new exhaust

[los-lowrider]

Hey all,

I'm planning to build a new exhaust system for my 305 with edl shorty headers. My imagine was a double system with flowmaster 40 series which shoul end right and left in front of the rear wheels. For the diameter my idea is 2,5.
So what do think? Is this the correct size and mufflers. The most important thing for me is an agressiv sound, which my stock engine doesn't deliver right now.
I am very thankful for any tips or ideas to turn my ideas into reality.
Thank you.
Michel

[75stepside]

love the stepside!

i went with 2.5" on my exhaust system... into 40 series flowmasters and i'm very happy with the results... i think your on the right track!

[SlapFish]

I've got a single 2.5" with a single glass pack which then splits into two monster chrome tips. Sounds awesome, but isn't dreadfully loud and annoying. Good set-up for a daily driver.

[koreric75]

Here is a vid of my 350 through 2.5" true duals, dynomax headers and 40 series flowmasters, i had em come out the back, i just like it that way, i'm sure they'd sound great on the side as well. I had this set up with the old 305 before and they still sounded pretty good. Gotta give a honorable mention to my dedicated wife who sucked fumes just to help me get the video. I'm pretty sure next time i'll be using the tripod...lol.

http://www.jusspress.com/day.php?use...entTime=193133

[bigarmzz]

Originally Posted by koreric75

Here is a vid of my 350 through 2.5" true duals, dynomax headers and 40 series flowmasters, i had em come out the back, i just like it that way, i'm sure they'd sound great on the side as well. I had this set up with the old 305 before and they still sounded pretty good. Gotta give a honorable mention to my dedicated wife who sucked fumes just to help me get the video. I'm pretty sure next time i'll be using the tripod...lol.

http://www.jusspress.com/day.php?use...entTime=193133

sounds killer man!...gotta love flowmaster 40's

[Russell]

I'll take a clip of my 89 for you tommorow. Its got a set of Midas "super performance" mufflers on it. No idea what brand, but she sounds really good for a DD. Nice BRRRAAAP when you get on it, but when you are cruising, it is very quiet. Won't wake the neighbours up when you start it, or come home late at night

[apstguy]

I have an Aerochamber and it makes my 305 sound like a beast. I personally like the Aerochamber sound over flowmaster.

[86 GMG]

true duals 2.5 w/flowmaster 40 series like everyone else i had him keep the bends to a minimum for restriction perposes now that i have my double humped tranny member i will be redoin a little bit to acomidate for an h pipe my tips are just pipe bent and angle cut pipe behind rear tire about 6 inches i really love the smooth raspy sound and like other have said it will usually talk to you the loudest when on the road shooting the gas to it (btw motor is 350 about 345 h.p 10.5 to 1 comp.) so the sound will be diffrent from motor to motor

[los-lowrider]

Hey guys,
thanks for your posts.
@koreric75: cool sounding truck, it would be great if mine would sound similar but I guess your engine has a lot more power, so I think I can't get such a result.
@all: If I understand you right my choice is not the baddest. In the moment I have a dual exhaust system with cherry bombs and 4 chrome tips. I took the stock y-pipe and built the dual straight through. The left y piece I took as an kind of h-pipe so I had a lot of welding. In fact the sound is not bad, but not what I want. I've this sytem for three yaers and now it has to go.

What is about an h-pipe for the new system? Is it necessary and where is the best place to locate it? I always heard that the best place is about 25% back from the headders. Is this correct? Also I am not sure if there is an difference with or without h-pipe.

I attache a few from behind on my current system!

Michel

[whiskey_marc]

I run no mufflers on my truck... sounds awesome

[Russell]

Alright, here we go

1989 Chevy 1/2 ton. TBI 355 with a mild cam. About 9.3:1 compression or so. Manifolds with true dual 2.25" pipes, coming out at 45 degrees to the rear wheels. No tips or anything on them. Again, not sure what type of muffler it is, but it makes that truck sound beastly, esspecially at an idle

When you accelerate, the truck has a very beefy sound to it, but if you have your windows up, it sounds very similar to a brand new truck with a 6 litre -- You hear it, but it isn't loud. Put the windows down, and you hear yourself bouncing off everything, esspecially fun under bridges The truck does not drone at any RPM, you can carry a normal conversation without any problems at all I wish I knew what type of mufflers they are, so I could get a set for my GMC -- Its way too loud with the dual 2.5" pipes, flo-pro mufflers, and full length headers.

This sound clip was taken with the camera just below the driver's side exhaust pipe, with a couple 2800 rpm revs. She idles at 560 rpm, way too low, if you listen carefully to the idle portion, you can hear it struggling a bit... Its extremely rich due to the 02 sensor detecting overlap, and reporting a phantom lean condition. Get her up to 800 rpm, and it doesn't run rich anymore. New prom is in order methinks

http://www.zieglerdigital.ca/downloads/89rev.wma

[los-lowrider]

@Russell: Man that's a great sound. This comes very nera to myimgines of a powerful and deep sound. Congrats.

[los-lowrider]

@whiskey marc: good idea, but in Germany this is not allowed. We have a certification station where we have have to go every two years and I can tell you they don't like American steel. It is allways a problem to get the certification. I have to say that an pick up is rather rare here so they don't know al parts but if your car is louder than 92db for oldtimers after 1958 you have no chance to pass it.

[Russell]

My 89 sounded very similar with the 305 I had in it before. Only a little bit quieter.

I've got a dB meter that I used when I was running sound before, and measured the 89. I put the meter right under the truck, and at it's loudest (when it makes that BRAP noise right after I left off the throttle, about 2800 rpm) it is 86 dB

GMC on the other hand, was about 108 dB -- like 12 dB below the threshold of pain, lol - Wayyy too loud...

[Tom]

I had the exact setup you listed in the first post minus the headers. I had 2" ramhorns into dual 2.5" with catco convertors and flowmaster 40 series exiting before the rear tires into Z28 tips. With the vortec 350 in the truck it was a loud, bad arse system. Then I put a tired 305 in it to sell with the truck. The sound changed a lot. Much more quiet, but still good sounding. Kinda sounded like I had changed the mufflers to 50 series to be honest.

[piecesparts]

When I built the 84 SWB into a truck with more performance, I called the guys at Flowmaster to see what would work best. At the time I was considering 3" duals, but they told me different. The representative said that they had a computer program that evluates the performance of an engine and the drivetrain with what exhaust works best. It turned out that a set of headers (ceramic coated dynomax, long tube) into 2.5" pipes and a cross-over about where the tranny ends going into two Flowmaster 40s and running 2.5" all the way to the rear was the best for my engine. This of course, took into consideration how and where I drive---Mostly highway around 75 MPH, also some city driving. I run a bored and stroked 383 engine with a 700R4 tranny and 3.73 gears in the rear. This motor sounds good and tough with the system and it averages 15 MPG with the 400+ motor. It is great. In my state the trucks don't have to have a cat system, so I do not have them on there now.