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FJ Land speed racer

Started by fj1289, July 20, 2015, 07:24:30 PM

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fj1289

Thanks Tekime!  I agree whole heartedly about Randy's engine work!   I have fired myself as an engine builder    :pardon:

There have definitely been some frustrations along the way – but it's all excitement now!  It feels so much better to have a good running bike and be able to test well BEFORE the event this year!  Of course, as always, I have another overseas trip for work before the Colorado Mile – but we are scheduled to return on August 17th.  That at least gives a two week buffer this year with an already running bike.   

I'm sure we'll keep working on details all the way to the event.  Things on the task list now include installing the larger injectors and making any tuning changes necessary – idle and off-idle will probably need the most work since we may be getting close to the injector dead time.  That makes tuning at the low demand areas harder – but not as critical on a race bike vice a true street bike.  And some basic aero improvements – focused now on a seat cowl.   

The seat cowl is going to take a bit longer than I first expected.  Learning to work with the spray foam has been interesting.  Learned to mist the buck with water BEFORE spraying with foam as well as misting the foam with water after spraying it.  The foam "cures" much quicker and more completely that way.  The foam cures by reacting with moisture in the air – not a lot of that in Colorado sometimes!  First attempt had pockets of gooey foam still uncured after 2 days.  Carve a little off with a knife and the uncured foam starts oozing out and expanding again! 

Second mold started out better.  Got the foam carved and sanded to shape fairly well, or so I thought, and then covered it with a single layer of fiberglass.  The plan was to fill the low spots with some bondo, sand it smooth and be ready for paint.  The shape wasn't nearly as close as I thought...on the third coat of bondo...and more work to go...

While the bondo has been drying, I've been on eBay.  Now there's a hayabusa front fender and an 84 tail fairing on the way.  When those, and the seatbase from fj johhie show up, we'll get started on the next step of aero mods.

43 days until we get to turn a wheel in competition – after two and half years of work!     :yahoo:

fj1289

A couple quick shots of the seat cowl in work.  It probably has 2 thin coats of bondo and 2 coats (at this point) of bondo-glass (has short strands of fiberglass embedded in it to hold better for thicker coats).  

It's getting closer but still needs quite a bit of work...


This side is still a bit farther out - block sanded it this morning and added another coat of bondo-glass



This side is looking better - also block sanded it and added another thin coat of bondo-glass



I'm debating at this point whether to finish out the bondo work and paint it, or to add a layer of fiberglass over the bondo work and then do the final finish work and paint.  I'll probably go with a layer of fiberglass to add support and strength to the final piece.

Also - a big thanks to Robert at RPM for his call this morning.  I had sent an email a week or so ago asking about custom length brake lines from spiegler.  Robert is placing an order with spiegler today and asked if I had the measurements needed so he could add them to the order.  Amazing customer service - thanks!


fj1289

Made a fairly big change to the program on Friday - decided to change fuels. 

I "thought" I had been running Sunoco E85R - a spec racing fuel (85% ethanol and 15% Sunoco racing fuel base).  Turned out I had been using Sunoco E85 -- biggest difference is the ethanol is "cut" with 88 octane pump gas to an actual blend of 84% ethanol/16% gas - the advantage is a consistent blend compared to pump E85 - but still falls short of the race version.   This all came to light on Friday when I drove across town in lunch hour traffic to buy two pails (5 gal cans) of E85R.   The gentleman asked for 180 plus dollars vice the 45 or so I had been quoted (mistakenly) the day prior.    A rather long discussion ensued...  In the end I left with one pail of Sunoco 260 GT Plus - a "gas" based fuel vice an ethanol based fuel.   

I was on the fence previously about switching to a race "gas" from ethanol due to concerns over the ability of the fuel system to flow enough fuel to support  the amount of power that's going to be needed.  So I took this "opportunity" to learn what was available and what were good options -- especially with the restrictions on fuel additives in Colorado (even for off-road use!). 

According to my calculations based on using E85 with the 75 HP shot of nitrous - the existing fuel system (with the new fuel)  should support the full capacity of the nitrous system (150 HP shot).  The reason comes from the stoichiometric ratio of each of the fuels.  E85 stoichiometric is about 9.8:1 vice 13.7:1 for the 260 GT+.   E85 requires 140% (13.7/9.8 ) as much fuel to achieve the same air-fuel ratio for the race gas.  Or said another way, the race gas will support 40% more horsepower for the same volume of fuel.   With the Microsoft ECU all I have to do is change a fuel constant - no other tuning required more normal running.  The added fuel for the nitrous will have to be adjusted manually since it is specified directly as an injector pulse width vice calculated from the VE table. 

