BoosterPlug Fuel Injection Tuning for the Hypermotard-Hyperstrada

This device has come up in a few threads but wanted to get a dedicated post for it. Please comment if you installed one and give your impression.

Booster Plug

Quick Overview (1-10 scale):
-Installation Difficulty - 3
-Cost - 5
-Function - 10
-Customer Support - 10

The debate about why the Hyper 821 (and later) engine is so difficult below 5K rpm is over. It's fueled very lean from factory down low for a variety of reasons. Tuners can obviously help with this issue but if they work with the O2 sensors, which good ones should, this issue still persists in the lower power band. Why clicking "ignore O2" option on RapidBike Evo doesn't solve this is beyond my technical limit. So, trick or bypass the O2's, right?

The Booster Plug does this in a devilishly simple way. It fools the ECU into thinking the ambient temp is 20-30 degrees F cooler than actual conditions. This triggers the ECU to richen the mixture in this low powerband. There's discussion elsewhere about what happens to ECU maps and tuning as the RPMs climb but, at some point, the O2's are ignored.

I was skeptical at first glance because it looked like one of those eBay "just plug it in and go!" scams, like the device you plug in your powerlet port for "MORE POWER!!!". Couple minutes on youtube and I realized this at least did what it advertises - fix nasty fuel/ throttle function in the low band. Basically, you are just spoofing the ECU by plugging a modified temp probe in line with the OEM ambient temp sensor.

I installed this and put about 40 miles on it yesterday. It radically changes the low speed demeanor of the Hyper. It's just soft, slow and civilized in that once dreaded 1st - 2nd gear, 5 - 30 mph zone. I downshifted from 2nd to 1st at about 30 mph going up a fairly steep overpass and my mind nearly exploded into my helmet. This would normally have been a particularly harsh evolution but it was buttery smooth working the throttle in 1st gear up the slope. I was also in Sport/ PWR HIGH/ DTC - 0. Same goes for the nasty on/off machine gun nature of the throttle in slow traffic situations. I can't really speak to highway speed in upper gears as my tuner has this pretty ironed out already. Didn't notice anything off hand but will feel it out more later. Some users report better start and idle. Maybe. I'll keep my eye on this but it didn't jump out at me. Honestly, I have so many other starting issues right now that I just focus on the bitch turning over period.

Installation:
Not terrible. If you can change the headlight bulb, you can do this. Included a few diagrams to help with locating the OEM probe. Pull the nose fairing, then the headlight housing. Locate the OEM temp probe in the recess behind the large wire looms that lead to the dashboard. Remove the sensor from the recess that holds it in place behind the dash and disconnect the lead. Plug the marked Booster Plug leads to the probe and ECU lead and do your best to find a home inside the dash area behind the headlight housing. OEM probe goes back in it's recess where you found it. The new probe does not have to be exposed to the open air. Re-install everything in reverse, minding the wires and looms as it gets very crowded back here and you can pinch or break something if not careful.

Note: This only affects ambient temp reading. No impact on coolant sensing and fan operation. I feel like this should be a bullet on their homepage because I had to look it up. Once you get the basic operation it makes sense but to a casual rider that doesn't get their hands dirty, would you know how the ECU processes all the temperature readings?

Customer Support:
I added this even though you probably won't need it. I reached out because I had an issue with shipping (no USPS available). The rep, who might have been the owner, responded immediately and actually carried on a very casual conversation with me. He was very personable and appreciated my interest in the product.

Also, really nice packaging and product quality. Easy to read instructions included and a couple nice farkles thrown in (ear plugs in a neat little case, neck muff, stickers). It feels very well built and they did a good job in making the device as small as possible. Makes that $170 price tag a little easier to swallow.

Cheers and be safe out there.

Should also note that Araitim and I are running this in tandem with a tuner (RapidBike Evo). I didn't notice any adverse reaction, though I have a laundry list of ECU and engine issues going in. I haven't adjusted any of the tuner settings yet but don't think it will cause any problems based on how non-intrusive this mod is.

And while the company touts this as an alternative to a power commander or tuner, it does not unlock any hidden power or have a traditional mapping ability. It just tricks the ECU into doing what it is coded to do with a large temperature delta. All it will perceivably do is smooth out the low end, which is does better than any other option on the market for our bikes.

Araitim said:

Have you opened up the auto tune perramiters now that the booster is on? I have been thinking about making the value under 5k -0- (which is neutral fueling for the ecu) and opening up the amount the auto tune can adjust. I have it turned off now and just the Kul map. In the past I turned on auto tune and only gave it a very small window of auto tune adjustability. I think the booster adds fuel everywhere, I wonder if we set the auto tune to function at 5k and above along with a +4 and -4 of adjustability and see what happens. What are your thoughts?

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Haven't touched the software. I just installed the BP and it's been a biblical 2 weeks straight of rain here. My bike lives in one of those clamshell tents so can't open up the guts when it's raining. I really don't know enough about ECU tuning to make educated adjustments. I always just copy what Kuksol or you did. My previous tinkering would be swapping between the Kuk map and full autotune, maybe toggling the O2 setting. I also don't have a very convenient or sterile environment for testing. The speed limit is 20 mph on my base and I have to dodge traffic and potholes off post.

Just remembered something else I noticed on first ride. The decel in that slow zone is considerably less violent. Rolling off throttle was gentle and smooth. It really is like a different bike in the urban/ slow zone now.

Tejas said:

Does everyone agree that the Booster Plug alone, without any other modifications, is the best way to start addressing this issue? Thanks!

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Well, it's the cheapest. If you're looking for a bit of smoothing and a tune, then a tuner/flash would be better. I'd say this alone is perfect if you just want a smoother low end and don't want to add a bunch of aftermarket parts or spend a lot of money.

I had a nice cool weather ride just a bit ago that ended in a really congested area. I feel it's much more noticeable after reaching full operating temp. I notice the smoothness at the end of my rides more than pulling out somewhat cold.

No tuner I know of taps into the ambient temp sensor. That's the only thing BP does, which is not a tuner. Makes the stock ECU richen mixture by fooling it. The RB Easy can manipulate AFR a bit, but not in this crappy low end because of the ECU construct. This is where my expertise ends as how the O2s and open/closed loop stuff works is black magic to me.