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Question for 11H or MuffMan...

G

GTKillerBee

GUEST
..Read both of your posts discussing the Flowmaster & Magnaflow mufflers. I think that I am leaning towards the Flowmaster 70 series w/ 3" in & dual 2 1/4" out. My question is regarding mandrel bending vs crush bending. So far, I haven't found anyone locally who uses mandrel bending, so if I go with crush bending, do I stay at 2 1/4" outs or do I need to go up to 2 1/2" outs? Also, what about the tips? I want stainless steel, but what size should I stay with? Pls advise. Thanks!
 
The Flow 70 has enough re-directional properties (back-pressure) to probably get away with 2 1/2 if crush bends are gonna be done ... If it were me, I would do 2 1/2 and do a procold intake to get any off- idle / bottom end response back that you "may" lose ... Besides going with 2 1/2 leaves you a little more outlet so if you decide to do a little bit more breathing / computer mods later you are bigger rather than smaller ... Although if you plan on a supercharger down the road, a Flow 70 wouldn't be my first choice ... There, I would stick with a straight shot muffler like a Magnaflow or Dynomax UltraFlo ...

If it were a Magnaflow, I would stick with the 2 1/4 pipe even with crush bends...

Now on the tips, they are not my forte, so Muffman will have to help here ...

11H
 
..thanks 11H! I've already got the pro-cold intake, so I guess I'll go with the 70 series with 2 1/2" outs. I like the dual exhaust look, which is why I'm asking what would be best. If you have any other thoughts, let me know. thanks again!
 
GT Killerbee,

Do NOT use 2 ? inch tailpipes with the Flowmaster. As I have said before, scavenging has always been the hallmark of Flowmaster's design. Remember, Flowmaster uses the pressure and sound energy released from an engine's combustion chamber into the exhaust system to create a low-pressure area between exhaust pulses. This design uses this energy to scavenge, or pull spent gases out of each cylinder more efficiently than even an open pipe system. What tailpipe size in your opinion would "pull" or "scavenge" better? Obviously the answer is smaller pipe. That is why I recommend the dual 2 1/4 inch tailpipes such as I use on my AV.

Further, remember, even if you use a 5-inch radius die to compression bend your tailpipes, very little actual linear distance is ?compressed? over the length of a 7-foot tail pipe.
 
I posted this in another thread, but I think here may be better since the original poster was talking about out pipes...

If I do a direct replacement of muffler only (probably a Flowmaster 40 delta or a 50 series) should I leave the factory Y behind the muffler?

Thanks,
Rich
 
muffman said:
GT Killerbee,

Do NOT use 2 ? inch tailpipes with the Flowmaster. As I have said before, scavenging has always been the hallmark of Flowmaster's design. Remember, Flowmaster uses the pressure and sound energy released from an engine's combustion chamber into the exhaust system to create a low-pressure area between exhaust pulses. This design uses this energy to scavenge, or pull spent gases out of each cylinder more efficiently than even an open pipe system. What tailpipe size in your opinion would "pull" or "scavenge" better? Obviously the answer is smaller pipe. That is why I recommend the dual 2 1/4 inch tailpipes such as I use on my AV.

Further, remember, even if you use a 5-inch radius die to compression bend your tailpipes, very little actual linear distance is ?compressed? over the length of a 7-foot tail pipe.
Click to expand...

muff,,,

Do the Flowmasters show the same 'alleged' scavenging in the 3" single mufflers ?

11H
 
RichUF said:
I posted this in another thread, but I think here may be better since the original poster was talking about out pipes...

If I do a direct replacement of muffler only (probably a Flowmaster 40 delta or a 50 series) should I leave the factory Y behind the muffler?

Thanks,
Rich
Click to expand...

mine Y is left in....suppose to help reduce resonance....hell I did not care....and well it fit up well to the FM that way....

HTH
 
I'm going to try the 50 delta, single, leaving all other stock pipe alone. I'll let you know how it goes.
 
YGMN,

Your right about the stock "Y" reducing resonance with the stock muffler. With an aftermarket performance muffler, doesn't help, doesn't hurt.

RichUF, you'll be sorrrrrrrrrrrrry with that 50 series. Unless you are real young, don't like to hear your stereo, don't have a wife (she will be all over you if you do, something about women and resonance, must be the way they are built, lol), and love droning and resonance in your ears at around 50mph to 60 mph.

Flowmaster not only recommends the big block 70 series, but with a resonator (although I do not recommend the resonator)!
 
