I was curious, as most people talk about CFM and how it should relate to exhaust..

This is what I was told..

CFM is the only way for competitors to attack Flowmaster. Flowmaster designs their mufflers to work with the exhaust pulses (since they are pulses and not a continuous flow) and actually create a low pressure area that PULLS the exhaust out of the pipe. CFM tests wont show that.. Intake CFM is where that measurement should be kept.

Companies like Spintech and Ravin have both tried ways of creating a muffler that will beat the Flowmaster but have been unsuccessful. Flowmaster has tried those designs earlier and has deemed them as not good enough. The plate design they use now has been what they find to be the best.

I also talked to him about SS (stainless steel) vs. Aluminized Steel.
I have been told that SS becomes brittle over time when exposed to heat. I have experienced this on my Porsche and on my friends SLP exhaust. He too confirmed this and stated that AS actually has some give to it that helps keep it from cracking/breaking. Flowmaster will be offering a 408 series stainless steel, but that is only because of the market. I personally will continue to use AS over SS. Looks are completly secondary to performance when it comes to my $$ being spent. I dont often find people laying under my car looking at parts.


I asked him about the single tip units and why they were not available as a kit for my LS1. He stated what I had suspected. Most people just want the look and do not care about performace. Singles outflow duals but for some reason everyone wants two pipes out the rear.

I was given the following part numbers:
For the cheapest muffler change
Setup A:
Part number - 53033-12
Size 3.0"
30 series muffler
Simply have a shop weld this muffler in place and use a single 3" out.

A little more expensive but still cheaper that most:
Setup B:
part number - 53533-12
Size 3.5"
30 series
This is the muffler that comes with a mufflex 3.5" catback.


This conversation has left me with my going roadmap of mods which are in order:

I think with the power i am making stock and these mods, I can really see 12's consistantly for a total of less than $1500.
time will tell.

Just thought I would share my findings.

 

I've heard once from a junior college auto tech teacher stainless steel expands under heat and can deform probable cause it to be brittle. Still would never put another Flowmaster muffler on another car again. I have 3-chm's on my 5.0 stang and all they do is drown horrible at 2000rpm and sound silent above that. After a drive on the freeway my ears still ring. I still want a Corsa exhaust. First reason is the sound ,which is like a roaring tiger, very exotic and second is the look and third for hp reasons. Since I hear the rearends in out cars are week your drag radials will sooner or later blow the rear. Stupid how Gm put such a weak rear in a high hp vehicle. I totally agree with no reason to add power if you can't get it to the ground. Ours cars have the power to run the high 12's stock. I only went to a track once in my stang and can see how it would become additive but then doing it a lot involves breaking parts. Your car will never be fast enough. This is one reason I haven't been back to a track and have no care to do so. I didn't buy my Z for track use but to just enjoy driving a new fast car.

 

actually, I am odd in that respect (sure in others as well)...

I am fully content with a 12 sec car. Why waste money on trying to be faster when there are plenty that are.. Why not just be content with faster than most (which is true on the street).

My goals for the LT1 were the same.. 12 Sec car without headers. Wasnt easy but it was possible. I am trying for consisitant 12's in this car and do not want to use the dremel at all..

I dont have the desire to do any other mods that what I listed mainly because there is no point to it.. Racing on the street is just for fun.. you cant be at all serious because there are too many variables such as road condidtions and whatnot.. For the $ I am spending, I would rather keep the car looking like new as long as possible.

As for the rear, I am not entirely convinced its that bad. My LT1 only broke the ring and pinion and those were Auburn aftermarket ones. Once I replaced them with Strange and there were no problems.

Drag radial may add to the forces they will have to endure but I dont think with a stock motor that it will be enough to really be that bad. If so, heck, it will be upgraded and life will go on.. again why add more power if you cant use it...

 

I always wondered about why Flowmaster never offered the single out cat back for the LS1. I bought the `96-7 Camaro single out cat back for mine, because after researching several cars I found that the Y-pipe connections are in the same place.
Which means any cat back exhaust from a dual cat LT1 will bolt up to an LS1 Y-pipe. And vise versa.

