I have a '68 with a 302. It already has headers (although they are a little rusty and could use replacing, I don't have a lot of money for the time being). I want that classic Mustang sound, but very deep and very loud.

I know the H-pipe is what gives it the drone that I'm looking for (which I have). My question is pipe size. How big can I go?? I understand the physics behind it, and the bigger the pipe, the deeper the sound; but how big is too big? I really want a 3" for that deep rumble, but I - along with some friends of mine - have worries that it is too big, and I will lose back pressure and the noise level will actually be reduced.

I have a high rise air intake with the K&N air filter and a 650 Holly carb. I am putting super 40 flowmasters on to help with the volume level. I do not want to put glass packs on it!

 

I forgot to mention that it does have a cam. I don't know that it really makes a big difference with regard to what I'm asking, but it does have a nice lope to it.

 

Why are you posting this in the mass section?

 

when i saw your name as a reply, i knew you were gunna say sumthing like this lol

 

I mean hes from AR, give me a break. Don't see where you mix that up with mass.

Only thought is he saw the most recent post in the reginal sections was about exhaust from mass so posted here?

That means he would of actually had to look and see he's posting in the REGIONAL section, in the MASSACHUSETTS thread, and think to himself "Yea this is a good idea"

OP, sorry for the rant, I can't for the life of me figure out how people post in the wrong sections, I apologize if you took any of this personally.

 

maybe the country thinks that Mass mustangs owners know their stuff... and we are the place to go for answers

 

I'm aware that MA is not AR. It's shoes and teeth that we lack down here - not maps. I honestly posted to MA because I couldn't see where AR had a regional thread and MA had the most threads and responses. Which led me to believe that there were more enthusiast that would try to help me.

Suppose I should have stuck to the south haha!

 

it's not that we don't want to help you...i personally don't know about the exhaust system for your car, and the people that usually come in the regional section do so to post about cruises and car shows...you MIGHT get a person that comes in here that knows what you want, but it's not likely...there should be a section in here somewhere that is for your model year musang...there is where you would get a better response

https://mustangforums.com/forum/classic-mustangs-16/

good luck

 

Haha good reply! Thats at least a good reason, however as shad said we don't have many buddies with 68's running around to help.

As its been pointed out we do have our own classics section here, so I would look around there for exhaust threads. If you don't find what you're looking for, then make a new post.

Pics of car?

 

I hate to use a Miata site as a reference, but this page discusses pipe diameter, exhaust velocity, back pressure and scavenging in a way that's as simple to follow as any writeup I've seen:

http://www.miata.net/garage/KnowYourCar/S4_Back.html

Since you car is cammed, and has more valve overlap than an average 302, the engine has a bit more time to move the spent gasses out, but if it were my car, I'd still be a bit conservative with pipe size. Scavenging helps, and dual 3" pipes will make for a pretty leisurely exhaust velocity.