Ive seen alot of chat about the exaust sizes for optimal street performance, ie MPG and power. Do you recomend 2 1/4" pipe all the way or just for the head pipe? What have you found works best. I have a 225 with stock carb at the moment, will change to super six when I find one so it should be best with the 2 barrel set up.

thanks

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Grandpa's 1974 Dart Custom 4 door 225 auto, Aluminum Radiator, 1920 Holley.

With the stock carb 2 1/4 all the way back works great! Try to get them mandrel bent for extra smooth bends.
There are three of us in our neighborhood that have made the switch.
No losses, performance gains only.

I am going to try a Super Six set up and have a four barrel set up waiting as well.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I thought I saw someone suggest a smaller diameter for the tail pipe, why would this be better if at all?

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Grandpa's 1974 Dart Custom 4 door 225 auto, Aluminum Radiator, 1920 Holley.

The only advantages I can think of are that it's fractionally lighter and has just a little bit more clearance. Once you're downstream of the header collector or manifold, it's hard to hurt the engine's performance with too big a pipe.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

I think they went to smaller tail pipe to cut costs....technically once the exhaust gases start to cool they don't need as much room. Another point is to reduce sound levels.

Personally with my tall gearing the 2 1/4 pipe isn't that noisy because I cruise at 2500 rpm which is 60 mph. So from 50 to 60 it is pretty quiet. At 3000 to 4000 rpm the noise level is another matter. You definitely know something is going on......

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

No it's because you have a small opening on the intake side (1 barrel carb) which also determines how your exhaust sounds due to the reversion waves... Once you go for the 4 barrel and open air cleaner it'll get more annoying at that cruise level...

The most talked about single pipe is 2.25" from the exhaust manifold to the muffler, then neck down to a 2" or 1 7/8" to keep the noise down (especially if you choose a cheap turbo muffler as the quickie exhaust shop). If it's all correct this might garner about 1-2 mpg highway over the stock noodle pipe, and a smidge of power as the engine can now get the exhaust out a bit faster...

I just got my old pipe out of the 'shed' which is built this same way and about to install it into 'beater' valiant so I can see how much HP and MPG I get from going to this over stock...

good luck,

-D.Idiot

So a two barrel is going to be allot noisier?

I have fully covered (not open) stock air cleaner housings for all three setups with cold air intake hoses for each of them.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

What is the stock exaust tube diameter of a '74 225 dart? Mine is at the shop or I would go out and measure it myself.

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Grandpa's 1974 Dart Custom 4 door 225 auto, Aluminum Radiator, 1920 Holley.

1.875" ID
Stock Super Six, no...closed stock (silenced) air cleaner
Open Air Cleaner, no restrictions...yes... (use a Holley 500, definately yes...)
Used a cheap muffler/glass pack/ $50 turbo muffler... yes...

I just swapped the pipe two hours ago on the Beater Valiant (stock 1 barrel/ 1973 silenced aircleaner...and the noise is about as quiet, but the tone is lower...can't wait until the Holley 2300 goes on... )

-D.Idiot

p.s. I just passed a 'fart' 280zx in traffic this morning... the Hpak Duster with dual 2" to the back, was louder than that vehicle when I let the clutch out at 2500 rpm...

In reality, the OE mufflers had baffles and packing.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I am running a 2 1/4 from front to silencer and a 2 from there out to the back.

Was wondering if i should double this system when I have my headers made up

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Regards,
Fanie Gerber
It's never junk, it's just a part you're not currently using

http://www.valiant50.co.za
Just say I own a few Mopars

68 Barracuda
Thats what I am doing from my headers on my 66.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

If a stock.....mufflerd 65 Valiant can scare the crap outta you when it starts , you had better run and hide when I start my car.......

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Yeah....Im the one who destroyed this rare, vintage automobile.....

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I know I can with my '68 Dart. I'm looking to do a 2.25 when the time comes, and it has a 4brl offie

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My Car Domain