Hi Mike,

I just ordered the Xcal2 from you 2 days ago and had a couple of questions.
Right now I have a 50 series 3 chamber flowmaster cat-back 3" in 2.5" out. Im getting your tunes for 87 tow-safe, 93 tow-safe, and 93 max-perf. Would it be worth it to switch out to a magnaflow muffler in terms of performance gains over flowmaster? And if so is it going to matter as to what kind of programming you give me? Cause I filled out in your paper work that I had a flowmaster. Other than that exhaust the only other aftermarket performance part I have is the Airaid JR kit.

Would you know which magnaflow muffler I should order to sound as loud or maybe a little louder than the flowmaster 50 series?
I had a magnaflow 5x8x24 and it was way too quiet and the guy at the muffler shop talked me into the flowmaster, but would a 5x8x18 be much louder than my previous one?

If anyone else has any experience between flowmaster 50 sound and magnaflow 5x8x18 how do they compare outside the truck? I want something that sounds like a V-8

Truck is a 2004 Fx4 with 5.4L

Thanks for any info

 

Hi Trriton 2,

Exhaust is really outside of the realm of this section of the boards, so you really need to give us a call to go over this in proper detail.

Though it's not an absolute must, yes, we do recommend getting rid of the "Slowmaster" muffler and replacing it with an appropriate Magnaflow unit - that will help to improve torque. Now exactly which muffler you use will depend on what kind of sound characteristics you want, so that's why you need to call, so we can go over all of that with you. It's not just length alone, for example.

What that Flowmaster setup is doing is actually *reducing* torque on part throttle at any rpm, and reducing torque below about 3000 rpm a at any throttle position - and that is due to all those silly baffles & chambers they use as part of their "sound engineering" - all they are is impediments to airflow, and slow down exhaust gas velocity, which is why you don't see much in the way of HP gains form them, and actually lose torque, especially in the lower rpm ranges. When it comes to torque, exhaust gas *velocity* is absolutely key.

No, we will not need to change what we do in the tuning if you change to a different cat-back exhaust system or just do a muffler change like that - that will be fine.

Just give us a call to go over all the details & we'll help you get this taken care of.

 

so is no muffler better?

 

No a better flowing muffler is better

 

so i would gain hp if i put my magnaflow on.. i have nothing now

 

If I understand the question correctly, yes - putting a Magnaflow muffler on a stock exhaust will get you some power gains - it won't be as much as the cat-back system, but doing a swap our for your stock muffler with the Magnaflow unit will still help, that is true.

 

no i meant i have straight pipes(no muffler just pipe) with y duals.. so if i put my magnaflow(used to have but took off) will i get more hp?

 

OK on this exhaust velocity issue...
Would dual 2.25" or 2.5" piping be better for torque (NA)?
I'm guessing this would have more of an effect on the system as a whole than the muffler(s)...

 

i ran 2.25" true duals over 2.5" for maximum tq- my van is ~8500 lbs- my tq peaks ~300 rear wheel ft lbs @ 2500 rpms and stays to that nujmber til 4300 rpms and drops to 270 then nosedives-phil




"

 

Thanks for explaining how low end is effected Mike.

 

For FX4 - Ahh, now I understand. So you have straight true dual pipes, as I understand it. Yes, you actually *can* improve on that, but this needs to be done with 1 of 2 very specific mufflers to get proper results, and that *would*( get you an increase in power - there is also one other option if you wanted to sped a bit more, but all of this if really outside the realm of this section and gets into more detail that I can type out here - so what I suggest if for you give us a call so I can to go over this with you properly, explain the options, how to do it, along with your pricing, etc., OK?

For Silverfish, Melovidov21, etc - first, that explanation appears to be from an older post, but is still correct, & you're very welcome, I hope it helped.

With regard to doing 2.25" diameter versus 2.5" diameter for a true dual setup, it's a matter of how much power you are making, and the rpm range of the engine, etc - for most of these trucks with light mods, going 2.25" diameter is better, as you will keep the exhaust gas velocity up higher, and thus get better part-throttle torque without losing peak HP. But again, it's a matter of how much power we are talking about & at what rpm range before we start running into limitations.

If anyone needs specific advice on their setup, just give us a call and we can go over that with you so you will get the best results, OK?