TR650's need a Power Commander, a Booster Plug, a Wuka King or similar to improve the all-to-common lean mixture in the open loop portion of the FI map. Some people don't even know their bike COULD be running better. What if you found a mod that corrects the issue for $20? What if it worked BETTER than those other spoofers with the sensing probes? What if it added NO clutter to your bike? Introducing... IAT Modification (intake air thermistor mod) Dateline 8-1-13 I received my new thermistors from Avnet yesterday, $20.12 including the $8 for FEDEX. (8 qty part #B57861S 104F 40) Vendor list here... http://octopart.com/b57861s104f40-epcos-851024 International vendor here (search for part #706-2765P) ... http://www.rs-components.com/index.html Note If you own an ohm meter it would be a good idea to check each thermistor before assembly, they should all measure very close to each other with their heads subjected to the same temperature. Then check one at or near 25C, it will measure at or near 100K ohms. This step will ensure you where shipped the correct thermistors. These little guys look exactly like the thermistor inside our bike's IAT. It is highly likely they are the SAME mfr & build specification as the OEM, here are the semen swimmers... I sawed off the cage of my OEM IAT with a dremel, you can see the thermistor supported inside now... I cut the head off the thermistor - cutting the plastic center support thingy is optional... I pulled back the teflon insulation on the new thermistors, no need to try & strip the wires, though I did use a razor to sort-of scrape & pick the insulation off the wires from the IAT... There's 8 thermistors, twist them in pairs, you'll now have 4-sets, then twist those in pairs, you'll now have 2 sets, OK to use pliers to tighten up your twists, looks like this... Twist again & cut the ends off to make them even, slip over some heatshrink tubing, looks like this... Solder away, tin your leads first, use rosin core solder, plumbers solder & flux would be OK if you cleaned the flux off, picture shows bottom connector is cleaned top connector still dirty... Apply heat with heat gun or use the fast waiving bic lighter technique to shrink your tubing... I applied a few layers of heat shrink until I was happy with the rigidity-ness of the thing. Note heat shrink is over plastic base AND the leads. I protected the thermistor heads from being exposed unnecessarily to heat while blasting it with the heat gun, it now looks like this... Yes it is taller than the OEM, I left the leads on the new thermistors their full length b/c they would be better protected from heat while soldering & for ease of working with them. But you can cut them shorter. Considering the new height I'll have about 1/2" clearance to the ceiling once inside the airbox. A note from the thermistor mfr about cutting the leads & soldering... When soldering, care must be taken that the NTC thermistors are not damaged by excessive heat. The following maximum temperatures, maximum time spans and minimum distances have to be observed: Dip soldering Iron soldering 360 °C max. Soldering time max. 2s. Distance from thermistor min. 6 mm min. Under more severe soldering conditions the resistance may change. Congratulations!! You have The ERUPTION!!! It measures & compares like so... The ERUPTION - about this mod This mod is for anyone who wants a spoofer for their TR or for any BMW that uses an IAT that's interchangeable with the TR's. A spoofer is a device designed to fool the ECU into richening up the mixture to improve engine ride-ability. A lot of new bikes suffer from overly lean fuel mixtures. For the TR, it’s commonly reported the bike benefits from fuel enrichment in the open loop map. Some popular spoofers have evolved into devices that use external temperature probes that plug inline with the IAT. Because they endeavor to modify the existing IAT R/T curve, & b/c their external probes are sometimes subjected to false temperature influences, they can be a bit imprecise at hitting their target. Depends on the device, the installation & the ambient temperature. By comparison The Eruption is simple & accurate at hitting its target fuel enrichment through the widest temperature range. Should you ever want to reverse the mod, simply reinstall a stock IAT, cost has been reported to be around $25 with shipping. BMW P/N 1739510. It's not clear how dealers or mfrs would view any spoofer installation should an engine warranty situation occur. Probably the same way they view a PC but who knows? The Eruption replaces the single 5k NTC in the IAT with 8- 100k NTC thermistors to spoof the ECU into thinking it's 20C colder than it really is to get a 6% enrichment while operating in the open loop map. It maintains that 20C offset really well no matter what the real temperature happens to be. This gives a consistent fuel mixture enrichment. Credit to Italian friends Gaspare & Belinassu for their development & testing work plus everyone who provided information in this thread which was used to keep this initial post up-to-date. Don't do this mod if you already use a spoofer Some benefits over other spoofers are... This arrangement follows the non-linear curve of the OEM 5kNTC intake air thermistor VERY well. The temperature measured IS the actual air temp for combustion with no false heat influences. The IAT stays dry & isn't subject to false cold influences (wetbulb temps). Bike outwardly looks stock, no extra wires, switches or sensors running about. Inexpensive. Q & A Will this mod stop stalling problems? That was the motivation for this TR