Topic: Let's go roadracing...continuing saga

[simon#42]

all the rotax race two strokes use an o ring to seal the combustion , as do yamaha tz's , aprilias and honda rs's . the problem with them is they dont last very long , not a big issue on a two stroke that comes apart every 200 miles but a pain on a bike that doesn't [ mind you i bet you wish your engine would last 200 miles at the moment ]  . check the wills rings out [ they are a development of cooper rings , and if you had ever tried to race a hillman imp you would love these ] they are used by the car people in high boost turbo engines and in alot of racing bike engines .
mind you once you get the block straight you may not need to bother .  they have probably over heated the block getting the liners out .

[bwaller]

My race bike is allergic to dynomometers. 

To recap, last year at this time I experienced some teething problems with ignition (changed to Dyna coils, had a ground fault with a Dyna 2000 pickup) but all were resolved. With dyno time & numerous plug chops the jetting was dialed in and I enjoyed a well sorted bike throughout the season needing only to change 1 mainjet size to compensate for changes in temperature/humidity.

This winter I fixed a head gasket sealing issue with a better copper gasket and sleeve top o-rings. I ran it briefly on the street (that's a whole other tale) and it was perfect.

I had a dyno appointment this morning to work through some options I wanted to try. Since the last dyno visit I had reduced ignition advance to 28d, gone up 1 full mainjet size, plus now have good compression sealing. We made three pulls with last years NGK D9's to 11000, then switched to new Iridiums. Two more clean pulls then on the third it broke up @ 10K. I made several more attempts with jetting/plugs/battery/wires, every damn thing I could think of but to no avail. It would pull (although not without a bit of missing) to 10K and no further.

Last year I had an issue with an crank trigger. It would start, idle fine but break up @5500. I'm not sure why this happens but when it was up to temp today this started happening and I fear it may be the same problem as a year ago. I will install the ignition plate again off my 750 to test 

This is a print out from one run this a.m. plus the last pull from last year where I removed the v-stacks to see what would happen without compensating with correct jets.....ran out of time then. Otherwise last year was 59.6hp, this year 61.6......................so far. 

[physician]

nice build, i just realize it was your bike at the montreal motorcycle show i was drooling on..

keep on tuning it, they sometime take time to get the reward...

[Tintop]

Torque looks very nice BW.  Looks like you've added about 750rpm across a spread that's above last year's peak.  

HP looks like it was a smoother curve as well.  To bad about the ignition issues.

Wonder how that 550 hybrid compairs.

[Doctor_D]

An improvement is an improvement, so don't beat yourself up too badly.

What's the AF curve look like?  Not saying that this has anything to do with it, but that oscillation at the top end looks like what I've seen on motors dyno'd with the carb tops off.

How did you tune your intake tract length?  I use Pipemax, http://maxracesoftware.com/pipemax36xp2.htm, and have been pretty happy with it.

In any case, looks pretty good.

[bwaller]

Hey Dave, I've said before I refuse to be disappointed with whatever numbers are produced. I don't need to tell you how valuable time on the dyno is though.

The A/F graph showed straight through 12.5-13  but as far as the oscillation up top I think it may be the v-stacks and/or foam filters. I was planning to try different things to improve that power on top, that's why I was disappointed not being able to.

Bottom line is the problem was another faulty Dyna 2000 crank trigger module. I replaced the whole igniton plate with a second I have and it revs clean through where it broke up before. The electronic tach was acting eradically as well, fine with the replacement plate. This is the second and last bloody time. I have stood by Dyna because this ignition was exactly what I needed, but enough is enough.

[turboguzzi]

gee brent, i read on the old graph 57.6 not 59.6..... and the new curve looks way better, +4 hp, what are you complaining about?

not sure what is your bottom line on stacks, but when i was running VM's, i had lot of trouble making them work with stacks, was getting similar break ups up high, ended up running without.  VM's have this stepped venturi, i believe that the stacks where creating too strong a pressure signal.

one thing that helped back at the time was running both R plugs AND resistance caps,

+ make sure you have good contact at the caps, caught me out once.

Dave, would it be too much to ask you to run my motor parameters on your SW? just curious

[bwaller]

Believe me I'm not complaining about numbers, only about faulty ignition components that waste my time & money. 

