Did I Give Up Too Soon On Total Loss?

[Waternut]

Maybe we have differing opinions on what "light switch" power is. It seems some are thinking the light switch is when you nail the throttle from idle and it ramps up smoothly and then kicks hard in the middle of the rpm range like a turbocharger.

My idea of a light switch is when you nail the throttle from idle it yanks your arms hard, then if you back off and maintain speed in the middle rpms and nail the throttle again, it yanks your arms in roughly the same way. Then if you're cruising along at half throttle and let off, you get eye opening deceleration. I can finesse the throttle if necessary but I use the big throttle hit way more than I patty cake the throttle.

 

[junkyardj]

The flywheel is a mechanical energy storage device. The heavier it is, the more energy it will store that could otherwise go to the impeller.
It doesn't "smooth" things out, it takes power away.


Note that a heavier flywheel will release that energy back into the driveline when you let off the throttle. The ski won't "brake" quite as quickly.

i wonder if this why people at attribute TL with light swtich effect because there isnt as much momentum due to the light fly so you get rapid drop in rpm's

 

[WaveDemon]

Maybe we have differing opinions on what "light switch" power is. It seems some are thinking the light switch is when you nail the throttle from idle and it ramps up smoothly and then kicks hard in the middle of the rpm range like a turbocharger.

My idea of a light switch is when you nail the throttle from idle it yanks your arms hard, then if you back off and maintain speed in the middle rpms and nail the throttle again, it yanks your arms in roughly the same way. Then if you're cruising along at half throttle and let off, you get eye opening deceleration. I can finesse the throttle if necessary but I use the big throttle hit way more than I patty cake the throttle.

that is not what has been traditionally called light switch power. no time to describe, maybe later...

 

[Foximus]

The flywheel is a mechanical energy storage device. The heavier it is, the more energy it will store that could otherwise go to the impeller.
It doesn't "smooth" things out, it takes power away.


Note that a heavier flywheel will release that energy back into the driveline when you let off the throttle. The ski won't "brake" quite as quickly.

Yes thats all true when your talking about such things as a stock flywheel to a killer aftermarket or total loss flywheel, but really lets talk about such things as getting weight savings on a 19lbs crank! :booty:

 

[Idok]

IC, you're saying the heavier weight of the flywheel smooths out the power.

not really....but I see where you get that


and I suppose its not even really a fair comparison unless the impellers are the same....

for my style of riding, the lightened stocker allows the engine to rev in a very smooth manner...and when you let off throttle, the fly/prop combination allow for the pefect amount of engine braking

not to much, not too little

 

[Shadow7874]

When your talking about rotating masses like the flywheel inertia is what is going to affect your power. More inertia means the flywheel will store more energy like said before and thus will take more power to spin up and slow down. Torque is rotational acceleration which gets the prop spinning. More torque obviously means more acceleration which seems to be what everyone ones. Rotational acceleration=Torque divided by inertia. So if you make inertia smaller, acceleration gets bigger. Inertia is calculated my mass, radius, and the distribution of mass. You can have a heavy flywheel spin up faster then a lighter one if its mass is located closer to the center of rotation. Ideally you would want the flywheel as light as possible but you want as much weight as possible concentrated around the center of it and not the outside. I cant speak for TL but as far as a flywheel thats what i know about the physics behind it.

 

[masterblaster]

foximus.....its not bull bud,none of those flywheels work with the advent anolog to dig converting cdi,so unless the epic is very diff?

Chris,I took your answer in the other thread "If the aftermarket flywheels give the same output from the stator it would work, however none of the flywheels I have come across do this, they all have their quirks" to mean basically they would not? I know tbm did a redesign on their second fw to have a more precise pickup and some other things to emulate the stock fw,and work with the advent ign.but its just another $600 to spend.If testing is done to prove they work with the rad or jetinetics,you have 2 igns sold to me

Scott. I think your single carb atp setup cc size and prop have much more to do with your smoother powerband than Corys,I rode both your skis and they are a ton different in power curve. Smooth is a realitive word,I thought your ski felt great,but it would be better with a a/m lite fw. More torque to the prop,it would be just as smooth,just a little faster revs. Tl delivers a more punchy curve based on a REAL lite fw and a ton more timing down low.Setting the curve right for a linear powerband is where its at.

 

[QJS]

Chris,I took your answer in the other thread "If the aftermarket flywheels give the same output from the stator it would work, however none of the flywheels I have come across do this, they all have their quirks" to mean basically they would not?
.

I didn't word this very well, the "quirks" I refer to have nothing to do with my testing with EPIC, this is just stuff I have picked up over the years. What I know is that RAD flywheels tend to advance ignition and Jetinetics retard the ignition. I have also had a close friend that had a Jetinetics flywheel overide the rev limiter on an engine that was on his dyno, and just to even things out our own lightweight flywheel seems to bring the rev limiter in early causing a mis-fire which is remedied by disconnecting the rev limiter.
All of this makes me cautious so at this point EPIC has never been tested with anything other than a stock flywheel which seemed like a sensible starting point. We could without doubt spend countless hours going through every flywheel and making a version of the EPIC to suit it if in fact it is necesary, it is possible that it will work fine.
to be cont........

