Project 68 k10 LWB..aka "The Hulk"

[First c10]

How do you think it would sound? Would dual sound better?

[First c10]

According to this a 3" pipe would handle 339 hp.

[swamp rat]

probably sound a little deeper than a stock single exhaust due to diameter, but what mufflers of course is the variable.

[First c10]

Magnaflow, flow master, those are the popular ones right? I looked on YouTube but really can't find anything but catback systems for single exhaust so that tells me true duals would be the best.

[cmabolt]

Since I am at this point right now in my build I have done a lot of looking regarding pipe size/headers etc. One thing I have read and heard over and over is don't go too big or it will rob torque. Velocity is also a key factor and if pipes are too large velocity is lost. Outside of that each engine hp combo is different.
I will be using 2.5" pipes to accommodate upgrades to the motor in the future, but that is probably even a little big for my 6.0L with roughly 328hp. Just my 2 cents

Chris

[First c10]

Originally Posted by cmabolt

Since I am at this point right now in my build I have done a lot of looking regarding pipe size/headers etc. One thing I have read and heard over and over is don't go too big or it will rob torque. Velocity is also a key factor and if pipes are too large velocity is lost. Outside of that each engine hp combo is different.
I will be using 2.5" pipes to accommodate upgrades to the motor in the future, but that is probably even a little big for my 6.0L with roughly 328hp. Just my 2 cents

Chris

Chris thanks for the 2 cents...
On my sons 5.3 LC9 we went with 2.5" duals with 40 flowmasters. The stock motor was 320 HP before doing anything to it. Not sure if it would have been better to go with 2.25 or not. with the tune and upgrades it runs strong. What do you think on running two 2-1/2" in to one 3"? pros/cons???
Thanks
Scott

[DWilbur]

Only one way to find out give it a try. I ran 3" duel exhaust 40 series Flow masters in my 84 Chevy 454 engine about 300 hp and it worked good at idle it was quite at full throttle I gat a couple of tickets. I installed 3" exhaust in my 73 Plymouth 390 stroker motor and it is way to loud at idle or full throttle. for my 71 Chevy I installed 2-1/2" duel exhaust with Magna Flow mufflers it will be a while before I get it running. Then theirs my Ram 2500 4" single exhaust straight pipe with tuner and it runs like a bat out of hell and quite at idle not bad at full throttle.

[cmabolt]

Originally Posted by First c10

Chris thanks for the 2 cents...
On my sons 5.3 LC9 we went with 2.5" duals with 40 flowmasters. The stock motor was 320 HP before doing anything to it. Not sure if it would have been better to go with 2.25 or not. with the tune and upgrades it runs strong. What do you think on running two 2-1/2" in to one 3"? pros/cons???
Thanks
Scott

Hey Scott.
It is my understanding that velocity increases as the passage way reduces in size. Seems logical to me anyway. Just like reducing pipe size to increase water pressure at the outlet. For headers, I have read that 1 5/8 primaries into 2.5 collectors and staying with 2.5" duals all the way is best. But sometimes headers combos that actually fit don't help. As long as 3" is reduced to to 2.5" velocity should be effected in a good way. Honestly I am not sure about dual 2.5" into single 3". That may have a negative effect on velocity in the form of scavenging or back pressure if the 3" doesn't have enough capacity for the cfm being jammed thru it. I think 3.5 or 4" would probably yield better results but I would look to a pipe calculator to get better numbers. In general I doubt if any of us would feel the difference in our seats. I think you do the best you can with budget and what will fit your rig while trying to apply common sense.

[First c10]

The picture below is what I was thinking. Please don't. I know I can't draw lol.

I understand the idea of high velocity in a small pipe with back pressure verse larger size less back pressure and Low velocity. The above chart reads in cfm flow and hp. So single 3" can flow 747cfm and 339 hp. That would say that the 243 heads I have on the motor need to flow 373.5 cfm each. Which I don't think this motor can do NA. The hp number is what has me puzzled. My 08 Duramax has 3.5" after the turbo and before the cat and 4.5 after thru a single muffler (can't remember the brand of the catback system ) motor is 325 hp 600+ torque stock. Probably not the same since it's an oil burner.
I am just thinking it would be different. Maybe put a large nasty chrome tip on it.

[First c10]

OK so.....
This is what my mind comes up with(based on the above chart)
2.5 pipe = an area of .034ft2 at 509cfm = 14970.6 ft/min or 249.5 fps

3.0 pipe = an area of .049ft2 at 747cfm = 15244.9 ft/min or 237.4 fps

So bigger pipe more cfm but less velocity. 5% less velocity in the 3" then the 2.5"
now that we have had an algebra lesson.....it all comes down to sound! What to you guys think it will sound like? good or bad?

[swamp rat]

Magnaflow gets my vote, deeper sound, Flowmasters are a more raspy sound, that said i run Magnaflows on the rat. My DD originally had dual Glass packs and the system ran side by side, the packs burned out but the forward pipes were still solid so i left them and had a 2 in 2 out 70 series Flowmaster installed, but also has 2 20" resonators installed so its deeper and not as raspy sounding.

Start combing Youtube and the MFG sites for sound clips.

