| Author | Message | ||
     Xelerator |
I'd like to see dyno runs with IAT-graph (Intake Air Temperature), showing the influence of the radiator fans blowing towards the intake funnel. Cold air is the key to further gains. Thanks Chris Here is what "Highscore" found out: http://www.badweatherbikers.com/cgibin/discus/show .cgi?tpc=290431&post=1687923#POST1687923} | ||
| Moosestang |
I suspect a cold motor is more important than cold air. | ||
| Easyrider |
The IAT sensor is really a interesting sensor. When shutting off the 02 sensor It still is able to make more then 1 AF difference.. | ||
| Justa4banger |
1 full point? like 14/1 to 13/1... or 14/1 to 15/1...... wow thats a hell of an adjustment...... Also which way does it go? rich or lean? | ||
| 1_mike |
Moosestang - Not correct. Cool fuel and air (read that dense) make power. The water temp. needs to be up around 180F/190F for all around best performance. Proven many time over. Mike | ||
| Moosestang |
I know cold air makes more power. I just don't believe the radiators are making that much difference in normal riding. My air temps are pretty much ambient when I'm riding at any speed. It was 36 degrees this morning and my AT showed 36 below 50 mph. It showed 29 at 73mph in a low lying area. I guess if you want the best dyno numbers then it does make a difference. My car always traps higher when the motor is cool, below 160. | ||
| Redscuell |
" I just don't believe the radiators are making that much difference in normal riding. " I think you're spot-on, moose. I had a pair of remote temp sensors rigged to my R for awhile, with one at the nose of the upper fairing and one on the upper triple clamp (and therefore proximate my XB-style intake cover inlet); and the three temps were within a degree or two at road speeds. Therefore I removed the remotes, as they were only informative in slow traffic, in which case I was at the mercy of the ambient and radiator temps (so intake temp c/b in the 50s C). | ||
| Xelerator |
That's what I expected, no significant influence in normal riding but on the other hand, dyno numbers seem to suffer from the radiator heat. I doubt if dyno operators always clamp the dyno-ambient-temp-sensor to the intake funnel of the bike. | ||
| Easyrider |
Justa4banger, That depends on more then 1 variable. It all depends on how the fuelmap is, learned AF. Then the measeared Temp from the IAT is sending signals to the ECM to correct fuel. It is 1 full AF minimal depending on what it is reading, is this making sense?... | ||
| Easyrider |
sorry (Message edited by easyrider on December 30, 2009) | ||
| Cataract2 |
I hate to say it, but the only times I notice the rads affecting the IAT is in stop and go when it starts to get hot. While on the move the IAT reading (you get it on your dash also, the AT #) is close (mine is within +/- 3 degrees) to the actual air temp outside, depending on how hot or cold it is that day. So, the only time you will notice the rads heat affecting you is on a dyno. For tuning purposes I'm certain this can be really annoying, for everyday riding I doubt you will notice anything. | ||
| Easyrider |
Cataract2 , you are right, But when you looked better also at different temp, (when you start the bike) it is able to move 10 degree.. (-; For tuning now an airco (big one) is necesarry to keep it in place.. You don't feel the difference, But i promise you the engine will.. | ||
| Highscore |
Most cars, as for example old Japanese inline 4s too, use a coolant system with a huge delta-T, this is the temperature difference between radiator inlet and out. Here the coolant system features rather large and bulky radiators of reasonable thermal capacity, to avoid the engine temperature from fluctuations. Therefore the cooler ventilator starts blowing just, when the thermal reserve of the radiator is exhausted and coolant temperature raises in consequence. The Helicon coolant system works different. It is designed to work with small, low-volume radiators. This system features a powerful water pump, which assures a fast water circulation thru the system. So the temperature difference of radiator inlet and outlet is low, just a few degrees. This is the design of sport cars like F1 where because of the aerodynamics the radiators must be small . The preferred thermal window is 80-85° C for the Helicon engine - not uncommon for a street vehicle. But here the coolant system has now pretty shy volume and thereby limited thermal reserves. For this reason the radiator fans start blowing pretty early, when the coolant reaches the upper limit of the preferred temperature range. This explains furthermore why the fans seem to blow rather constantly when the ambient temperature is high enough for riding without winter clothes. This hot air by the radiator fans blowing onto the engineīs airbox inlet makes only trouble