Thoughts on pinging

[vulcanero03]

well guys, i have decided after much thought, to relocate the air temp sensor. so far i have tried everything possible and i minimized it about 95% it only pings very so slightly when the outside temp is above 90 degrees. mind you. my purpose is to get rid of the pinging in 100% stock form. no expensive mods to speak of. i discovered that both sides of the engine right around the two round filter covers the air gets really hot because of the heat from the radiator. so i went to osh and bought a piece of AC line insulator black foam just to add sort of a "snorkle" if you will, so that the engine scoops the air from the left side above and ahead of the radiator. it looks ugly but i just did it as a test, this weekend i am relocating the air sensor to the left side at the air inlet of the filter, where the air is the coolest. and if that works. i will send some photos to browndodge so that he can post them. i also am running a 1/2 inch hose from the front of the frame to the air sensor, that helped somewhat but like i said, still pings a little. and my thoughts are that, the sensor gets hot no matter what, so it needs to coold down to change the values. good luck to all.

jesus Granados(vulcanero03)

[scion0]

Originally Posted by Blowndodge "Darksider"

resistor mod..... I went all the way up to 2K resistor. Yes I can still find situations that can make it ping (I'm running 89) but its sooooo much better now that I can live with it. I used to get ping running premium in 1st gear in the summertime!!! It was awful.

What wattage are the resisitors used (1/4 watt)?

[blowndodge]

yes 1/4 watt. I mispoke on the value, it's 1.5K ohm.

[scion0]

Originally Posted by Blowndodge "Darksider"

yes 1/4 watt. I mispoke on the value, it's 1.5K ohm.

No problem. Thanks.

[vulcanero03]

I am back with this subject, I drilled the left cover(bottom half) changed the air sensor to the front of the engine, (where it scoops cold air) designed a "cold air ram intake" on the top of the cold air box, and all fo these things did cure the pinging up to a point, but when it got hot, the dammn pinging came back slightly, i was determined to find a solution to the problem without spending money on aftermarket parts, no luck!!
sooo! i ordered the cobra FI2000R and installed it friday, started with the default settings 2.0-2.0 -0 took it for a ride, no difference, went with the following 2.0-2.5-1.0 slight improvement on roll on acceleration, though still a very slight pinging on full throttle, changed the settings again, 2.0-3.0-1.0 and inmediately, the bike felt like a new bike, i tesyed under a hot day, 98 degrees or so, and going around 55 miles/hr. rolled the throttle wide open and i felt a really smooth power surge like i have never felt it before. it took 1 hour to install the cobra unit, lift the tank, unplug the injectors, plug the cobra harness, re-connect the injector wiring over the cobra connectors, and ground the only wire to the battery negative and, presto!! i took a drive up to solvang this weekend to try it, and we were riding in 101-102 degrees, up the hills, never once did i hear any pinging, my mileage doesn't appear to have suffered any, i still got about 39 to 40 miles per gallon. all in all, my bike feels like a new bike, smooth strong and much more enjoyable. I sincerely recomend it, i hope this helps someone else find that sweet spot.
sincerely.

Vulcanero.

[doctorgski]

It appears that I have found a sure fix to the pinging. Move to the mountains. ;) Not to be smart, but most of the time we ride at sea level in hot temps, (pinging all the time, even when it's cool). We come to Colorado in the summer, at 9600 feet and I can't get the bike to ping, I don't care how hard I lug it! I hypothesize that the lack of O2 at this higher elevation makes the bike run richer.

[cactusjack]

I agree. I went on a ride Saturday that took me from the Valley (~1200') up to around 6000' in Presott, Jerome and Camp Verde. The bike runs like crazy up there with no pinging. I come back to the Valley and once I get below about 3000 feet, the pinging is back. Temps were in the 80's up in the mountains and over 100 in the Valley.

[blowndodge]

The higher the altitude the less dense the air is and the compression ratio is lower inside your engine. Ain't that right cadd! Fuel injection has a sensor to compensate for the mixtue at higher altitudes so mixture is ok. It's the altitude boys. Of course I know it's cooler in the mountains but i've been in 85 degrees @ 7000 feet and it didn't ping at all.

[ells]

Actually, the compression ratio stays the same, it is the final pressure that determines how the gas burns. So if the starting pressure is lower (high altitude) then the final pressure is lower and less octane rating is needed to slow the explosion. Or at least that's what I hear tell.

