There has been a few times I felt maybe I said too muchLol flattop1 if you ask someone where we race that I would say you would need more than a tissue
Don't forget barometric pressure, it's just as important as temperature. Better yet, get an air density gauge, it measures barometric pressure against temperature.Then why when we dyno put in the correction factors for that dyno pull if it made no difference then why put it in or use auto correction heck they are none even turning them close to 5500 on the track I have even made several (over 20 ) pulls with the governor set at 56 to 5800 and most at 4800 drop drastically in hp and yes humidity and temperatures has a big difference in hp and torque if not get on your dyno and do some testing for the public like some on here do
As the air gets better (higher air density) of course the engine makes more HP. If the motor "leans", (more air means you need more fuel ) that means you didn't have it jetted right in the first place. A 1% increase in air density, according to Longacre, calls for a 1% increase in jet area. With a .038" jet, a 1% increase in jet area is about .0002" in diameter. Understand the difference between "diameter" and "area".I dyno in a non climate control shop. I have seen a difference in hp between night and day, even with correction factors. What I suspect is ,if you are on a .031 jet . A .0305 might be what you really need . As the air gets better the motor leans and makes more hp.
Stiffer spring on the governor, or, as suggested, a zip tie thru a portion of the existing spring, making it a stiffer acting spring.So, back to the original question. If I want to set up a stock predator to run, how do you get it to turn 5k without removing the governor?. There is a series here in NC that runs Hoosier tires, no prep allowed, that I want to run.
Track rule is stock motor, may change jetting, 5500rpm Max checked on stand, must surge.Stiffer spring on the governor, or, as suggested, a zip tie thru a portion of the existing spring, making it a stiffer acting spring.
If your rule is 5000 rpm on the stand, the engine will start falling off (ie governor closing throttle blade) somewhere below this number.
To get 5000 rpm on the track, you may need to be somewhere above 5500 rpm on the stand. Camshaft / valve springs may be falling off as well.
Spring stiffness and position on the lever will alter this slightly.
Look at these two dyno charts. Notice the HP numbers are identical. Notice the torque numbers are all different. Notice that the correction factor number is different. Notice the barometric pressure is the same but the temperature is different. The correction factor is calculated using the barometric pressure and temperature as data points. If your dyno is not doing something similar to this, then your have a problem with the software.I dyno in a non climate control shop. I have seen a difference in hp between night and day, even with correction factors. What I suspect is ,if you are on a .031 jet . A .0305 might be what you really need . As the air gets better the motor leans and makes more hp.
If you can get it to turn 5500 on the stand you will win races at 4850 to 5050. Do not plan on seeing anything above that on the trackTrack rule is stock motor, may change jetting, 5500rpm Max checked on stand, must surge.
I have heard that some motors don't surge at peak RPM, what causes this, and how do you correct it?If you can get it to turn 5500 on the stand you will win races at 4850 to 5050. Do not plan on seeing anything above that on the track
My only concern is that the rules state that the engine must surge on stand when Max RPM is checkedThe surge is most likely from a not so strong spring. Some do and some dont. I am not positive of my answer but I have encountered both ( surge and non surge ) in the engines i have teched. It does not matter if it surges on the stand when checking maximum RPMs. It will not surge on the race track if the engine is set at 5500 because the engine on the track is only going to turn between 4850 and 5050
That rule makes no sense as it has no purpose.My only concern is that the rules state that the engine must surge on stand when Max RPM is checked
That is what I'm worried about. I have four different predator, and clone engines in the garage, only one surges, and it's no where near 5500rpm. It's bone stock.Whoever made up that rule needs to do some research. There will be some racers dq’ed unnecessarily.