 

Good information Psycho, this is what I have been telling people all along about Flowmaster. Everyone seems to think CFM is everything...well it isn't.

 

I am really having to hope you are wrong.. I would of loved to keep my Force II!! ARGH!

 

psychocabbage;

I to have done some research on this matter, and I went to a local custom exhaust shop, and was told this basic answer:

"For F-body cars, the 2 on the left (i.e one pipe into the muffler, two pipes exiting the muffler on the same side) evacuates the exhaust gasses with far less terbulance (sp), than one pipe into the muffler, and two pipes out, one on each side (i.e. stock setup)."

I was also told that most people are concerned with "the look" instead of total performance in an exhaust system.

I am going to look into a true duel exhaust set up, with an "X" pipe. This custom shop ONLY deals in aluminized steel, and will not use stainless.

SteveC

 

Theres reasons FLowmasters arent #1 on the list of turbo cars they dont flow

Used to run a dyno here.. if you guys only seen what ive seen

 

Drag radials Why not go for Drag tires (slicks)..... I don’t know really recommend Using Drag radials on the street I had a bad experience in the rain. At 40 MPH… so I recommend switching the tires when going to the track. Besides you will get more traction with Slicks… as for the flow masters I heard blacknight talk about his 3 chambers Well if you are going to go with flowmasters go with the 2 chambers. I used them on my 5.0 GT and really liked them….. I however am 31 now and don’t do much Racing so now I just want something that sounds good and looks good.. I will stay with the Duel pipes.

 

I agree that is the best set up, I disagree with flowmeiser I mean master sorry. Yeah scavenging on headers with the right length primarys, but no muffler creates this. IMHO. I really don't see what the big deal is, the muffler with the LEAST resistance is going to flow the best. Pick one up and look at all the baffles and plates the exahust has to travel through.
"For F-body cars, the 2 on the left (i.e one pipe into the muffler, two pipes exiting the muffler on the same side)evacuates the exhaust gasses with far less terbulance (sp), than one pipe into the muffler, and two pipes out, one on each side (i.e. stock setup)."
This or a borla (no plate), or cut outs. These are the best flowing setups other than dual exhaust, and Im not talking about dual outlets, I mean DUAL exahust.
"For F-body cars, the 2 on the left (i.e one pipe into the muffler, two pipes exiting the muffler on the same side" Flowmaster also makes this along with SLP. Flowmaster's is half the size of the SLP's and WAY cheaper.

 

Great information from your contact at Flowmaster. My only concern relating to his facts lies in the comment about stainless steel becoming brittle. Did he state which of the steels do this or just "blanket" them all ? The reason I offer a comment is most "premium" calbacks are constructed of 304 ss which is far superior to any mild steel or aluminized for that matter when it comes to use in high heat, corrosion resistance and life span. Keep in mind, these systems would not come with lifetime warranties if they became brittle with use and required warranty replacement.

 

The exhaust flow on turbo cars is dfferent than that of a non turbo car...
Most likely why flowmaster doesnt work well with them.. The tech also noted that and stated that they dont recommend the muffler for turbo cars.

 

I will be switching the tires when I get to the track, but quite honestly, I dont want to deal with a tire that has a tube in it..

I would never drive on the street with drag radials as I too have heard of too many people finding a slick road... Not fun..

I figured it would give me something to do while I cool the car down... Change the tires out and if I keep the tires in the car, i can add weight! hehe
Or I will just leave them in my pit...

 

Thats where technology comes in... see what that plate (this is what the tech said) does is that I creates a low pressure zone at teh rear of the muffler.. That in a sense creates a vacuum that helps suck the exhaust out... but it is also because exhaust is a pulse not a constant flow.. so it was designed to work with that in mind..

 

Actually that is WHY they come with them!
My friends SS SLP unit broke all over.. He could of replaced it but decided that it wasnt worth it.. He got a Force II catback.. (after hearing his on a dyno, I got mine!)
My Porsche had SS exhaust but not sure what type.. Its not a blanket statement.. He (the flowmaster tech) did state that they were going to be using 408SS to create a Catback.. He did state that while testing 409SS Mufflers, they would crack under the heat. SS is simply just not as "giving" as aluminized steel.