ESE's works engine tuner

[husaberg]

Nice article, thank you Frits
Does anyone have any information and or suggestions with regards to an inline twin such as the Rotax, DEA, FPE Kart engines and the balance issues if the cranks were to be phased at 180* instead of the current phasing of both pistons at TDC at the same time

Thanks

The torsional loads on the crank drive will be much higher with a 180 cranks ( I'm assuming you are talking tandem twin ). You WILL have to have a stronger gear to crank attachment. Rising and falling together pistons are even loads from crank to crank. I know I built one ( 180, same rotation ) and couldn't keep the joining gears from failure. But it did run smooth as far as balance went.

No idea, stumbled on that looking for some ADM 500 stuff, that was a single he did for an RS chassis

http://2stroker.createforumhosting.c...-t6505-15.html
http://www.adm-racing.ch/index.html

Must not be the one. i was thinking of then i think the exulted great leader was involved but i could be wrong.
Frits will know the one i mean. (pretty sure he and Jan had commented on it on the site) it was i think on the pitlane thread but i can't find it. It had beefy looking gears for the drive compared to the RSA. looked to be simpler set up but may have lacked the finesse of the RSA

[TZ350]

water cooled CPU radiator

This is the sort of thing I had in mind for inside the plenum. One or two of these with fans circulating the plenum air through the ice water cooled radiators. I am picking that because the plenum is ten times the engine size then some of the plenum air will be passed through the radiators and cooled before its ingested by the engine.

[Moooools]

This is the sort of thing I had in mind for inside the plenum. One or two of these with fans circulating the plenum air through the ice water cooled radiators. I am picking that because the plenum is ten times the engine then some of the plenum air will be passed through the radiators before its ingested.

Are you aware that even with 10 times the cylinder capacity it still only takes 0.04 seconds to drain the plenum? But that doesn't really matter if you just look at an AVERAGE of how long a single charge of air has spent in contact with the rad. Which is the length of time between intake strokes (0.004s). It cannot possibly average out to any more as the amount of air coming into the plenum must match that leaving.

And with only a 20ish degree temperature differential cooling is going to be really slow.

Average as idea sorry. Not buying this one unless you start using liquid nitrogen or dry ice. Get a bigger temp drop between rad and air and you might see something happen.

[wax]

Do you think the extra weight will effect the power to weight and handling in more of negative way than the power gained

[husaberg]

At the risk of sounding like an industry insider, i are just not getting it Rob.

The Vehicles that i am aware of that run inter-cooling pressurize the intake, Thereby greatly heating the charge, prior to induction. I can't see how you could achieve a large drop in intake temp, with ambilent air temp without a lot of restriction or over complication.
Beer i mind, I am often wrong though. just mussing.

OK but those 24 liters of air what is the contact time the air would have with you medium?

Anyway my all time favourite dubious use of cooling intakes.

Yes but
30HP/85kg=.353kg/hp
34hp/95kg=.357kg/hp

If you were to pursue this path wouldn't a long thin intake give you a greater surface area for potential cooling like a RSW intake for instance.

Are you aware that even with 10 times the cylinder capacity it still only takes 0.04 seconds to drain the plenum? But that doesn't really matter if you just look at an AVERAGE of how long a single charge of air has spent in contact with the rad. Which is the length of time between intake strokes (0.004s). It cannot possibly average out to any more as the amount of air coming into the plenum must match that leaving.

And with only a 20ish degree temperature differential cooling is going to be really slow.

Average as idea sorry. Not buying this one unless you start using liquid nitrogen or dry ice. Get a bigger temp drop between rad and air and you might see something happen.

Do you think the extra weight will effect the power to weight and handling in more of negative way than the power gained

there must be an echo

Liquid nitrogen is out but Dry ice now that goes solid to Gas no liquid its a rule bender's dream, plus its in the rules "that you must have a fire extinquisher in the pits "

[TZ350]

Do you think the extra weight will effect the power to weight and handling in more of negative way than the power gained

I would really need to test the idea on the dyno to see if its worth while.

Not buying this one unless you start using liquid nitrogen or dry ice. Get a bigger temp drop between rad and air and you might see something happen.

Thanks for the numbers, they make sense. I wanted to use ice as its readily available, dry ice is harder to organize and not available everywhere.

I do have an air to air turbo intercooler that could be modified to use dry ice and be plumbed into an inlet system that runs from the high pressure area just under the front number board to the plenum. So hopefully there would not be much pressure loss in the plenum from having to pass all the air through the intercooler.

[husaberg]

Thanks for the numbers, they make sense. I wanted to use ice as its readily available, dry ice is harder to organize and not available everywhere.

