double exhaust 2.5 inches

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   Has anybody runned a 2.5  inches  double  exhaust on a 69 AMX with same suspenders and routing as the oem double exhaust???  
What are the problems i might encounter??

I'd like to know before i start cause my regular exhaust is fine would prefer 2.5 but want to keep original look as much as possible

I got a 390, .030 over, RB4 dog legs manifolds  little camed and Edelbrock  650 and would like to ear your suggestion on mufflers too 

I wish to get a little roarr but not to wake up neihbors in the morning just a nice v8 sound

I know exhausts are purely  individual taste but smtg  like mopar new vehicle or mustangs are both legal and ok for an old timer like me thks for your time

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jeanbonjeanbon1 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jan/26/2014 Location: Quebec Status: Offline Points: 194	Post Options Post Reply Quote jeanbonjeanbon1 Report Post Thanks(0) Quote Reply Topic: double exhaust 2.5 inches Posted: Dec/07/2018 at 1:16pm
	Has anybody runned a 2.5 inches double exhaust on a 69 AMX with same suspenders and routing as the oem double exhaust??? What are the problems i might encounter?? I'd like to know before i start cause my regular exhaust is fine would prefer 2.5 but want to keep original look as much as possible I got a 390, .030 over, RB4 dog legs manifolds little camed and Edelbrock 650 and would like to ear your suggestion on mufflers too I wish to get a little roarr but not to wake up neihbors in the morning just a nice v8 sound I know exhausts are purely individual taste but smtg like mopar new vehicle or mustangs are both legal and ok for an old timer like me thks for your time
	Regards,Jean BBBQ Big Bad Blue Quebec Amx 1969 F150 2013 crv 2016 roadstar 2003

Someassemblyrqd Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/02/2012 Location: Renton, wa Status: Offline Points: 458	Post Options Post Reply Quote Someassemblyrqd Report Post Thanks(0) Quote Reply Posted: Dec/07/2018 at 1:51pm
	I have 2.5" on my '70 AMX with no routing issues. For mufflers, it's really an individual taste. As a recommendation, consider a 3 chamber as it will be a bit quieter inside the car, particularly if you have no additional sound deadener, yet, when you get on the gas, the 3 chamber will give you the additional rumble you want.
	Greg E.

PHAT69AMX Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/07/2007 Location: West Virginia Status: Offline Points: 5919	Post Options Post Reply Quote PHAT69AMX Report Post Thanks(0) Quote Reply Posted: Dec/07/2018 at 3:21pm
	Had 2-1/2 on a '69 AMX, they were Flowmaster Mandrel Bent for some year Mustang and fit. Someone long ago posted here 3 inch pipes they made that fit, their picture I saved, not mine. For reference pics of stock type tailpipes. Challenge is over the axle and those 90 deg turns outwards in front of and around the gas tank. Probably of little use, but here are Tailpipe Bend Cards.
	Link to a Short YouTube Burnout Video

jeanbonjeanbon1 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jan/26/2014 Location: Quebec Status: Offline Points: 194	Post Options Post Reply Quote jeanbonjeanbon1 Report Post Thanks(0) Quote Reply Posted: Dec/07/2018 at 5:52pm
	hi thanks for reply Ijust went on you tube and found the sound comparaison of the same en gine with 5 different mufflers quite interesting for thos hho want hear the difference,just folloow the lien https://www.youtube.com/watch?v=hd56tUWvpJg the 3inches pipes really look nice but far more than i need, good looking though. happy to see there's no rooting problem i will probably opt for 2.5 since it's enough for my hp and already restricted my choice on two mufflers by listening the vidéo it will be flowmaster super 44 or hushpower hp2, flowmaster prefered
	Regards,Jean BBBQ Big Bad Blue Quebec Amx 1969 F150 2013 crv 2016 roadstar 2003

WesternRed Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Online Points: 5799	Post Options Post Reply Quote WesternRed Report Post Thanks(0) Quote Reply Posted: Dec/08/2018 at 9:04pm
	Twin 2.5" on mine all the way to the rear bumper without any issues. I actually run an x-pipe up front that is located pretty much under the front uni-joint and have 3" pipes from the headers back to the x and 2.5" from there back.
	I've finally given up drinking for good...........now I only drink for evil.

