[M&M]

Has anyone heard, or better yet, owned, both the Pypes and Flowmaster crossflow systems for the '70's f-bodies? Again, the crossflows only (single mufler behind the rear end), please.

How would you compare them? Volume? Tone?

Thanks in advance
Mack

[Z Code 400]

Mack,

I have the Flowmaster Crossflow (#42585) on my 1975 Formula. It is very quiet and has NO interior resonance AFTER I replaced the factory rubber isolators with new ones.

My only complaint is the inlet pipes, that enter the top of the muffler case, interfere with the disc brake 10-bolt that I am in the process of installing. It is for this reason and this reason only, that I am considering the Pype's system.

However, this morning I ran into a fellow who was using a Magnaflow crossflow system on a 1974 camaro and it sounded great.

That is, perhaps, another option....Robert

[M&M]

Originally Posted by Z Code 400

Mack,

I have the Flowmaster Crossflow (#42585) on my 1975 Formula. It is very quiet and has NO interior resonance AFTER I replaced the factory rubber isolators with new ones.

My only complaint is the inlet pipes, that enter the top of the muffler case, interfere with the disc brake 10-bolt that I am in the process of installing. It is for this reason and this reason only, that I am considering the Pype's system.

However, this morning I ran into a fellow who was using a Magnaflow crossflow system on a 1974 camaro and it sounded great.

That is, perhaps, another option....Robert

I too, am currently using the Flowmaster system. My problem is the inlet pipes also. When my differental moves up with the suspension, it nails the pipes feeding the muffler hard enough to slam the pipes under the car into the floorboard.

How would you compare the sound of the Flowmaster to theMagnaflow?

Thanks again
Mack

[Tom Hand]

Mack,
The Magnaflow system will be a tad louder than the Pypes; if I remember correctly, the Magnaflow has a bit shorter muffler with it, 18" maybe?

Regarding sound levels, some mufflers sound quiet to some people, others are loud, and it all depends upon the person's preference. However, I can tell you the Flowmaster and other non-packed mufflers that we tested, had the highest sound level of any of the ones we ran, 2.5" or 3.0". Seems I recall we saw over 100 dBA levels without even being under a load at around 3500 rpm on a typical 455 with the Flowmaster crossflow.

This is directly from Flowmaster:

"Deep, Aggressive Tone: The Flowmaster 80 Series Cross-Flow muffler offers a very aggressive tone that offers a deep, powerful sound. It will sound great inside or outside the vehicle and it's guaranteed to turn heads."


The crossflow from Pypes, if I recall correctly, is in the 91 to 94 dBA level at the same rpm. This is a VERY SIGNIFICANT level reduction. Bob Chumley can hop on here and read off the values if he still has them around.

The level numbers can tell you one part of the characteristics you buy mufflers for, but your ears and personal preference for sound quality and style will help you decide. Rocky has had both styles, maybe he can offer his thoughts here too.

Tom

[jwcfbd]

Here is a vid I took of my 67 running flowmaster's crossflow system with headers. It was a little loud on the highway (inside) when I had the 4 speed in it but once I switched to the 5 speed and got the revs down it is so much better.
http://www.youtube.com/watch?v=XyMRq8ne_WQ

[Z Code 400]

I heard a second generation Firebird in Fresno this weekend with the Pype's crossflow. Sounds just like glasspacks, which one would expect from a fiber-packed, straight-through muffler.

Tom mentions sound levels. The big difference between the two, in my opinion, is sound frequency and not volume. The Flowmaster has a thinner, more hollow, higher frequency sound that switches to a roar under WOT. The Pype's with the straight-through, fiber-packed crossflow has a deeper, more traditional 'galsspack' style sound that remains deeper at higher RPMS.

Honestly, they are both loud outside the car, almost equal to my ears, but the Pype's is a deeper, bassier sounding setup. I think the Pype's crossflow sounds really good and very traditional. My neighbor's 1970 Firebird has 2.50" true dual exhaust with 18" 2.50" perforated core glasspacks. It sounds identical to the fiber-packed Pype's crossflow....deep and mellow...Robert

[M&M]

My thanks to everybody for your replies and input.