My concern is I have no idea how much the fuel rail can flow.  I know the fuel pump and injectors are up to the task - but I don't know what the FJR fuel rail can handle.  During testing of the nitrous system late last year I discovered the stock inlet fitting was restricting fuel flow.  I drilled and tapped the end of the fuel rail for a large radius brass fitting.  That solved the flow issue for that level, but i haven't pushed beyond that yet.  By switching fuels that removes one potential issue that would be very difficult to solve in a timely manner at the track. 

Firehawk068

Are you actually changing the "Flow"?
Or keeping the same amount of fuel, just changing to a different type of fuel (with more energy/per unit of fuel)?

I don't know a ton about the fuel that you are using, but I know that you would need more E85 to make the same amount of power as regular fuel. (as it has less energy potential)

Seems to me, if you are switching the other way, and you already know your fuel system is capable of flowing enough E85, then it should be more than capable of flowing enough race-gas?  :scratch_one-s_head:
Alan H.
Denver, CO
'90 FJ1200

Firehawk068

Nevermind Chris..................
I read the above post as a concern.
After I re-read it, I figured out that it was a concern that you fixed by switching fuels.....................As you were.  :good2:
Alan H.
Denver, CO
'90 FJ1200

fj1289

Quote from: Firehawk068 on July 25, 2016, 05:32:11 PM
Nevermind Chris..................
I read the above post as a concern.
After I re-read it, I figured out that it was a concern that you fixed by switching fuels.....................As you were.  :good2:
[/quotfe]

Yes - I worded that poorly - it is confusing - sorry about that. 

I think we will be good to go with the new fuel.  Definitely want to get out for one more test before the event. 

This Wednesday is out since Bandimere is not holding g the usual test and tune this week.  I'm going to try for Aug 3rd - but I'm scheduled to go get an airplane Aug 4th - 18th right now, so we'll see if there is time. 

Firehawk068

I'm ready to meet you at Bandimere on the 3rd.
Alan H.
Denver, CO
'90 FJ1200

fj1289

Thanks Alan!  Fingers crossed now for good weather. 

Did a little tuning with the new race fuel last night.  Found a few things that needed to be tweaked in the tune - especially the target AFR table for part throttle running.   I was getting some lean surging at slow cruising/small throttle openings (like would be used to ride back to the pits after a run) -  seems it was bouncing in and out of the bottom row of the target AFR table that I had set very lean to simulate a fuel cut for overrun - good for gas mileage on the street bike -- totally unnecessary for the race bike!  I'll still set the lower rows of the table to shoot for 13.2 AFR to help keep plugs from fouling, but still richer than would be used for "gas mileage" concerns. 


fj1289

UGH!

I've been doing a bunch of reading on race fuels the last few days (getting stuck in an airport for 5 1/2 hours can be good for that).  Think I'm changing fuels again.  I'm not convinced the 260 GT Plus is a good fuel for the amount of nitrous we may need to spray.  I'm going to go with the safe bet on this one and use VP C16 - it is pretty much the "go to" fuel for heavy nitrous use. I originally wanted to stay away from leaded fuels - but I'm pretty sure the O2 sensor will last for one weekend on the nasty fuel!  Besides, buying a spare O2 sensor is a LOT cheaper than repairing another head or buying new pistons!   As an added bonus, C16 is available in pails for close to the same price as the 260 GT Plus -- and is about 30 miles closer to me!

The stoichiometric ratio of C16 is even higher than of 260GT Plus (15.0:1 vice 13.7:1) so it will require even less fuel volume (roughly 8-9% less) - even better!

Just 5 more weeks!  Hopefully by this time then we'll have our pit area set up and will have gone thru tech and the mandatory drivers meeting and be ready to line up early Friday morning for our first license run...





I'll save the 260 GT Plus for 50 HP of nitrous or less when I go back to the dragstrip after the Colorado Mile and start working toward that 9 second pass again... 

fj1289

Last test session before the Colorado Mile was a mixed bag.  Only got one good run in -first run without nitrous - good info from the datalog to tweak the base fuel map for the new C16 fuel.   Alan came out and was a huge help. Had the weather cooperated better his assistance would have made for a very productive night. 

As it was we only got two runs in for the night before the weather set in.  The second run - 50 shot of nitrous from 2nd gear up - started well with a good launch despite the 18/38 gearing on it now, but went south quickly after that.  Shift early to second and the bike falls on its face.  WTF!?  Try to keep it running so I can clear the track.  Seems to recover if I close the throttle - but dies if I gas it.  I switch off the nitrous system and it seems to recover and rides normally at this point. 

