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Discussion Starter #1
hey what would the difference be between a bird runnin a dual 2.25'' and one runnin a dual 2.50'' exhuast set up?:confused:
 

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Discussion Starter #2
is there a diff between horsepower and torque or gas milage?
 

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Are you going to be running the stock cats up front? Because those are the main restrictions in the exhaust. If you open it up you will lose back pressure in the system that will cause you to lose some torque. You might free up some horsepower up top but you'll lose some torque that you will notice. but hey thats what a higher stall converter is for :)
 

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With basically a stock setup, all you would need is 2.25". Anything bigger is just gonna hurt you without producing more HP. Unless you are looking at producing 300+ HP stick with 2.25".

Some go 2.5" for the sound, at the cost of performance on a stock setup. Im not really sure how the sound differs from 2.25" to 2.5", but honestly my 2.25" sounds pretty good, and I get a lot of compliments on it as well. I would imagine 2.5" is slightly deeper in tone.
 

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2.50 , 2 reasons, 1 better scavenging, 2 free- flowing. with the way these cars are run with exhaust, you will be better off with 2.50 . with what you will lose in the bends it will act more like a 2.25
 

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yea so far my motor is stock cept for a cold air intake and removed mufflers.
 

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I don't know about it acting like a 2.25 but you will lose flow because of the compression bends. I wish we could find a company to do mandrel bent stainless steel setups for our cars. Oh I wish the ART systems were still available.
 

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What ahout with the Explorer motor swap? 2.5 still too much? Intend to have high flow cats as well.

C.Hill
 

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its as simple as this

if you plan on replacing the exhaust don't waste your time on anything less than 2.5 all the way back

if you just want a little more sound more power more hp and better gas mileage...

remove the cats and weld in stright pipes, then cut the pipes at the rear mufflers

low end will suffer slightly but its well worth it and it will give you great highway mileage
 

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so i should jus go with the 2.50'' setup then . i want the best, power, torque and gas milage. mine's a dailey driver so it's not like im gonna be revvin the motor or anything. im jus kinda on a budget. gonna have a baby soon. u know how that goes..
 

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2.5in has a much deeper tone. then again i have a DI/DO magnaflow with my stock cats up front. but that will soon change to high flows and headers, explore swap yada yada yada.....:thumbsup:
i just went with 2.5 becuase i didn't want to change out the exhaust again as i upgraded the cars power. it just made more sense to plan ahead. that just my $.02
 

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I had gone 2.5" true dual since I was planning to go with a PI motor and Vortech. If I didn't have plans for the Vortech, I would have stuck with 2.25" though I didn't notice any lack of performance with 2.5" on a stock NPI 4.6L.

-Melon
 

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I can only speak in terms of the 5.0 mustang I had, but I do know that going too big can kill your low end. I put on some 1 5/8" primary shorty headers on a basically stock engine, and it really took away the low end torque, although it did help on the high end.

I also had 2.5 inch "off-road" h-pipe and 2.25 back with summit turbo mufflers. I think it sounded great. It had a nice little burble at idle, and some good roar when pushed, otherwise it was fairly tame and very liveable
 

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I would go with a 2 1/2 inch set up. It leaves room for future modifications and again this Loss of low end torque is somewhat misleading. the rpm range which you make power with the 2.5 system over stock is pushed a bit furthur up the rpm band. a ball park would be from your stop idle till about 2k rpms, yes you may see a power drop. typically its around 2-5 at the wheels. which is negligible. some people think they can feel it but no ones butt is that sensative. what most people feel and think its aloss of power is the vibration from the exhaust. I have experienced this myself where i felt like the car was slower till we put it on the dyno to find out it made similar power numbers from stop idle till right around 2200 rpms, and then jumped up noticeably between 2500 and 5500 rpms (a perfect range for a mostly stock car to make its power) with a usually steep drop off after 5500 due to lack of air coming in (ie the mostly stock intake set up).

high flow cats and no cats should run about the same if the computer stays within its fuel trim parameters. If the car goes to run rich, there goes any power gains out the window. for anyone going withflowmaster mufflers, highflow cats will help reduce the interior drone a little bit. the rest is just a decision if you want to stay emissions compliant.

IF you don't plan on many other mods than some intake and exhaust work (including a PI swap) 2.25 true duals will support the power with relative ease. for a Y pipe set up 2.5 or even 2.75 piping will support it no problemo. both systems should make similar power numbers, typically true duals have a better sound and with a yp ipe set up you gotta watch what mufflers you use due to a raspy tinny sound you can get from the y merger. dunno why it does it but for some reason intermediate pipes can sometimes give a fart cannon sound around 2k rpms.

Good luck with your set up. also call around to local exhaust shops. we gotta few down here in mississippi that make H pipes to fit any car without cats for around 50 bucks. we just made a set for a 95 cougar running it otu the back with hangers, no mufflers, no cats for 125. I put small notches where the mufflers could go in with ease so the person could cut the pipe and put mufflers in with some standard sized slant tips. I ran this set up in the car after we finished up and without mufflers and no cats its quite loud but sounds real good. :)

Travis
 

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OK, Boys and Girls, my take is go with the 2.25" pipes and get this: http://www.performancepeddler.com/products_details.asp?PRODUCT_ID=MAG23325

You get mandrel bends, Stainless Steel pipes 2.25", and NEW High Flow Cats. The bonus is that this piece is DIRECT FIT. Bolt in!!!
wouldnt waste my time with that unless you have some crazy emissions laws, theres no need for three cats i had one for each side on my last car and it passed no problem. ( come to think of it i have no cats now and they didnt say anything to me but i cant recall if they even looked or not)
 

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California is very anal about having 3 cats if your car came with 3 cats, and they can't be hollowed out. That is why my daughter is selling her 88 bird to the scrapper next month before she leave CA for good. She doesn't trust the car for a long desert trip, and the cats have been gutted so the car can't be sold and licensed in CA.
 
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