AM

Resonators will help as well

12-15-2018, 11:50 PM	#1
njc1230 Registered User Join Date: Dec 2015 Location: Phoenix, AZ Posts: 5	1966 C10 Exhaust Resnonance issues Hi guys, hoping ya'll mind might have some answers to this conundrum. My 1966 C10(short wheelbase) has a 350 Chevy(w/headers) and 700r4 swap and I just took it out for a test drive after finishing a 2.25" exhaust system. Above 1800 rpm, or so, the exhaust is tolerable, but when it drops below 1800 rpm it develops an unbearable resonance. Could barely talk to my dad in the seat next too me, and it quite literally started to give the both of us a headache. I'm using 2 chamber mufflers included with a Speedway Motors kit I ordered a few months ago and I'm less than confident that the mufflers are quality. When I got the truck it had this horrendous 2" exhaust system with glass packs that made it loud, but had no resonance. However, I've seen people put in more restrictive mufflers and have no resonance issues either. Do I need to go back to glasspacks or a less restrictive muffler, or can I go to a quieter muffler? The kit: https://www.speedwaymotors.com/DIY-U...-4,284231.html

12-16-2018, 12:06 AM	#2
cwcarpenter98 Senior Member Join Date: Jan 2018 Location: Hickory Flat, GA Posts: 4,483	Re: 1966 C10 Exhaust Resnonance issues I run a Black Widow Exhaust Venom 250 with my 283, and I absolutely love it. I have the stock ish looking pipes (2 inch) for the whole way except for the muffler that is a 2.5 inch. I love the sound it makes when I floor it, and even better is that it does not seem to drone at all. Black Widow sells mufflers that are louder than the Venom 250, but for me, I like the quite sound in the cab at cruising speed, and when I floor it, she wakes up and gets loud. I have not heard what it sounds like outside of the truck when I floor it, but my friends say its pretty loud. Hope that all makes sense __________________ Christian Carpenter 1963 C10 - Frankentruck 283, Muncie 3 speed with overdrive Overdrive wiring here 1963-ish truck bed trailer - Half-Wit 1981 C10 - Penny 305, th350 --> Soon to be 350, Saginaw 4 speed 1995 Dodge Dakota Sport "I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson

12-16-2018, 10:09 AM	#3
vin63 It's Better With Nitro Join Date: Apr 2008 Location: Chino Hills, CA Posts: 2,262	Re: 1966 C10 Exhaust Resnonance issues Where/location did you mount the muffler (under the cab, under bed, etc.)? __________________ 1963 C-10: Deluxe-optioned cab, shortbed, fleetside Pontiac 462 ci, Kauffman D-Port alum. heads 4L80E, narrowed sheetmetal Ford 9-inch Tubular front and rear suspension Custom 6-piston front disc and 4-piston rear disc brakes

12-16-2018, 10:52 AM	#4
Indian113 Registered User Join Date: Sep 2009 Location: Monroe,Iowa Posts: 4,370	Re: 1966 C10 Exhaust Resnonance issues Do you have a X or H pipe built into your exhaust? I put a H pipe in mine and lost the drone.

12-16-2018, 11:18 AM	#5
Chevy Fleetside Registered User Join Date: Sep 2006 Location: San Francisco Posts: 4,781	Re: 1966 C10 Exhaust Resnonance issues When the exhaust was put in my truck, the exhaust guy put in two resonators. I am running 2 1/2" exhaust with Flow master 40's. At first it was really quiet but now sounds real nice. Not to loud and not to quiet. I also had a cross over pipe installed. This is with a Big Block. __________________ "A man and his truck, what a beautiful thing" 65 Short Fleetside BBC 65 Long Fleetside 283 3 on the tree for now. my build thread http://www.67-72chevytrucks.com/vboa...d.php?t=259536

12-16-2018, 03:47 PM	#6
njc1230 Registered User Join Date: Dec 2015 Location: Phoenix, AZ Posts: 5	Re: 1966 C10 Exhaust Resnonance issues Hi guys, thanks for all the responses. With the short wheelbase, the mufflers are underneath the cab, and theres nothing in the exhaust system other than the mufflers. No x pipe, h pipe, resonators, etc. I found these mufflers from Walker on Summit called "SoundFX" that are supposedly really quiet and Im considering putting those in. Yes, they wouldnt be the best for performance, but its already plenty fast for me. https://www.summitracing.com/parts/wlk-17808/

12-16-2018, 04:55 PM	#7
vin63 It's Better With Nitro Join Date: Apr 2008 Location: Chino Hills, CA Posts: 2,262	Re: 1966 C10 Exhaust Resnonance issues Before spending money on another set of mufflers, try moving the mufflers as far back as possible under the bed (out from under the cab). __________________ 1963 C-10: Deluxe-optioned cab, shortbed, fleetside Pontiac 462 ci, Kauffman D-Port alum. heads 4L80E, narrowed sheetmetal Ford 9-inch Tubular front and rear suspension Custom 6-piston front disc and 4-piston rear disc brakes

12-16-2018, 05:00 PM	#8
bigmoe Registered User Join Date: Oct 2014 Location: Brandon, Manitoba, Canada Posts: 983	Re: 1966 C10 Exhaust Resnonance issues A buddy told me a lot of newer exhaust systems have weights clamped to them to decrease drone. Might be worth investigating. Edit* If you google 10199232 you can see a pic of a dampner GM used in the 90's. Last edited by bigmoe; 12-16-2018 at 05:26 PM.

12-17-2018, 08:07 AM	#9
PGSigns Senior Member Join Date: Jan 2011 Location: Hayes Va Posts: 4,569	Re: 1966 C10 Exhaust Resnonance issues Put a H pipe in it. Made a world of difference in mine. Jimmy __________________ 60 to 66 Chevy and GMC window decals http://67-72chevytrucks.com/vboard/s...d.php?t=661131 Good friends, good food and a hotrod what else do you need? 1966 BBW long fleet Daily driver 1965 BBW short fleet Sold and going to a good home 1965 Suburban 2003 3500 Duramax 2005 Ultra Classic

12-17-2018, 11:55 AM	#11
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,662	Re: 1966 C10 Exhaust Resnonance issues Resonators will help as well __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver



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