I didn't get much help from Flowmaster on the phone, except that they recommend either the 50 or the 70. They did say stay away from the 40, and not because I said I was worried about noise, but because they just don't recommend this muffler for the Av. Then on top of that, I get everyone with 40's around here (single AND dual) praising them. I realize it is extremely subjective, but If I'm not going to hear it, I may as well not change it what with the limited amount of performance gain anyway.

Warning duly noted and appreciated, though. If I hate it, I'll change it to the 70 I guess :cautious:
 
Why is the 40 not recommended? curious?

And I guess resonance is subjective.....as no one has ever complained about my truck who has ridden in it....most say "cool" hehehehe

I guess I am deaf at those frequencies hehehe
 
The gentleman I spoke with wasn't being very technical with me, but he said the 40 is chambered differently than the 50 and 70. He *seemed* to be alluding to backpressure, but he did not say that specifically. That combined with me being a little nervous about the 40 delta was enough for me, so I didn't ask for further details.

Anyone else care to call them at (800) 544-4761 and see what they say about application for the Av and if they care to elaborate?

P.S. I'm leaving the Y in place on the off chance that I want to cut it off later and run "faux" duals.

 
Muff,
If I weere to add a Magne Charger Radix Supercharger to my mix, would the stock muffler work well, or would I need to upgrade?
Which Muffler setup would you recommend with the Radix system.
This is hypothetically speaking right now, since it's out of my budget.
But I want to know for the future.
Thanks

Rob
 
Rich,

I don't need to call tech support for Flowmaster, I'm a Flowmaster dealer, I've talked to them hundreds of times, I've talked to the engineers and designers, hell, I've talked to Ray Flugger. I own and have operated 6 custom exhaust shops for the past 25 years. I'm not guessing about the advice I'm giving you.

The muffer recommended by the engineers for the AV, 2002, 2003, 2004, 5.3L is the 70 series big block, with resonator. This is the muffler that comes in their kits as well (exept for American Thunder, loud 30 series). Although, as I have said before, the resonator is not needed.

Like ygmn said, resonance is subjective, heck I have had people with Caddy's who want duals with 40 series! However, ygmn lives on a balcony on bourbon street, go figure.....lol.

I can tell you from experience, that women tend to complain more about resonance, so if you have a wife, error on the side of caution. I can't count the number of times we warned people with their new $40K+ SUV/trucks about resonance, but they want noise, and the next day they are back, wife in tow giving us the hard scowl, leading their husbands (insert YOU here) around by their collective noses. If you drive 70 mph all the time, you'll be fine, the resonance significantly reduces at that speed, but that isn't very practical is it.
 
whoa...

My post was in response to YGMN's question about Flowmaster's recommendation for the Av. I wasn't suggesting that your recommendation was wrong, just that the recommendation that I got from Flowmaster didn't coincide with what you offered. I was inviting anyone who may be frustrated with this issue to call FM and see what info they could get.

But now that we are on the subject, here's my rant for Flowmaster...it would be helpful that if the 70 series is indeed Flowmaster's sole recommendation for the Av then:

1) They should put it on their website. Right now there is nothing specified for the '02 or '03 Av, or the Suburban for that matter. It would probably help if their search drop down spelled Avalanche properly, but who knows why nothing is listed :rolleyes:

2) they should state such when called and asked that very question after one can't find such information on their website.

Please know that I really do appreciate your advice. One thing I'm not clear on, though: do they recommend ONLY the 70 series for the AV strictly because of the noise issue? Seems silly if that's the case as they go to great lengths on their website to compare the difference in volume both inside and out. If they only recommend the 70 series for a performance reason, then let me know.

Thanks
 
I'm a bit picky on sound (both inside and out) and I know it's subjective but I went with the Flowmaster Delta Flow 50 series 1 in 2 out w/2.25" pipes and I love the sound.
I put the stock filter and intake back on and noise level was minimized to almost nothing. IMHO the after market intake added more noise level than my 50 series does, although I will agree I do get some interior resonance.
 
Rich,

I wasn't jumping down your throat, sorry it felt that way. I just couldn?t understand why you want people to continue to call Flowmaster, when I clearly told you what the application data was.

Look, starting this year, Flowmaster doesn't even have a muffler "by application" section in their own company catalog for dealers. Why do you ask? Because of the myriad of application scenarios, it is no longer a slam-dunk application wise, and they have made many mistakes in the past 3 years that has cost us, the dealers money. That in conjunction with the dreaded "drone" and "resonation" problems that are only worsening for trucks and SUV?s, Flowmaster doesn't want to be "culpable" anymore.

Additionally, you have to remember that Flowmaster is a business. Is it likely that you will spend over a hundred bucks for a 70 series, or under a hundred for a 40 or 50 series? They want the sale, period, especially with the advent of so many other decent performance muffler companies. Or better yet, buy the damn Force II kit, that?s what they really want.