owner to find a solution. The Strada would stall & though the dealer's "program update" helped matters it didn't eliminate the occasional & sometimes ill-timed lean stall. Several magazine articles have also mentioned the issue. The Eruption solved the problem. How do I get to my IAT to do this mod? Remove the left side plastic body panel, for tips on how this is done see High Five's "How to" post #189. Remove the IAT Bosch connector plug (hint; depress the metal clip) located here. Thanks again to HighFive. Depress the small plastic dog leg release on the side of the IAT (see photo above) & pull down from the airbox. Why is there eight thermistors? It had to be to get the correct T/R values. The new thermistors look identical to the OEM but they are higher values. Combining them gets us to our target values. The new thermistors measure 100k ohms at 25C & once completed The Eruption will measure 12.5K ohms at 25C. I have The Eruption now there's a symbol displayed on my dash? If you select to display ambient temp on the dash it will now show 20C colder (36F) than what it really is. Also a small snowflake icon will appear about 20C/36F above what it otherwise would, it's there to warn the rider of potential icy road conditions. This is a common tradeoff for all of the IAT spoofers used on the TR (BoosterPlug, WK The Juice) as it uses the same thermistor(s) for outside air temp display & ECU computations. The snowflake is small & not annoying. I have The Eruption now the Check Engine Light comes on when it's freezing outside, why? With the stock IAT the CEL will illuminate on the TR around 0F. It's not known with any specificity why the engineers designed this to happen. Any IAT spoofer will fool the ECU into thinking it's colder than it really is, so once installed, expect the CEL to illuminate around freezing temperature on the TR no matter if you're using Booster Plug, Wuka King, The Juice or The Eruption. UPDATED UPDATED Are there any downsides? UPDATED UPDATED Evidence has been presented that any open loop spoofer can be rendered less effective over time by the ECU & Lambda working to counter it's inputs. Evidence suggests that other devices such as Power Commander, LC2, EJK, AF-Xied are a more encompassing strategy than an IAT spoofer. Therefore you are encouraged to look into & consider alternatives that are capable of modifying the entire fuel map without being subject to mitigation of effectiveness. The Eruption has stopped dangerous engine stalls & continues to perform in that regard for many, also it may be used in conjunction with some of the above mentioned strategies. Expect the bike to run rich during cold-start / warm-up but not smokey rough running rich. It's not uncommon for the richer mixture to change the color inside the muffler outlet to something darker. You will burn 6% more fuel when the bike is operating in the open loop map, steady state throttle is closed loop so no fuel change there. Any 20C offset spoofer (Booster Plug, Wuka King, The Juice) will be the same in these regards, they just don't mention it. OK I'm going to do it - is there anything else I should know? While you have your side panels off you may want to consider doing a canisterectomy (tips, small fuel filter can be found at O'Reilly autoparts, also vinyl (colored) vacuum plug caps like these will last longer than the rubber ones, it's not too difficult to remove the hose at the throttle body & use a vinyl plug there). The Eruption works well with a cat-be-gone mod & is expected to work well with after market slip-ons. _______________________________________________________________________ This section is for those that want to know more, please ignore what follows... This table was used for proof of concept purposes...it compares our OEM IAT's 5k NTC thermistor temp/resistance readings with a typical 5k NTC (just to see that it doesn't have any odd characteristics) then two targets for a 20C offset (just to see that using either as a target would be OK) & a look at how we could expect our modded IAT to do at hitting those targets… Credit to hassepfeffer for making this graph... ________________________________________________________________________ BTW this is how I think the cabled spoofers like "BoosterPlug" & "The Juice" are constructed, in case anyone wants to make one or improve on it... But why would you want to make a cabled spoofer when you can have The Eruption! _____________________________________________________________________ If anyone has a cabled spoofer & you'd like to see how close to target it gets, post the resistance values at 0, 25 & 50C so we can compare. ______________________________________________________________________
If you twist the tails together and put an alligator clip between the thermistors and the solder site , it would act as a heatsink and you could shorten then considerably. To be safe, grab the wires or clip with a pair of pliers IMMEDIATELY after soldering to bleed even more heat. What is the physics of this? Parallel resistance to what end? Have you explained it elsewhere in the forum it might allow me to tailor it to local conditions. Thanks BTW very well thought out informative photos
Why would I post how it's made all over the internet if I wanted to sell them??? The time consuming developing has been done, no sense in anyone else having to do it if they don't want to. My goal is to let TR owners know there's a solution to a problem. In my mind, if you want a spoofer this is the new standard. Beyond this it's a Power Commander. A lot of people stand to benefit from The Eruption!!!