Back in my running around days, (I'm showing my age here), the performance mufflers of the time were Cherry Bomb and Thrush. I can expect the Pypes Crossflow to sound like those glass packs?

Thanks again
Mack

[Z Code 400]

The Pype's Fibre-Packed, Straight-Through Crossflow will have a deeper and more mellow, yet very familiar sound....Robert

[Tom Hand]

M&M, sorry for the delay but I figured you wanted facts and not speculation and heresay. I emailed a good friend of mine that has run many crossflow mufflers and searched for the best. He stopped looking after the PYPES/Walker muffler setup. His FAST Camaro runs a 427 and Polyglas tires. Here are his words:

"I'll tell you this, I ran the flowmaster setup for a few years, in all kinds of air, and had never been 116mph...well, when I went to the Walker ("PYPES"-sold) setup, I skipped 116 and went straight to 117, and have been over 118 a few times. Anyway, I've got over 500 passes on this engine/combo, so its pretty easy to do a-b-a tests with it. On our Polyglass tires its hard to make comparisons et-wise, but the (Pypes-sold) crossflow was worth close to a tenth or so down track for me (and the couple of MPH's.. TH-added). I know, pretty big claims, but I swear by that Walker crossflow...matter of fact, another friend built his Camaro's system around that muffler several years ago, and will run nothing else."

M&M, this guy runs his a lot and has done so for many, many passes. He verified what I had said previously, this muffler and pipe setup outruns the others that are more restrictive plus you get the bonus of a lower sound level and significantly less resonance.

The one we helped PYPEs create does not sound like Flowmaster's so if you like that sound, it is not the one you want. But if you want max performance with the other benefits I mentioned, it is the best F-Body setup you can buy.

Take care,
Tom

[Z Code 400]

Originally Posted by Tom Hand

"The one we helped PYPEs create does not sound like Flowmaster's so if you like that sound, it is not the one you want. Take care, Tom

I don't buy a camshaft for the type of idle it will give me, neither do I buy a muffler based on its sound production. Ideally, I would like to have a dead-quiet exhaust system, if only I could get one to flow enough to support 450 horsepower. As long as it flows enough to support my power production levels, my BIGGEST concern is how it fits under the car. The Pype's system is pretty good in my opinion.

I don't swear alligence to any exhaust manufacturer. Dad and I used perforated (not louvered) glasspacks for years and he has been using them since the 1950's. Now everyone is praising the 'straight through' style of muffler, saying they make more HP and TQ than anything else. Hmmmm....Dad's been saying this since the 1950's....Funny, isn't it????

I have friend's running the Flowmaster Crossflow, the Magnaflow Crossflow and now, one that decided to use the Pype's Crossflow for disc brake differential clearance. All three second generation cars literally fly and all three are loud as hell @ WOT.

Pick your posion...

On a second generation Camaro/Firebird, your biggest considerations should be will this muffler clear my disc brakes??? Will the inlet pipes rub the center section if I lower the car??? How much clearance will my tailpipes have around my leaf springs???? Can I used an aluminum truss differential cover????

In every case, the Magnaflow seems to have more overall room under the car, the Pype's Crossflow is in second place and the Flowmaster will cause some suspension interference if you lower the car.

The Flowmaster WILL NOT work with rear disc brakes on a Second Generation car PERIOD. I'll send you the photos if you like to prove it.

As far as performance goes, it has been said that the Pype's Crossflow is worth a "couple of tenths and a few MPH" in 'real world' testing. Believe that and ignore the claims that this will give you '20 RWHP' and you will be OK.

The Pype's syetsm is money well spent, just don't expect it to turn a 14 second car into a 10 second car....Robert

[Tom Hand]

Well said Robert on all accounts!

[Chevy454]

Originally Posted by Z Code 400

As far as performance goes, it has been said that the Pype's Crossflow is worth a "couple of tenths and a few MPH" in 'real world' testing. Believe that and ignore the claims that this will give you '20 RWHP' and you will be OK.

