Honda Grom banner

1 - 4 of 4 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
Hi Everyone

I may have found a possible way to add autotune to the PV3 on the monkey and the grom, but I'm not sure if anyone here has tried this already. For reference, I have an Aus Monkey 125.

One of the variables in the learning section of the PV3 tune is the "O2 Transition Voltage (Target AFR) Threshold". This is the narrowband voltage that the ecu targets when adjusting trims in closed loop. The stock value for an Aus Monkey is 0.605v, and I have set mine to 0.7v which gives a similar outcome to using an EFIE.

The min/max values that can be inputted for this variable are 0V and 4.98V, respectively. My idea is that you could wire up the 5V output from a wideband gauge to the narrowband wire and set the target to 1.5V which gives an AFR of 13 (for gauges which output [email protected] and [email protected]).

If this works, the benefits are getting an "Autotune" of sorts and also a much cheaper wideband set up. The dynojet WBCX is 350USD, vs say a Spartan 2 for 125USD. You'd have to flash the closest premade map to your setup, set the target voltage to whatever AFR you want, and then the ecu would trim to target that.

The PV3 software also allows you to alter the closed loop rev cutoff, so if this worked, theres no reason why you couldn't have it trim all the way to the limiter.

Let me know in the comments what you think. If anyone out there has a wideband gauge with 5V output and a PV3, I'd love to know if this works. Otherwise, I'll just have to get a Spartan 2 and test it myself in the near future.
 

·
Registered
Joined
·
508 Posts
Dynojet has a WidebandCX just for PV3 now... this is exactly what they were accomplishing. I don't see a need to reinvent the wheel.
 

·
Registered
Joined
·
793 Posts
Hi Everyone

I may have found a possible way to add autotune to the PV3 on the monkey and the grom, but I'm not sure if anyone here has tried this already. For reference, I have an Aus Monkey 125.

One of the variables in the learning section of the PV3 tune is the "O2 Transition Voltage (Target AFR) Threshold". This is the narrowband voltage that the ecu targets when adjusting trims in closed loop. The stock value for an Aus Monkey is 0.605v, and I have set mine to 0.7v which gives a similar outcome to using an EFIE.

The min/max values that can be inputted for this variable are 0V and 4.98V, respectively. My idea is that you could wire up the 5V output from a wideband gauge to the narrowband wire and set the target to 1.5V which gives an AFR of 13 (for gauges which output [email protected] and [email protected]).

If this works, the benefits are getting an "Autotune" of sorts and also a much cheaper wideband set up. The dynojet WBCX is 350USD, vs say a Spartan 2 for 125USD. You'd have to flash the closest premade map to your setup, set the target voltage to whatever AFR you want, and then the ecu would trim to target that.

The PV3 software also allows you to alter the closed loop rev cutoff, so if this worked, theres no reason why you couldn't have it trim all the way to the limiter.

Let me know in the comments what you think. If anyone out there has a wideband gauge with 5V output and a PV3, I'd love to know if this works. Otherwise, I'll just have to get a Spartan 2 and test it myself in the near future.
I think this is awesome! Give it a a shot. I'm all for an alternative to the overpriced WBCX. And for as unhappy as I have been with the PV3 and Dynojet's lack of support I'm all for not giving them anymore money.


Dynojet has a WidebandCX just for PV3 now... this is exactly what they were accomplishing. I don't see a need to reinvent the wheel.
If it's cheaper and works as well or better I say go for it.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #4
I've got a duplicate post in the grom performance page. There's a bit more discussion over there, so please reply on that post.

Sent from my Pixel 2 using Tapatalk
 
1 - 4 of 4 Posts
Top