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Whoever made up the numbers on that 928 MS page doesn't know enough about engines to even make up the data to be internally consistent.Kevin Johnson wrote: ↑Sun Jun 02, 2019 10:43 am 928 Motorsports uses the dyno testing data by Ed Peters on our 2.4 Dodge system as advertisement for their version of our 928 system; it's not a big deal to us. I am glad they trust the data that much.![]()
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In any case, here's my question to you. Your dyno data is here:
http://www.928motorsports.com/parts/ima ... tChart.jpg.
Perhaps I am missing something, but the torque and hp values are not
possible. Torque in ftlb = power in hp * (5250/rpm), d Torque in ftlb
= d power in hp * (5250/rpm) holding rpm constant. That is, both your
torque and power increase columns can't be true.
rpm reported hp change reported torque change hp implied torque change
4000 0 3 -
5000 2 7 1.90
6000 3 8 3.43
7000 5 10 6.67
7500 7 13 10.00
What's the explanation? Do you have the raw dyno run data, like the
dynojet files? If this is just an eyeballing error from separately
eyeballing the curves from a chart, I recommend you revise the table
to be consistent.
It's been a few years now but this question came up before. I believe that the hp numbers were obtained while running steady state (in order to get the oil and coolant temps stabilized at the indicated rpm). The torque values were obtained from rpm sweep tests. I am afraid that I do not know the rpm/sec rate. I do know that his dyno cell was air conditioned to control the humidity level and air temperature. They had to put off dyno testing when it was raining heavily because the system could not keep up with dehumidification. That is a bit different and more accurate than using correction factors. Chrysler Corporate trusted his numbers.ptuomov wrote: ↑Sun Jun 02, 2019 11:00 amWhoever made up the numbers on that 928 MS page doesn't know enough about engines to even make up the data to be internally consistent.Kevin Johnson wrote: ↑Sun Jun 02, 2019 10:43 am 928 Motorsports uses the dyno testing data by Ed Peters on our 2.4 Dodge system as advertisement for their version of our 928 system; it's not a big deal to us. I am glad they trust the data that much.![]()
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I did email them this comment some years back n 2012, but it looks like it "didn't take":
In any case, here's my question to you. Your dyno data is here:
http://www.928motorsports.com/parts/ima ... tChart.jpg.
Perhaps I am missing something, but the torque and hp values are not
possible. Torque in ftlb = power in hp * (5250/rpm), d Torque in ftlb
= d power in hp * (5250/rpm) holding rpm constant. That is, both your
torque and power increase columns can't be true.
rpm reported hp change reported torque change hp implied torque change
4000 0 3 -
5000 2 7 1.90
6000 3 8 3.43
7000 5 10 6.67
7500 7 13 10.00
What's the explanation? Do you have the raw dyno run data, like the
dynojet files? If this is just an eyeballing error from separately
eyeballing the curves from a chart, I recommend you revise the table
to be consistent.
I might also want to unhook my phone and shoot visitors if I had published torque and power numbers that don’t add up!Kevin Johnson wrote: ↑Sun Jun 02, 2019 11:50 amIt's been a few years now but this question came up before. I believe that the hp numbers were obtained while running steady state (in order to get the oil and coolant temps stabilized at the indicated rpm). The torque values were obtained from rpm sweep tests. I am afraid that I do not know the rpm/sec rate. I do know that his dyno cell was air conditioned to control the humidity level and air temperature. They had to put off dyno testing when it was raining heavily because the system could not keep up with dehumidification. That is a bit different and more accurate than using correction factors. Chrysler Corporate trusted his numbers.ptuomov wrote: ↑Sun Jun 02, 2019 11:00 amWhoever made up the numbers on that 928 MS page doesn't know enough about engines to even make up the data to be internally consistent.Kevin Johnson wrote: ↑Sun Jun 02, 2019 10:43 am 928 Motorsports uses the dyno testing data by Ed Peters on our 2.4 Dodge system as advertisement for their version of our 928 system; it's not a big deal to us. I am glad they trust the data that much.![]()
![]()
I did email them this comment some years back n 2012, but it looks like it "didn't take":
In any case, here's my question to you. Your dyno data is here:
http://www.928motorsports.com/parts/ima ... tChart.jpg.