bcsideshow Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: May/19/2010 Location: Kenosha Status: Offline Points: 1228	Post Options Post Reply Quote bcsideshow Report Post Thanks(0) Quote Reply Posted: Dec/08/2018 at 10:32pm
	2.5 inch, x pipe, and flowmaster super 40 or 44 (don't recall) but went with stainless 2nd time around due to rust out... love it.
	1969 SCRambler "B" 1970 AMX 390 Auto 1968 AMX 390 Auto 1970 Rebel Machine Project 1969 AMX 390 4SPD Project 1969 AMX 390 Auto Project 1969 Javelin 390 project 1997 Cherokee lifted 1998 TJ Lifted

ccowx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Nov/03/2010 Location: Yukon Status: Offline Points: 3510	Post Options Post Reply Quote ccowx Report Post Thanks(0) Quote Reply Posted: Dec/08/2018 at 11:14pm
	For your engine 2.25" are likely adequate. I have 2.25" from front to back and it is enough for a mild 390. Online calculators suggest that 2.25" will support 400 or so hp, so not much margin. The slightly smaller pipes might even help your low end torque. People I know have found 2.5" a bit tough to get over the axle, though others have said no problem. What I have seen done is to use 2.5" up to the mufflers and then 2.25" over the axle. As the exhaust gas cools it shrinks so the slightly smaller diameter is not so critical. Also, 2.25" allows for stock exhaust tips. As for mufflers, I agree with everything above, but bear in mind that 3 chamber mufflers will have a serious negative effect on performance. I went from 3 chamber to a set of Magnaflows and gained .4 of a second in the quarter with no other chnages. I also gained a bit more noise, so you pays your money and you makes your choices! Flowmasters are a love 'em or hate 'em thing. They often have a drone to them, depending on several factors, and can be raspy. Each combination is different and what sounds great on one car can be a disaster on another. And of course, personal taste! Chris

jeanbonjeanbon1 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jan/26/2014 Location: Quebec Status: Offline Points: 194	Post Options Post Reply Quote jeanbonjeanbon1 Report Post Thanks(0) Quote Reply Posted: Dec/09/2018 at 6:58am
	Wow i knew i would start a discussion here and apreciate each and every comment. I'm not gonna race the car in any ways and will drive it to the shows and for pleasure on sunny days since it's been under restauration for three years now and is a reversible over restored car. I never saw it on the road before. This car is my teen's souvenir since i had one when i was 20 long time ago now hihiihhihi. Rust won't be an issue since i won't drive it on rainy days unless i get caught. I will have to get the front pipe done for shure since i changed the exhaust manifolds for dog legs. This is why i am considering the 2.5 actually. I am now thinking of 2.5 to the mufflers and standard 2.25 from there to the end as suggested by coowx. The lines i have are from Arizona and praticaly rust free so might use them and paint them with high heat paint. I stil keep on looking for mufflers. I had straight pipes on my bike and finaly went back to oem cause they were too lousy even after throwing in all kinds of baffles. This is why i will consider three chambers flowmasters 50 series and now will try to get the magnaflows a look on you tube thanks for all your sharing and i'll keep on reading till my final decision but what i wish to get is a nice roarr as newer v8 cars but not too loud I wish to get the car bback on the road next summer preferably at spring time so got a little time to argue ihihhi
	Regards,Jean BBBQ Big Bad Blue Quebec Amx 1969 F150 2013 crv 2016 roadstar 2003

Shawn_Watson Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Dec/05/2018 Location: Carlsbad, NM Status: Offline Points: 117	Post Options Post Reply Quote Shawn_Watson Report Post Thanks(0) Quote Reply Posted: Dec/09/2018 at 9:48am
	Have a look at Hooker Aerochambers. They have a great sound but can be a little snotty at WOT without an h-pipe, depending on how hot your engine is. I really like them. Shawn

ccowx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Nov/03/2010 Location: Yukon Status: Offline Points: 3510	Post Options Post Reply Quote ccowx Report Post Thanks(0) Quote Reply Posted: Dec/09/2018 at 10:08am
	Not sure whatyou mean by "standard 2.25". The original pipes were 2" and I will say that is probably not enough for your engine. 2.25" is probably the smallest you can use without losing some power, especially at high rpms. Another thing to remember is that smaller pipes will tend to be a bit quieter. 20 was a while back here too. Great to relive our youth! Chris