I do have an air to air turbo intercooler that could be modified to use dry ice and be plumbed into an inlet system that runs from the high pressure area just under the front number board to the plenum. So hopefully there would not be much pressure loss in the plenum from having to pass all the air through the intercooler.

For making Dry ice= bucket, towel.CO2 fire extinguisher
Marine cooler is more sexy and would be potentially less problematic to fit in as well

if you visit the site here it has the pressure drops through various intercoolers
http://www.autospeed.com/cms/article.html?&A=1931

[2T Institute]

Nice article, thank you Frits
Does anyone have any information and or suggestions with regards to an inline twin such as the Rotax, DEA, FPE Kart engines and the balance issues if the cranks were to be phased at 180* instead of the current phasing of both pistons at TDC at the same time

Thanks

Tried 90 and 180 deg phasing all you get is a numb bum. Back to twingle they go.




* Brock was fine by the Entrants Association which he was presumably a member, so he was judged by cheats and rule benders

[TZ350]

Thought I should get the tape measure out and compare the RS and NSR chassis.

It turns out that the distance between the front axial and swing arm are pretty much the same at 800mm, so I probably wont shorten the chassis. But the NSR swing arm is 100mm longer than the RS. Shortening the NSR swing arm would take weight off the front wheel.

[richban]

Thought I should get the tape measure out and compare the RS and NSR chassis.

It turns out that the distance between the front axial and swing arm are pretty much the same at 800mm, so I probably wont shorten the chassis. But the NSR swing arm is 100mm longer than the RS. Shortening the NSR swing arm would take weight off the front wheel.

How are you planning on correcting the lazy steering angel of the NSR? Would also be interesting to measure a later RS. My nsr is 22.2 degrees on the front and it is solid as tipping in. That could be because it is long as well. Oh and heavy.

[TZ350]

How are you planning on correcting the lazy steering angel of the NSR?

Dropping the forks through the tripple trees and jacking the back up, not sure how much yet. I will have to wait untill I get the frame back from Gigglebutton who is modifying the top stearing head bearing so it can take a special front end that I have.

[husaberg]

Thought I should get the tape measure out and compare the RS and NSR chassis.

It turns out that the distance between the front axial and swing arm are pretty much the same at 800mm, so I probably wont shorten the chassis. But the NSR swing arm is 100mm longer than the RS. Shortening the NSR swing arm would take weight off the front wheel.

Rob that 800mm, Is that with the NSR's forks still compressed vs the NF4 rs125's in the normal position? the NF4 also has a good few kgs well forward with the radiator position.
Cause as it is . It looks way longer. I'm picking the NX4 is a Good 150mm shorter front axle to swing-arm pivot as well, as Rich hinted.

[TZ350]

Rob that 800mm, Is that with the NSR's forks still compressed vs the NF4 rs125's in the normal position?

Both compressed, I will have to check with the NSR back in the normal position and tomorrow I will measure up the later RS chassis too.

[TZ350]

Alpha-N EFI Map



Finally got the Alpha-N Load map, mapped against TPS and RPM.



Another colorful map. You can see the effect of the pipe going in and out of resonance as the RPM goes up.



Delivery Ratio Graph of multiple runs done in EngMod2T at different TPS (throttle) positions. The colorful Alpha-N map pretty much follows the EngMod simulations.



To get the resolution required I used the EngMod graphing options to expand selected sections of the graphs.

[chrisc]

Posted because someone was asking me about it ....
Buckets post has links to detailed pictures of how we built the early engine.
We got most of our improvement by opening up the rear transfer ports. Nothing fancy, a 13mm drill or ball end long series milling cutter will do the trick. These two posts are worth a look to see how rough you can be and still get a good result.

STA's for the triple port show that with a bit of work reasonable numbers are possible from the old Suzuki cylinder.

STA's for a single port Suzuki GP125 cylinder.

Avs bike is a single port with the Exhaust opening 80 degrees ATDC 72% wide, Transfers 114 ATDC and Inlet opening 145 BTDC and closing 80 ATDC. Its a very easy bike to ride with a smooth flat torque curve. The carb is a taper bored 24mm OKO and is 30mm at the engine end and the rotary valve port window area has an effective diameter of 36mm.

If we were doing it again we would probably pay more attention to widening the rear "B" transfers and opening them a little later, like in the EngMod2T data sheets above.

Remember to get those transfers low and wide to maximize specific blow down time area of the exhaust port.

I take the "Effective port diameter (mm)" to mean the chord width of the cylinder? Please confirm