Greetings - 100cc M/F for 2014

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Mon Nov 14, 2011 10:40 pm

Hi Bones,

Yep, the DLRA record is open at the moment. I'm running in modified production class so I'm a little unsure how much I can modify the frame before it becomes a special build. I know I could lengthen the swingarm by up to 10%. I suppose the overall height of the thing is a tradeoff between the frame height, suspension height and rear wheel diameter. As it is, I can't drop the suspension any lower due to the height of the rear wheel wanting to rub on the seat pan. To get my body down low I have to push my backside as far back as I can which means I'm right on top of the back wheel. If I got any lower, I'd be in danger of the rear wheel chewing through the seat pan and into my nuts (not ideal). Extending the swingarm by 10% (5cm) would only let me get my body maybe 2cm lower so I doubt I'll bother going down that road for now. A lot of work for not much gain.

The ignition is magneto / CDI but I'll have a battery on the bike to power the data logging computer and fuel solenoid valve and I'll run a relay for the earth on the CDI so the kill switch will shut off both the fuel and spark. I'll seal it up good so the salt won't get at it.

The RS125 engine is a whole lot better than what I'm using. And those guys have money to play with. I'll be happy if I can get it down the salt at anything near 100mph without it becoming a rolling fireball at my first attempt. I'm not quite 40 yet so hopefully I'll have many years of this to come.

Chris.

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BONES
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Re: Greetings - 100cc M/F for 2014

Post by BONES » Tue Nov 15, 2011 9:07 pm

Chris,
check the rules-- because you are using a 100 angine in a 175 frame I think you will be in special construction.
I think the bike must use the original frame and motor to be in modified
Tuck your nuts up and be as low as possible .
cheers Bones

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Tue Nov 15, 2011 9:15 pm

BONES wrote:Chris,
check the rules-- because you are using a 100 angine in a 175 frame I think you will be in special construction.
I think the bike must use the original frame and motor to be in modified
Tuck your nuts up and be as low as possible .
cheers Bones
Modified Production rules say:

• Frames shall be based on an OEM type frame or production replacement having similar geometry.
• The engine shall be from the same manufacturer as the frame.
• A single engine with maximum displacement limited to 3000cc.
• A maximum wheelbase not to exceed the original OEM specification plus 10%. Entrants shall provide acceptable documentation
for record certification.
• Handlebar grips and rider seating position shall be above the top of the rear tire with the rider seated, unless original OEM
design.


So I think I'm OK with the frame/engine combo. They're both Yamaha. If I had a YZ100 engine I'd use that instead.
On the wheelbase, I had thought that I could only extend the swingarm by 10%. Looks like I can increase the whole wheelbase by 10%. But after having a look at it, now that I'm going to run it as a hard tail, my seat height is already the same as the top of the rear tyre which is slightly behind the seat. So, I can't run it any lower anyway. That leaves me with about an inch of clearance between the tyre and seat pan which should be enough now that suspension travel is gone.
Rules say:

7.F.1 Foot Rests:
Shall be ahead of the rear axle at least by 6 in.


The idea of increasing the length of the swingarm does appeal a bit as it would allow me to run the footpegs further back which would put my legs in a little bit more of an aerodynamic position. The wheelbase is 1300mm so we're only talking 13cm difference.

I also have shorter set of forks which will allow me to drop the front a fair bit more than what's on it.
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BONES
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Re: Greetings - 100cc M/F for 2014

Post by BONES » Tue Nov 15, 2011 9:34 pm

Looks like you'r in
Best I read the rule book again
I'm easily confused-- 3 bikes on the go
Have a look on Landracing.com-- loads of infrmation and pics
cheers Bones

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Sun Feb 10, 2013 6:48 pm

It's been a busy year. Sadly not with bike building. I finished uni and started a new job. So after 3 years in the financial wilderness, I have an income again so I can continue the build on this bike. Still on track (and now on budget) for 2014 speed week.

I've ordered all the gear I need for the fuel shutoff and lanyard kill switch. I've done a heap of work on my engine simulation software and am now anticipating 35HP on methanol.

I'll be using an RZ350 front end on it (32mm forks). I'm searching for a YZ125A rear wheel and hub which will hopefully match the rear hub sprocket offset to the DT100D counter shaft sprocket offset (or at least near enough so I can machine a mm off here or there to make it spot on).

I'm looking into running a Mikuni TMX35 carb through a V-Force reed block. The '93-'01 YZ85 reed block has the same mounting holes and would only require minor machining work to the barrel to make it fit. It's an easy (almost) bolt on 1 - 2HP across the entire curve (according to my simulations, not the marketing guff). Every bit counts.

I still need to fabricate a rear tank mount and seat pan for it as well as a rear mudguard and chain guard.

After that it's a bit of porting and build the expansion chamber then hit the dyno to see what I've got.

It's good to be able to see the light at the end of the tunnel again.

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Mon Feb 11, 2013 9:18 pm

I've just invested in a Mychron 4 2T. I looked around at heaps of data loggers for two strokes and it seems to be about the best value for what I want.

Image

RPM, CHT & EGT as well as Lambda plus GPS speed and mapping. Can download it all into the laptop after each run.

It will display the temps and Lambda on the dash so it'll be worth its weight in peanut butter sandwiches if it saves me seizing an engine.

Anyone else using these or other units like it?

