Ok, I realize that Magnaflow is about the only (not quite sure the ONLY one) exhaust system that has been proven ON A DYNO to provide low RPM power gains rather than a loss.

I also realize that due their stainless steel construction, they're expensive as hell.

So here is my question: if I were to go to an exhaust shop that stocked/used mandrel bent pipes, could I have them weld up pipes (same size as a Magnaflow catback uses) with a Magnaflow muffler and tip and expect the same results as if I had paid $500 for the real deal? I'm assuming so, since most of the design is in the muffler, not really the pipe. A mandrel bent pipe is a mandrel bent pipe as far as flow characteristics, right? Most of the engineering goes into the muffler, I think.

The reason I'm asking is that because down here in TX, we don't get snow or anything that warrants us putting corrosive stuff on the roads, so rusting exhaust systems isn't really a problem. I'd like some performance gains as much as the next guy, but the SS pipes just aren't worth the money. The SS muffler is though. Anyway... just a thought.

 

You bing a good question not often asked.
First the cats make acid that will eat uncoated mufflers and pipe from the inside out.
Granted there is corrosion from outside but it is not nearly the problem that acid is from inside.
Aways use aluma coated pipes and coated muffler.
Using anything less will last about a year from the time you put it on.
Been there many many times over the years.
SS will last almost as long as you have the truck and may be cheaper in the long run when compared to more than one replacement of standard parts over the same time interval.

 

That went about 10 feet over my head

 

Cool! That was the answer I was hoping for. Ok, so say the muffler shops stocks aluminized steel mandrel bent exhaust pipes. I can just buy a Magnaflow muffler (SS since the muffler itself isn't that much more than aluminized steel) and I could have a near identical Magnaflow catback, only with aluminized pipes?

If this is the case, then an exhaust for me just became affordable...

 

What is affordable?

The F150 systems should be available for about $450-$550
see here:
99-03 http://www.hottexhaust.com/detail.asp?PRODUCT_ID=15609
04-05 http://www.hottexhaust.com/detail.asp?PRODUCT_ID=16612

 

ONLY $450? That's a crap load of money to a college student! haha People are always looking for a cheaper route. Not that we want to do a "half ***" job, but sometimes you have to sacrifice a little quality for economy.

Also, why the hell are the truck exhaust systems so expensive? I was looking for a Magnaflow exhaust system for the 99 Mustang GT I traded in on the truck, and they cost about $360. And it's got TWO mufflers and probably the same overall length of pipe!

 

yeh aluminized pipes will last u a good bit most people get 5-10 years out of em before they rust out depending on how hard to drive ur vehicle and ur climate like acid rain or near the ocean... but yeh that's a cheaper alternative to spending gobs on magnaflow catback

 

To answer your question, yes you can just have a muff shop weld on a Magnaflow muffler and use their pipe for your tailpipes. One thing about Magnaflow is they are PRETTY to look at! I had a complete cat-back with the Pack's on my 01 Mustang GT and paid $300 for the complete kit. Magnaflow sounds awesome but you don't "need" to have the complete system to benefit from having the muffler. Guys on Stangnet did what you're talking about all the time on their Stangs to save some money. My F150 has stock exhaust and I'm planning on doing the same thing you are to save money. As far as price being so high on trucks, I think it's supply and demand and maybe not as much competition in the trucks as there are with cars like Stangs. But that's just a guess. Hope this helps!

 

Sorry, I didnt mean to make $450 sound like it was chump change BUT ... consider the world of stainless exhausts it IS quite affordable. A MagnaFlow muffler alone on stock piping is usually good for 50-70% the power increases of the complete system. Mandrel bent pipe and enlarged tubing make up the the rest of the power based upon the application. I have seen my fair share of crush bent muffler shop systems cost $300-400 and anothe 50-100 doesn't seem like so much in that context.

Richard

 

What you mentioned above is exactly what I had done. Where I live in Idaho we really don't get too much snow. They spread sand on the roads instead of salt. I went to a local muffler shop and had them order me a mandrel bent 3" tail pipe that would exit the same as stock, they also ordered me a 5x8x18" magnaflow muffler. They already had a new 3" pipe for the input side of the muffler. They cut my Y pipe far enough back towards the Y to get 3 inches. They welded (no clamps) the 3" pipe to the Y and the muffler input. They welded the mandrel bent tail pipe to the muffler output side and ran it out behind the rear tire. The whole set up including muffler is aluminumized (?). The owner of the shop said it will last longer then me. He said the muffler has a lifetime warranty so I really didn't need stainless. He said to bring the muffler back if anything ever went wrong with it. It is the very same setup as magnaflow #16612. They didn't have to put a single bend in anything for the install. The only bend is the mandrel bent tail pipe. The total cost including tip and labor was $240.00. I thought that was pretty fair. The sound is right on the money for me. Not loud at idle, nice cruising tone, and a real bark when jumped on. I picked up somewhere from 1.5 to 2 mpg's. The low end power still seems to be there, although I really never drive her too hard. Its just nice to know she will respond if needed...

 

I just did what you were asking about yesterday with my '05 F-150 SCREW. I'm happy with the results. They too used mandrel bent pipes. I think it should have about the same result as buying a catback.

 

Well it's good to hear that guys... looks like I might have a new exhaust set up soon.

 

Also, have any of you replaced the y-pipe with the Dual 2.5: In/ Single 3" out Magnaflow piece and used a 3' SI/SO catback set up?

I'm thinking with the money I save, I could probably do this and have the total cost still cheaper than a real Magnaflow catback!

 

There is really no reason to replace the Y pipe itself to acheive this (dual 2.5 in 3" out) unless you feel a bad urge to do it. All the installer has to do is cut the single or output side of the Y pipe back far enough towards the dual 2.5" inputs to get the required 3 inches. This is what was done to mine, it is a complete 3" SI/SO catback set up. It is just custom made and a lot cheaper then from Magnaflow.

 

But I thought the factory y-pipe was dual 2.5" in and single 2.5" out, not 3" out? Because, isn't the factory tail pipe 2.5" diameter?

Also, could you just eliminate the y-pipe section and use a 2.5" DI/3" SO Magnaflow muffler? How would this affect performance?