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aRacer MiniX & AF2 experience (Finally bit the bullet)

14K views 72 replies 11 participants last post by  Pard 
#1 ·
Bought these for my 2017 (still waiting for the AF2), figured I would start a thread to document my experiences, as aRacer is new to me.

Back story on my Grom as it sits:

  • Yuminashi 143 kit (cheap AF, don't judge me..... LOL), may go bigger in the future (164 kit is pretty cheap too :cool: )
  • Old very rare in the USA, Yuminashi Hi Lift cam, originally came with their "160cc Ultimate" kit but was later sold separately (see specs below)
  • Matching special Yuminashi Hi Lift (stock size) valves, double valve springs, and retainers (zero float even above 12.5k (limiter is set to 12.5 now & I try to stay off it))
  • GromFatherz Rev Wedge, matched to a backcut OEM throttle body & ported head
  • ported head, matched to a Finbro High Mount Exhaust (also rare in the USA)
  • 120cc Yuminashi injector (have a 140 on standby, but do not see the need)
  • Original DB Short Ram intake with K&N filter
  • Yuminashi v9.1 Stand Alone ECU with BT app for tuning (old & hasn't been updated since 2019)
  • WB O2 standalone gauge that also inputs to the Yuminashi ECU (BIG reason of all of this, no Autotune capabilities)

Because the Yumi ECU was for OG I had to repin the harness (will reverse before installing aRacer stuff), and cold start DID NOT WORK, actually had to unplug the CS connector cause it made a hideous constant clicking sound with this ECU. Even the cold start settings for the ECU app/PC program DO NOTHING, so I have to hold the throttle until it gets some temp into it or it will stall.

Bike runs really good once warmed up, tops out around 82 mph GPS with a 14t front & stock rear sprocket (full tuck) & is super fun to ride. But the amount of time I spend getting it tuned could have been better spent enjoying the ride, & its still needs more dialing in to be "right".

For reference, my girl's OG has the same 143 kit, TB cam, stock airbox with a Koso tube & BMC race filter, that was tuned & flashed on DHM's dyno. Hers is 14.2hp & a tick under 10ft lb torque, & never needs to be adjusted, just works every time. She always gets a jump on me off the line til about 40mph, then I roll right on by & leave her....

Will update this thread once I get the AF2 & MiniX installed. If anyone has any pointers to get me going in the right direction with the aRacer stuff, feel free to chime in. I have been studying for a while before pulling the trigger & kind of get the gist of it, but expect a bit of a learning curve.

Don't know if anyone remembers this cam or not, but here's what they had to say about it:
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#4 · (Edited)
Both units have arrived, and are installed. Super simple stuff, and it allowed me to get rid of my stand alone WB O2 gauge.

Took a min to figure out how to do the initial Quick Burn, found no mention anywhere that I needed to set the access point in the X-Tune app for the ECU to connect to my home WI-FI in order to download the base map files needed, even CJR does not mention this on his site's instructions. Maybe there's another way, I don't know, but I managed to get it done.

Was also a pain to get the thing to start at first, but remembered I had the cold start solenoid unplugged due to my other ECU. Then getting it to idle, then idle w/o hanging at 3k after a throttle blip, but she's purring now.

Let the auto-tuning begin.... Too bad there is not a database to download map files closer to my mods to start with, but it is what it is...

Gadget Packaging and labeling Font Carton Box


List of upgrades/features already available (missed the rest below this). Really don't find the need for any that are not preinstalled until after I get it dialed in some, may add a quickshifter later.

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#5 ·
Thanks for sharing this. Currently running the mini 5 with the AF1. Wonder if the X with af2 is worth upgrading to.

When cold, the aracer has never given me a solid idle. Once warm, it is fine.

I use auto tune but played around with the targer afr setting compared to stock aracer targets. I run it a bit more rich at high power settings.

One day I should get it to a dyno and have a tuner dial it in.
 