Rather than destroy the stock one, can that plug end be found in an electronics store and just be custom made from scratch?
I don't think so, but there's a guy in the Booster Plug thread (towards the end) that says he works for the company that makes a lot or most or all of the electrical connectors on BMW bikes, he'd be the guy to ask.
Hi run-it, Let me just say.... Thank you So Much! For taking the time to post'n'share... You should get an award! Now I'm not sure if this is or should be in the stoopid questions section, but the first thing that popped into my head was why couldn't you have a switch in this little mod? Rather than spend the extra $25- on a spare IAT? Why couldn't or should I ask Could you have a switch wired into this for on- off (effectively 'mod ' on/ or 'stock' off) operation? On this same thought process could you have a 3-way switch that allowed for 'off' = stock/ 'pos 1' = -10 deg operation/ and 'pos 2' = -20 deg operation. Sorry if it seems I'm trying to make a very elegant simple solution overly complicated, I'm not. It's really trying to get better functionality so it can be simply returned to stock setting and I live in the sub-tropics so maybe -10 deg operation may be more appropriate in certain weather conditions? : dunno? Sorry again if this is really a stoopid question, I was just wondering?
mag00 said: ↑ Rather than destroy the stock one, can that plug end be found in an electronics store and just be custom made from scratch? Essentially, you only keep the original as a mounting platform correct? By cutting the original thermister you end up with just wires correct? Some say this is just standard Bosch connections. As someone mentioned, if a new one is only 23 bucks, fine, if I would ever want to go back to stock for a warranty issue, it looks fairly easy to do so. I already bought the wuka, but this looks to be much cleaner install. Why eight vs just one? One that may be calibrated slightly different to original, or does that just not exist?
Over in the booster plug thread I put my deal up on this from the advrider thread. I did a few things slightly different, and didn't go into the details. But I was just looking at my receipt, the stock AIT was 14.99 from Hall's, it was $9 shipping. Runs much better, still not perfect.
Yes, cutting off the head removes the bit that reacts to temperature, leaving only wires to solder the new NTCs to. 8 are required because a 12.5k NTC does not exist. All NTCs have a non linear R/T curve and are rated at 25 degree C. It just so happens that 8 parallel 100k NTCs of the part number above, give an R/T curve remarkably close to the 20 degree offset curve required for the 5k NTC that the TR uses for the AIT. If a 50k NTC was available that gave the same curve with 4 in parallel, it'd be even nicer. I did the calcs and the available EPCOS 50k NTC gave a curve that was closer to the Booster plug. It would still work, just the 8 x 100k is almost identical, at least over the normal temperature ranges everyone will be riding their bike in. The formula for calculating parallel resistance is 1/Rt = 1/R1 + 1/R2 + 1/R3 + 1/R4 + ...and so on. When resistances are all the same, this boils down to 1/Rt = (total number of resistors)/Resistance, or Rt = Resistance / (total number of resistors). So 8 100k in parallel will be 12.5k at 25 deg C, and you can calculate all the other resistances for this R/T curve. Paralleling the NTCs is nice as they will be more easily incorporated in the existing mount.
You mention this mod applies to the open loop operation of the ECU. It has been my experience (Keihin FI on KTM 990 and 690 which probably doesn't apply -- I don't even know what ECU is used on the Husky) that open loop operation is used only during warm up and as soon as the O2 sensors are up to operating temperature, the ECU switches to closed loop operation with the ECU applying mixture corrections from the O2 sensor inputs. Admittedly, temperature inputs are used to determine mixture in closed loop operation, so the the question is, How well does your clever mod work on your bike? With the 990 and 690, we just use TuneECU to modify the fueling tables.
Right, closed loop is typically locked out until engine temperature is reached, ie post warm-up. At that point a closed loop is in effect, move the throttle & you're back to open loop. That's why with any spoofing mod, if you already had some slight lean surge, hunting of RPM during idle, they won't correct that. I'm pleased with it's performance on the bike, & as of now, I see no reason to do anything further with it. But, all spoofers should be evaluated over a broad range of ambient temperatures on a per bike/model basis. I expect The Eruption to perform better than others at the extremes. I'd like for someone to post actual R/T values for BP and/or WK @ 0C, 25C & 50C. We can then compare with my estimates for those devices. Again I'd like to credit Gaspare & Belinassu for sharing their work. You're lucky to have access to freeware mapping software that works with your bike.
For information: The Husky has a Magnetti Marelli ECU and because of that the 911 BMW CANbus tool won't work unfortunately.
