ESE's works engine tuner

[malcy25]

Stinger size?

Same pipes and set up on identical bike, no issues.

[ief]

This ryger buisness...

Red a lot of Luc's work, he's been around for some time. Makes exhaust/ head calc's and the one I saw was great, in simulation and real life.

Why he behaves in this manner on this topic has me baffeled. although he likes to shield his knowledge (but with reason I could see that)

It ain't that complicataded....

Nuff said allready but I just don't get it.

adagenes, love your work, specialy the latest vid, bit of editing goes a long way

(saiyng that here since I don't have youtube account)

[peewee]

After run oils are essential to prevent bearing failure. Nitromethane/methanol fuels are much less explosive than gasoline.

Lohring Miller, NAMBA Safety Director

im only going by what I see on tv as I know nothing about nitro. doesn't seem uncommon for top fuel cars to pop the blower off and create a fireball, im guessing that's why they use the safety straps so engine pieces will be some what contained. that's why I was always hesitant to use it as a fuel, considering if the head explodes on a motorcycle your in serious trouble

ive always used 6% castor oil in methanol, and 6% castor in the petrol to flush the engine and never had bearing trouble . on top of the 6%, would another separate oil also be needed to flush the engine ? and my next question tied to this topic, 8oz or so of petrol is all the engine will manage to consume (which seems to only take a minute or so but ive never timed it), with the even larger fuel passages needed for nitro I wonder if the engine would even run at all with petrol ? constantly tearing it down to clean the inside components would be a huge hassle for me

[TZ350]

EFI really needs to accurately know the changes in airflow vis changes in throttle position.

So I thought it about time I checked the airflow behaviour through my ball valve throttle.

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.



Got old trusty BigSucker and attached it to the exhaust port and purchased a cheap Anemometer (wind speed meter) of Trademe.



My EFI Maps have 16 air flow steps. So I measured the maximum and minimum air flow then used Excel to calculate 16 even airflow steps from min to max airflow.

Then I recorded the 16 TPS positions from 0% to 100% that corresponded to the 16 even airflow steps.



The 16 TPS steps required to give 16 even increases in airflow through the Ball Valve throttle body.

Basically it was linear from 8 to 30% TPS and 55% gave 94% Airflow. I can use this information with the Alpha-N map.

Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port and how they behave on/off the pipe. Once I know that, I can develop a VE volumetric efficiency map for when the engine drops off the pipe at high RPM.

[jasonu]

Ahh your turn of phrase is brilliant

Damn foreigners mate!!!

[jasonu]

EFI really needs to accurately know the changes in airflow vis changes in throttle position.

So I thought it about time I checked the airflow behaviour through my ball valve throttle.

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.



Got old trusty BigSucker and attached it to the exhaust port and purchased a cheap Anemometer (wind speed meter) of Trademe.



My EFI Maps have 16 air flow steps. So I measured the maximum and minimum air flow then used Excel to calculate 16 even airflow steps from min to max airflow.

Then I recorded the 16 TPS positions from 0% to 100% that corresponded to the 16 even airflow steps.



The 16 TPS steps required to give 16 even increases in airflow through the Ball Valve throttle body.

Basically it was linear from 8 to 30% TPS and 55% gave 94% Airflow. I can use this information with the Alpha-N map.

Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port and how they behave on/off the pipe. Once I know that, I can develop a VE volumetric efficiency map for when the engine drops off the pipe at high RPM.

Mate you are genius! Buckets at its best!

[Frits Overmars]

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.

That's quite a late-closing inlet or early-opening exhaust. Your logic seems a bit shaky though; it doesn't matter when the inlet closes, but it should open before the transfers close.

Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port.

The exhaust opening pressure may be lot more than 2 bar....

[speedpro]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

[Flettner]

I agree with you regarding the difficulty. Good news is, KTM just announced their 2018 enduro models which will meet Euro4 emissions standard using transfer port injection.

Personally, I don't regard transfer port injection as 'revolutionary' (revolutionary for me would have been high pressure direct injection and no more scavenging losses at all and thus a real step forward in cleanliness, but hey, as a company you always go for the most economical way to achieve your targets), but I like the fact that one will be able to buy new two-stroke bikes in the future, too.