Getting pinging with mine for the first time with mixture of mid and high octane (87 and 91, Denver) in the highest heat in the plains about 5000ft but gets better going up to 10,000 plus. Still don't understand some people saying they never get any pinging with regular, might be low compression??

[blowndodge]

To be more specific, the "cranking pressure" is lower in higher climates.

Originally Posted by Blowndodge "Darksider"

The higher the altitude the less dense the air is and the compression ratio is lower inside your engine. Ain't that right cadd!

Oooooh! I wasn't gonna but remember that you asked!

The compression ratio doesn't change. That ratio is a function of geometry and nothing more. If the piston squeezes a 100cc chamber down to a 10cc chamber the ratio is 10:1 and that can't change unless you tear that engine apart.

But the absolute compression pressure (and therefore horsepower)can change a lot. Less air pressure = less BMEP (Brake Mean Effective Pressure) = less HP.

Originally Posted by Blowndodge "Darksider"

Fuel injection has a sensor to compensate for the mixtue at higher altitudes so mixture is ok. It's the altitude boys. Of course I know it's cooler in the mountains but i've been in 85 degrees @ 7000 feet and it didn't ping at all.

That IS essentially correct. The FI adjusts automatically to the ambient air pressure (and other things.) The higher the altitude, the less the pressure.

[blowndodge]

see posting about on cranking pressure above. Yes I know compression ratio is the total volume reduced to ending volume at TDC or TV/EV.

I forgot that the engineer police is structure proofing everything I post for errors. Sorry

Again, generic terminology. Most understand 13:1 has a higher cold cranking compression than 9:1 so I was using compression ratios. Cranking pressure is actually the complete definition. This is usually measured cold or CCP

If standard atmospheric pressure is "about" 14.7 psi then one can extropolate that a 10:1 engine has a cold cranking pressure of "about" 147lbs per sq in if heat and compression temp increases weren't in play. Therefore a lower compression ratio will have a lower cranking pressure before the thermo dynamic of compressing the mixture. This is called the universal gas laws.

I really don't think we need to know this as Nomad owners but as with many years of drag racing I needed to to air temp, air pressure, track temp and altitude. Again. I was just giving a generic response.

So to make everone happy the total cranking pressure is lower as you go up in altitude. So if CCP is 147lbs per sq in. then it is lower as you go up.

How much lower? I'm sure cadd will have the formula for reduction in total CCP per 1000 feet rise in elevation factoring in air temp He's our in-house engineer. I used to know the rough equation but I don't remember. Something like 4500 ft you lose 10% in CCP but I'm not TOTALLY SURE!!! ::)

Turbocharging was invented in the early 1900's originally to be applied to aircraft. To make up for lost pressure inside the combustion chamber at extreme altitude.

Yep. Ditto with nitrous oxide injection. They were trying to maintain performance where there was less air pressure and less oxygen to burn.

Off hand I don't remember the figures for losses due to atmospheric pressure change, but that sounds about right.

Here's what I notice: At Tioga Pass, which is nearly 10,000 feet, I lose a small amount of horsepower and torque. Because the Nomad generates little horsepower from its torque due to the low RPM possible, it gives up a lesser percentage of its horsepower than some bikes. Light aircraft engines and Nomad engines are very similar in that respect. They deliver their peak at very low RPM, and not depending on "breathing" as much as a high RPM engine, they give up less of what they do have at high altitudes.

[blowndodge]

Originally Posted by caddmannq

Yep. Ditto with nitrous oxide injection. They were trying to maintain performance where there was less air pressure and less oxygen to burn.

Off hand I don't remember the figures for losses due to atmospheric pressure change, but that sounds about right.

Here's what I notice: At Tioga Pass, which is nearly 10,000 feet, I lose a small amount of horsepower and torque. Because the Nomad generates little horsepower from its torque due to the low RPM possible, it gives up a lesser percentage of its horsepower than some bikes. Light aircraft engines and Nomad engines are very similar in that respect. They deliver their peak at very low RPM, and not depending on "breathing" as much as a high RPM engine, they give up less of what they do have at high altitudes.

Thats why turbo's are so cool. The engine is no longer an "induction" motor but a pressurized pump. No longer relying on vacuum to fill the cylinders but force feeding them. No fancy cams with huge lift or overlap. No need for big compression. Just force feed the MOFO !!!

When I first went to B mod turbo in drag racing I remember what a breeze it was to find HP!!!

[cactusjack]

I just ordered a Cobra FI2000R (92-1963) from Motorcycle Pro Shop for $188 shipped. Best deal I could find. They have decent prices on tires and other accessories, too.