Max Flow vs. Glass Pack vs. Spiral
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Joined: Apr 2007
Posts: 68
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From: Annapolis Maryland
Max Flow vs. Glass Pack vs. Spiral
Putting my side pipes on soon. In possession of hooker glass packs but have read on the forum of the inadequacy of the flow and sound. Read many opinions on several options. Hoping to come to some sort of conclusion. Want a nice, throaty sound for my 350 SB but don't want "my ears bleeding" at highway speeds. Also want a good product to maintain solid performance. Hear that the max flos are great flow but very loud. Spiral inserts get a good rep also. Any opinions would be much appreciated
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
I've tried just about everything in my 78'. Here's my opinion for what it's worth:
Hooker glass packs= restrictive not real loud.
Hooker reverse flows= very restrictive but quiet.
Hooker Max Flows= free flowing but loud. sound nice at idle but really bark at freeway speeds.
STS Spiral baffels= free flowing with acceptable noise levels at speed.
I ended up with staying with the STS baffels and am very happy with the overall performance and sound.
I'm sure you will get lots of other opinions.
Gary
Hooker glass packs= restrictive not real loud.
Hooker reverse flows= very restrictive but quiet.
Hooker Max Flows= free flowing but loud. sound nice at idle but really bark at freeway speeds.
STS Spiral baffels= free flowing with acceptable noise levels at speed.
I ended up with staying with the STS baffels and am very happy with the overall performance and sound.
I'm sure you will get lots of other opinions.
Gary
Racer
Joined: Jul 2004
Posts: 444
Likes: 0
From: Dallas TX
I have the glass packs and they sound fantastic with a nice deep rumble. They are a little quiet at idle and have a nice sound and volume at cruise. You still have to raise your voice a little to talk, but you certainly won't go deaf. At full throttle they are plenty loud and sound wonderful going up through the gears.
As for flow restriction, my car has no issues spinning the tires in first and second so I'm not concerned. I wonder if anyone has actually done a dyno test with the same engine and different inserts. Just because something looks restrictive doesn't necessarily mean it hurts power.
It isn't real hard to swap them out so give the glass packs you have a try and see what you think.
As for flow restriction, my car has no issues spinning the tires in first and second so I'm not concerned. I wonder if anyone has actually done a dyno test with the same engine and different inserts. Just because something looks restrictive doesn't necessarily mean it hurts power.
It isn't real hard to swap them out so give the glass packs you have a try and see what you think.
Instructor
Joined: Jun 2008
Posts: 249
Likes: 0
From: Avon Connecticut
I have the glass packs and they sound fantastic with a nice deep rumble. They are a little quiet at idle and have a nice sound and volume at cruise. You still have to raise your voice a little to talk, but you certainly won't go deaf. At full throttle they are plenty loud and sound wonderful going up through the gears.
As for flow restriction, my car has no issues spinning the tires in first and second so I'm not concerned. I wonder if anyone has actually done a dyno test with the same engine and different inserts. Just because something looks restrictive doesn't necessarily mean it hurts power.
It isn't real hard to swap them out so give the glass packs you have a try and see what you think.
As for flow restriction, my car has no issues spinning the tires in first and second so I'm not concerned. I wonder if anyone has actually done a dyno test with the same engine and different inserts. Just because something looks restrictive doesn't necessarily mean it hurts power.
It isn't real hard to swap them out so give the glass packs you have a try and see what you think.
Racer
Joined: Jul 2004
Posts: 444
Likes: 0
From: Dallas TX
to each his own
Everyone has their own opinion on the sound quality they like and that's ok. That's why I suggested trying them for yourself since you've already got them and swap it if you don't like it. 
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
I have a feeling that you have the reverse flows. The glass packs sound very good, they just don't flow very well. I have the max flos and they're a bit too loud for me.
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
http://www.spiralturbobaffles.com/product_tests.html
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque.
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Drifting
Joined: Jun 2007
Posts: 1,404
Likes: 1
From: Ansonia/NYC CT
Yes, testing has been done. And restrictions always cause a loss of power.
http://www.spiralturbobaffles.com/product_tests.html
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque.
http://www.spiralturbobaffles.com/product_tests.html
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque.
Racer
Joined: Nov 2006
Posts: 357
Likes: 8
From: Champaign Urbana IL
I just got the max flows about a week ago and love them. They have a nice deep rumble really sound great overall and were everything i wanted. I have about a 15 commute on the interstate into town and they can get a little annoying. I have a L-82 and at drive on the interstate at about 3000 rpm's. I can hear the radio, but have to turn it up pretty loud. It doesn't make my hears ring or anything, just kinda gets on your nerves. Amazon has them for $160 with free shipping, i would try um out first because they are about half the price of the spirals and if you don't like um you can sell them and get most of your money back.
Le Mans Master
Joined: Jan 2005
Posts: 8,226
Likes: 2
From: Lake Wylie SC
I like my sidepipes with spirals
If you are installing spirals into sidepipes and have the option on where to place your spirals, the closer to the front the higher the velocity will be. A lot of the design of the spirals is based around velocity...... they will not increase the velocity but will keep it sustained over a greater length that in turn increases the scavenging effect of the exhaust system.
