What exhaust to use? Suggestions and pics

[BADPURPLE70CHEVY]

Currently have 2 and a half inch pipe with flowmasters. Don't remember series. Exhaust is ran past cab with turndowns. Old motor was 350 with about 320 horses. New motor is 406 with around 550 horses. Built very strong. Wont an aggresive sound but not annoying. Interested to get some other opinions with pics of how they were ran. Thanks

[Gobbles]

I have flowmasters on my 454 and they drone at idle quite a bit, I don't mind the bass drone, but some people do. They do sound really nice driving and in park though. So maybe stick with what you have and if you don't like it, try something new.

[BADPURPLE70CHEVY]

Any other ideas?

[Davetopay]

With that kind of hp on tap, Flows could be a bit annoying....especially if they were 2 chamber. Dynomax Super turbos might sound good, but would kill a few hp. If you want to keep it reasonably quiet, and not absolutely choke it off, look into using some Dynomax race bullets as resonators and a large case straight through style muff like the Dynomax welded series or the Magnaflows.

[BADPURPLE70CHEVY]

Originally Posted by Davetopay

With that kind of hp on tap, Flows could be a bit annoying....especially if they were 2 chamber. Dynomax Super turbos might sound good, but would kill a few hp. If you want to keep it reasonably quiet, and not absolutely choke it off, look into using some Dynomax race bullets as resonators and a large case straight through style muff like the Dynomax welded series or the Magnaflows.

Any one got pics of there set ups?

[Davetopay]

Originally Posted by BADPURPLE70CHEVY

Any one got pics of there set ups?

Sorry, mine is a mundane LMC dual kit hooked to ramshorn manifolds with turbo muffs.....no pics. I was just pontificating about ways it could be done.

[bigsnookmaster]

I run a 4/7 swap.580 lift mechanical roller 406 with shaft rockers and Victor jr aluminum heads. I have Hooker Super Comps, 3" mandrel bent exhaust with an X-pipe and run Dynomax Super Turbo's. I built the exhaust myself out of Flowmaster kits, and had it coated locally. I really like the sound, as I call it,"Quiet Fast". It's really not loud, and it responds real well. I also ran the exhaust over the rear end. First time out it ran 7.80's in the 1/8th. Here's a couple pics: The chains were temporarily in place of the shocks so the rear wouldn't hang down on the lift.

[BADPURPLE70CHEVY]

Originally Posted by bigsnookmaster

I run a 4/7 swap.580 lift mechanical roller 406 with shaft rockers and Victor jr aluminum heads. I have Hooker Super Comps, 3" mandrel bent exhaust with an X-pipe and run Dynomax Super Turbo's. I built the exhaust myself out of Flowmaster kits, and had it coated locally. I really like the sound, as I call it,"Quiet Fast". It's really not loud, and it responds real well. I also ran the exhaust over the rear end. First time out it ran 7.80's in the 1/8th. Here's a couple pics: The chains were temporarily in place of the shocks so the rear wouldn't hang down on the lift.

Thanks for the pics...nice truck to.

[brans72]

Also going to run Dynomx Super Turbo Mufflers alot of great reviews!

[BADPURPLE70CHEVY]

Originally Posted by brans72

Also going to run Dynomx Super Turbo Mufflers alot of great reviews!

How do dynomax sound?

[bigsnookmaster]

Pics were kind of crappy. I like the sound of the Super Turbo's better than any other.JMO

[lakeroadster]

I ran 2-1/2" all the way to the back of the truck, but ran the tail pipes on the outside of the frame since I am running a rear fuel tank.

I prefer the old school sound of Cherry Bombs, and with the long tail pipes they sound really good, IMHO.

More details of the install can be found here http://67-72chevytrucks.com/vboard/s...=363509&page=6

and here is a video clip

YouTube - Lakeroadster's 1965 Chevrolet...

Hope this helps!

[brans72]

I pullled the sound up using google and they where on a C10 sound great super to no drone in my book. Brandon

[brn agn]

I have been a fan of Dynomax for a long time. I am still piecing together the exhaust on my truck and found a good deal on Dynomax Super Turbo mufflers today at www.rockauto.com. The part number is 17732 and they are 2.25" offset inlet/offset outlet. Just type the number into the part number search and set the manufacturer as Walker. Once the product comes up, select the drop down box and you will see them priced at $25.79. This same muffler sells for $46.95 at Summit Racing.

[llowlife]

If you truely will be building 550 hp you will need 2.2-2.5 cfm exhaust flow per hp or roughly 1100 cfm. You will need to ditch the FM and buy some Magnaflows or Dynomax mufflers. 1" square will flow roughly 115 depends on bends etc. 2.5 inch pipe will flow a whisker over 500 x 2 for dual exhaust. 3" is sneaking up on too big but is still fine for 550 hp as it has about 7 sq inch or roughly 800 cfm x2=1600 cfm. I would go 3" if it were me in this situation. Flowmaster mufflers kill HP....Period....Dynos don't lie. The dynomax turbos will kill HP too as if I remember correctly they are a 3 pass system. Buy a straight through muffler. All glasspacks are straight through but are not necessarily built the same. All numbers are a bit "loose" as I couldn't find the calculator so I had to do them by hand.

