Road Glide banner

1 - 20 of 27 Posts

·
Registered
Joined
·
331 Posts
Has anyone gone to Stage III on the M8 engine yet? The claimed HP & TQ numbers are impressive. But what does that do to the MPGs?

Bikepsych
 

·
Registered
Joined
·
2,090 Posts
My neighbor just had the dealer put one on his 2017. I don't think he has 100 miles on it. The dealer flashed a tune on it and said once he's done his 1000 mile service they will dyno it.
 

·
Registered
Joined
·
77 Posts
I talked to the dealer about this kit over the weekend. The kit is $2,000 and another $1.000-1200 in labor. They only did 1 so far. As far as the numbers it is still hard to compare it to the 103 or 110. Since none of the exhaust companies have come out with their full exhausts yet without the cat, we still really don't know what kind of numbers the M8 107 will do with a full exhaust, AC, and aftermarket cam; so we still can't really compare it to the 103 yet. Looking forward to the 2-into-1 full exhausts from FuelMoto, Dragos, and Rush Racing. Doing dyno runs with the cat in place is a waste of time and money right now.
 

·
Registered
Joined
·
331 Posts
I disagree. I think you can get both. If you tune an engine right, you can get both a lot of power AND good efficiency. In the long run, isn't an engine with better efficiency going to make more power? If it's wasting fuel, its not running efficiently. I've got a 103 build with 109HP and 116tq and getting 45mpg at 70-80mph. On a recent run to Colorado it got up to 52 at high elevation. The bigger engine is naturally going to suck more fuel, but it shouldn't kill the fuel mileage that much. I've heard that the stock 107's are getting around 50 on the highway, so a drop down to around 40-43 should be realistic with the right tune.
 

·
Registered
Joined
·
110 Posts
I disagree. I think you can get both. If you tune an engine right, you can get both a lot of power AND good efficiency. In the long run, isn't an engine with better efficiency going to make more power? If it's wasting fuel, its not running efficiently. I've got a 103 build with 109HP and 116tq and getting 45mpg at 70-80mph. On a recent run to Colorado it got up to 52 at high elevation. The bigger engine is naturally going to suck more fuel, but it shouldn't kill the fuel mileage that much. I've heard that the stock 107's are getting around 50 on the highway, so a drop down to around 40-43 should be realistic with the right tune.
If it can be done, why worry about it? Build it and enjoy it.
 

·
Registered
Joined
·
4,391 Posts
I I've heard that the stock 107's are getting around 50 on the highway, so a drop down to around 40-43 should be realistic with the right tune.
I wonder where they are riding. My m8 Road King average is 41.5 in 2500 miles. Highest 43.1mpg.

I have squeaked 46 out of the 103 road glide on flat 2000 rpm 6th gear for 100 miles.
 

·
Registered
Joined
·
12 Posts
I just traded my 2012 103 with a stage 4 kit installed, and got 45mpg highway on long runs no problem. Dropped to high 30s around town. The 2017 is having a 114 stage 3 installed on delivery, ill be anxious to see how it compares in HP torq and MPG.
 

·
Registered
Joined
·
83 Posts
Has anyone gone to Stage III on the M8 engine yet? The claimed HP & TQ numbers are impressive. But what does that do to the MPGs?

Bikepsych
I had the stage 3 kit done at Harley In Manchester NH, shortly after posting how amazing it was, a user here notified me, approximately 4 days after getting my bike back, that Harley released the stage IV! Having some extra disposable income from hitting not one but two 40k jackpots on the Wheel of Fortune slot machine at Foxwoods casino, I sent the bike back to have it installed, I saved a few bucks because some of the parts that were included in the stage 3 were in the stage IV, not much, but some. I paid roughly 3600 including labor.

Now some may say that's crazy because i had just paid 2,500 not even 2 weeks prior and for the most part you'd probably be right, but I can tell you after I got on it and hit the throttle.. boy is it worth worth every penny.

My bike was the first stage IV done at that particular Harley and I have yet to get it on the Dyno because I need to break it in first. So I have no Dyno sheet to show but I can assure you its going to be well over 130hp the way its tuned right now. I still only have 750 miles on my bike and its hard to believe all the money I've put into it this off season, i just need the weather here in New England to cooperate now..

I know with the stage 3 and my tune prior I was getting roughly 35mpg.
 

·
Registered
Joined
·
42 Posts
I've got almost 700 miles on my stage 3. Liking it a lot. Went with the torque cam instead of the power cam. SE heavy breather and forsch slip-on's. I get just under 40 mpg's depending on how hard I am in the throttle.
 

Attachments

·
Registered
Joined
·
656 Posts
my bike is my toy.who cares about mileage,if I can run 200 miles on a tank I am happy.after 200 miles it's time to stretch.i ride 2011 with 110-108 hp-115 tq.the idea of more power is nice but with riding around 15000 miles a year I like the idea of no problems
 

·
Registered
Joined
·
331 Posts
I had the stage 3 kit done at Harley In Manchester NH, shortly after posting how amazing it was, a user here notified me, approximately 4 days after getting my bike back, that Harley released the stage IV! Having some extra disposable income from hitting not one but two 40k jackpots on the Wheel of Fortune slot machine at Foxwoods casino, I sent the bike back to have it installed, I saved a few bucks because some of the parts that were included in the stage 3 were in the stage IV, not much, but some. I paid roughly 3600 including labor.

Now some may say that's crazy because i had just paid 2,500 not even 2 weeks prior and for the most part you'd probably be right, but I can tell you after I got on it and hit the throttle.. boy is it worth worth every penny.

My bike was the first stage IV done at that particular Harley and I have yet to get it on the Dyno because I need to break it in first. So I have no Dyno sheet to show but I can assure you its going to be well over 130hp the way its tuned right now. I still only have 750 miles on my bike and its hard to believe all the money I've put into it this off season, i just need the weather here in New England to cooperate now..

I know with the stage 3 and my tune prior I was getting roughly 35mpg.
So, tell us more about your build! How did the dyno run turn out? What MPG's are you seeing? Which tuner are you using? I know...nag nag nag. ;-)
BG
 
1 - 20 of 27 Posts
Top