I try a couple "test hits" on the return road and figure out as soon as the nitrous system is activated the bike seems to cut out and the AFR gauge shows dead lean.  Can't figure out what would cause the fuel to totally cut off when the nitrous activates?  Get back to the pits and we download the datalog.  As I start to explain to Alan what I'm looking for on the datalog the "dumbass" light goes off in my head!   The night before I was attempting to troubleshoot an old input problem on the microsquirt.  In the middle of this the "hot start" issue from the last test session returned -- but the engine wasn't hot.   Battery is good and starter is good - last time we had to hit the starter directly with 12 volts to start it - starter relay going bad!  Swapped to the old Ford relay I used on the dragbike before - which required some minor wiring mods.  Unfortunately, about the time I finished up it was time to read to my daughter and get her to bed.  So no more testing on the dragbike for the night.  As I put everything away for the night I forgot to undo the changes I made in the ECU.  While troubleshooting with the updated firmware in the ECU I swapped two of the inputs.  I  had reassigned the input I use for nitrous to the launch control (2 step) function.  So, on that run, each time I thought I was activating the nitrous I was cutting out the ignition instead!  F()¢K!   :mad:

Check the tune file - yep, that was the problem.  A couple quick changes, load the new tune, and we're off to try again. 

And the lightning show begins followed shortly by rain. 

Big thanks again to Alan for his assistance last night!  So much better to have the extra brain power, hands and eyes to keep things on track.   :hi:

Firehawk068

It would have been great to have better weather, and more runs.
It sucks we were right in the path of that thunderstorm!
It was a pleasure to give you a hand.
I'll try and meet you over there during test-night in the fall if it works out.

Alan H.
Denver, CO
'90 FJ1200

fj1289

Well, in preparation for the 2nd annual Colorado Mile, my company sends me on an international trip to accept and ferry an aircraft.  Last years trip should have been pretty easy - a well made German designed and built airplane that has good performance and range and has just been refurbished.  The delays on that trip eventually cost us the time we needed to get the bike running for last year.

This year's trip sent us to a location much further away to ferry a used, soviet designed, polish built aircraft meant for operating in and out of rough, short locations, doesn't have good range, and is unpressurized.  Not a good plan for keeping to a schedule...luckily this year we made it back as planned with minimal issues!  I take that as a good omen for the Mile this year!    :drinks:

FJmonkey

Sounds like lots of short hops, but all your landings were clearly good enough. Looking forward to seeing more posts of your progress. Time for some low level high speed runs now....
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

fj1289

Quote from: FJmonkey on August 18, 2016, 02:28:25 PM
Sounds like lots of short hops, but all your landings were clearly good enough. Looking forward to seeing more posts of your progress. Time for some low level high speed runs now....

Well...I did find a good test spot to do a quick test with a 50HP shot on the new fuel.  Need to adjust the fueling a bit for that (very rich on the test). 

The task list is quite short at this time - trim the Busa front fender a bit where Alan pointed out it was rubbing the fork and finish the race cowl for the seat.  Oil change, safety wire, soak the chain, go over everything with a fine toothed comb, etc.  A great place to be at this point! 

Got most of the tools gathered back up and sorted again.  Figuring out how we want to load out the trailer is the biggest task left!

fj1289

Trailer is loaded!  Headed out to Front Range Airport in a couple hours to get checked in, setup our pit space, attend the drivers meeting, pre-drive the course, and get the bike thru tech. 

Plan is then be there when they open the gates on Friday and hopefully get the license runs complete.  I'm starting with a class C license - limited to 165 mph.  I'll need to satisfactorily complete one run between 140 and 165 mph  to license up to class B.  Class B lets you run up to 199 mph.  To license up you have to satisfactorily complete one run between 180 and 199 mph.  The class A license allows you to run up to 220 mph.  You need a class AA license to go faster than that - not really a concern!. 

Plan for Friday is make two runs on motor only.  First one I'll limit to 8500 RPM in 5th with 18/38 gearing.  That should put me right in the middle of the speed window to license up.  The next pass I plan to see what the top speed I can get on motor only - this will help determine how much power we're making at altitude here and how effective some of the streamlining is.  That speed will then give some ideas what we can expect to see on the nitrous runs and be able to tell if we are getting the amount of power we expect from the nitrous.  The third run will be a 50 shot of nitrous with 18/35 gearing.  Pretty much anything in the 8200-10,000 rpm range at the speed trap should put us in the window to license up for the A license.  The fourth run will probably another run with a 50 shot of nitrous with a bit of tuning to the fuel and maybe ignition depending on the data logs and speed attained. 

If we get that far it will be a very successful Friday!