I have 2 1/2 inch stainless exhaust with Magnaflow mufflers. Where the chrome tail pipe comes out of the muffler it is sized down to a 2 inch pipe then back up to the 2 1/2 chrome tail pipe. Here's a pic:



Will this restriction cause any flow problems? re: performance or possible damage? TIA

shmoky

 

Nope. Factory mufflers came with a 2" outlet from '68 to '72........

 

From the looks of your picture, you could cut off the restricted tube with a zip wheel, and weld back on the appropriate size tube and then add your chrome tip on after....it may change the sound somewhat

 

Yes, That is a big restriction on a roller cammed 454. I probably affects power once your into the operating range of the cam. If the spiral turbo baffles cost 75 HP capped that restriction might be costing you that on your build. Pretty cheap HP to up that to 2 1/2 all the way through. It won't damage your motor running restricted , actually it is easier on it to not be able to make full power.

 

The STS Baffles didn't cost 75 HP capped. Nothing was ever figured for parisitic things. Alternator, water pump, trans, rear end, etc. And that person in question that claimed that really didn't seem to know what was up. (ddn)
Chuck Harmons L88 at about 560-570 flywheel HP, made 483RWHP with the side pipes OPEN. Baffles capped came in at approx. 440RWHP. Caps off and back to 477RWHP. Chuck said that had he rejetted the carb he could have gained the 6 lost HP. This test was done by Chuck back in 2004-5.........So nothing new learned here with the 75HP loss. I'll give ddn 40HP capped maybe, but not all 75. Just a good point of not knowing HOW to use something. Block off 25%+ of ANY exhaust, and you'll loose power. Not hard to figure out.
Cap the baffles for SOUND reduction. (lower HP engines) Uncap the baffles for HIGH power. (high power, high sound) Partially cap the baffles for an inbetween range of sound/power.
So I guess I could split hairs with the " always suspected" guy, and "Mr Smooch" (ehy), and we can't leave out the " made too much power for me" guy either. Although I will say after 7 years (2002) at taking shots at the baffles, but especially the people here on the forum that buy them, you'd think it would be time to move on.
So the baffles are not for everyone, but at least know how to use them before you open and insert...................JCL

* 800 RWHP and 70 dB's will not happen in your life time.......

 

At that point in the system,I doubt it.By the time the exhaust gases have reached the end,they have likely cooled and therefore condensed enough a 1.5'' outlet would be big enough.Magnaflow builds a decent product(at least I hope so,I have a system on order!)one would hope they might know what they are doing.

 

to a certain extent. Exhaust does cool and hence less volume of gasses flowing. The 2.5 system is a major restriction to posters hp. He really needs to look into some kind of 3 inch with a cross over or x-pipe