SAAC Forum

The Cars => 1969-1970 Shelby GT350/500 => Topic started by: Fastback66 on February 10, 2018, 09:31:07 PM

Title: Exhaust Sound
Post by: Fastback66 on February 10, 2018, 09:31:07 PM
Does anyone have a clip of their exhaust sound they could share. I'm trying to figure out what to do with my 70 GT350, it has what I think is an old incorrect reproduction exhaust system but it sounds very quiet, not like a muscle car at all, more like a 4 cylinder Fox Body.  I don't think it's correct but I've never hear a 69-70 with stock exhaust. Thoughts or advice on a good repo exhaust system that looks correct? The car is a driver and I plan to keep it that way for a few more years. Should I spend the money on the correct exhaust or go with repo?
Title: Re: Exhaust Sound
Post by: Chris Thauberger on February 10, 2018, 10:02:51 PM
Fuller exhaust all the way. Fits perfectly the first time and look 100% original.

You will not regret the investment

Chris
Title: Re: Exhaust Sound
Post by: Fastback66 on February 10, 2018, 10:21:48 PM
Sound good?
Title: Re: Exhaust Sound
Post by: TOBKOB on February 10, 2018, 10:49:35 PM
Yes...Scott Fuller is the way to go... :)

TOB
Title: Re: Exhaust Sound
Post by: Bob Gaines on February 10, 2018, 10:50:20 PM
Does anyone have a clip of their exhaust sound they could share. I'm trying to figure out what to do with my 70 GT350, it has what I think is an old incorrect reproduction exhaust system but it sounds very quiet, not like a muscle car at all, more like a 4 cylinder Fox Body.  I don't think it's correct but I've never hear a 69-70 with stock exhaust. Thoughts or advice on a good repo exhaust system that looks correct? The car is a driver and I plan to keep it that way for a few more years. Should I spend the money on the correct exhaust or go with repo?
That sentence is a good example of what a oxymoron is defined as.   Sorry the short answer is no ,not with out various degrees of compromise. Too quite is a matter of perception also.   If too quite take out the transverse muffler. If still too quite increase size of pipe to 2 1/2 . If still too quite change out to different maybe shorter resonators. If you had to go to all these different steps then the money you spent to get there you could have bought the more expensive Fuller exhaust which is a relative spot on match and be assured of getting original sound .That is if original sound is your objective.
Title: Re: Exhaust Sound
Post by: FL SAAC on February 10, 2018, 11:03:33 PM
Does anyone have a clip of their exhaust sound they could share. I'm trying to figure out what to do with my 70 GT350, it has what I think is an old incorrect reproduction exhaust system but it sounds very quiet, not like a muscle car at all, more like a 4 cylinder Fox Body.  I don't think it's correct but I've never hear a 69-70 with stock exhaust. Thoughts or advice on a good repo exhaust system that looks correct? The car is a driver and I plan to keep it that way for a few more years. Should I spend the money on the correct exhaust or go with repo?

we comprehend what you mean as we have two 69 gt500s the stock exhaust we also found to be on the mild or quite side.

we opted to remove the transverse mufflers and resonators  installing a true dual exhaust that feeds into the rear center collector

although not factory correct, we love how our cars sound

the next care taker can easily return it to its stock form

do what makes you happy

just our two cents
Title: Re: Exhaust Sound
Post by: Fastback66 on February 11, 2018, 09:10:20 AM
Does anyone have a clip of their exhaust sound they could share. I'm trying to figure out what to do with my 70 GT350, it has what I think is an old incorrect reproduction exhaust system but it sounds very quiet, not like a muscle car at all, more like a 4 cylinder Fox Body.  I don't think it's correct but I've never hear a 69-70 with stock exhaust. Thoughts or advice on a good repo exhaust system that looks correct? The car is a driver and I plan to keep it that way for a few more years. Should I spend the money on the correct exhaust or go with repo?
That sentence is a good example of what a oxymoron is defined as.   Sorry the short answer is no ,not with out various degrees of compromise. Too quite is a matter of perception also.   If too quite take out the transverse muffler. If still too quite increase size of pipe to 2 1/2 . If still too quite change out to different maybe shorter resonators. If you had to go to all these different steps then the money you spent to get there you could have bought the more expensive Fuller exhaust which is a relative spot on match and be assured of getting original sound .That is if original sound is your objective.


I'm not sure if original sound is my objective or not, as I stated above I've never hear a stock exhaust. I don't see 69-70 Shelby's very often and I go to a lot of shows. I see 65's more than I do those cars for some reason.
 I'm still a bit undecided because the car is only a driver quality car and maybe not quite worthy of a $3000 exhaust system just yet.  I've got some mulling over to continue. Thank you.
Title: Re: Exhaust Sound
Post by: FL SAAC on February 11, 2018, 09:22:04 AM
on our 69s we had a local friend who owns a Midas muffler shop do the exhaust from the head pipes back.

eliminated the resonators put two turbo mufflers like a boss 302 exhaust and out the center.

pipes, mufflers and labor was about $500 on one and about $600 on the other
Title: Re: Exhaust Sound
Post by: Bill on February 11, 2018, 09:23:27 AM
Fuller exhaust all the way. Fits perfectly the first time and look 100% original.

You will not regret the investment

Chris

Another vote for Scott's excellent reproduction exhaust system.


Do it once, do it right, you will not have to do it again.

