FJ Land speed racer

[fj1289]

Thanks!  It previewed good on my phone... 

Going to try to take advantage of the weather here and get it out a couple times this weekend - tweak the base line tune, check the airshifter/autoshift function, and check the ECU tuning and progressive controller settings for the lowest level nitrous jets for 2nd and 3rd gear.   Then I'll be satisfied she's ready to go to the dyno. 

[fj1289]

Took it out for a quick test on Sunday.  Its definitely a strong running engine!   

Air shifter worked - along with auto shifting from the ECU - but seemed to get some electrical feedback from the air shifter solenoid.  The feedback appears to be resetting the ECU which interferes with the nitrous operation on the ECU side.  Ordered a couple diodes that should clear up any electrical noise from the shift solenoid.  Also need to go over the recent changes to the wiring to see if any of it could be the cause.  More testing needed - but there's plenty of time now!

[fj1289]

While working on this I've been looking for any FJs with some kind of proof of going 200 mph.   One of the closest that seemed a reasonable claim was on here a few years ago.  He was selling a chassis that he claimed they had run 190's at Maxton with a big bore engine on nitrous.   He said they never could quite get it to 200 mph -- thought it may have been an issue with airflow into the engine. 

I assume Black Sunshine had enough horsepower - don't know if he had it setup for that kind of top end.  It takes more than just gearing for that - sustainable fuel flow, oiling and cooling, etc.    But while reading thru the articles on Black Sunshine I saw his reference to an FJ1380 Turbo Nitrous entry in an early UFO competition.  After a bit of research I found the article and then found the magazine on eBay. 

Unfortunately there's no listed estimated horsepower.  The performance figures were 9.25 at 154.63 mph, and top speed of 214.285 mph!  Body work looks like mostly stock FJ1100 fairing with stock FJ1200 tail (with the rear fender removed). 

I've tried scanning the article - half the pages are getting cut off.  Here are the page on the FJ and the page with the results.

[fj1289]

Had some time this weekend to do some troubleshooting on the air shifter and nitrous systems.   Rewired the shift system to simplify the setup (removed a relay) and use the ECU to directly trigger the shift solenoid (using the grounded output).  It worked well on the first test ride - both shifting off the button and letting the ECU autoshift.   But the nitrous system wouldn't fire.   It took while to sort, but the Dyna shift counter (DSC) wasn't receiving the shift signal.  The DSC "counts" the shifts from the air shifter so it acts like a very basic gear position sensor.  The DSC is set to send a signal to the ECU to arm the nitrous in second gear -- then the ECU activates the nitrous based on an RPM window and minimum throttle position. 

In order to get the shift signal to the DSC, I went back to using a delay to "swap" the ground signal from the ECU to a 12 volt signal needed for the DSC.  This required rewiring the shift solenoid and the shift button too.

Two more test rides and all systems are tested and good to go! 

Now, back to a problem that raised it's head last year -- one of three ECU general purpose inputs doesn't function.  Two inputs are used for the shift kill and for the nitrous.  I'd like to get the third input functioning - to use for the map switch function.  This may be a firmware issue, or may be a hardware issue - either internal to the microsquirt or external. 

The plan would be to use the third input to switch to a "small" nitrous map -- for a small stage shot of nitrous.  Then use the current nitrous setup for the large second stage shot. 

[fj1289]

Had a little fun in the garage this morning....





Pieces of foil and charred black stuff it blew out!




Put the batteries on the chargers to top them off before riding to work today (while the front end on my pathfinder was disassembled).  This was an OLD ballistic 12 cell battery I purchased for the initial build of the drag bike - maybe 7 or 8 years ago.   This battery has been abused repeatedly -- fully discharged, over charged, under charged, etc.  Amazed it lasted this long - and was probably over due for a cell to "pop".   That's a big difference between the first generation " shrink wrapped"  LiPo batteries and the current ones with internal balancing and cell protection like the Shorai batteries RPM carries.

The fiberglass battery tray handled it OK - no real damage.   Hope I can find another battery that will fit in the same space. 

[Pat Conlon]

That looks exciting

Did it make a noise?

[FJmonkey]

That looks exciting

Did it make a noise?

Looks like it took place in perfect silence... At least when the tree fell, no MAN was wrong... 

[fj1289]

That looks exciting

Did it make a noise?

It was more of a loud pop than a bang.  I had some trouble getting the charger to start charging it -- but I occasionally have a little trouble from this charger and didn't think anything of it.  Maybe 10 or 15 minutes later I heard a small pop - turned and looked from across the garage but didn't see anything out of sorts.   Then a couple minutes later the loud pop and a bunch of smoke.   Quickly pulled the charger off the pigtail, yanked the quick disconnect, and pulled the battery out with a pair of pliers.   