I think they will be using what I call DTPI, 'delayed transfer port injection' , as I have done on the YZ. This approach allows for the fuel to be delivered at such a time as to NOT escape out the exhaust. It would take a LOT of time to fully map an engine to get best results and some flash equipment but the upshot is nearly as good as DFI. This approach lends to cheap and durable hardware and allows for better fuel air mixing than DFI (I guess certainly in terms of cost)
We didn't have flash equipment for the YZ, just fuel burn results and seat of the pants (and a home made oscilloscope of sorts) but to show how easily it can be done we were getting between 14% and 21% fuel savings (compared to an identical YZ with a carb), same top end power!
So I would say DTPI is certainly not to be disregarded as a useful technology.
Now all they need is a sliding cylinder and HCCI and no oil burn at all! AND a chamber wave modifier, could be called an exhaust throttle.

[TZ350]

That's quite a late-closing inlet or early-opening exhaust. Your logic seems a bit shaky though; through-sucking requires inlet/exhaust/transfer overlap. Just saying

Ex opens 80 ATDC Inlet closes 90 ATDC Transfers open 115 ATDC

Yes you are right, if the inlet is still open after the transfers open I have a real problem. But the inlet should open 30 deg before the transfers close so maybe I don't have a problem.

Inlet opens 145 BTDC Transfers close 115 BTDC ex closes 80 BTDC so on the induction side they could all be open together.

I better re-check the rotary valve disk timing. ...

The exhaust opening pressure may be lot more than 2 bar....

Thanks for the heads up.

[TZ350]

Its all good, I had the inlet on the induction opening side.....

[adegnes]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

Fascinating to watch that transition!
Wish I could find a video of someone running a bit of hydrazine, with the infamous green flames and all.

About exploding engines, I think that's often caused by the ignition cutting out, not the explosive nature of nitro.
When you pump more fuel than air(ok, by weight so not as extreme as it sounds) into the combustion chamber and it fails to fire it hydrolocks.

[peewee]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

any chance you saw how they flushed the engine afterwards and what fuel they used ?

[husaberg]

I think they will be using what I call DTPI, 'delayed transfer port injection' , as I have done on the YZ. This approach allows for the fuel to be delivered at such a time as to NOT escape out the exhaust. It would take a LOT of time to fully map an engine to get best results and some flash equipment but the upshot is nearly as good as DFI. This approach lends to cheap and durable hardware and allows for better fuel air mixing than DFI (I guess certainly in terms of cost)
We didn't have flash equipment for the YZ, just fuel burn results and seat of the pants (and a home made oscilloscope of sorts) but to show how easily it can be done we were getting between 14% and 21% fuel savings (compared to an identical YZ with a carb), same top end power!
So I would say DTPI is certainly not to be disregarded as a useful technology.
Now all they need is a sliding cylinder and HCCI and no oil burn at all! AND a chamber wave modifier, could be called an exhaust throttle.

Hybrid indirect and direct injection system artic cat
http://www.google.com/patents/US7168401

[oldjohnno]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

They generally start the engine on petrol from a squirt bottle; it runs and sounds quite smooth on this. Often they'll stay on a lean setting until they're staging and the changeover to the rich race setting is very plain to hear. You can see and hear it here:


Usually if they're just doing a warm-up in the pits they'll shut the fuel off and let it run for a few seconds on petrol from the sauce bottle, and again it sounds very mild and smooth. The fuel isn't particularly explosive - they do cough the blower off occasionally but that's to be expected if an intake valve hangs open and remember there's quite a few litres of compressed air/fuel mixture in the manifold at maybe 4 bars of pressure. You can hear it here (and see the "nitro-rain"):


The fuel flow required to make upwards of 1000hp per cylinder is astounding; you can see it here (the first few seconds is at idle) :


I think two-strokes are always going to be severely limited in the use of these fuels by piston temperature. Four-strokes have the benefit of more "cold" strokes plus they don't wash the piston crown in hot exhaust gas as it exits the cylinder, but even so they often smoke the pistons towards the end of a run. I imagine the practical limit of nitro percentage in a two stroke would be quite low.