Title: Re: Exhaust Sound
Post by: FL SAAC on February 11, 2018, 09:46:33 AM
on our 69s we had a local friend who owns a Midas muffler shop do the exhaust from the head pipes back.

eliminated the resonators put two turbo mufflers like a boss 302 exhaust and out the center.

pipes, mufflers and labor was about $500 on one and about $600 on the other

mufflers used where the flowmaster brand
Title: Re: Exhaust Sound
Post by: Bigfoot on February 11, 2018, 11:38:12 AM
If you want a perfect OEM style exhaust then you have the input here for that.
If you want your car to sound more bad azz then go with Tonys suggestion which is what I would do.
We just put hooker headers and fat exhaust on my sons 70 Fastback which has a 351-4v.
Sounds great.
Title: Re: Exhaust Sound
Post by: 69 GT350 Vert on March 08, 2018, 06:07:53 PM
I installed a NOS transverse muffler and accurate repro H pipe, resonators 2 years ago on my 69 GT350.  It was very quiet with the stock engine and stock cam.  Last year, I had the engine rebuilt with a moderate performance cam.  The same exact exhaust system is now pretty loud and the car sounds like it has aftermarket exhaust.   
Title: Re: Exhaust Sound
Post by: Rickmustang on March 08, 2018, 06:40:12 PM
Check Precision Exhaust. Specialize in Mustangs, but especially big blocks. Did a system for me but in 2.5 inch that fit perfectly from exhaust manifolds back. Price outstanding. But I also support Scott s exhaust for concourse. Its a work of art. Rick.
Title: Re: Exhaust Sound
Post by: Fastback66 on March 08, 2018, 06:57:28 PM
Check Precision Exhaust. Specialize in Mustangs, but especially big blocks. Did a system for me but in 2.5 inch that fit perfectly from exhaust manifolds back. Price outstanding. But I also support Scott s exhaust for concourse. Its a work of art. Rick.

Good to know, I'll look them up. Thanks.
Title: Re: Exhaust Sound
Post by: Fastback66 on March 08, 2018, 06:58:49 PM
I installed a NOS transverse muffler and accurate repro H pipe, resonators 2 years ago on my 69 GT350.  It was very quiet with the stock engine and stock cam.  Last year, I had the engine rebuilt with a moderate performance cam.  The same exact exhaust system is now pretty loud and the car sounds like it has aftermarket exhaust.   

That's good to know. What cam did you use? I'm rebuilding my engine now and I am considering Comp Cams 268H or something similar.
Title: Re: Exhaust Sound
Post by: shelbydoug on March 08, 2018, 07:09:44 PM
I haven't had to think about this in a long time but I believe that the stock exhaust is essentially tuned to the camshaft the car was originally built with.

Virtually any aftermarket cam is going to be more aggressive and the difference you are going to hear through the exhaust.

I don't know how to keep that burbling sound that you get with the 69 Shelby when you back off of the accelerator? I don't think that you can.

There are inserts that are made to slide into mufflers BUT they need length to have some effect. They were originally intended for Corvettes with factory sidepipes, then adapted to the Cobra sidepipes. They just "take the edge" off of the noise. Officially the number given to me is that they drop the sound by 5 decibels.



I remember when I first bought my 68 GT350 in 1972, it needed a new exhaust system so I bought a complete original Ford system which included the in line resonators.

At the same time I rebuilt the engine and installed a Crower 280 hydraulic cam. The cam made such a drastic change to the sound of the exhaust, it set me off on a exhaust project beyond the stock.

It eventually went to headers, 2-1/2" od pipes with "Corvair Turbo" mufflers. Those were eventually replaced with Flomaster mufflers.

No inline resonators. That's about the quietest it is ever going to be. Oh, 82 decibels is what it measures immediately behind the car. 85 when you rev it. Maybe it's 85 at idle? I haven't checked that recently.

The cross flow muffler is essentially an rpm limiter set at about 6,000rpm, i.e, a "cork" in the system . So depending on what you want to do with the car is what you should do with the exhaust.

I seem to remember difficulty with keeping the main pipes connected to the transverse muffler. They would "blow off".
Title: Re: Exhaust Sound
Post by: FL SAAC on March 08, 2018, 07:55:47 PM
+ 1 shelbydoug
Title: Re: Exhaust Sound
Post by: 427heaven on March 08, 2018, 08:33:10 PM
Fastback- There are 2 types of CAR guys, Original sounding and looking types that have to be correct in all aspects, and the others that want that Sound and performance from their cars. Where the waters get a little muddy on this site is to help people with their immediate needs what ever it may be. These cars were meant to go fast and sound great but 50 years ago straight pipes,cherry bombs, turbos were the way to go. Fast forward 50 years and technology comes to the rescue,there are so many GREAT SOUNDING systems you just have to ask around what others are using. A nasty camshaft and and a new set of Flowmasters or Borlas is what most performance or race car guys that are required by their track, are using. They make MANY different sounding sets so ask around you will find what your for. Good Luck!
Title: Re: Exhaust Sound
Post by: 69 GT350 Vert on March 08, 2018, 09:25:20 PM

That's good to know. What cam did you use? I'm rebuilding my engine now and I am considering Comp Cams 268H or something similar.

I used this cam.  Nice lope, but not over the top.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=896&sb=2
Title: Re: Exhaust Sound
Post by: Stubee on March 09, 2018, 04:02:51 AM
(http://)

NOS 1969 Muffler with original manifolds with reproduction pipes a d resonators.
Enjoy.
Title: Re: Exhaust Sound
Post by: Stubee on March 09, 2018, 04:04:25 AM
Sorry unsuccessful link.
Title: Re: Exhaust Sound
Post by: 69 GT350 Vert on April 30, 2018, 08:45:31 PM
Stock ford transverse muffler. 
https://youtu.be/wIK8uK-JZFA