[giantkiller]

I always heard they could blow up. But always just dismissed it. But over the years I've had 2 conventional car batteries blow up on forklifts. That I was sitting on at the time. One had enough force to bend the side of the hood out a couple of inches. Now that was exciting.

[fj1289]

I'd much rather have one of these cells pop than have a car battery go!  I'm thinking the whole acid thing would be a lot more dangerous...

I'm working through three different replacement options now -- found a company called MOTY that makes the "shrink wrapped" style LiPo batteries that would pretty much be a direct replacement, a small cased Shorai that will fit in the same place with some minor mods, or a larger EarthX LiPo that has built in cell balancing and over discharge protection -- but would have to be mounted somewhere else (swing arm maybe?  - between the nitrous bottle and the shock).

[jscgdunn]

I'd much rather have one of these cells pop than have a car battery go!  I'm thinking the whole acid thing would be a lot more dangerous...

I'm working through three different replacement options now -- found a company called MOTY that makes the "shrink wrapped" style LiPo batteries that would pretty much be a direct replacement, a small cased Shorai that will fit in the same place with some minor mods, or a larger EarthX LiPo that has built in cell balancing and over discharge protection -- but would have to be mounted somewhere else (swing arm maybe?  - between the nitrous bottle and the shock).

I think you want to go with the LiFePO batteries.  They are typically used in motorcycles

https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

https://www.batterystuff.com/powersports-batteries/LFX14L2-BS12.html

Lipo batteries are more finicky:

https://en.wikipedia.org/wiki/Lithium_polymer_battery

[fj1289]

You are spot on about the lithium iron batteries -- pretty sure that is about the only ones sold now unless you go specifically looking for them.  Then again - maybe I need to double check a couple of my options...

I should have been more clear - I use "LiPo" to refer to all the Lithium based batteries. 

[jscgdunn]

Yes it is pretty confusing.....I was looking into to build my own battery.....I know I saw the shrink wrapped ones like the one in your pic somewhere in China for $49.00...good quality individual cells (A23) are around $10.00 each. There are a few you tube videos on how to build your own.

[fj1289]

Yes it is pretty confusing.....I was looking into to build my own battery.....I know I saw the shrink wrapped ones like the one in your pic somewhere in China for $49.00...good quality individual cells (A23) are around $10.00 each. There are a few you tube videos on how to build your own.

I thought about that -  but decided not to with the potential to damage the cells with the sustained heat of soldering vice the quick spot weld. 

Doing some more research I think I'm going to go with an EarthX lithium battery.  This battery gets used as a 24volt starting battery and to power the nitrous bottle warmer. The latter tends to over discharge the battery.  The EarthX battery has a built in protection against over discharge, shorts, over charge, etc.  I know that would have saved me more than once with the old battery!

[fj1289]

Reviewed some of the recent datalogs and noticed something that looked wrong.  I've never been satisfied that the battery voltage being recorded by the microsquirt was accurate, but I always chalked it up to either differential grounds or needing to "calibrate" the voltage to the microsquirt.  What I noticed was the voltage DECREASING with increased RPMs...   So I checked it with a multimeter in the driveway - yep, not charging.   

Did a little troubleshooting -- the rotor is bad.  Time to push the easy button and swap in a spare alternator -- NOPE!  My spares are FJ1100 cases that require the old (and I think discontinued) "wide" o-ring.  I've been down this road before....the oil leak appears to be coming from the seal around the clutch rod (aka kitty killer).  Replace that seal and you still have a leak -- only to start tracing the leak UP to the alternator.   Eventually I talked myself into disassembling the two alternators and swapping the good rotor into the 1200 alternator case.  This means I have to solder the stator leads back to the rectifier.  I suck at soldering.  Maybe part of it is my tools suck for soldering -- probably both are to blame!  I have to "tune-up" my soldering gun (the tip tends to not heat up well if I don't disassemble it and clean all the contacts each time I try to mangle something with it -- then again, using it for fairing repairs probably didn't do it any favors either!).  Seems to put out OK heat - and the repairs seems solid. 

Get the bike out for a quick run - everything seems good.  Download the data -- yay!  14.4 - 14.8 volts!  But wait, after I turn around and head back, I'm only seeing 12.3 - 12.8 or so...WTF!   

Dug into it again last night - found one of my solder joints had come loose - only connected to 2 of 3 diodes.  Tuned up the solder gun again - seemed a lot hotter this time - and the solder seems to flow well into the joint.  Driveway test confirms good function again.  Hopefully I'll get a chance to try it again this evening.  Seems like it's always something!

Now I'm thinking the alternator hasn't really been putting out good power from the beginning -- and maybe the battery isn't as weak as I suspected.     Either way, the EarthX should be here today or tomorrow.  Interested to see how easily it spins over the engine.  Wondering if I can simplify the electrics back to a single battery -- and have enough power to also run the nitrous bottle warmer...I could eliminate a battery, not have to charge up two batteries between runs, free up space in the tail for a second nitrous controller...