Consequently the further in the system from the motor that they are located at the less the benefit from spirals.
Doug
If you are installing spirals into sidepipes and have the option on where to place your spirals, the closer to the front the higher the velocity will be. A lot of the design of the spirals is based around velocity...... they will not increase the velocity but will keep it sustained over a greater length that in turn increases the scavenging effect of the exhaust system.
Consequently the further in the system from the motor that they are located at the less the benefit from spirals.
Doug
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
Yes, testing has been done. And restrictions always cause a loss of power.
http://www.spiralturbobaffles.com/product_tests.html
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque.
http://www.spiralturbobaffles.com/product_tests.html
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque.
I'm certain that a direct comparison to another type, oh say the Max Flow for example would yield far less dramatic results. Possibly one they would rather not publish
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
That was my car in the test that SteveG75 referenced. It was before I did my motor over. Since then I have done two separate engine dyno test sessions. In one of them, I tested a muffler configured very much like a max flow. It was a perforated core, 2.5 inch glasspack made by Loback. It was down on power to the baffles in uncapped form. Not sure about capped up since I had already cut the cap. In measured area, however, there is more than a 2.5 inch pipe with the baffles. Now, keep in mind, these later tests were on a 614 horse motor. A mild 350, as Yellow72 said, would surely show less of a difference than a more radical motor. I am sure of one thing, however, the max flows will not make more power than open pipe like the website says.
My testing experience says baffles, and the sound is tunable as well. Just drill holes or remove the cap for more sound/flow.
Bill
My testing experience says baffles, and the sound is tunable as well. Just drill holes or remove the cap for more sound/flow.
Bill
Last edited by 69ttop502; Apr 6, 2009 at 06:01 PM.
Thread Starter
Advanced
Joined: Apr 2007
Posts: 68
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From: Annapolis Maryland
based on all of the good info I'm leaning towards the spiral baffles....saw a posting regarding the placement of the baffles; closer to engine creates better flow due to the velocity of the gasses closer to the powerplant....what produces a better sound? in the aforementioned place or closer to the end of the pipe? thanks
Melting Slicks
Joined: Nov 2003
Posts: 2,362
Likes: 1
From: San Antonio TX
As said there is a cap on the Spiral Baffles of which you can leave on. And they are loud with the cap but also as others have mentioned you can drill out the cap the desired amount to change how loud they are or remove it.
I know on a healthy 406CI SB they are loud but sound great with the cap on with no hole lol. The person I helped with the install does not wish to make it louder at this point lol. But it sure sounds great.
I hope with in the next few months I get to try them out with a mild 468 BB 550HP and see how it goes.
. Run Neighbors Run lol. Or is that Forest lol.
I know on a healthy 406CI SB they are loud but sound great with the cap on with no hole lol. The person I helped with the install does not wish to make it louder at this point lol. But it sure sounds great.
I hope with in the next few months I get to try them out with a mild 468 BB 550HP and see how it goes.
. Run Neighbors Run lol. Or is that Forest lol.
Le Mans Master
Joined: Jan 2005
Posts: 8,226
Likes: 2
From: Lake Wylie SC
IMO drilling the end cap is not advisable if you have any neighbors........ and you had better have an OD gear for the freeway.
As it is with the caps on I can set alarms off and just about blow the bird's nests out of the trees when I put my foot in it.
Just driving down the road with a big cam and capped spirals makes everyone turn to see what is coming there way........ I cannot imagine the need for anyone to have it any louder than that.
Doug
As it is with the caps on I can set alarms off and just about blow the bird's nests out of the trees when I put my foot in it.
Just driving down the road with a big cam and capped spirals makes everyone turn to see what is coming there way........ I cannot imagine the need for anyone to have it any louder than that.
Doug
Drifting
Joined: Jul 2005
Posts: 1,623
Likes: 29
From: The Netherlands
I have the reverse flows and they were quiet indeed. I drilled the caps on both sides of the inserts (3x10mm holes) and now they sound and probably flow about the same as the glasspacks. Before I drilled them I had 205 rwhp, haven't done an after test yet though. Decent dyno's are scarce in The Netherlands and it's a 2 hours drive from where I live.
However, not to hijack the topic, since everyone is stating they're easy to swap: how do you easily get the pipes form the header? Eacht time I did it, it cost me half an hour of wriggling and jiggling per side!
However, not to hijack the topic, since everyone is stating they're easy to swap: how do you easily get the pipes form the header? Eacht time I did it, it cost me half an hour of wriggling and jiggling per side!
Racer
Joined: Jul 2004
Posts: 444
Likes: 0
From: Dallas TX
Pull harder...
Mine wasn't bad when I took them apart but then again I hadn't run it yet. The point is things aren't all welded together which would make a swap a pain in the butt.
Racer
Joined: Nov 2006
Posts: 357
Likes: 8
From: Champaign Urbana IL
I put antiseeze in between the header and sidepipe. It helps seal it and also makes it really easy to get off. takes about 1 minute for me