during cruising. When driving faster and the airspeed around the bike sufficient high, this hot curl of air is blown away. So this phenomenon is more a problem of dyno testing the 1125 than of real world driving. You may test easily the extent of the "hot-air-problem" by sensing "AT" in the dashboard. When holding at a red light, this reading raises, when driving at a sufficient speed it goes down to normal ambient temperature. But you will see, this sensor needs a considerable time to react to the new air temperature at the engine air intake, when you speed up after the red light. During this period the ECU is now misinformed by the IAT-sensor, sensing still "hot summer" to it although the real air, charging the engine, is in fact cooler. But this should also be no problem of real world driving, again this shows more effect in the laboratory, at the dyno. @ Easyrider: Do you really think, you are out of these thermal troubles on your dyno, because you have air condition? Sorry, I guess not. Your dyno cell is anything but perfect: It is just to small. It is a small container, isnītīit? So its volume is .... Remember: A combustion engine is anything but a perfect engine. So for cranking out 100 kw engine power it burns fuel to release a heat energy of 300kw. So when you see 100 kw on your dyno, the engine presses accordingly 200 kw heat energy into the dyno cell, and this not over minutes but in a sudden. This heat, realased when making a dyno run, should act inside a small volume container similar to a Molotow cocktail thrown into, regarding the thermal impact. For this reason the installed 20 kw cooling power (I guess 20 kw per hour, not second) of the aircon sound impressive, but are never able to compensate really the missing volume of your dyno chamber. Of course it helps, as a good ventilation helps. But the only way to solve this problem really and to keep the conditions constant during dyno testing, is volume: a sufficient large dyno cell offering sufficient thermal reserves by its sheer mass for soaking up this sudden impact of engine heat. Again it looks like as I am here to criticize you, Easyrider. But this is not true, I appreciate your work and enthusiasm really,I just want i understand its back ground better. I am aware, the workshop space is not deliberately expandable. So you try your best to make your working conditions acceptable, but your dyno is still far away of perfection. BTW: "Dynostar" - is this company a subsidiary of Maha? Highscore (Message edited by Highscore on December 30, 2009) | ||
| Vtwinbuell |
I don't know why people fight about which dyno is better. It only matters that it is repeatable Maybe this will help out a little. http://www.engineeringtoolbox.com/air-temperature- pressure-density-d_771.html I would assume the ECM adjusts the fuel based on the IAT sensor similar to the change in the density of air. This would mean less air and fuel with a higher IAT temp, so less power. This is not much of a concern at speed, considering the amount of air flowing by the bike. You could try using a snorkel to route cool air to the intake on a dyno. Make sure that it is large enough that it will not considerably restrict airflow. | ||
| Moosestang |
So would there be any adverse effects to moving the IAT sensor. I'd like to try moving it away from the heat and see if it helps with surging while cruising. Assuming it reads colder air and adds more fuel. | ||
| Vtwinbuell |
The IAT needs to read the temp of the incoming air to be useful, otherwise, it will not adjust the fuel properly. If you adjust it with a resistor, it may lower the AFR for a while till the bike adjusts itself. Eventually the AFV value would probably change to compensate for the sensor being off to adjust the AFR to it's programmed value. I plan on tuning my bike with xtopii's spread sheets once they are done and a data logger program that I intend on making for my bike. | ||
| Marcodesade |
I'm reading this all and wondering: if the snorkel is importing heated air (and I see there's some debate about this), would it help to fashion some kind of extension so it pulls the air from further forward (say, just under the headlights)? | ||
| Vtwinbuell |
would it help to fashion some kind of extension so it pulls the air from further forward (say, just under the headlights)? I believe it would slightly at slow speeds under 40 or 50, just make sure not to make the cross section perpendicular to bike travel larger than the stock intake. This would increase the ram air effect at higher speeds and lean out the AFR. | ||
| 1_mike |
Wont make much difference in the winter...but as I put my CR back together from its valve relash, I'm going to do up a extension to pick up cooler air outside of the crappy, as designed hot air envelope. The first design may be out of black painted aluminum. It's gotta clear the left side fork though. Mike | ||