#7 ·
Mine seems to start right up & idle with no throttle input now..... Forgot how nice it was to have that, LOL.... The sub 2 minute Quick Burn is nice vs 10ish minutes on the old units.

Have you installed the AF2 sensor in the head like you had the old WB sensor or in the header pipe?
Sensor is in the head with an angled adapter.

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#8 ·
Getting my feet wet on this. Can you put the WB O2 in the stock location?
I wasn't aware of the additional fees with the app. I need to plant more money trees.
Good to know about setting up the app on home wifi.
 
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#9 · (Edited)
Getting my feet wet on this. Can you put the WB O2 in the stock location?
I wasn't aware of the additional fees with the app. I need to plant more money trees.
Good to know about setting up the app on home wifi.
Yes, you can follow the instructions on CJR's site to get started, but when it came to the quick burn nothing worked until I found the extra setting to connect the MiniX to the home WIFI (sucks that aRacer has no documentation or instructions on their product yet). Was pulling out my hair for a minute & I cannot afford to spare any at my age, LOL.

You can get the WB sensor in the head where the stock sensor is, but you need this adapter & you have to cut the ridge off the head to be able to spin the adapter into the head. I had a straight adapter in there before but found this one that allows you to angle the sensor up better. Helps keep moisture out of the pricy sensor :cool:

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#10 ·
You can get the WB sensor in the head where the stock sensor is, but you need this adapter & you have to cut the ridge off the head to be able to spin the adapter into the head. I had a straight adapter in there before but found this one that allows you to angle the sensor up better. Helps keep moisture out of the pricy sensor :cool:

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That's awesome. Now I don't have to be limited on obtaining an exhaust with a hole and or having a fitting installed.
 
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#11 · (Edited)
That's awesome. Now I don't have to be limited on obtaining an exhaust with a hole and or having a fitting installed.
Same reason I went this route, did not want to trust my expensive (to me, definitely more expensive out there) & rare exhaust to some hack at an exhaust shop, & the guy I used to used to weld stuff for me died years ago.

Found a pic with the guard off when I installed it, you can see the fins I had to cut off with a die grinder (disregard the grinder dust).

Automotive fuel system Motor vehicle Automotive tire Automotive lighting Automotive exhaust
 
#12 ·
Anyone have feedback on the accuracy of the aRacer temp readings? I also have a Koso Temp gauge & they are WAY off, unless I set the Koso to T-2A (Grom is supposed to be T-2), they they match up almost perfect. I also have to change the setting EVERY TIME I turn off the key now, very annoying.
 
#15 · (Edited)
Think I answered my own question.... Pretty sure my TINY AZZ Battery Tender battery is on its way out or just not enough for the ECU. Ordered a nice 4ah gel battery to replace after reading about aRacer having connection issues with lithium battery's. May explain some of the AT issues I think its experiencing so far, will know Saturday. I'll just stick the BT battery in my scooter that only needs it for lights & the TrailTech dash.

This tiny thing is what I've had in there for a while now..... weighs around 1lb!
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#13 ·
how did you decide on the cam?
What's the difference on all of these?
There's the TB cam for only $76.99
The DHM S1 (Gen2) $139.00
Then there's the DHM S1 for the 2022+ for $179.00
Oh, let's not forget the Takegawa from HR for $119.00
 
#14 · (Edited)
Bought the Yuminashi cam years ago when TB cam was new to the market & didn't have any real world reviews..... Held onto the TB cam in case the Yuminashi wasn't going to work for my bike, but fell in love with how high in RPM it made power. Coming from a Two Stroke background, it just felt right to me, not much down low but when it started making power it came on strong & fast like a 2T. That was all on a stock bore, & the cam works even better on a 143...... Can't wait to see what it can do on a 164 :cool:.

TB (for OG & SF) is probably the best bang for the buck on the market given its price & proven performance.

Noticed you threw the S1 for 22 in that list, not many cams out there for those yet that I have heard of.
 
