Bigger Exhuast

[m-35tom]

RE: Location for pyro

since there is no back pressure, i fail to see how larger exhaust is of any use. there is a limit to how much power you will get from a engine with such poorly flowing heads. redesign the heads, add oil cooled pistons, larger oil cooler, bigger turbo, more fuel........ oh wait, why not just put a 5.9 in and it's already done for you.

 

[wadereg]

RE: Location for pyro

does a 5.9 bolt right in though?

 

[GunnersHusband]

RE: Location for pyro

bump?

 

[jwaller]

RE: Location for pyro

it too bad I got into this topic so late but I'll give you my results of water injection as I have this on my deuce.

Water injection works
methanol injection does not.

With methanol it instantly burns as soon as it gets into the motor. thus causing uncontrolled combustion.

water injection works like a champ. so far i have been able to run 20psi of boost and keep the egt's pre turbo to 1100. this takes a lot of water and thus you need a large tank. My system is purely and totally progressive based off a 3bar map sensor. the higher the boost the more water is injected.

I can also set the boost level that it begins to come on. so when driving easy I can keep the system from coming on or off by how hard I set on it. I can also adjust the rate of delivery such that I can adjust for humidity and OAT.

 

[brianp454]

More info would help

I would love to know more about your setup. Have you taken time to document it or share with others here?

In response to post above:

"it too bad I got into this topic so late but I'll give you my results of water injection as I have this on my deuce.

Water injection works
methanol injection does not.

With methanol it instantly burns as soon as it gets into the motor. thus causing uncontrolled combustion.

water injection works like a champ. so far i have been able to run 20psi of boost and keep the egt's pre turbo to 1100. this takes a lot of water and thus you need a large tank. My system is purely and totally progressive based off a 3bar map sensor. the higher the boost the more water is injected.

I can also set the boost level that it begins to come on. so when driving easy I can keep the system from coming on or off by how hard I set on it. I can also adjust the rate of delivery such that I can adjust for humidity and OAT. "

 

[jwaller]

I would love to know more about your setup. Have you taken time to document it or share with others here?

In response to post above:

"it too bad I got into this topic so late but I'll give you my results of water injection as I have this on my deuce.

Water injection works
methanol injection does not.

With methanol it instantly burns as soon as it gets into the motor. thus causing uncontrolled combustion.

water injection works like a champ. so far i have been able to run 20psi of boost and keep the egt's pre turbo to 1100. this takes a lot of water and thus you need a large tank. My system is purely and totally progressive based off a 3bar map sensor. the higher the boost the more water is injected.

I can also set the boost level that it begins to come on. so when driving easy I can keep the system from coming on or off by how hard I set on it. I can also adjust the rate of delivery such that I can adjust for humidity and OAT. "

I have written an entire long post about this topic. I have used and had water Inj on my deuce for about 5 years now and I would be lost without it. It provides much more power at far lower and safer EGT's than anything else that can be done to the truck.

 

[brianp454]

Data? & agreement

since there is no back pressure, i fail to see how larger exhaust is of any use. there is a limit to how much power you will get from a engine with such poorly flowing heads. redesign the heads, add oil cooled pistons, larger oil cooler, bigger turbo, more fuel........ oh wait, why not just put a 5.9 in and it's already done for you.

Do you have any data that shows no back pressure after the turbo? Have you ever hooked up a gage to show this at high RPM & loading (max power)?

My observations is that the turbo exit is ~3 inches, gently tapers out in the elbow to 4 inches, has a 4 inch piece of flex, the J pipe, and then a straight 4 inch exhaust. Given the general HP level and gaging it by other engines with 4 inch exhausts, I cannot image that there's any significant backpressure after the turbo.

Do you know if anyone has flow data on the heads, 3 inch turbo (LDT-465), and 4 inch turbo (LDS-465)?

My thinking is that it would be best to run the MF until it has significant trouble and enjoy it, then swap in a more efficient, powerful engine, with better RPM capability when disaster strikes. Cummins sounds good!

 

[Wildchild467]

The exhaust on the Deuce is 3.5 inch. I often thought about going to a 5 inch stack right after it exits the fender and still trying to make it look stock. It sounded awesome after I slipped a 5 inch stack extension over the tip of my Deuce exhaust but right now, it works and I am no way going to cut up a perfectly good J-pipe.

 

[Tlauden]

Excuse my ignorance, but on a non turbo'd truck it exits the muffler into i believe a 2inch stack, would it hurt anything to remove the muffler and straight pipe it using a 4 inch stack. Just curious

 

[eagle4g63]

Any time you make a turn in an exhaust pipe, you create back pressure.........however slight. The exhaust is flowing through the pipe in a rippled effect........the larger the pipe the less it will hit on the way through the curves and bounce back and forth instead of out..........so yes going to a larger pipe makes a difference.............EVEN ON A NON MUFFLED EXHAUST!!!

If you really want to have a little fun.........and you have a pyro.........run it with the pipe on(get a reading) and then open it up after the flex pipe and watch just how much cooler the temps are and how much faster the turbo winds up!!

 

[JasonS]

My dodge/ cummins with 100 more horsepower has a smaller and longer exhaust. I doubt that there is much magic to be found by a larger exhaust in the M35.