Dual Exhaust with stock exhaust manifolds:

[Stewart G Griffin]

Do you feel dual exhaust really makes a difference (power and/or mpg) if you are using the stock exhaust manifolds?


a) in general

b) if the engine is only 262 CID AND is only used for transportation AND will rarely be turned over 3500 rpm?

[zieg85]

My gut feeling is you are going to loose low end torque, and you will need as much as you can get with that 2.56  If you want to run duals I would use small diameter pipes

[Irish_Alley]

with the 262 i think
1 it will should like crap with duals
2 you will lose the tq
3 too much work for nothing in return

[1979mmx350]

How well would dual exhausts work on a stock 350 4spd with a fresh assembly?

[Stewart G Griffin]

How well would dual exhausts work on a stock 350 4spd with a fresh assembly?

i ran duals for all the time i was running the 350 and 305 and it seemed ok.  But the main reason why i ran it is because it came with the truck.  And it seemed to work well, so i wasn't motivated to change it.

i don't think it's clearly understood about running stock manifolds with dual exhaust---whether there's any real benefit, and in fact it may hurt performance?

Read this:
http://www.castheads.com/manifolds-carb/exhaust-manifolds/2-into-1-exhaust-collector-systems/


That being stated, i'm probably just going to go the exhaust shop and have them connect the duals up to the 4.3's manifolds because it seems like it's the easiest/cheapest way.  This is not a race car and i don't plan on reving over 3000 very much.   i don't care if i lose a little torque, if in fact this is what happens if you run duals off of the stock manifolds.......

[Irish_Alley]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

[Stewart G Griffin]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

i was running true duals, but the pipe size after the downpipes are, i think 2.5"  which may be too much for my engines, but at the same token they don't start until at least 2-3 feet AFTER the downpipes----exhaust shop used original downpipes and connected them to aftermarket pipes.

Flowmaster 40's which i'm not crazy about, but like i said they seem to do a good job.

i'll try to dig up a pic asap.

[Irish_Alley]

How well would dual exhausts work on a stock 350 4spd with a fresh assembly?

stew it was directed towards him, hes asking a question and left somethings out

[1979mmx350]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

Anyone know the diameter of the stock exhaust?

What are the advantages or disadvantages of either type or even something like an x or h pipe? I'm looking for a cheap way to increase the engine's ability to push out gas without affecting my engine's power on the low end. I'm picking up what I hope is heavy enough equipment for my clutch and the last thing I would wanna have on dirt is a truck that has to rev up a ton just to keep moving.

Edit: I'm probably gonna stick to the stock exhaust diameter or go up a quarter to half an inch.

[1979mmx350]

That being stated, i'm probably just going to go the exhaust shop and have them connect the duals up to the 4.3's manifolds because it seems like it's the easiest/cheapest way.  This is not a race car and i don't plan on reving over 3000 very much.   i don't care if i lose a little torque, if in fact this is what happens if you run duals off of the stock manifolds.......

Then I guess it'd probably be a solid idea to wait until I had enough for performance headers and some new pipes.

[1979mmx350]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

i was running true duals, but the pipe size after the downpipes are, i think 2.5"  which may be too much for my engines, but at the same token they don't start until at least 2-3 feet AFTER the downpipes----exhaust shop used original downpipes and connected them to aftermarket pipes.

Flowmaster 40's which i'm not crazy about, but like i said they seem to do a good job.

i'll try to dig up a pic asap.

What size engine you running? V8 right?

[Don5]

How well would dual exhausts work on a stock 350 4spd with a fresh assembly?

They should work pretty good. I ran true duals on my stock 350 for quite awhile until I could put a set of headers on it. I had 2 1/4 inch exhaust straight out the back under the bumper. I know that it threw a lot of condensation out the back when it warmed up. It also had some pretty good back pressure also. When I replaced the exhaust I had the guy put in 2 1/2 inch exhaust and had it turned out behind the rear wheels. I am going to run a drop V bumper. I also had him weld on 3 inch angle cut stainless tips that are 17 inches long. When my truck is idling you can feel the exhaust like 5 feet away. The exhaust is also more free flowing because it doesn't have much back pressure either. You will hear the exhaust more if it exits out the side instead of the back. I also have a set of Flowmaster 44's on it. It sounds really good.

[philo_beddoe]

My 77 c-10 came with true duals, i replaced the whole system due to rust. I went with all factory,  still had a kind of loud jalopy sound.  My mechanic saId three reasons.  I have duals, no cat conv, and large pipes.  Makes sense, no restrictions=good for the motor........right?


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[Stewart G Griffin]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

Anyone know the diameter of the stock exhaust?

What are the advantages or disadvantages of either type or even something like an x or h pipe? I'm looking for a cheap way to increase the engine's ability to push out gas without affecting my engine's power on the low end. I'm picking up what I hope is heavy enough equipment for my clutch and the last thing I would wanna have on dirt is a truck that has to rev up a ton just to keep moving.

Edit: I'm probably gonna stick to the stock exhaust diameter or go up a quarter to half an inch.

Actually i think it's 2.5"   which means i'm running 3" after the downpipes which is probably too much for my engines.

[Stewart G Griffin]

you talking about true duals or "Y"ed
what size pipe?
mufflers?

i was running true duals, but the pipe size after the downpipes are, i think 2.5"  which may be too much for my engines, but at the same token they don't start until at least 2-3 feet AFTER the downpipes----exhaust shop used original downpipes and connected them to aftermarket pipes.

Flowmaster 40's which i'm not crazy about, but like i said they seem to do a good job.

i'll try to dig up a pic asap.

What size engine you running? V8 right?

i was running a 350, then a valve dropped i kept trying to run the engine then said valve stuck itself into piston #4 then the engine stopped turning, this in turn caused cyl#4 to develop a massive crack in the cylinder wall.  Then i ran a 305,  i got stupid running without a fan(long story) AND a grill dam and the engine i think overheated.  So now i'm running a 4.3 v-6.