The Pype's syetsm is money well spent, just don't expect it to turn a 14 second car into a 10 second car....Robert

The rule of thumb in most racing circles is 2 tenths = ~20hp...and while the Pype's system may not turn a 14 second ride into a 10 second monster, I'd bet you dollars to doughnuts that it will out perform the Flowmaster piece. Just look at the 2 muffler designs...the Pypes piece is a straight through design, with a large radius bend to get into/out of the muffler itself, while the Flowmaster has a gradual bend to get up then down into the muffler with an abrupt bend in the muffler itself, with the same gradual bend exiting...in the part of the system where velocity is oh so important (versus more of a volume/area concern further forward). From my experience, the only thing Flowmaster does better is "marketing"...

[Z Code 400]

454,

Run any computer program you want and I will send you timeslips that will trump the 'rule of thumb' philosophy. I've seen chassis changes pick up 2/10ths. How do you explain that with no more HP or TQ?????

The Pype's is a great copy of the HO Racing crossflow using 1950's glasspack technology. It's proven, it works, it has low restriction and I think it is a great system. However, there is no 'magic bullet' muffler and I doubt the exhaust change is worth 20 HP. So, to mirror what Dad has been saying since the 1950's, glasspacks are the way to go. Nothing new here.

The Flowmaster might indeed be a POS, but for a 572 CID engine to run into the 11.00's, I doubt it is that bad. I've been to the track and watched this car run enought times to know. I listen to it start up every Friday morning when my neighbor leaves for work on his 'casual days.' I've helped him uncork it only to see a minor, insignificant gain.

My point is, lots of people buying the X-pipe and 'trick' straight-through' exhaust systems and picking up NOTHING. So, how do you explain Cliff Ruggles running compression-bent tubing, a 'H'-pipe and 40 series Blowmasters and 2.50" tailpipes and running 11,50's????? Oh! That can't happen because your world is one of absolutes.

All of this is relative and what one guy might gain, the next guy will not. I've seen all the tricks, like guys swapping exhaust and then fiddling with the carb, the ignition and the chassis and then announcing, "Look!!! My exhaust have me two tenths!" When, in reality, all the changes were responsible for the gain.

How many exhaust systems do you think a post like that will sell????

I prefer twin 'rack mount' 2.50" perforated core, stainless steel glaspacks. More clearance for a differential girdle and suspension articulation that drag guys would never dream of. Has anyone asked whether or not the Pype's core is louvered against the direction of flow?????....Robert

[Z Code 400]

Originally Posted by Chevy454

"From my experience, the only thing Flowmaster does better is "marketing"..."

Hmmmmm.....Any good business will market it's product. That's what's happening in this thread!

[Tom Hand]

To answer the question posed, PYPES' crossflow uses perforated tubing. Early ones were louvered and still flowed significantly more air than the chambered crossflow.

For anyone interested, dual glasspacks instead of one large shell muffler will not be as quiet because they do not have as much total case volume.

Some generalities: mufflers respond in this way: restriction is bad for power, volume is good for sound level reduction and power, acoustic material is good to remove high frequencies, large cases minimize low frequencies, and these reasons are why the PYPES system works so well compared to previously available mufflers.

Mack, I hope this helps.
Tom




The largethey

[Tom Hand]

Mack,

Here is some more data for you. Check out my pal's 1969 Yenko Camaro.This is the one I referenced above. It is louder than the 1970 and later F-body setup due to the short side exit tail pipes.

This car used to run the Flowmaster setup but he swapped it and went from typically less than 115 mph to often-times now higher than 118. This takes 20 to 25 HP (at peak speed) to do this on a typical 3500 to 3700 pound car. The ET drop also indicates the same relative power increase. All this with stock manifolds and 2.5" pipes too. To get this from the pipe/muffler change is pretty remarkable as it is very tough to find 20 HP in this class. If you want some formulas, I will be glad to share them with you too.

Anyway Mack, with a 4.56 gear and two Camaros together, you can get a relative sound check from this video.

Tom


http://www.youtube.com/watch?v=GgzhF...eature=channel

[Z Code 400]

I agree, Tom, pretty hard to pick up that kind of power from a muffler change alone.

Answer me this question:

A few years ago, I built a 406 SBC for a deputy sheriff friend of mine. It was a 9.50:1 SCR motor with one of my 'potent' custom-ground Iskenderian solid lifter camshafts. He used full-length headers and the 'funky' Flowmaster 42585 Crossflow that has the pipes going into the top of the case. I told him I wouldn't use that muffler on my lawnmower, but he insisted.

