M8 power vs Gearing is a good thing
#1
10-22-2016, 08:40 AM
M8 power vs Gearing is a good thing
I'll start by comparing my 96ci TC Softail to My 2017 Street Glide.
The 2009 TC 6 speed was geared slightly higher in all gears. 55 mph was not possible in 6th gear due to HP/TQ. I rarely used 6th unless above 70 mph and even at turnpike speeds, accelerating to pass required down shifting to get decent acceleration.
I've noticed with the M8 that sometimes you forget what gear you are in. It will accelerate smoothly from 45 mph in 6th without lugging. Granted that down shifting will give you much better acceleration. I contribute this to more HP/TQ of course, and a little bit lower gearing in the transmission compared to the TC softail. The M8 matched with a little lower gearing is a huge difference.
The TQ curve of the M8 is smoother and peak range is more inline with RPM ranges where most ride compared to the stock 103 as well. The M8 only varies by about 4 ft/lbs from 2500-4000 rpm. IMO the TQ power band being in this range is what makes it so much better. I don't buy into the Max HP numbers being significant as I don't ride at 5000-6000 rpm range. IMO the Max HP numbers are just hype to sell performance parts. TQ is where its at.
Source: Fuel Moto
Stock 103
rpm 2500 HP 38 TQ 80 TQ peak 86 @ 3300
rpm 3000 HP 48 TQ 84/85 HP/TQ dip @ 2700 HP/TQ bump @ 3300
Stock 107
rpm 2500 HP 44/45 TQ 94 TQ Peak 98 @ 3000-3400
rpm 3000 HP 56/57 TQ 98 TQ 94-98 from 2500-4000
Primary ratio and Transmission Ratio’s are the same.
I used these RPM figures as the 107 Street Glide runs at about 3000 rpm @ 78 mph and 4000 rpm @ 100 mph (no death wobble).
Most highway riding is in the 2500-3000 rpm range excluding aggressive acceleration.
My main point being, not only is the M8 smoother (engine and Tranny) and more powerful, but the power is also enhanced by a better match to the gearing compared to any other HD I've owned. (2016 and 2017 gearing in the Street glide being the same). 10-15 increase in TQ numbers really makes the biggest difference IMO. If I was going to build up an M8, I would aim towards increasing the TQ in the 2-4K rpm range and not worry so much about peak HP.
The 2009 TC 6 speed was geared slightly higher in all gears. 55 mph was not possible in 6th gear due to HP/TQ. I rarely used 6th unless above 70 mph and even at turnpike speeds, accelerating to pass required down shifting to get decent acceleration.
I've noticed with the M8 that sometimes you forget what gear you are in. It will accelerate smoothly from 45 mph in 6th without lugging. Granted that down shifting will give you much better acceleration. I contribute this to more HP/TQ of course, and a little bit lower gearing in the transmission compared to the TC softail. The M8 matched with a little lower gearing is a huge difference.
The TQ curve of the M8 is smoother and peak range is more inline with RPM ranges where most ride compared to the stock 103 as well. The M8 only varies by about 4 ft/lbs from 2500-4000 rpm. IMO the TQ power band being in this range is what makes it so much better. I don't buy into the Max HP numbers being significant as I don't ride at 5000-6000 rpm range. IMO the Max HP numbers are just hype to sell performance parts. TQ is where its at.
Source: Fuel Moto
Stock 103
rpm 2500 HP 38 TQ 80 TQ peak 86 @ 3300
rpm 3000 HP 48 TQ 84/85 HP/TQ dip @ 2700 HP/TQ bump @ 3300
Stock 107
rpm 2500 HP 44/45 TQ 94 TQ Peak 98 @ 3000-3400
rpm 3000 HP 56/57 TQ 98 TQ 94-98 from 2500-4000
Primary ratio and Transmission Ratio’s are the same.
I used these RPM figures as the 107 Street Glide runs at about 3000 rpm @ 78 mph and 4000 rpm @ 100 mph (no death wobble).
Most highway riding is in the 2500-3000 rpm range excluding aggressive acceleration.
My main point being, not only is the M8 smoother (engine and Tranny) and more powerful, but the power is also enhanced by a better match to the gearing compared to any other HD I've owned. (2016 and 2017 gearing in the Street glide being the same). 10-15 increase in TQ numbers really makes the biggest difference IMO. If I was going to build up an M8, I would aim towards increasing the TQ in the 2-4K rpm range and not worry so much about peak HP.
Last edited by MysticPurple; 10-22-2016 at 09:08 AM.