59.6 was the best number last year with stacks & filters. That 57.6 was the very last pull when I removed the foam socks and it upset jetting. So this year up 2hp so far and that's great.

TG, I expect you're on the money about the what causes the oscillation in the very top of the graph. Quite possibly the stacks but I'm sure the foam sock filters play a big part too. I will remove them next time on the dyno to see what happens.

[Doctor_D]

Dave, would it be too much to ask you to run my motor parameters on your SW? just curious

Sure. Happy to help.  I'll PM you with the list of data needed.

[bwaller]

Back to the dyno today with a wholesale ignition change. All else being equal, this erases any doubt about the outcome. I'm flabergasted but otherwise happy tonight. Just in time, I have a track day Monday and a race at Laconia NH next weekend.

This print out is from the very first pull today and as mentioned the exact setup as the best pull last week (before a crank trigger failure) that produced 61.6hp & 36.4ft/lbs. Today 65.5 & 37.8. The difference is all ignition and obviously the original system was likely the cause for the oscillation at the top end of the graph in previous testing.





We couldn't use the sniffer, it doesn't like lead and the 50% mix of C12 leaded race gas is enough to cause it grief. So I cancelled some testing without filters or stacks. I did try different advance settings up and down. It is happiest at 28-29 degrees. I also tried a 1" baffle instead of the 2" and it lost a bit of power. 

So I think this engine is at it's peak power with stock valves and my velocity stacks with foam sock filters. It is for sure without the filters I could jet it for a bit more power but I choose to use some filtering.

My son took his GoPro and I'll add some footage later.

[andy750]

Wow Brent!!! Amazing numbers and what a great analysis of the initial problem. Good luck at Laconia next week - sure you will do great with this bike. I cant believe I am going to miss it but I am currently in Denmark for work and wont be back in time.

Good luck!
Andy

[brandEn]

How have I missed this thread, great info in here.

[turboguzzi]

sweet

[RAFster122s]

Congrats! That is some great numbers!

Best of luck at Laconia.

[bwaller]

This isn't my dyno room, doesn't get much use anymore and is obviously a bit messy, please don't judge. Not sure why I look so grumpy, I'm quite happy with my day!


http://youtu.be/a3EEDagOTsU

[Doctor_D]

Great results. That's definitely enough of a difference to feel on the track.

Good luck next week.

[MRieck]

There is certainly more HP available in that engine too.

[bwaller]

You know Dave, you're right. This things revs fast anyway but after the new ignition was installed & timed I took it for a quick test ride & remarked later to my wife that it seemed to pull harder on the pipe.

[MRieck]

All seems a bit unfair for the competition Brent. Maybe you should spot everybody a 1/2 lap lead before you start.

[Sam Green Racing]

Great result Brent, cleaned that top end up nicley.
Good luck for the race next week.

Sam.

[TimV840]

All seems a bit unfair for the competition Brent. Maybe you should spot everybody a 1/2 lap lead before you start.

Please and thank you!

Nice work Brent. 

TimV

[bwaller]

All seems a bit unfair for the competition Brent. Maybe you should spot everybody a 1/2 lap lead before you start.

There are new bikes, new riders and new riders on old bikes this year! Even if the class hotshoe remains retired,  this is a competitive class. Having more bikes on the grid will be great and any one of five guys can win, especially the previous poster.

[Bill/BentON Racing]

Brent,way cool #'s.You gonna notice it..and the competetion!I wasted so ,much time and DYNO time chasing that same ignition.I'll stick with Dyna S and MSD box and 3.0 ohm Dyna coils,but NO Dyna 2000,15 wasted hrs @ dyno Sat before Easter,so glad you got it figured out.They going to be running for 2nd place when they see you show up!! Bill

[bwaller]

Bill it's really disappointing, but all's well me thinks. TG always claimed he could get more time out of a battery running total loss than I ever could. It'll be interesting to see what happens now. Those things really seem to draw current.

[Retro Rocket]

Brent, have a chat to Hondaman {forum name} he runs a resistor somewhere and it lowers the load on the alternator, don't ask me any more than that though...