The car was dyno'd at Roger Vogt's Performance Automotive in Visalia, California and cranked out over 450 HP @ 6000 rpm and a shade over 500 lbs/ft of TQ at 4000 rpm. This is what I would consider average power from a 400+ CID small block Chevrolet. I have made much, much more HP and TQ with SBC's, but this is decent power output.

I argued with him for over a year that he could probably make more HP and TQ if he ran dual glasspacks. I suggested we test the muffler by putting a fitting in both intermediate pipes and attach electronic pressure transducers and monitor any pressure in the system with his Snap-On Vantage Data Tester.

We drove the car, making 6000-6500 rpm upshifts and we put it back on the rollers and again verified the power output. At no time did the exhaust system go into pressure....period. After that, I quit badmouthing the funky muffler.

Now, if a 450+ HP 406 CID engine, turning 6500 rpm can't push that goofy system into pressure, where is the restriction coming from????

The Pype's system is quieter...we all agree on that. The Pype's system is straight-through, ironically, just like a 75 year old glasspack, but with more case volume for better sound dissapation....again, we agree on this point too. However, I find it slightly suspect that going from a 2.50" mandrel bent system to another 2.50" mandrel bent system, essentially, ONLY changing the muffler, would net a 20 HP gain, with no other changes.

In 25 years of working with cars, I have learned that cars, nothing is impossible. I have witnessed two people, building two identical engines, to the exact same formula and not experience similar results. We have put full-tube headers on 425 Horse 440 Chryslers that gained NOTHING on the dyno. This would indicate the stock system was more than adequate.

I would buy the Pype's Crossflow for rear axle clearance and stainless steel construction. However, I wouldn't buy the Pype's Crossflow and wager on a 20 horsepower gain. While this is not impossible, I consider it unlikely in all but isolated instances....Robert

P.S. I'd be interested in seeing your formulas.

[Chevy454]

Originally Posted by Z Code 400

454,

Run any computer program you want and I will send you timeslips that will trump the 'rule of thumb' philosophy.

Computer program? No thanks...as for the time slips, are these *your* time slips? How about some more details on your experiences?? I may not be Austin Coil, but I've spent some hours tinkering on the dyno, and have had the same combo on both the engine/chassis dyno before, and even got to play on a chassis dyno @ a track and then make some passes...so I'm gonna stick with my rule of thumb if you don't mind. It may not stick to *every* car/combo out there, but it's good enough for the internet...

I've seen chassis changes pick up 2/10ths. How do you explain that with no more HP or TQ?????

I'd explain by looking at the time slip...did it pick up in the short time (ie, less spin)? At the 330?? Last 1/8??? MPH is a better representative of HP, but added HP normally brings lower ETs...and chassis changes means said HP is getting to the track more efficiently.

[Z Code 400]

Chevy454,

I don't doubt your claims, but keep in mind that 'rule of thumb' estimations are speculative at best, so I responded in kind. You are also correct in your assessment of chassis changes netting lower elapsed times, so your are definitely looking at the big picture.

I will say this again....

I would not buy or recommend the Pype's Crossflow to anyone, banking on it to yield a 20 HP gain and 2/10ths. I think this is possible, but an isolated case, based on our efforts to detect restriction.

I have had several people IM me and argue that there is NO WAY that Cliff Ruggle's 455 Ventura could have run 11.50's with an 'H' pipe, 40 series Flowmasters and 2.50" compression bent tailpipes, but his timeslips prove otherwise.

Just keep an open mind and don't believe every "20 HP" claim you hear, when deciding on buying a product....Robert

[Z Code 400]

Ok,

While many will subscribe to Comp Cam's marketing strategy of "this cam will give you that racey sound at idle," or will buy a muffler based on the sound it produces, let me again point out the Two Most Important Advantages of the Pypes Crossflow over the Flowmaster Crossflow:

#1: More Clearance for Disc Brake Rear Axles and Suspension Travel

#2: Stainless Steel Construction

That's it in a nutshell. I'll bet dollars to doughnuts I can make 450+ HP (and I have with the 42585) with either one, so I could care less what it sounds like, as long as it clears the axle over a road course and flows enough to support my HP target...Robert