MagnaFlow XL Turbo mufflers.

[markup97]

I have been doing quite a bit of research here on exhaust and who like what/for what reason. Seems the MagnaFlow brand is the logical choice to go with for these cars, so that is what I will do. Now, for my questions:


1) I see quite a few of you use the MagnaFlow 2in/2out 'X' (pn;14568) in place of the 3rd cat. I plan to run mid-length headers with integrated high-flow cats (3" in and necked down to 2.5" on the outflow side) in the collector area. The 2.5" out would line up nice with the 2.5" in of the 'X'. Would this provide a good flow and be able to support future engine mods?

2) With the above set-up, would running 2.5" duals back to MagnaFlow 'XL Turbos' provide ample flow for future mods?

3) Does anybody have any experience with using the 'XL Turbo' series mufflers on these cars (or others) and what was/is your opinion on sound quality?




Future engine mods include either:

1) A 5.0L or 5.2L stroke-job with Comp Cams XE series sticks, intake work, bumped-up injector rates and safe tuning for an 11:1 compression ratio.

2) A 5.0L or 5.2L stroke-job with custom sticks, serious intake work, turbocharged over a 9:1 compression ratio (keeping the 'B' heads)

3) A 5.0L or 5.2L stroke job with Comp Cams XE sticks, custom 'B'head-to-'C'intake IMCR delete plates/adapters, GT500 blower over a 9:1 compression ratio.



As a Post Script: these engine combos may see some Nitrous and Meth/Propane injection at some point as well.

 

[markup97]

Nobody has any thoughts or experience with this stuff? Guess I will be the first and report back as to how well it works and what sound quality I perceive.

 

[driller]

I don't have the 2-in/2-out piece nor the "XL Turbo" mufflers but I do have the MagnaFlow mufflers with a single X pipe using 2-1/2" dual pipes with Cobra manifolds (no cats) on my '96. I love the exhaust tone and it will flow plenty to support major HP modifications.

 

[dnsherrill]

o.p.; there are hundreds, maybe even thousands of Mark VIII exhaust threads online. having said that, I just bought some used MF XL's and plan to replace my flowmaster 40's for a different, less-loud sound.
On my brown car i have no 3rd cat or resonator, 2.5'' duals with an unmuffled x-pipe mid body going to the mufflers (40's now, soon to be MF's). My ivory mark is stock exh...big difference

 

[markup97]

Driller, thanks for your input, as it will come in handy when I do choose the pipe size!

Dnsherrill, I have worn out YouTube buzzing through all of the MKVIII sound clips. Believe me, I did NOT ask my questions without prior investigation. That is why I asked for users opinions of the system and/or components. Overall, I am putting together a system of 'common' parts, and I wanted honest evaluations of those parts from actual users versus just some random YouTube video (as we all know video feeds do not do some systems justice while they mask other systems inferiorities). Also, for flow reasons and supporting horsepower increases I ask about tubing size and restrictive nature of the parts mentioned. I thank you for your input on what your cars are running, as it too will help me ultimately decide on future exhaust components.

 

[Ritegroove1]

Are the Cobra manifolds as good as a set of headers?
What if I eliminate all the Cats use an X and run Magnas or Borlas out back? Has any one tried this,,?
Am I just asking for tickets?
Will there be a substantial loss of backpreasure,,,bad for valves?

 

[markup97]

There has been discussion on the Cobra manifolds. It appears that you will have to modify your steering shaft no matter what you use (unless you get the $800 set of Kooks mids, and even then I believe it is advised to modify the shaft anyway). If you are going headers, NO, the Cobra manifolds are not as good. If you are just stepping up from stock, yes they are better. Eliminating the cats, running an 'X' and then just a set of rear mufflers will produce a bit of noise, as you have just the 14"-18" muffler and a 9" tailpipe to quiet it down. You may also end up with a drone at certain rpms (note I said MIGHT).

As to your final comment: this is a peeve of mine and no offense to you is meant. Backpressure has NOTHING to do with this. Exhaust scavenging and thermal velocities/reversion control has everything to do with exhaust set-up. Backpressure is an enemy in any exhaust system, where proper scavenging is your friend. Correct primary tube diameter and heat retention capabilities, coupled with proper collector taper/length/heat retention capabilities, and then proper 'X' or 'H' placement are your biggest concerns to keep both velocity and scavenging where it should be. Follow that up with correct tube diameter for the rest of the exhaust (as air velocity slows as it gets cooler) and you will have a very efficient system. Are you going to stay pretty much stock on the engine or are you going to build an NA/Boost monster? Big inch with gnarly head/cams? Compression ratios? These are all to be considered when choosing your exhaust header primary tube diameter.

As to my set-up, once installed and tuned, I will throw a video clip up so you all can critique it and offer your opinions of it. I value my fellow forum friends' thoughts (just ask JP, I bug the SNOT out of him!).

 

[chestnut101]

I don't have the 2-in/2-out piece nor the "XL Turbo" mufflers but I do have the MagnaFlow mufflers with a single X pipe using 2-1/2" dual pipes with Cobra manifolds (no cats) on my '96. I love the exhaust tone and it will flow plenty to support major HP modifications.

Driller what did you use for hpipe from the headers? Thanks ken

 

[driller]

A pair of SS "Y" pipes for cutouts and a SS single "X" piece.

 

[beerdog]

I have the cobra manifolds with an Xpipe, cat delete, steering mod, and stock muffs. Yes, you heard me....stock mufflers. Just never got around to adding better mufflers. No drone and I feel the added power. The cobra manifolds sound good in the car when you lay on it. The mufflers sound like crap from outside the car. I have a pair of LMS muffs waiting to get installed. I think the steering mod improves steering feel and is worth the doing even if you don't upgrade the exhaust.

 

[markup97]

The steering shaft mod will be done no matter whether I go serious aftermarket exhaust or not. That is just one area I can't leave be!

As to exhaust, I want a good flowing system that won't scream to Johnny Law "Here I am!" yet still have good flow and a nice tone (hence choosing the components I am). I will also have them thermal-coated before they are installed (as best as I can get them coated anyway) so as to retain the heat where it needs to be. All of this for a car I intended to use just for a drivetrain donor, and then switched it to daily-driver duty when I realized it was too nice to kill. What is it with car guys and not being able to leave anything motorized stock?

 

[markup97]

Looks like the car is going to sport a set of DynoMax units for a while (before the total change-over). A friend had a set of new 14" case 2.5"-in-2.5" out DynoMax with 100 miles on them for $50. Yeah I know, but I couldn't say no, especially for an intermittent units that can be used on another project later. They will go on as soon as I get back to Florida.

 

[SCTBIRD1173]

I used to run Dynomax super turbos on my '89 Notch and they sounded great. I know a modular 4.6 sounds nothing like a Windsor 5.0 but still seems like a good buy anyway.

 

[markup97]

I figured for $50 I couldn't really go too awful wrong, especially for interum units.