|
|
|
Your donations help keep this valuable resource free and growing. Thank you.
|
double exhaust 2.5 inches |
Post Reply 
|
Page <12 |
| Author | |
Mopar_guy 
Supporter of TheAMCForum 
Joined: Jun/07/2009 Location: Ohio Status: Offline Points: 4826 |
 Post Options
 Thanks(0)
 Quote Reply
 Posted: Dec/09/2018 at 10:10am |
|
For a street driven car like mine where I put a lot of miles on it, I wouldn't put any Flowmaster on it even if you gave them to me. The drone will drive you crazy. I highly recommend DynoMax Super Turbos. I did all new exhaust this summer on my car and got talked onto Xlerator mufflers because the exhaust shop claimed they wouldn't drone. 3 weeks later they were taking them off and putting DynoMax Super Turbos on it like I wanted in the first place. They sound good but with no drone. I have 2.5" all the way out the back with an X pipe. The guy at the exhaust was complaining that I could lose some power and I said who cares if I can't stand to drive it which is what I built it to do!
|
|
 |
|
|
67 Marlin
AMC Addicted 
Joined: Feb/21/2015 Location: Minnesota Status: Offline Points: 877 |
Post Options
Thanks(0)
Quote Reply
Posted: Dec/09/2018 at 10:08pm |
|
The dogleg manifolds have 2.25 diameter outlets. If you have the tubing mandrel bent, then 2.25 will he ok - no need for anything larger than the manifold outlet. If using tubing that's crimp-bent, then you'll need larger diameter tubing to ensure the crimped section isn't smaller than the 2.25 manifold outlet.
Edit - I defer to what Chris says (next post). Edited by 67 Marlin - Dec/10/2018 at 8:30am |
|
|
|
|
ccowx
AMC Addicted
Joined: Nov/03/2010 Location: Yukon Status: Offline Points: 3510 |
Post Options
Thanks(0)
Quote Reply
Posted: Dec/09/2018 at 10:54pm |
|
Exhaust have many possible restrictions. Could be the crush clamps, the bends, inside the mufflers, you name it. Also, as I mentioned before, the farther downstream you are, the smaller diameter you need. Rebel Machines had 2.25" pipes at the manifolds with 2" from the muffler back. If the 2" part was a major issue, why did the factory waste considerable money with new manifolds and larger pipes? Because the most critical flow is closer to the engine.
My pipes are not mandrel bent and it does not seem to hurt them much. Mind you, the only places that are bent enough to be restrictive are the parts up and over the axle. By that time the gas has cooled considerably, velocity is slower, pulses are evened out, etc so it is a different thing than up at the head pipes. Here is a good basic primer on exhaust requirements: My car is pushing about 300 hp even at the rear wheels, or likely about 375-390 at the crank. 2" pipes were inadequate. 2.25" seem about right, though I think with a 3 chamber muffler they are a bit restrictive. My Magnaflows have 2.5" pipes inside and 2.25" in and out. That made a world of difference, though mainly at the track. Seat of the pants is hard to feel when you are going flat out! Chris PS: It is worth reading through some of the messages posted on the link above. It has some discussion of torque and other effects of slightly smaller vs larger pipes. PPS: Something else to consider about mandrel bends. The maximum flow is going to be at the outside of the bend, just like a river. The crimping restriction on a non-mandrel bent pipe is going to be on the inside of the bend. Not that mandrel bends are a bad thing, but they are not a make or break thing and depending on their location and a million factors of your particular system, they may make less difference than you might think.
Edited by ccowx - Dec/09/2018 at 11:09pm |
|
|
|
|
Post Reply
|
Page <12 |
Tweet
|
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
Click for TheAMCForum Rules
Topic Options