#17 ·
Thing is just off.... Sometimes it reads & runs right (great when it does), other times I does not read the TPS until 1.8+%, which throws the tune off all over the map, will not idle, stalls at lights, PITA to start! Anyone else have this happen? Just bought, charged, and installed a NEW 4ah AGM battery with 80CCA, should be plenty since I have nothing else connected to the bike but a KOSO temp gauge that is on with the key..
 
#18 ·
Thing is just off.... Sometimes it reads & runs right (great when it does), other times I does not read the TPS until 1.8+%, which throws the tune off all over the map, will not idle, stalls at lights, PITA to start! Anyone else have this happen? Just bought, charged, and installed a NEW 4ah AGM battery with 80CCA, should be plenty since I have nothing else connected to the bike.
I am sure your battery is fine.

I have the same complaints about idle. Sucks.

BUT it does the job where it counts near redline under demand.

I got used to having to milk the throttle a bit at idle to not stall . I avoid stopping in general :)

Run a higher than typical idle speed, adjusted by the cable adjustment and set screw, to get a reliable, but high speed (2K), idle.

Never paid attention to TPS after initial setup and autotune.
 
#20 ·
Just found a FB post talking about nearly the same exact issues as mine..... Apparently low voltage on the AF1/2 & ECU causes all kinds of issues. So bad someone even made a jumper harness to fix the problem!

 
#28 ·
Did a little test & put the bike on a power supply @ 13.5V this morning to see if holding a steady voltage made a difference. Stalled 1st hit of the key, but when the ECU realized it was getting more power, 2nd attempt it fired up & idles without any struggle or throttle input. Battery voltage at the battery was 12.8V before I put the power supply on it, so I know the battery is putting out enough power. That harness, albeit kind of pricey @ $35 shipped (AF1 harness is cheaper), should work perfect for me. Seems the AF1-2 are drawing the power down on the ECU when plugged direct into it & causing odd issues for me, so separating the power supply of the two only makes sense.

Bike ran nearly perfect all the way to work (5 minute ride), ran closed loop until it was warm enough to auto tune, then switched it over to try & get a cleaner map the rest of the ride.
 
#29 ·
Another day another problem.....

Purchased Launch Control & it shows up as purchased in the app. The lock is gone on the xTune app monitor screen, but I cannot turn it on. Every time I click the LC "on" button the app crashes!
 
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#34 ·
Finally had to time to really get a good AT base map. Starts easy, idles smooth, runs great, but no matter what I do it hangs at 3600-3800 idle. Took some timing out at zero throttle from 3200 to 4800, seems to have helped some but still hangs, even with the Koso Air screw installed. Found I was getting some odd inconsitent AFR readings, pulled the O2 sensor & it was black AF! Cleaned it & let it dry, reads perfect & consistent again.

Played a little with the rev limiter too..... 12.5k is my sweet spot I think :cool:. With a 14t front & Superlite stock toothed rear, it hits the limiter @ 34mph in 1st gear, 56 in 2nd, shifted from 3rd at 71 still had not hit the limiter yet, LOL. Obviously pulls better/harder shifting before the limiter somewhere in the 11-11.5k+ range seems about right.

Screenshot of the AFR chart in the upper RPM range :cool: . More time will clean that up even better now that everything seems to be working as it should. TPS was the biggest issue with getting consistent repeatable AT maps going... The WickedGrom power harness I believe had some influence on that, cause it actually tuned the low throttle openings easily this time around.
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#35 ·
I had the exact same issues with mine. Changed the battery out as it was 2 year old (only 400km but) and new battery works a treat. Might try seperate routing of the AF2 module as I noticed a massive difference in voltage when I unplug the AF2 module. I was seriously cursing the AF2 module until I changed the battery.
 
#36 · (Edited)
Been through 2 new batteries since installing aRacer stuff in hopes of better results..... Just got a WickedGrom power harness HERE, that separated the power feeding the AF2 from the MiniX, reads 12-13v on the ECU now (through the app). Still 13+ at idle & over 14v above 3k at the battery. Harness basically moves the power supply source of the AF1/AF2 from the ECU to the tail light circuit, seems to have taken a load off the ECU so it acts better both get a steadier power source.