 

[seatsR4toilets]

I saw a TBM new style lightweight charging FW for the first time yesterday. It's light. Just holding it in your hand and looking at it you can tell it's a very nice piece. One of the things I found strange is the threaded holes for the puller....they were tapped, but not drilled all the way through the flywheel itself. It appears to be a MUCH nicer piece then the RAD or Jetnetics flywheels that I've owned.

BUT....

If I'm understanding this thread correctly, my idea of going with an MSD enhancer and a new style TBM charging flywheel (for, say, about $750), I'm really not going to get what I should be getting or expecting out of the motor package that I have due to TIMING CURVES and not ROTATING WEIGHT (or mass), which would all be corrected with a total loss system.

Is that correct?

 

[Foximus]

Like I said... as long as your paying attention, just sit there with a timing light and take notice of exactly how your mapping your ignition curve.


Basically the same as programming a fuel curve on a car. Just pay attention and you'll be fine.

I will be buying one soon enough to use on my RAD.

 

[Matt_E]

Is that correct?

Yes.

 

[QJS]

If in fact timing variations are the only issue it is simple, just put a flat curve in EPIC at say 21 degrees then put a timing light on your engine and see what it reads. There is a useful feature on EPIC that allows you to put an offset figure in which will take everything up or down by a given amount. So for example if you had a curve programmed at 21* and your timing light told you it was 24* you would offset the timing by minus 3* and everything would be correct. It may however not be that simple....
At this point I would rather not give too much more away except to say that I don't know at this point what voltage aftermarket flywheels are generating, they all have one thing in common and that is in order to reduce weight, the mass and surface area of the magnets are changed, this has a few effects on the resulting waveform that is output from the stator. The EPIC has a way of dealing with variations in this voltage but if it were too much then the internal components could be stressed but the outputting voltage is not the only issue.
What I have decided to do is design a flywheel that mimicks the electrical characteristics of the OEM unit as closely as possible (we have the means to do these tests), that way the flywheel would work with EPIC and in theory any other aftermarket ignition. I have already machined a prototype and we should soon be in a position to start electrical analysis, however, we are a small business and these things take time. The EPIC for example was first put on a ski and run in January 08 which was before we launched Flame.
Not trying to hyjack here, just trying to answer some of the questions.
Chris.
Chris.

 

[judd17]

I have a tbm and a epic on the way, I'll let you know how it goes.....

 

[seatsR4toilets]

That would be good to know how that works.

 

[masterblaster]

Chris,I have heard those things about the rad and jetinetics as well,and some say they do not time out accurately, although I have both and have used a dig advance timing light that reads rpms in 2 stroke mode and found them both to be perfect static and total timing up to 7500.rather the stator is advanced or not,I get a true reading the same as a stock fw I have never had a issue with the rev lim either.but im using the msd enhancer with them,not sure what others have used to see this issue happen.
The new tbm fw is basically what you are describing,I talked to them for awhile about it,alot of work went into getting it precise voltage and some other things I cant even remember,We wanted it for a advent we were running,becasue the other 2 a/m fws above deff wouldnt work according to advent. 600 bucks wasnt worth it to run a unreliable ign,so it was sold and went back to enhancer with the flywheels we already had.Do you have any curves you can post up that work well for freeride motors,the advent had a few really aggressive sets that fitzgerald programmed for pump gas.that were 36 deg through the low to mid range to 5000rpm.and another for race gas that held up to 30 deg higher to 5750rpm.

fox. let me know how it works out with your Rad fw.your rolling the dice though.

 

[Matt_E]

It reads RPM's in 2-stroke mode? How does that work?

 

[masterblaster]

dig advance gun,its got a 2 stroke mode button that allows you to go between reading rpms and timing. you can set the advance you want with a button and dig readout on the gun,it shows you how far you are off on the flywheel with the light.

 

[Foximus]

dig advance gun,its got a 2 stroke mode button that allows you to go between reading rpms and timing. you can set the advance you want with a button and dig readout on the gun,it shows you how far you are off on the flywheel with the light.

Yea, those guns are nice. I used to have one. And then I lent it out and it brokes mysteriously.... hmmm


Half my ski build was me rolling the dice. I'm used to that. I make a logical conclusion and stick to my guns... lol

 

[Citizen]

@Seats

If I read all your posts right you would like to try TL again, but don't want to lose your ass when you sell your blaster correct?

Buy another, install, and just put stock one back in when you sell..then you can toss it into your next ski.

From what i have read here TL is well worth it and yours just wasn't dialed in correctly, so I'd say give it another shot and transfer it from ski to ski to avoid losing money.

 

[masterblaster]

I get alot of mixed reviews from Tl users who ride surf,even when ts has set them up.Im still going to try tl but it will be in my backup ski/test boat. I wouldnt use it in my main ride because reliability is always #1 in my book,thats why I like this epic ign so much,I really hope it works well with the rad fw

Seats..I was standing there with Craig when you were trying to get the ski started back up,backfiring and misfiring with that fried tl,sometimes it not worth all the trauma if its going to be the only ski you bring. Im going to try jss with a waterproff box and my tl in the backup ski,any drama and its gettin sold right off,Im not fighting with it.