Scored an unused muffler from my old man the other week, a Thrush Turbo Tube- its near 10 years old, but still in the box. Supposed to sound great, 3", high flow etc. I know its more of an old school product, but what the hey. Was originally bought to go in a '69 Mustang. Will talk to some exhaust places to see what they think, but would like to hear from anyone here

 

3" is waaaay to big for the RA

 

What is recommended then? I've known ppl to use 2 1/2 inch with RA's... not knowing a hell of a lot about all this, is a half inch in diametre that big a deal?

 

Probably not that big of a deal if only the muffler is 3", and you leave the rest of the exhaust at the stock 2.25". I don't know how easy it'd be to couple a 2.25" pipe to a 3" one.

 

u will loose power with a 3'' ........... 2 1/2 is the perfect size that a 2.4 liter engine needs.

 

He knows all about the 2 1/2 inch....everytime he goes to the restroom.

On a more serious note...if you go with 3 inch, you will have crap for backpressure and your car will actually be slower.

 

I seriously doubt putting the muffler on the end of his stock tubing is going to cause him to lose power. Or he could go and get 2.5" piping from the cat back and then a exapnder on the end to go to the muffler - again, I doubt that will hurt him. Hook it up and see.

 

If he still has a catalytic converter then that will give him all the backpressure he needs.

 

Its not that he NEEDS backpressure, its just that unless the engine revs like an F1 or produces a hole lot of power (like with a turbo), the engine wont be able to produce enough exhaust flow to take advantage of the 3" pipe. There is an old thread about a VRS exhaust where someone said that the bigger the piping, the more the powerband shifted to the right, so imagine the pipe being so big that throughout our rev range the car wouldnt produce any power at all....

When you think about it, you dont want backpressure, because it would make the exhaust gases go back into the combustion chamber, creating turbulence and robbing power. What you want is low pressure created by the gases themselves (thanks to the pipe form). This would help the scavenging effect on the headers, etc. and thus helping the engine by not making it work as hard to push the exhaust gases out the exahust pipe.

Then again, its like Otter said, if the piping is the right size and the only 3" part is the muffler, then maybe, just maybe he would have nothing to worry about (theoretically speaking).

 

I really appreciate the input from you guys, just gone back to look at this thing and I think growing up metri may be an issue: the whole thing is 3" and the inside closer to 2... or just a bit under. Says '3" diametre for offroad clearance.
Pics attached: Zippo and X-box controller there for scale.
I'd still like to use this thing as its supposed to be a good product, but if its going to work against me - my dad can have it back and I'll just get a whole new exhaust... thats what birthdays are for afterall.

 

I'm going to really show my age on this one.

This looks like a section of the chambered exhaust which was an option on 65 and 66 HiPo Mustangs. They had a wonderful (to me) sound that I always loved, a rasppy popping sound, realy wonderful, but loud.
The way the chambers are crimped you'll certainly have no worry about too little backpresure.
the pipe does look too long to work without some mods.
If you have the wherewithall to get installed I for one would say go for it.
Let me know how it sounds, I'd love to here a clip. They were wonderfull sounding
on the old 289 HiPo's

 

Yeah, looks waaay too long to me too. Its going to take some crazy angle to get it to work and its probably going to end up not looking too cool, but I understand wanting to try it because its free - I just don't think its worth the hassle of making it fit.

 

you might fit it in if you sacrifice the stock resonator but hey thats the intention of that thing....
if you have the flange welded to one end you might use it....

 

I figured they would just chop out the resonator, put that in, then a cannon muffler or something at the end. I'll probably have a chat with the exhaust centre boys down the road tomorrow about it I guess, if they think it do-able and a good move, then i'll go for it. If not, I'll thank my Dad but return it. And get a good cat back done.

 

speaking of the stock resonator, about how much power are we losing with this in place? I have the RRM DP and a high flow cat, would I get a difference if I remove the resonator, or will it just change the sound? Oh, and how would the sound change? sorry to highjack the thread, I imagine your questions have been answered anyway.