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internetscooter
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Re: Greetings - 100cc M/F for 2014

Post by internetscooter » Mon Feb 11, 2013 9:47 pm

I am building my own http://www.vespalabs.org/Projects/Scooter_Computer_II - after next week I am going to be extremely broke for a long time :( So my plan is to finish all the projects I started before buying anything more ;)

Lambada - have you got the sensor? GPS too? Have you got he whole lot?

Personally have not found EGT any good on it's own, it varies too much with RPM (though matched datalogging RPM to EGT should be excellent).

CHT is only good as a symptom checker - it won't stop a seize unless you see something is up early e.g. change fuel/jetting and see it is 20 degrees hotter than last time.

Lambda is excellent but don't have it on all the time as you will stuff up the sensor with oil - also it chews through power as it is heating the unit.

Hope the above helps ;)
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Mon Feb 11, 2013 10:12 pm

Thanks, Paul.

That computer you're putting together there looks cool. Lots of work in that. Good luck with it.

Yeah, I bought the lot. In for a penny ... and as I alluded to before, it'll hopefully pay for itself in pistons I don't have to buy.

The GPS option is expensive when compared with buying a stand alone unit but I figured having it integrated into the data logging system would make analysing the data much more useful.

I wonder how the O2 sensor will go with methanol. I gather the methanol itself doesn't hurt the sensor but with the oil mixed in I wonder if that'll be better or worse for it than if I was running avgas. I'd have thought it'd run cleaner. The sensor itself is just a standard Bosch LSU 4.9 item. Nothing special about it and easily replaced.

I'll be putting a decent sized battery in the thing as I also have to pull a fuel shutoff solenoid and a couple of relays, not to mention the data logging stuff. I'd rather not be charging it during the day.

At least the ignition is CDI magneto.

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Re: Greetings - 100cc M/F for 2014

Post by internetscooter » Tue Feb 12, 2013 6:23 am

Chris,

Here are my notes on the first setup I did (o2 only) and you'll find the Bosch info in a pdf at the bottom. From memory it has details on how much contamination it is designed for and how long it will last. I think the main thing is to have it running or have it unplugged as the heating helps it stay clean.

http://www.vespalabs.org/User:Internets ... Lab_Notes)

I am now using this http://www.vespalabs.org/User:Internets ... gen_Sensor

The GPS will be useful - the very first things I will be doing is going on the GPS track, comparing rear wheel speed with GPS and looking at the o2 to adjust my jetting for the lake. I think your unit has wheel speed so connect it to the rear wheel to give you more info.
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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Greg Watters
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Re: Greetings - 100cc M/F for 2014

Post by Greg Watters » Tue Feb 12, 2013 7:56 am

I use a garmin gps18on my logger, may replace it later with any of the cheaper stuff on ebay , currently running at 1hz but would prefer 5 or 10 hz sample rate
just too much distance between samples to cross reference with wheel speed

egt is good on a run
your looking for it to rise to a reasonable level then flat line,once you get that you can hold it WFO for a long time if it continues to rise you will be lucky to see the full measured mile

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Wed Feb 13, 2013 8:24 pm

Thanks Greg. Any idea what would be a good EGT to shoot for with an air cooled two stroke on methanol? I'd have thought around 1000 deg F (540 deg C) would be about as hot as I'd want to get it.

Presumably it also depends where the probe is in the pipe as to what kind of accuracy one gets.

Likewise with EGO.

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Mon Feb 18, 2013 10:56 pm

Hey Paul,

I took a look at your website (which is great, by the way) . You seem to have your EGO bung about 300mm from the exhaust port. I'm just wondering if you had an expansion chamber on it as well when you were running it like that? All I can see from the photo is what looks like a straight pipe.

I'm still trying to work out how far down the pipe to run it.

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Re: Greetings - 100cc M/F for 2014

Post by internetscooter » Tue Feb 19, 2013 6:17 am

The instructions should tell you, I started off using a techedge unit and their instructions are here: http://wbo2.com/lsu/position.htm - I have a bung set up on every pipe I own ;) What you are trying to do is save on power without overheating the sensor, leaning towards not overheating. Too hot and bad things happen, too cool and the internal heater will kick in and heat it up (hence you can tail pipe sniff). So I take the recommended spot and move it down the pipe to the best physical position. Be careful to take into account things that move like stands.

If you have the EGT you could wait and use that to find the best spot.
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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ChrisACT
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Re: Greetings - 100cc M/F for 2014

Post by ChrisACT » Tue Feb 19, 2013 9:01 pm

I'm using MOTA software to work out the engine tuning. It has an animated wave display that shows purity and temperature through the pipe for the duration of the cycle at a given RPM.

By the looks of that, the EGT should be about 150mm from the piston (about the hottest part of the pipe) and the O2 sensor about 400mm from the piston (cooler and the purity is fairly stable).

That'll probably be my starting point.

I've seen a product by KOSO. http://www.kosonorthamerica.com/new/sho ... daptor-4/#

It's a bung extender and heat sink which is supposed to be used for two stroke engines. Allegedly, it increases the life of O2 sensors.

I am unsure as to why it needs a heat sink. The sensor is supposed to handle 700 deg C. If you're getting exhaust gasses that hot on a two stroke, surely you'd be melting pistons.

More boxes of bits arrived today. My lanyard kill switch and a bunch of Aeroflow stuff. Yeah, it's just fuel lines and adapters but they're so blue and shiny. :mrgreen:

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Re: Greetings - 100cc M/F for 2014

Post by internetscooter » Tue Feb 19, 2013 9:17 pm

The heat keeps the sensor clean - shiny and clean ;)
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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