I forget what mufflers i have but they are the largest body Magnaflows that were available, i wanted quiet after 20 years of headers and flowmaster 40's.

https://www.youtube.com/watch?v=ZyYm...ature=youtu.be

https://www.youtube.com/watch?v=wH4Qq3m7PPo

[DWilbur]

The way I look at it is it's your sons truck make on the loud side that way you will hear him coming home late at night after party'n all night or nit

[First c10]

Originally Posted by DWilbur

The way I look at it is it's your sons truck make on the loud side that way you will hear him coming home late at night after party'n all night or nit

Loud I get. The partying I don't think so!!!

Thanks guys I will check out videos on it. Not sure what I showing to but thanks for helping me think about it football practice is taking up a lot of time. Next week is no practice so hopefully I can get back on the truck.

[sleepertruck72]

Hulk is coming along really nice !

[First c10]

Thanks sleepertruck72
I haven't been able to really work on it this past couple weeks hopefully I can get on it soon.

[7dee2]

Originally Posted by First c10

OK so.....
This is what my mind comes up with(based on the above chart)
2.5 pipe = an area of .034ft2 at 509cfm = 14970.6 ft/min or 249.5 fps

3.0 pipe = an area of .049ft2 at 747cfm = 15244.9 ft/min or 237.4 fps

So bigger pipe more cfm but less velocity. 5% less velocity in the 3" then the 2.5"
now that we have had an algebra lesson.....it all comes down to sound! What to you guys think it will sound like? good or bad?

It's gonna sound great and I like your idea for this truck. I've had a few people suggest this style exhaust for projects in the past and curious to see how you guys like it once done.

[First c10]

Originally Posted by 7dee2

It's gonna sound great and I like your idea for this truck. I've had a few people suggest this style exhaust for projects in the past and curious to see how you guys like it once done.

Thanks Brett,

I am thinking it would be different to have a large pipe exhaust.

Scott

[cmabolt]

Originally Posted by First c10

The picture below is what I was thinking. Please don't. I know I can't draw lol.

I understand the idea of high velocity in a small pipe with back pressure verse larger size less back pressure and Low velocity. The above chart reads in cfm flow and hp. So single 3" can flow 747cfm and 339 hp. That would say that the 243 heads I have on the motor need to flow 373.5 cfm each. Which I don't think this motor can do NA. The hp number is what has me puzzled. My 08 Duramax has 3.5" after the turbo and before the cat and 4.5 after thru a single muffler (can't remember the brand of the catback system ) motor is 325 hp 600+ torque stock. Probably not the same since it's an oil burner.
I am just thinking it would be different. Maybe put a large nasty chrome tip on it.

I think this will look pretty cool. Large single pipe on the back. It will probably end up flowing better than duals. Lookin forward to seeing that one put together.
Chris

[First c10]

Originally Posted by cmabolt

I think this will look pretty cool. Large single pipe on the back. It will probably end up flowing better than duals. Lookin forward to seeing that one put together.
Chris

It will be different for sure...
so what muffler would you recommend? Size? 3" or 3.5"?

[First c10]

Also spent some money and bought HP Tuners. going to play with my others sons 5.3 LC9 truck...

[cmabolt]

Originally Posted by First c10

It will be different for sure...
so what muffler would you recommend? Size? 3" or 3.5"?

Same size as your extension pipe from header/manifold to muffler. Once you come off header and go to single pipe, it should stay the same the rest of the way. There is some info about stepping up, but none I've found that
shows proof of a performance gain. I am a flomaster guy so that's what I would get.

Let me know how tough the learning curve is with HP tuners. I use computers every day and have been thinking about buying and getting to know the ins and out of tuning the LS motors. Like anything, I'm sure it's a matter of understanding the user interface, but have never heard how difficult that is
self teaching.

Chris

[First c10]

Originally Posted by cmabolt

Same size as your extension pipe from header/manifold to muffler. Once you come off header and go to single pipe, it should stay the same the rest of the way. There is some info about stepping up, but none I've found that
shows proof of a performance gain. I am a flomaster guy so that's what I would get.

Let me know how tough the learning curve is with HP tuners. I use computers every day and have been thinking about buying and getting to know the ins and out of tuning the LS motors. Like anything, I'm sure it's a matter of understanding the user interface, but have never heard how difficult that is
self teaching.

Chris

Chris thanks for the information that is what is great about this site a lot of info. I like the sound of flomasters also just not sure how a single muffler (of any kind) will sound so need to do some research.

I paid about 400$ on the C10 truck tune and it still needs some trans tuning so I don't want to spend anymore money to someone else. figure I will spend it on learning material....All the tuners on this site say read ,read, read, and read some more!!!
so now I just need to learn to read!!!

[DWilbur]

I'm thinking about tuning the engine as well. I hear stories about guy and tuner blowing up engines tuning them. I'm installing wide band O2 sensor on my truck so I can keep an eye on fuel air mixture.

[First c10]

Yes I figured I learned how to weld and do all the other mechanical stuff. It might take me a while but I should be able to get the computer stuff done. As for blowing up stuff I think that's people trying to do more with the tune then there abilities I am going to start with the easy stuff like trans shift points and such before I really start tuning anything on the k20. Understanding the terminology I think will be the toughest to learn and Understand

[swamp rat]

It will sound great with a single, don't sweat the sound part too much, just run stock diameter pipes out of the headers or manifold to where they tie together, i don't know if there is a pre made collector out there or not.

Another option may be to find a dual in single out muffler, something to look into.