As far as giving the retail customer more information on their website? Companies like mine have been lobbying Flowmaster to quit putting more info on their site, so the customer if forced to come to their dealers, us, to get product and information. We (dealers) have been threatening Flowmaster for years to quit dumping their product on the Internet at prices near that of cost for their own dealers.

Many Flowmaster Dealers have left Flowmaster, in favor of Magnaflow for example because of Magnaflows awareness of this problem. Companies like Magnaflow are instituting MAP's (Minimum Advertised Price)

A quote from Brian Van Dyke at Magnaflow:

"Casey, we are in the middle of instituting a MAP (Minimum Advertised Price) policy which will take effect December 1. It is in response to this type of on-line pricing. We are seeing this pop up ever more frequently, and we are taking steps to control it. The MAP program will be a policy requiring the product to be advertised at a certain price, and strict penalties for going below it."

Sorry about the rant, a little off topic, but related, anyway, if you want to know the "recommended" muffler for any application, call tech support, and ask what muffler is used in the Force II kit for a given application. It's that easy.

As far as number "2", look, the 1-800 number was originally created for "dealer installers", not for every Tom, Dick and Harry to call and clog up the system, I'm sorry but that is the hard facts. I don't think the "non dealer" is a big priority for Flowmaster, hence the service you receive.

And yes, they primarily recommend the 70 series to combat resonance, but look, as far as volumetric displacement, it's an awesome muffler, originally designed for big blocks. Further, a little additional backpressure doesn't affect the "scavenging" characteristics the Flowmaster. Remember, backpressure relief isn't the panacea, there are other factors involved, and if backpressure was the only issue, we would all have straight through performance mufflers such as Magnaflow, Xlerator, Borla, Ultraflow, etc.

Cheers >:D

 
Thanks for the info muffman!

So, is the 50 delta a poor choice for the Av for any other reason than noise?

P.S. Don't forget about Prince_FuFu's question...I didn't mean to bury it...sorry
 
Rich,

I believe the 70 series also has better volumetric efficiency. The large case is for macimum volume and efficiency. Flowmaster recommends the 70 series (if price isn't a problem) for all of the following:

The 70 Big Block series:

-Newer Trucks
-Tow vehicles & RV's
-Trucks with Dual exhaust

The 50 Delta Flow series:

-Street and Strip
-Same Performance as 40 series
-vehicles with/without catalytic converters

The 50 series SUV:

-Large displacement street cars
-sport utility & truck applications
-early era muscle cars

The 40 series Delta Flow:

-Those wanting the original Flowmaster tone
-Those wanting a powerfull aggressive tone
-vehicles with/without catalytic converters

The 40 series:

-Those wanting the original Flowmaster tone
-off road & race applications
-noticeable interior resonace

Some of that is pretty vague, and there are duplications, but that is intentional on Flowmaster's part.
 
Muff,,

Did you see my question above ? ... I was wondering; if the scavenging effect of the Flowmasters you mention (as in the 70 series) is so forthcoming in the 5.3, then how come they don't produce gains on the dyno ?

I have seen them installed in single, and dual setups, and the shop I dyno at installs 2 1/4" tail on the dual outlets, and full 3" on the singles ... Then a trip 15 feet to the dyno after a pcm reset nets the same or maybe 2 or 3 over stock!?

Now how is the scavenging making power? ... (result: Customer gets pissed that he just wasted a $110 on flow 70, buys a Magnaflow 3" for $80 and makes 10 or more max -- usually 12-14 and in over 70% of the power curve, he's making more than half that... I mean a Magna 12579 is making power from 2000 rpm on up... The flow 70 if it makes anything makes a tad on bottom and maybe a bit on top) ... I can show you sheets ... And this shop isn't a Magnaflow or Flowmaster dealer... They carry bulk custom welded stuff for some serious setups ... I think a guy in KY is making their custom mufflers... I will say there's a big pile of flowmasters in the corner ... off single Y'ed new trucks >:D

Now I like flows, but only in mid-mount true dual applications and only in high VE motors in the 40 series ... Now there I believe in the scavenging they tout, but in a near rear mounted muffler, with our oem exhaust systems, I don't buy it that a flow 70 is scavenging; not with the small deflector they use and not that far back ... If it is, it's not enough to be beneficial in RWHP ... (I had a flow 70 on my av... I had the Dynomax UltraFlo first, then the flow 70, then the Magna 12579) ... The flow 70 didn't make any more than stock ... I believe it was the 53071 (offset inlet 3"/center outlet 3") ...

