Tune differences

[earthling]

But with a stock muffler is the thinking/experience here saying its harder on fuel?

I was hoping with a SM tune removing some of the safety gap it would still run less rich so more efficient...

Not legal here and I like a quite ride on them long days. Don't want to relive the Apex drone. ha ha

Didn't realize when there was talk of better mpg it was always with an after market muffler. Makes sense but I'm still disappointed.

It isn't limited to the aftermarket muffler. The 240 SS SM gets better mileage than stock according to Dave, the best of all of the SM tunes. Tuning is as much about timing as it is about AFR.

The reason that the tuners want to know if you are running a performance muffler and/or header is so they can add more fuel to the maps to avoid lean/detonation conditions brought on by improved flow through the engine, but to be safe in all temperatures/conditions/etc they have to run rich. The only way to offset this, and this applies to your 240 SS SM tune, is by adding a wideband O2 sensor and the closed loop option. With the closed loop system the ECU can adjust AFR to the current conditions in real-time running closer to optimal.

 

[Doc Harley]

More fuel & freer flowing exhaust = less throttle position to achieve the same goal, in terms of acceleration or maintaining speeds. I'm not talking about WOT.

 

[STAIN]

I have ridden the Hurricane performance trail muffler and a SM 240ss tune back-to-back. The Hurricane muffler is significantly louder. Good throttle response--yes, quiet--no.

 

[earthling]

More fuel & freer flowing exhaust = less throttle position to achieve the same goal, in terms of acceleration or maintaining speeds. I'm not talking about WOT.

Less throttle position only because throttle position is mapped to a higher range of potential horsepower. Consumption of fuel/air is the same, and the only way to reduce consumption is to run closer to ideal AFR (from rich) or to change gearing.

 

[hellflyer]

I have the 240ss tune and I ran with a stock winder for 700km last week and I was always a couple L less every top up at about 1/2tank fill up. But my buddy multi tune at 240 was almost 3L more every time set at 240 also.i think it's all about how it's se up. I'm at 6/1 on my Dalton B/O . At 6/2 it was worse on fuel

 

[Doc Harley]

Less throttle position only because throttle position is mapped to a higher range of potential horsepower. Consumption of fuel/air is the same, and the only way to reduce consumption is to run closer to ideal AFR (from rich) or to change gearing.

I've polled the internet a few times. Seemingly the answer is the same. Most whom have added a pm to their tune, has provided a decrease in fuel consumption.
Your comment would have me believe that opening the exhaust would have zero effect on efficiency. Or how about we agree that the pm tunes are closer to 14.7 ratio (during cruising) then non muffler tune?!?! Idk...idk lol.
There is an 80/20 rule that applies to most things in this world. And I would say from my gatherings, 80% claim getter Better mpg.
I'm positive Ben at Turbo dynamics has made the same claim. But I take his input with some salt, due to his position. Total respect.

 

[1nc 2000]

Real world experience is the correct answer to fuel mileage.
Most with tuned sleds will agree they give it the gas more coming off the corners to feel the power!
You want 10 mpg or 18mpg?
Just go find some snow and ride your sleds!

 

[earthling]

I've polled the internet a few times. Seemingly the answer is the same. Most whom have added a pm to their tune, has provided a decrease in fuel consumption.
Your comment would have me believe that opening the exhaust would have zero effect on efficiency. Or how about we agree that the pm tunes are closer to 14.7 ratio (during cruising) then non muffler tune?!?! Idk...idk lol.
There is an 80/20 rule that applies to most things in this world. And I would say from my gatherings, 80% claim getter Better mpg.
I'm positive Ben at Turbo dynamics has made the same claim. But I take his input with some salt, due to his position. Total respect.

My point is that throttle position is less evidence of fuel consumption and more related to how much juice you have on tap. It makes sense that the more HP on tap, the less throttle input required. Fuel consumption is dictated by volumetric processing over time, the more air you process, the more fuel you consume. Do I believe that these tunes give you better than stock fuel mileage... sure, because by design and intent they are processing more efficiently (timing/mapping). A more effective way to get better fuel consumption is either through closed loop operation where the ECM can manage AFR in real-time and/or better gear selection.

 

[fourload]

Powertrail is also the same as stock.

