Flowmaster Mufflers on Turbocharged Engines.....

GEMELLI

The Best of Both Worlds
Re: Flowmaster Mufflers on Turbocharged Engines.....

Dang! Even I'm starting to be convinced. I'm at least as much concerned about sound as performance, so I'm off to look for a thread with high quality audio of different exhaust systems.
 

hatrik8

Donating Member

dgoodhue

BuSTeD 4.3
Re: Flowmaster Mufflers on Turbocharged Engines.....

it does, thats what was happening on wifes truck at WOT you could watch the boost fluctuate

10-15-10-15

My stock turbo trucks went from mid 12's to 15psi for boost control. I changed the stock dynomax's to Borla on my Syclone and to ATR on my Typhoon neither helped my boost control. Do you have a cat? I put on on a high flow cat on my Syclone and it cause my boost to be flat but that is because it was slightly out of control; with the wastegate solenoid unplugged it crept up to 16psi in 3rd gear. (My boost should have been only 8-9psi like that).
 

warmpancakes

New member
Re: Flowmaster Mufflers on Turbocharged Engines.....

My stock turbo trucks went from mid 12's to 15psi for boost control. I changed the stock dynomax's to Borla on my Syclone and to ATR on my Typhoon neither helped my boost control. Do you have a cat? I put on on a high flow cat on my Syclone and it cause my boost to be flat but that is because it was slightly out of control; with the wastegate solenoid unplugged it crept up to 16psi in 3rd gear. (My boost should have been only 8-9psi like that).

had a gutted cat the boost would flucuate I could watch on autometer on pillar, swapped to test pipe from flowmaster and it 95% went away
 

Aeroking

e.i.
Re: Flowmaster Mufflers on Turbocharged Engines.....

the ideal exhaust system for a turbo engine is straight pipe no obstructions. A Magnaflow (perforated tube) gives you that design, with minmal flow obstruction. So why would anyone want a muffler with chambers, and diverters and baffles. All that does is create air turbulence, hurting flow and pressure.

Look at the mufflers, and make a common sense decision... which would flow better?

Flowmaster-Cutaway.jpg


OR

42713d1179452909-questions-buying-magnaflow-muffler-img_1123.jpg


It sucks for you guys in California with all the smog regulations. Sadly, your trucks will always be slower, lol :lol:
 

warmpancakes

New member
Re: Flowmaster Mufflers on Turbocharged Engines.....

t

42713d1179452909-questions-buying-magnaflow-muffler-img_1123.jpg


It sucks for you guys in California with all the smog regulations. Sadly, your trucks will always be slower, lol :lol:


whats on your truck, anybody who wants a badass sounding truck needs to know
 

Aeroking

e.i.
Re: Flowmaster Mufflers on Turbocharged Engines.....

whats on your truck, anybody who wants a badass sounding truck needs to know

open turbo, don't even fuss with a downpipe.

actually, i'm running 2 magnaflows in series. Different size/style cases on each muffler.
 

GEMELLI

The Best of Both Worlds
Re: Flowmaster Mufflers on Turbocharged Engines.....

I'm still very interested in this topic, mostly because I love the sound of a 40 series Flow. I know there is lots of "info" about how FMs just don't flow as much as a straight through design, but why? We all know what a good head porting job does for power, but those bigger ports become less effective vs. stock ports when a compressor is pushing air through them. Why isn't the same true for exhaust? As the back pressure in the exhaust system increases, doesn't the muffler exit velocity increase, thus providing a bit of a scavenging effect? It works at the end of a header. Maybe I'm over thinking or under thinking or missing something, but like I said, I'm still interested in this topic.
 

chelo

filthy sy
Re: Flowmaster Mufflers on Turbocharged Engines.....

When my original mufflers were damaged I ended up changing to dynomax. I kept the original design, but at the same time changed my catalytic convertor. I spent some extra money on a high flow and boost spike was not much of a concern. Do keep in mind I was at or about 15lbs. I cant recall why the exhaust guy did not sell me the flow masters but he knew that my truck was turbo and he does some high performance cars.
I currently have an rpm 3" exhaust system with the straight through muffler. I love the quality and polished look. It sounds amazing when you open it up but I would rather have a more mellow tone for daily driving. Not much data from me.
As for the smog regulations. My truck passes extremely clean. If I can find the printout I'll post it up.
 

Don W.

Stab it and steer it
Re: Flowmaster Mufflers on Turbocharged Engines.....

Interesting post from another forum. Is it really the case that no back-pressure is best for a turbo motor?? Or is it that the curve has shifted back and you still want to find the right configuration for your setup.

http://www.thirdgen.org/techboard/exhaust/338421-more-than-you-ever.html

Being the sometimes picky little twit that I am :rotf: There's an error in his HP/ torque graphs. torque and HP match at 5252 RPM, his apparently arbitrary graphs don't.

IMHO his info would apply AHEAD of the turbo, not after. I doubt there are many "pulses" after the turbo. If we had the correct turbo to go with the split manifold we'd have a "pulsed" turbo. Cummins diesels did this years ago when they switched from a log type manifold to a so-called pulse manifold which was kinda like a header.

Interesting side note. from the site:

"This means that your INTAKE and EXHAUST pipes are TUNED for ONE specific RPM."

Well not always true. One example would be the old Can Am cars (Gotta be old, it's about when the "Rat" motor was first seen). Anyway those motors had a very "peaky" HP/torque curve. The cure, at least part of it, was to give the intake stacks two different lengths. IE 1/2 the cyls would peak at a slightly different RPM then the other half hence flattening the curves a bit.

How's that for trivia??
 
Re: Flowmaster Mufflers on Turbocharged Engines.....

A magnaflow XL muffler sounds very very similar to a chokemaster and flows considerably more. The XL is a straight through design just like the other MF mufflers but has a chambered sound, it is also 316/304 SS (can't remember which one) so it won't rust like a 409 SS or steely flowmaster.
 

alwayscode390

pppssssshhhhhtttttttttttt
Re: Flowmaster Mufflers on Turbocharged Engines.....

it does, thats what was happening on wifes truck at WOT you could watch the boost fluctuate

10-15-10-15

This same thing happened to me when I was running a Flowmaster.

I have a Flowmaster sound clip if someone wants to hear it ... I loved the way it sounded at idle ... not so much at WOT ---
 

Damian

Member
Re: Flowmaster Mufflers on Turbocharged Engines.....

My GT37 with a .89AR exhaust wheel hits 18psi by 3000rpm with a 2400rpm stall no problem. With a boosted motor, you want the most free flowing muffler you can get to achieve full boost as soon as possible. Many of the Evo guys run straight through mufflers to achieve this. I used the same Dynomax muffler on my turbo Eclipse with great success. Many mufflers even post a cfm rating to their mufflers as well. To me, a straight through muffler has minimal restrictions as compared to a chambered muffler that has all the baffles and what not in them.

I'm probably gonna put a 40 series on my Durango, but I'd never put one on a turboed motor like my Typhoon.
 
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