Running pretty good now, definitely auto-tuning easier & the TPS actually reads like it should.
 
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#37 ·
aRacer FINALLY got back to me about the launch control issue.... they said the app dev has had other reports of the same problem & that they are working on an update to fix it. Fingers crossed! LOL
 
#38 · (Edited)
Still waiting for an update to fix the upgrades crashing the app. Also have glitches since updating the wifi as recommended on the FB group. Thing is constantly freezing up while AT is running..... Apparently the MiniX does not like voltage drop during startup, & it freaks it out enough to make the TPS not read right & that is causing all sorts of trouble. Will be testing a capacitor bank added to the battery to see if it will help the voltage drop during startup (bike is apart currently). Seems aRacer should have done more testing before releasing the MiniX.....
 
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#39 · (Edited)
Crappy weather & irritation caused by things not working, haven't ridden it much in the last week or so. So in the meantime, I got a 34mm TB & intake. Had to take a lot of material from the intake port to match the Koso 30.5mm opening. Still a little cleanup on the EX side to do, but the intake side is ready for action :cool:

Before:
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After:
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EX after (forgot to take a before):
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Little more cleanup & EX is also ready for action:
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#41 · (Edited)
Apparently, it's what the fast guys do..... LOL :cool:

Just got it all back together, what a difference! Butt dyno says 15+++ hp from a cheap cheap Yuminashi 143 kit. Old SX290 8.2 Yuminashi hi lift cam I have been running has been waiting to be allowed to breathe.
 
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#42 · (Edited)
Also tested the capacitors on the battery, seems to have helped keep the voltage steady 11 ish volts during startup, so the TPS readings don't go crazy. If it catches the piston on the compression stroke it still struggles, but I can bump the starter to get it past the compression stroke & it fires off easily. MiniX seems to like this much better.

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#46 ·
Works good, now that I have most of the bugs worked out, bike is running better & stronger than it ever has now...... That's the reason for this post in the 1st place..... To hopefully help others not have to struggle as much as I have to get theirs going right.

I think they rushed the release of these, with minimum real world testing.....
 
#47 ·
Thanks for all the work on this. Looks like at the end of the day the AF2 needs to be powered separately. New battery helps along with a few caps.
 
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#48 ·
Pretty much..... And don't run Auto-Tune with dec fuel cut on, or you'll be sitting on the side of the road trying to figure out why the bike was running so good then just died like mine did this morning. Guessing it was just DUMPING fuel because it thought it was lean when off throttle. LOL

Good thing I have two AT maps saved so I can reload the map real quick when something acts weird.
 
#49 · (Edited)
Several hundred miles now since the upgrades & app update. Bike is running amazing! I have added timing back where I had pulled it to combat the idle hang. Pard, I have discovered that with closed loop turned on, and Dec Fuel Cut (DFC) on, there is ZERO idle hang, but every time I turn those off & try to auto-tune again it is there. After AT session, turn CL & DFC back on, idle hang is gone.

Cliff notes: Yuminashi 143 kit + Old Yuminashi 8.2 Hi lift cam/valves/retainers/double valve springs + Old Finbro 125cc exhaust w/ CF LeoVince can + aRacer MiniX + aRacer AF2 + Wicked Grom AF2 power harness + heavily ported stock head matched to Koso 30.5 to 34mm intake + 34mm Throttle Body & 120cc injector + 2" diameter 90 degree silicone hose & aluminum coupler so I could get the filter off the TB (did weird midrange things like that) = bike runs amazing! 70 mph GPS in 3rd gear, on a 14t front sprocket, amazing.

Going to the track Saturday for the 1st time with the 143 installed, should be interesting. Also going to head to the DYNO soon to get a proper tune, now that I FINALLY have all the bugs worked out.
 
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