| Marcodesade |
Vtwin, I'm not sure I get your meaning. I'll start by admitting that I know nothing. So I read what little there was on Wikipedia about ram air. If I understood it correctly (and I'm willing to hear that I did not if that's the case), the ram air effect is caused by the increasing the cross-section (i.e. small snorkel to a large air box); that decreases the air speed and thereby increases the air pressure (kind of a reverse Bernoulli thing). So if that's true, wouldn't decreasing the cross-sectional difference (say, by widening the snorkel) DECREASE the ram air effect --- not increase it as you pointed out? Not trying to argue trivia; I'm honestly trying to understand more about all this . . . | ||
| Westmoorenerd |
By widening the snorkel you increase the Bernoulli effect, which will lead to an increase in air pressure. | ||
| Vtwinbuell |
I'm not sure what the Bernoulli effect is, but Westmoorenerd has it right. Ram air is like turbo charging the engine only at high speed. I havn't done the calculations for a while, but I think the size of the current air intake will create a ram air effect in fifth and sixth gear. this increases the air pressure in the air box above standard air pressure. A rough calculation can be made by taking the RPM/2*1125cc=air volume consumed by engine per minute. When cross section of the air intake multiplied by distance per minute is greater than the air volume consumed there is a ram air effect increasing the air density. I don't think the bike increases the fuel by a percentage based on which gear it is in, so it will lean out the mixture in higher gears. If there was a mass airflow sensor on the bike, it could adjust the fuel for the increased air density, but there is only a barometric pressure sensor and intake air temperature sensor to calculate the air density. | ||
| Bobbuell1961 |
Ride the bike and enjoy it! Bob | ||
| Vtwinbuell |
There is two feet of snow out there, its mod time now. | ||
| Easyrider |
I Love this topic.... Highscore, I have no Heat problems in the dyno.. I think you have.. (-:, and that is why you want to solve this IAT problem.. I Don't have any thermal troubles. If you ever think off doing something else then criticizing me, go and be a dyno room guru, I think it suits you very good.. No go back into your dyno room.. (-: and have a cold beer or 10 (Message edited by easyrider on December 31, 2009) | ||
| Buellishness |
we could solve this whole thing "turbo" bottom mounted lots of room in the air box even inter cool it. please, can someone get working on this! | ||
| Highscore |
In fact I should be on the way to a new year party. Regarding relocation of IAT-sensor: Test the effect. Relocating the sensor to a cooler part of the 1125 may help to reduce the lag, wherein the ECU receives wrong data. At an BMW 1150 GS I have relocated the IAT senor out of he airbox back to the rear frame. Things have been here little different here: This sensor has been heated by the engine most time. Was a mod before I was able to modify fueling directly by my "Kastl". Good effect, less surge, but increased fuel consumption. Regarding additional air ducting under the steering neck: Also a matter of test. May be there is a pressure drop, either explained by the Bernoulli effect or simply by wall friction, sacrificing engine out put. I see another reason, which could effect the engine negatively,even if the air flow is sufficient: harmful Resonances. The 1125-airbox acts as a two-stage resonator using its volume to couple to to independent sources for wave action together into a single system: the intake runner path to the intake valves + the stock airbox intake snorkel out of the airbox. This funnel "vibrates", when the engine is "inhaling" air, with its own amplitude. This resonance is changes, if the length of this funnel alters. The result is rather unpredictable. Unfortunately our human ability of understanding end, when there are more elements to consider in a unit than three . Here certainty ends and probability starts - in real world as in maths. So this mod is a pure candidate for testing. But you need a dyno for this job. Beyond 100 HP subjectively a motorcycle just "feels" strong, no matter if 5 HP occur or disappear. And we have an additional problem with this funnel: When the fork is compressed completely, the distance between front fender and steering neck is close to nothing (so is my memory) - a consequence of the Buell-style frame arrangement Therefore turbo charger + inter cooler here? I would say -sadly - no space. Highscore P.S. I am really impressed by the creativity here. Looks like as I here at the proper place to gain new ideas - Thank you and happy new year (Message edited by Highscore on December 31, 2009) (Message edited by Highscore on December 31, 2009) |