Not arguing, but I know you love this muffler, and push it big time; I just want to know why it's not making power ... This shop has used 2 1/4" pipe on all 5.3's and dual outlets since folks have claimed of loss of some response on bottom ... (The dyno says no loss, so it must be response)

Help me understand the scavenging benefit of a flow 70 on a 5.3 ...

Food for thought: I have a buddy with a 12 second Mustang (stroked cammed 302) and he's had every muffler, cat back, and custom setup on there in the 3 years he's had the car ... He had dual flows in that time ... He works for Lopers here ... The most power he ever made in max and under the curve was with Dynomax Bullets, the next was magnaflows ... The flowmasters were average with the rest ... Now I would think the scavenging theory would have put the flows ahead right ? ... (The first flow kit he had was the packaged force kit they engineered, and then he played with pipe size, different flow types, as he loves the flow sound on the mustang... He and others on fuel injected cars have come to think that through dyno pulls, and track times, that the flowmaster scavenging trademark is not what it is cracked up to be ...)

11H

 
Based on the reaction I got to my "dumb" questions earlier in this thread, this could get ugly now with all of this technical stuff.

I just wanted to post, FWIW, that I am looking for a bigger sound. Against the advice that I got here, I ordered a FM 50 delta. I will try it for a week and will absolutely and humbly admit here if I don't like it and give you ample opportunity to say "I told you so."

This quest is frustrating with all of the opinions flying around. I was contemplating the Magnaflow until I read about the rusting issue, and I don't need that. I know I like the FM sound, so I'm giving it a go.

Thanks for the help,
Rich :)

P.S. "you" is not specifically directed towards anyone in particular. It is for anyone who has provided information. I do appreciate all of the info and help.
 
There is always the option of getting the stainless Magnaflow.
 
11h,

Are you ADHD? LOL! We have discussed this over and over already :E:! Number one, I never stated that the Flowmaster 70 Series system I recommended developed the most rear wheel horsepower on the 5.3L AV.

Number two, my 5.3L 2003 AV following the installation of the Flowmaster system I have spoke of, showed a RW HP increase of 7.1 HP when compared to the baseline test taken 2 weeks after I purchased the AV. Not that it makes a difference, see number 1.

Number three, the system, and configuration I suggested is for on ?real world? driving, not racing on the track. As I have said before, this isn?t a Flowmaster love fest (you seem to believe I am overly enamored with Flowmaster, FYI in my six stores we sell twice as many Magnaflows as we do Flowmasters). I simply believe it is a very good choice for the 5.3L considering ALL things.

Number four, in your ?food for thought? you give a comparison of a friend with a 12 second Mustang? How does that balance against a system used in the ?real world? driving of an AV? I don?t know about you, but I spend most of the time accelerating from zero to maybe forty miles per hour, the rest of the time I?m cruising at maybe fifty-five, to sixty five on the freeway! The AV is not, and never will be a racecar.

Number five, if straight through mufflers such as Magnaflow, Borla, Xlerator, etc. are the panacea, everybody would use them. Our most common Magnaflow complaint on the Chevy 5.3L, 6.0L, and 8.1L is Drone, noise, popping but most noticeably, drop in bottom end power. Now I don?t know about you, but driving around a BIG, HEAVY, AV, I think bottom end power is pretty important in ?real world? driving.

My AV has plenty of power with just a set of JBA?s, the Flowmaster system I have mentioned, the Volant air intake kit, and the SuperChips programmer. I believe mine sounds better at ALL speeds and RPM?s (and I have heard plenty), and has a smooth power band with a GAIN in bottom end power, not a loss. But that is just my opinion.

Again, if your goal is simply to generate the most horsepower possible (even though it is only a slight increase), and you don?t care about drivability, or sound, or ?real world? use of your AV, use a straight through muffler. I think I can get some testimonials from many members of this forum who have come to one of my shops and had the system I recommended installed. NW_Nick for example had his Magnaflow system with one three inch tailpipe removed due to resonation and is very happy with the 70 series Flowmaster system I suggested. But I?m sure his main motive though isn?t to get the best ? mile time.

Right now I?m experimenting (not watching others do it, >:D) with both the SpeedRex (made in Israel) and the new Imco Performance mufflers. The early results are good, and these two might also be good options DTR. The Imco Performance muffler is very promising, and very affordable, AND 409 stainless! I just got back from their factory in Texas, and was able to see flow benching, and in ground dynoing of all the popular performance mufflers. It was quite interesting.

Well to each his own. But me, if I?m going to need brain surgery, I?m going to the surgeon, not the guy that ?saw it done?. LOL

Cheers ;D









 
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