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Max Headflow (10-24-2016),
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#3
10-22-2016, 09:29 PM
Road Warrior
#4
10-23-2016, 07:11 AM
I'll start by comparing my 96ci TC Softail to My 2017 Street Glide.
The 2009 TC 6 speed was geared slightly higher in all gears. 55 mph was not possible in 6th gear due to HP/TQ. I rarely used 6th unless above 70 mph and even at turnpike speeds, accelerating to pass required down shifting to get decent acceleration.
I've noticed with the M8 that sometimes you forget what gear you are in. It will accelerate smoothly from 45 mph in 6th without lugging. Granted that down shifting will give you much better acceleration. I contribute this to more HP/TQ of course, and a little bit lower gearing in the transmission compared to the TC softail. The M8 matched with a little lower gearing is a huge difference.
The TQ curve of the M8 is smoother and peak range is more inline with RPM ranges where most ride compared to the stock 103 as well. The M8 only varies by about 4 ft/lbs from 2500-4000 rpm. IMO the TQ power band being in this range is what makes it so much better. I don't buy into the Max HP numbers being significant as I don't ride at 5000-6000 rpm range. IMO the Max HP numbers are just hype to sell performance parts. TQ is where its at.
Source: Fuel Moto
Stock 103
rpm 2500 HP 38 TQ 80 TQ peak 86 @ 3300
rpm 3000 HP 48 TQ 84/85 HP/TQ dip @ 2700 HP/TQ bump @ 3300
Stock 107
rpm 2500 HP 44/45 TQ 94 TQ Peak 98 @ 3000-3400
rpm 3000 HP 56/57 TQ 98 TQ 94-98 from 2500-4000
Primary ratio and Transmission Ratio’s are the same.
I used these RPM figures as the 107 Street Glide runs at about 3000 rpm @ 78 mph and 4000 rpm @ 100 mph (no death wobble).
Most highway riding is in the 2500-3000 rpm range excluding aggressive acceleration.
My main point being, not only is the M8 smoother (engine and Tranny) and more powerful, but the power is also enhanced by a better match to the gearing compared to any other HD I've owned. (2016 and 2017 gearing in the Street glide being the same). 10-15 increase in TQ numbers really makes the biggest difference IMO. If I was going to build up an M8, I would aim towards increasing the TQ in the 2-4K rpm range and not worry so much about peak HP.
The 2009 TC 6 speed was geared slightly higher in all gears. 55 mph was not possible in 6th gear due to HP/TQ. I rarely used 6th unless above 70 mph and even at turnpike speeds, accelerating to pass required down shifting to get decent acceleration.
I've noticed with the M8 that sometimes you forget what gear you are in. It will accelerate smoothly from 45 mph in 6th without lugging. Granted that down shifting will give you much better acceleration. I contribute this to more HP/TQ of course, and a little bit lower gearing in the transmission compared to the TC softail. The M8 matched with a little lower gearing is a huge difference.
The TQ curve of the M8 is smoother and peak range is more inline with RPM ranges where most ride compared to the stock 103 as well. The M8 only varies by about 4 ft/lbs from 2500-4000 rpm. IMO the TQ power band being in this range is what makes it so much better. I don't buy into the Max HP numbers being significant as I don't ride at 5000-6000 rpm range. IMO the Max HP numbers are just hype to sell performance parts. TQ is where its at.
Source: Fuel Moto
Stock 103
rpm 2500 HP 38 TQ 80 TQ peak 86 @ 3300
rpm 3000 HP 48 TQ 84/85 HP/TQ dip @ 2700 HP/TQ bump @ 3300
Stock 107
rpm 2500 HP 44/45 TQ 94 TQ Peak 98 @ 3000-3400
rpm 3000 HP 56/57 TQ 98 TQ 94-98 from 2500-4000
Primary ratio and Transmission Ratio’s are the same.
I used these RPM figures as the 107 Street Glide runs at about 3000 rpm @ 78 mph and 4000 rpm @ 100 mph (no death wobble).
Most highway riding is in the 2500-3000 rpm range excluding aggressive acceleration.
My main point being, not only is the M8 smoother (engine and Tranny) and more powerful, but the power is also enhanced by a better match to the gearing compared to any other HD I've owned. (2016 and 2017 gearing in the Street glide being the same). 10-15 increase in TQ numbers really makes the biggest difference IMO. If I was going to build up an M8, I would aim towards increasing the TQ in the 2-4K rpm range and not worry so much about peak HP.
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ocezam (10-23-2016)
#5
10-26-2016, 09:12 AM
Grand HDF Member
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