Yamaha xs400 qs180 conversion

[bananu7]

It’s alive! It’s definitely sluggish off the line like you guys said.

First off, huge congrats on getting it running. I know first hand how big of a moment it is. Good job!

As far as being sluggish - you have a huge motor and a controller capable of a lot of phase amps. Is it actually giving it all it's got? I mentioned targetting the effiency peak; the gearing might be too tall, but that hugely depends on your target cruise speed.

 

[Wheelsandall]

Well funny story about that. The display always showed gear 2. I figured it wasn’t communicating whatever I would deal with it later. Then today I went to hook up a reverse button (yes I know it’s a bike, but ive done it before and it makes getting out of the garage a breeze) and when I hooked it up, I found the display would show “R”. Now I’m thinking maybe the speed lines aren’t actually hooked up. I’m only using the right side controls from the kit and there’s a 1,2,3 button on it so I assumed it was the speed control. Well I was wrong! I went to the controller and found the high and low speed wires and traced them to the front and found them in the blank connector for the left side controls. I rewired it to the right side controls and got my three speeds working!

I was riding around in 2. So I switched to 3. Woah! This thing pulls and pulls and pulls. It’s still a little slow off the line but man if you punch it at 40mph, you better be holds on because 60 comes very quick. I don’t see any reason it won’t do over 100mph. I’m still going to swap out the rear sprocket from 37t-47t but I want to do a speed run with it the way it is to get a baseline once the bike is in ready to run shape.

 

[Wheelsandall]

A few more updates. My original plan was to mount the charger inside the “gas tank”. When the charger showed up and I saw how big it was I put that on the back burner. I decided to give it a go today since the chopped up tank left so much extra room. A few more chops and it fit like a charm. The 110v plug comes up through the cap. When I get the new cap “I lost the keys” I’ll secure it to the cap somehow. The bonus is that I can see the voltage reading though the gas cap opening.

I also put some cooling fans in the side covers to get some air flow to the esc while it’s sitting.

 

[Wheelsandall]

Top speed so far. This is about half throttle and running out of road. Once I get it insured and legal I’ll take it out on the highway

 

[Wheelsandall]

Got the 47t sprocket on and a better DID chain. Definitely has more low end and noticeable higher rom at speed. I don’t know if the display is reading correct but it’s showing pretty high rpm. I’m getting conflicting reports on the max rpm of the qs180. Some say 4100 some say 7000 with field weakening. Does anyone know a safe max rpm for these motors?

 

[Wheelsandall]

I modified some Harley dyna glide shocks that I had laying around and cut some meat off the spring retainer to give it a little less preload.

Got the ignition switch and gas cap. Mounted some perforated metal to the bottom of the tank to cover the high voltage stuff. And best of all I found my old sissy bar in my parents garage! Aside from going with an xs650 dual front disc brakes and an active balance BMS to get full voltage out of these batteries, I think I’m done with the modifications for now (ya sure I am). Just going to try to nail down the best gear ratio and fine tune everything and see how long these batteries will last.

 

[j bjork]

Got the 47t sprocket on and a better DID chain. Definitely has more low end and noticeable higher rom at speed. I don’t know if the display is reading correct but it’s showing pretty high rpm. I’m getting conflicting reports on the max rpm of the qs180. Some say 4100 some say 7000 with field weakening. Does anyone know a safe max rpm for these motors?

I think I have seen a spec sheet saying 7000rpm, but I cant seem to find it now.
The ones I saw now didn't say anything about max rpm, but they ran it to 6000rpm in their efficiency map:

QS Motor 8000W QS 180 Motor QS Mid Drive Motor

It's QS Motor 8000W QS 180 Motor QSD180A-90 72V 150KPH Electric Mid Drive Motor For Adult Electric Motorcycle, which is QS most powerful mid driver motor.

www.cnqsmotor.com

 

[Wheelsandall]

Ok so I was reading the tach wrong. I had the max rpm set for 5k rpm which is a much bigger line than the small black line that is the current rpm. Anyway I’m at about 3500rpm at 65mph. I took it for a longer ride of about 5 miles and got it up to 80mph with plenty left. I don’t see it won’t do over 100mph. I still may gear it down but I do like cruising at lower rpm. It sure is hungry for battery but hopefully I’ll be 5v higher and higher capacity when the active BMS shows up and is installed.

 

[Wheelsandall]

Finally got it on the highway where I could open it up. I have the max rpm set to 5000rpm and got to 86mph. I’ll bump up the max to 7000 and see what it does. Also got the active balancer in which is actively balancing as we speak. Used a wopping 20% battery on a 12 minute ride.

 

[harrisonpatm]

Used a wopping 20% battery on a 12 minute ride.

