Jump to content

dual exhaust for my 71 vert with stock 302


Recommended Posts

I am considering adding dual exhaust to my 71 convertible. She has a original 302 and original style single exhaust now.

I want to hook up to existing manifolds and use H pipe with mild flow master mufflers. 

I would appreciate any recommendations and advice. The research I've done seems pretty confusing for  exhaust systems for the 302.

Would I be better to get mufflers and have muffler shop fabricate the system or is there a good kit?

Thanks in advance

 

Wayne

Link to comment
Share on other sites

try precision exhaust for a kit or if you have a competent exhaust shop you trust have them make it up. 

73 Grande H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

 

- Jason

 

 

082-hot-rod-power-tour-2017-1970-1970s.jpg

 

Link to comment
Share on other sites

51 minutes ago, 73pony said:

try precision exhaust for a kit or if you have a competent exhaust shop you trust have them make it up. 

+1 on Precision...

  • Like 1

"Yes dear", has kept me in the hobby a long time...

Link to comment
Share on other sites

26 minutes ago, Kilgon said:

You might want to consider going with headers also while your at it.  Will give you a better sound and a few extra pony's under the hood

Interesting.  is there a rule of thumb as to what a few pony's is?

Also  what does the dual exhaust over single exhaust do for performance?

Link to comment
Share on other sites

This would depend on if there are any other mods to the engine. IE 4bbl intake and carb? Cam? Head work? Both headers and dual exhaust allow the engine to breath easier on the way out but if you did not make any modification to allow more coming in then the performance gain is less than it would be had the intake side been done as well. Mods all have to work together to get the most bang for the buck. Say you did an intake swap to a 4bbl carb and left the single exhaust and stock manifolds on, you would gain some additional power. Then decided to swap to headers and dual exhaust later on. The gain from the exhaust swap would be greater in this scenario than leaving the intake a 2bbl and swapping out the exhaust. 

73 Grande H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

 

- Jason

 

 

082-hot-rod-power-tour-2017-1970-1970s.jpg

 

Link to comment
Share on other sites

24 minutes ago, 73pony said:

This would depend on if there are any other mods to the engine. IE 4bbl intake and carb? Cam? Head work? Both headers and dual exhaust allow the engine to breath easier on the way out but if you did not make any modification to allow more coming in then the performance gain is less than it would be had the intake side been done as well. Mods all have to work together to get the most bang for the buck. Say you did an intake swap to a 4bbl carb and left the single exhaust and stock manifolds on, you would gain some additional power. Then decided to swap to headers and dual exhaust later on. The gain from the exhaust swap would be greater in this scenario than leaving the intake a 2bbl and swapping out the exhaust. 

For now, I am leaving the original 2bbl and all original intake. So any increase in performance would be exhaust upgrade only.

Wayne

 

Link to comment
Share on other sites

Precision Exhaust is owned by Dave Eichner, who used to be one of the principles at Mustangs Unlimited. His dad Frank had a mint '73 Q-code 4 speed convertible. They are good people and will treat you right. 

 

 

Link to comment
Share on other sites

3 hours ago, Everwood said:

Interesting.  is there a rule of thumb as to what a few pony's is?

Also  what does the dual exhaust over single exhaust do for performance?

On most V8's without any mods done to the engine headers will add about 20 to 30 hp.  As 73pony mentioned, a lot of factors come into play when it comes to engine mods and hp.  Adding dual exhaust with your standard manifolds will not do much more than add a few hp and a different sound.  Headers, in simple terms, allow more of the exhaust gases to fully escape the cylinders allowing for a greater amount of fresh air/fuel mixture to enter thus providing more hp and torque.

Kilgon

 

 

"The only dumb question is the one not asked"

Link to comment
Share on other sites

14 hours ago, Everwood said:

Is the dual exhaust system for a convertible the same as a coupe or mach body style?

 

Wayne

In a factory sense, yes. Ford used the same system for all body styles. 

Since a dual exhaust for a 302 is a non-factory item, then it depends on who makes it. It would be fair to assume that Precision makes their H- and mid-pipes work for convertible cars, which by default, work on all others as they don't have the underfloor reinforcements. Tail pipes and mufflers are all the same, only differentiated by turn downs or tips through the valance. 

 

 

Link to comment
Share on other sites

  • 5 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...