Magna Flow Exhaust

[dsalinas]

I would really like to see a comparison of what kind of gains a 3" diameter exhaust system, has over a 2.5" exhaust system, on a Jeep HEMI, in regards to power and torque across the power-band. Anybody that has performed this type of testing? ACTUAL measurements?

[Kolak]

I would love to sponsor a test like that. However, the stock exhaust would be a better baseline as it's 2.75". I sold a Gibson 3" just last week. I will ask my customer if he has a dyno facility nearby. I'd like to get before and after tests and would be happy to pay for the dyno runs.

Originally Posted by dsalinas

I would really like to see a comparison of what kind of gains a 3" diameter exhaust system, has over a 2.5" exhaust system, on a Jeep HEMI, in regards to power and torque across the power-band. Anybody that has performed this type of testing? ACTUAL measurements?

[555ctsv]

I've never been a believer in catback systems. On the cts-v guys would pay up to $1,100 for cat back systems that were the same diameter pipes and new mufflers. I've also seen this on F150's and now the Jeeps. I would think just plain common sense would explain how a bigger pipe flows more air. Now if magnaflow has decided the engine actually needs more back pressure for better performance then the 2.5" could make sense, although that seems unlikely. I cant imagine a 5.7L v8 with a single (not dual) exhaust system needing more back pressure, but i really dont know. As much as i would love to think Magnaflow has my engines performance as top priority over making money, i doubt thats the case. In reality i bet they just dont have 2.75" pipe in stock and had to decide which pipe they have in stock that matches up with their standard diameter mufflers without any modifications. Also im pretty sure that the wk hemi systems represent only a small percentage of magnaflows sales, so prob not worth the time and cost to come up with something optimal that doesnt use their standard materials.

[vtxkc]

I was looking at Magnaflows website and didn't see a muffler with a 2.75" inlet. What muffler are you using? What about the resonator tip, is it stainless?

[Kolak]

You are extrmely insightful and you hit the nail right on the head - The factory exhaust is a metric size that's just about 2.75" and it is simpler and far less costly for them to use diameters they already have rather than think ouside the box.

Originally Posted by 555ctsv

I've never been a believer in catback systems. On the cts-v guys would pay up to $1,100 for cat back systems that were the same diameter pipes and new mufflers. I've also seen this on F150's and now the Jeeps. I would think just plan common sense would explain how a bigger pipe flows more air. Now if magnaflow has decided the engine actually needs more back pressure for better performance then the 2.5" could make sense, although that seems unlikely. I cant imagine a 5.7L v8 with a single (not dual) exhaust system needing more back pressure, but i really dont know. As much as i would love to think Magnaflow has my engines performance as top priority over making money, i doubt thats the case. In reality i bet they just dont have 2.75" pipe in stock and had to decide which pipe they have in stock that matches up with their standard diameter mufflers without any modifications. Also im pretty sure that the wk hemi systems represent only a small percentage of magnaflows sales, so prob not worth the time and cost to come up with something optimal that doesnt use their standard materials.

[Kolak]

What you do is to use a 3" Magnaflow muffler. The muffler shop just expands the stock tubing ever so slightly to match up with it.

The resonated tip is polished stainless, though on the HEMI you can just keep the stock resonator to save even more money.

Originally Posted by vtxkc

I was looking at Magnaflows website and didn't see a muffler with a 2.75" inlet. What muffler are you using? What about the resonator tip, is it stainless?

[555ctsv]

Originally Posted by Kolak

You are extrmely insightful and you hit the nail right on the head - The factory exhaust is a metric size that's just about 2.75" and it is simpler and far less costly for them to use diameters they already have rather than think ouside the box.

Thanks!

My Magnaflow just arrived at my office a few mins ago! Planning to take it to the performance shop tomorrow and hopefully see my assembled engine while im there! If nothing else the block better at least be there by then! For those who didnt read earlier, i am using a stock SRT8 catback to put this on, so yes i know it's a 3" dual in dual out

[dsalinas]

What a beautiful instrument of tone and performance

[vtxkc]

Well I got the Magnaflow Catback installed last night. This system is exactly what I was looking for. The sound is amazing. Not too loud and not too quiet, just a deep throaty V8 sound. Thanks for everyone's insight. I'm very happy with this system.

[N4x4M]

Originally Posted by Kolak

I've been designing Jeep exhausts for over 15 years. I certainly would not recommend a "hodgepodge" to anyone. If you search this forum, NAGCA, JeepsUnlimited, Google, and Youtube, you'll see there are thousands of Jeepers running my exhausts.

The aim of my post was to enlighten others as to the possibility of saving a lot of money as compared to a prepackaged catback.

The very same muffler that is used in the Magnaflow catback is just $110.00. Install that with your stock 2.75" exhaust and you will have a system that outflows the Magnaflow prepackaged catback. And it will sound the same because it's the same muffler.

An aftermarket resonated tip will kill any drone, or keep the stock resonator.


If you want optimal performance, Gibson makes a full 3" catback for the HEMI.

Again, just trying to save folks money. You won't be unhappy with your purchase but there are lots of people reading this thread who could benefit byt the potential savings of alternate approaches.

Me for one.......thanks for the heads up Kolak

[meep]

2.5, 2.75, 3.0"....

Keep in mind that these kits are designed as a package-- they are optimized together. Yes, a 3" flows more than a 2.5", but when combined with that particular muffler it may detract from feel and/or sound-- the whole experience.

The stock system in my 3.7 is much more open than any other vehicle I've ever owned. I'm sure much of this is to shoot for optimized comfort and mpg. good mpg also equates to good flow. Just how much will a bolt-on kit improve? I'd love to know-- please share your results! My guess is there will be some improvement but %-wise less than doing the same to a ZJ with that itty bitty pipe.

A good friend of mine was a trans tech for years and still does frame-up builds for fun. His got a LT1 powered S10 that's been on a few front covers. He swears by the magnaflow kits. Says you can try to piece together odd parts but that the kits are all designed by math then tuned by hand before going into production. You get a blend of performance (real and perceived) as well as tone.

Me-- I've never done it... just sharing what I have seen, heard, etc.

M

[jason915]

I just took my jeep back to the shop and had them take my magnaflow off it was too loud! Too much bass at cruise, now it has a superturbo much better.

[N4x4M]

Originally Posted by jason915

I just took my jeep back to the shop and had them take my magnaflow off it was too loud! Too much bass at cruise, now it has a superturbo much better.

Spending the money and then not beoing happy with the results because there is too much noise being transmitted to the cabin. So you are happy with your superturbo? Do you know the part # by chance?

[jason915]

Originally Posted by N4x4M

Spending the money and then not beoing happy with the results because there is too much noise being transmitted to the cabin. So you are happy with your superturbo? Do you know the part # by chance?

not sure of the part number but I am happy with the sound. It has a nice note at idle and it sounds good at WOT and cruise. The magnaflow was just too loud, it sounded mean but it had a bad bass drone at cruise.

[555ctsv]

I went to the Dynomax Website. The only have one model of superturbo with a Center in/Center out. It's 3" in and out. Assuming you did Center/Center this must be it