High speeds use exponentially higher power to achieve

 

[Wheelsandall]

High speeds use exponentially higher power to achieve

Ya I think I’m going to have to make level 3 for all pirated and level 2 for normal riding when I’m not messing around

 

[Wheelsandall]

Small update. I weighed the original engine and it comes in at about 120lbs, exhaust, fuel, original 12v battery id guess somewhere around 140lbs was removed. The batteries are 25lbs each, the motor is 50lbs then maybe 10lbs of steel for brackets and the battery tray totaling about 160lbs. So it might be 20lbs or so heavier than it was so I’ll take that trade off. Especially since it’s faster than it ever was with the gas engine in every way. It’s very well balanced even with the motor hanging off to the right side. It handles great. So far I’ve got to 93mph but still running out of road. I need to get it fully charged and take it out at night to get 100mph then I’ll be happy and I’ll change the gearing for more torque. So far I’m am super happy with it. If I never have to rebuild a motorcycle carburetor in my life, I’ll be happy.

 

[Wheelsandall]

I can not get this thing past 93mph. EXACTLY 93mph. I have field weakening set to 100% in all rpms. My max rpms are all high. It’s hard to look down at this tiny tachometer while I’m riding but by math 93mph should be less than 5000rpm. When I go full throttle at full speed it actually cuts out. I don’t think my voltage is dropping too low because it does it at different soc. I feel like the throttle isn’t calibrated right. I’ll keep messing with it but anyone got any ideas?

 

[Wheelsandall]

After doing some math 93.1mph is almost exactly 150kph. I wonder if this gps speedometer is limited to 150kph. I’m going to do a relearn on the motor and throttle and use my phone speedometer instead.

 

[Wheelsandall]

Well I think that I have to just be happy that 93mph is the top speed with these batteries and gear ratio. I tried lowering the field weakening percentage, fully charged the batteries increased the max rpm’s to the moon. No matter what it won’t get past 93mph. I think part of the problem is that I’m so used to ice engines where there’s always a little more to squeeze out of it but electric is a different animal.

I’m going to lower the front sprocket for more torque so maybe that will help at high speeds? Honestly 93 is fast enough on a small bike like this but 100 is a nice round number.

 

[j bjork]

What is your max rpm set to? If you post your settings there is a bigger chans that someone can help. I think my bike yz250f did a little over 100kph with somewhere 7.5 or 8-1 gearing without field weakening, but with mtpa. Higher voltage though, with 30s/108v nominal.
I think your gearing sounds crazy high, I would guess somewhere around 5-1 would make more sense, maybe closer to 6-1.

 

[Wheelsandall]

My current ratio is about 3.9:1. Max rpm is set to 8000 just to see what happens but it won’t get over 5. It’s just like a brick wall. I’ll post some setting when I get home. I don’t have many rear sprocket choices which is the problem if my other front sprockets ever show up, the highest I can go is 4.7:1.

 

[Wheelsandall]

What is your max rpm set to? If you post your settings there is a bigger chans that someone can help. I think my bike yz250f did a little over 100kph with somewhere 7.5 or 8-1 gearing without field weakening, but with mtpa. Higher voltage though, with 30s/108v nominal.
I think your gearing sounds crazy high, I would guess somewhere around 5-1 would make more sense, maybe closer to 6-1.

I’m confused by the mtpa. Is this a setting or is this just telling you that you’re getting your maximum torque per amp?

 

[Wheelsandall]

Here’s the current setup

 

[j bjork]

I’m confused by the mtpa. Is this a setting or is this just telling you that you’re getting your maximum torque per amp?

On my 3shul, vesc based controller it is a setting. I think it helps a little to get good power at high rpm without extending the max rpm as fw can. That and my higher voltage might give me another 1000rpm. 150kph is rather fast, so it sure takes some power to keep that speed. If you are at 5000rpm by then maybe you are running out of steam, as you probably already are in to fw to get there. Have you tried with and without fw to see the difference? I think it is "weak character" and "weak response" and "ratios in speed" that determine if and how the fw works.

 

[dominik h]

Weak response 7 is no field weakening.
Weak Charakter should not be changed according to the manual.

What is Your power requirement for 93mph?

Does your motor have a temperature sensor?
At the moment the controller is calculating the temperature.

 

[Wheelsandall]

The motor is getting warm to the touch. No matter which temp sensor I select it shows the wrong temp so I chose cacu and it seems close. I think im just running out of power the voltage drops to around 80v so I’m sure amps are dropping off as well I just don’t get why it takes power away when I go from 95% throttle to 100%.

 

[dominik h]

You can run a graph in the app, it writes down 50 seconds after turning the controller on.
There you can see rpm , voltage, line amps, throttle, weakening field

 

[Wheelsandall]

Ah ok. I’ll do that next time. I saw the option but I didn’t get into it.

 

[dominik h]

Or you can run a screen recorder while the app is open and is showing the meters, then we can have a look, what is going on.