 

[WinderFab]

Real world experience is the correct answer to fuel mileage.
Most with tuned sleds will agree they give it the gas more coming off the corners to feel the power!
You want 10 mpg or 18mpg?
Just go find some snow and ride your sleds!

Well said..
there’s so many variables to fuel mileage but I don’t understand why guys say that they ride fast and now with a tune get way better mileage than stock.. what is fast to them ??

 

[Doc Harley]

My point is that throttle position is less evidence of fuel consumption and more related to how much juice you have on tap. It makes sense that the more HP on tap, the less throttle input required. Fuel consumption is dictated by volumetric processing over time, the more air you process, the more fuel you consume. Do I believe that these tunes give you better than stock fuel mileage... sure, because by design and intent they are processing more efficiently (timing/mapping). A more effective way to get better fuel consumption is either through closed loop operation where the ECM can manage AFR in real-time and/or better gear selection.

Well said..
there’s so many variables to fuel mileage but I don’t understand why guys say that they ride fast and now with a tune get way better mileage than stock.. what is fast to them ??

With just my experience I know it to be true but if I decided to search the web I cannot find any articles where opening the exhaust decreases motor efficiency
Share with me one article explaining the polar opposite.

 

[idontknowjack]

You want a huge milage increase. Run good fuel. I increased my milage by 30% running AvGas. Ethanol is filler. You pay for it and get nothing out of it.

 

[stgdz]

I think I saw an increase of about 2mpg after the tune.

Also the hurricane 2.5 exhaust is really not that bad. It is the limit for loud enough but I would certainly buy another one. With ear plugs it's pretty much perfect.

I rode around without earplugs and it's just as loud as my stock exhaust zuke 800 at 70-80, being that the wind noise is louder than the exhaust.

 

[earthling]

I think Winderfab was asking a different question but anyhow.

With just my experience I know it to be true but if I decided to search the web I cannot find any articles where opening the exhaust decreases motor efficiency
Share with me one article explaining the polar opposite.
View attachment 170831

First of all, what do you expect an aftermarket exhaust company to say? Ask yourself this, in a world where people put fuel economy somewhere towards the top of the list in buying decisions, why wouldn't a car company simply drop another $20-40.00 (at their volumes) on a slightly bigger exhaust to get 2-5% more efficiency. Put simply, it doesn't happen because it doesn't matter and the snake oil exhaust guys know the average consumer cannot measure 2-3 or even 5% efficiency gains. Thats why we don't see a Prius from the factory with a 3" exhaust.

I think of it this way. Starting with the fact that we are restricted by pragmatic limitations in how loud an exhaust can be.

An engine is an air pump. At low-mid RPM and low boost it isn't moving a lot of air. At mid-high RPM it is (boost and RPM build). Cruising speeds tend to be that mid RPM range but lower boost. At low to mid you aren't moving so much air that the stock exhaust is an issue.. at all. You aren't putting enough volume of air through it for it to be a restriction. On a stock sled and WFO you are in the 200HP class and nearly 9000 RPM. At cruising speeds you are a third of that or less in HP, and half on RPM. Even the tuners don't recommend a larger exhaust until you get to the higher HP because the *peak* volumetric flow isn't there until you get above 260 or so, and therefore the stock exhaust is not a problem. How can there be an increase in efficiency if there is no restriction to efficient flow? That is the trick with exhaust systems, they are sized for efficiency at max volumetric flow (peak HP), they are not a restriction until you exceed their design for max volumetric capacity.

At higher cruising speeds, maybe your are putting the stock sled into the other side of the efficiency curve (torque demand) by pushing it harder (higher rpm) and a tune will certainly help there as long as you make the appropriate clutching changes and/or gears, but at even higher cruising speed, the exhaust still won't be a huge contributor either way until you get to higher flow rates.

As to how a big exhaust can hurt performance, google exhaust scavenging.

 

[Doc Harley]

I think I saw an increase of about 2mpg after the tune.

Also the hurricane 2.5 exhaust is really not that bad. It is the limit for loud enough but I would certainly buy another one. With ear plugs it's pretty much perfect.

I rode around without earplugs and it's just as loud as my stock exhaust zuke 800 at 70-80, being that the wind noise is louder than the exhaust.

Congratulations.... That's a huge increase. Which hp tune are you running?