Oh yeah run an "H" or "X" pipe as it will quiet it down and possibly add some HP over an otherwise "H less" system.

[swamp rat]

Llowlife,
On an "H" is there a limit to the distance between the 2 pipes where the H becomes ineffective? or will it equalise the pressures (or is it scavenging) ether way, long or short?

With 325 HP (calculated) will 2.25 pipe be sufficent or is 2.5 better?

[llowlife]

People have reported lengths to 36" have been used effectively with no noticeable effects. (Not by me in this instance). There is also an optimal distance from the collector. Collector size and length is king. I bow to Larry Meaux on these 2 calculations from Meaux racing heads though it can be calculated by hand my question is "why" would you want too. I'm willing to bet there would be no noticeable effects between the two diameters. An H pipe does not always increase HP but will not reduce it and will certainly reduce noise (David Vizard). The H pipe evens out (equalizes) pressure waves. Exhaust is not as ez to pin down as many have thought. I do not claim to know 1% of what Larry and DV know but I have spent the better part of over 2 decades trying to "find out things" and eventually in that time you gotta figure some stuff out even if its me.

[68Stepbed]

How do Flowmasters kill HP? I know in my own seat-of-the-pants tests, the Flows may not make more HP, but I know they produce more torque. This has been on stock and mildly modified 350's though. Is there something about high HP engines that the Flows don't work well with?

I personally don't really care for the sound of Magnaflows, but they have good reviews. A buddy of mine had a set put on a 650HP 502BB with 3" pipes and an X-pipe. Alothough it did sound decent, it certainly didn't sound like a 650HP BB should sound.

I know FLowmasters are louder than most mufflers and they defintely bring out the sound of the lopes of a good sounding cam. If you want to stay with Flows, I say go with a 50 series. They're not as loud as the 40 series. Also, run your pipes out to the rear of the truck. The shorter pipes and/or turndowns just make everything louder.

[llowlife]

Okay I will correct my statement. FM kill HP on Higher HP motors. THEy will flow ok for lower HP motors or lower RPM motors. I am not 100% certain why just that they do. They have a nice sound I will admit that and I haven't experienced every muffler FM makes but I haven't heard of one yet that flows much over 300 cfm. FM will tell you that the numbers means nothing when it comes to CFM so they don't rate them that way. CFM is one standard that I would like to see adopted so you can at least have some apples to apples comparison. Maybe it isn't the best but its a start. Irregarless though. If you can't get the flow out you can't use the HP you are making. FM used sound baffles to control their sound which is an excellent idea, just hasn't been perfected yet.

All opinions are by my own experiences or others I know. I have never tested all the combinations but if you look under my truck you will see Magnaflows even though I do like the FM sound. THey market the sound not the HP numbers. If you do searches I suspect you will see under FM I....love.....the ....sound.... NOT I am making big HP numbers. I am not knocking FM, if you want to run them run them I choose not too and if it starts to be a flame war. (which it is not currently) I will bow out of the subject matter at hand.
Our friend at the top has a 550 hp motor...FM will not net the same HP as Dyno's or Magnas.

Totally agree with exteriorizing the sound system. Now I'll open another can of worms. Run them to the backof the truck at a downward angle slightly tilted in towards the center of the truck

[lakeroadster]

Originally Posted by 68Stepbed

How do Flowmasters kill HP?

I think the more likely culprit is using exhaust tubing that is too large for the application. Seems like everybody wants to use 3" or larger, which is not recommended unless you are building a lot of HP.

This is especially true if you are running full length pipes to the back of the truck, which IMHO makes the exhaust tone sound so much better for a daily driver.

Motor Size Horsepower Dual Exhaust Size
150-200 CID 100 to 150 2"
200-250 CID 100 to 200 2" to 2-1/4"
250-300 CID 150 to 250 2" to 2-1/2"
300-350 CID 200 to 350 2-1/4" to 2-1/2"
350-400 CID 250 to 550 2-1/2" to 3"

http://www.magnaflow.com/wideopen/performdata.asp

Hope this helps

[llowlife]

Also it is conjectured that a 3" pipe will slow down the flow enough to cool it off which slows it down. The theory is sound but not sure about the actual application of it in automotive terms. THats why it is (in theory) best to mount the mufflers back as far as practical. I will attest to the pipe size theory from our racing briggs motors.....Yes I said "racing briggs" no snickering!!!!!!!

[clear]

You can't go wrong with bull-stacks.

[swamp rat]

Thanks Llowlife for the reply and Lakeroadster for the chart.

[bigsnookmaster]

If you have a 406 making 550 horse, I would go 3"

[BADPURPLE70CHEVY]

Originally Posted by bigsnookmaster

If you have a 406 making 550 horse, I would go 3"

I want to bring out the sound more. I would like to go three inch.Thanks for all the replies.