318 exhaust

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Small_Block

Small_Block

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i have a 74 Dart with the LA 318, currently the exhaust is still the tiny single exhaust from the factory. My plan is to put a 2.5 inch duals with an x pipe and turbo mufflers exiting out the sides before the rear tires. Will this set up have any noticeable power and mpg gains? I know the exhaust will have a positive effect over stock but what numbers would i be seeing?
 
Duals small cam (340), smal 4bbl on an Ed Performer, rework the distributor, and you'll be flabbergasted

I don't think that much work in the exhaust all by itself is going to impress ya much

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Minor power increase with no mileage gains. Loss of torque will be noticed.
 
Depends on the rest of the combo, and the muffler you have now. If you still have the 2 Bbl carb you'll mostly make the car sound different.

BUT without a more efficient exhaust, you'll also see little benefit from other modifications. I seriously doubt you'll lose any torque.
 
You gotta start somewhere. 2.5 might be a little much for a 318 though. I like distributor Recurve Idea. It Costs Almost Nothing And The Effects Are Pretty noticeable.
 
add a set of headers a good intakemanifold and a small fourbarrel to that 2½" dual exhaust and you will get a nice little powergain that wont cost you any more fuel,might even save you alitle. if it where me i would run the exhaust all the way out the back,looks cleaner and will be quieter while giving you better groundclearance
 
i wasn't too sure about being able to run the exhaust out the back because of the gas tank location and after seeing pictures and thinking about it more i agree with 1Fast340 with the ground clearance issue. i would love to put a small 4 bbl on it with an intake but i am on a bit of a budget at the moment. unless someone knows where i can pick one up relatively cheap
 
are you planning on running headers or keeping stock manifolds?honestly i think a 2.5 x pipe off stock manifolds would be kinda a waste.if you plan on keeping your stock manifolds id stick with a small dual system like 2" or 2.25" no larger.also dont under estimate how well a good single exhaust can work.look at the way the commando 273 exhaust systems were built.not only did they flow well they have a unique and cool sound to them,and they were a single....just food for thought.
 
I see no negative affects with adding dual exhaust. Stock manifolds I'd run 2-1/4" pipe. Probably go with the same size with just headers & no other mods. Mileage gains would depend on how efficiently it runs now.
 
It runs excellent right now, as for for the manifold vs headers i plan on keeping the manifolds for now, is there enough room on the passenger side of the gas tank to run the exhaust out the back?
 
don't listen even with stock manifolds Ur 318 will sound an flow better with a aftermarket exhaust, my 318 with 4bbl manifold and 4bbrl ,stock manifolds 2 1/2 duel exhaust duel fo-master fakes,
sounds great runs great and goes through twenty bucks in 4days of daily driving.
 
Small_Block said:
i wasn't too sure about being able to run the exhaust out the back because of the gas tank location and after seeing pictures and thinking about it more i agree with 1Fast340 with the ground clearance issue. i would love to put a small 4 bbl on it with an intake but i am on a bit of a budget at the moment. unless someone knows where i can pick one up relatively cheap
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Just thought you might want to do some more upgrades down the road so to speak it usualy happens:)

when i bought my Duster it had a 318 with stock 2barrel a set of headers and a pretty good dual 2½" exhaust and a 340cam ran pretty good for what it was,added a edelbrock performer intakemanifold and a 600cfm edelbrock carb and it ran real sweet for what it was and didnt use much fuel at all:)

nowadays the car has turned into a whole other animal but thats a different story
 
I'd stick with 2.25" pipe. Might save you a few bucks at the muffler shop and I am sure you'll still notice some power gain versus the factory exhaust without losing any torque from too much flow/not enough back pressure
 
63VALIANT*KISS said:
dont listen even with stock manifolds ur 318 will sound an flow better my 318 with 4bbl manifold and 4bbrl ,stock manifolds 2 1/2 duel exhaust duel fhomaster fakies
sounds great runs great and goes through twnty bucks in 4days of daily driving.
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Can somebody translate this into understandable English? I don't have any idea what this all means.
 
I think it's written in the inebriation dialect. As far as I know, the only one that can translate is Jack Daniels.
 
challengergary said:
I'd stick with 2.25" pipe. Might save you a few bucks at the muffler shop and I am sure you'll still notice some power gain versus the factory exhaust without losing any torque from too much flow/not enough back pressure
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sorry to say but the bold part is not true.
 
Also, if i ran a mild summit brand cam would i still be okay with 2.25? And would a mild cam decrease my gas mileage?
 
67Dart273 said:
Duals small cam (340), smal 4bbl on an Ed Performer, rework the distributor, and you'll be flabbergasted

I don't think that much work in the exhaust all by itself is going to impress ya much

158866_211478662206479_142549782432701_57292_1505_b.jpg
Click to expand...

what do u mean "rework the distributor", is you referring to the HEI swap?
 
There are always thrush welded mufflers too, affordable and are just like flowmasters. Sound awesome, not too loud either.
 
Id go 2.5" that way when you want more power down the road and add headers you don't have to redo the entire exhaust.
 
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