Perhaps I am missing something, but the torque and hp values are not
possible. Torque in ftlb = power in hp * (5250/rpm), d Torque in ftlb
= d power in hp * (5250/rpm) holding rpm constant. That is, both your
torque and power increase columns can't be true.
rpm reported hp change reported torque change hp implied torque change
4000 0 3 -
5000 2 7 1.90
6000 3 8 3.43
7000 5 10 6.67
7500 7 13 10.00
What's the explanation? Do you have the raw dyno run data, like the
dynojet files? If this is just an eyeballing error from separately
eyeballing the curves from a chart, I recommend you revise the table
to be consistent.
You could contact Ed Peters at Magnum Force Engineering located at 350 Gold Schaefer Rd, Fredericksburg, Texas, 78624 and ask him yourself. I suggest writing a letter to him as he rarely answers the phone.
Please be respectful and do not just show up and attempt to enter his property. In Texas and Florida, at least, that is a good way to get shot.
BILL-C wrote: ↑Sun Jun 02, 2019 11:43 am The majority of our race customers run american v-8's, but we still build a couple dozen l-6 and 4 cyl race engines a year. Many import customers have supplied windage trays/scrapers from Kxxxx xxxxxxx and all have been rewarded with steadier oil pressure and longer bearing life. Never did A-B-A testing for HP gains though.
He is very interesting to chat with. I believe he also ran one of Chrysler's plants down in Mexico.ptuomov wrote: ↑Sun Jun 02, 2019 12:00 pm ...
I might also want to unhook my phone and shoot visitors if I had published torque and power numbers that don’t add up!.
(That’s just a joke, of course, I don’t know anything about the person or the test. Still, you probably understand some degree of skepticism about numbers in which torque and power don’t match up.)
The predicted trajectories are shown in Fig. 4 for oil droplets having diameters larger than
25 microns. It is observed that there is no appreciable difference in the oil droplet motion with
initial release location around the bearing cage. The large initial azimuthal component of the
velocity means that the oil droplets travel in a predominantly straight line until they impact
with the wall film on the chamber housing, where the majority have sufficient energy to
promote splashing. This results in several smaller droplets being ejected back into the core
flow, a significant proportion of which have diameters less than 25 microns. These droplets are
strongly affected by the core airflow and travel several circuits of the chamber before again
impinging on the wall, or exiting the chamber through the vent pipe with the air.
-snip-
5. Conclusions
A composite numerical model combining a commercial CFD code with sub-models for oil
droplet/film interaction and the motion of the oil film has been presented. Preliminary results
show that oil droplets shed from the bearing cage have sufficient energy on impact with the
chamber housing and any associated wall film to promote splashing. As a result, droplets
having smaller diameters (more likely to be affected by the rotating airflow) are ejected back
into the core flow. This increases both the residence time of the oil in the chamber and the
proportion of the oil carried by the sealing airflow through the vent pipe. The model provides
valuable information regarding the film thickness distribution around the chamber housing
along with the effect of geometric features such as vent and scavenge pipes that can be used
for future heat transfer studies.
The tray shown (below) has many smooth areas that would allow droplet impact and "splashing" with multiple smaller droplets ejected which would then result in a locally denser composite atmosphere of air and suspended oil droplets.ptuomov wrote: ↑Sun Jun 02, 2019 9:35 amAs one would expect, that testing shows a power loss from the windage tray in a stationary dyno:Kevin Johnson wrote: ↑Sun Jun 02, 2019 9:25 am https://www.hotrod.com/articles/ctrp-06 ... dage-tech/
This is of course not the same as lap times.
One could even make the argument that if you’re not losing at least a little bit of power on a stationary dyno from a windage tray, then you’re not doing something right...
Hey, your friends at Chrysler have led you down a garden path. I just looked up the part numbers for the OEM "Baffle, crankshaft oil scraper" for the big cross plane V8 engines, namely the LA and RB. The part numbers are 2531945 (since 1968) and 2863983 (since 1967).ptuomov wrote: ↑Sun Jun 02, 2019 1:48 pm Oh so they just designed the tray wrong, so that’s why no gains on a stationary dyno?
What fraction of scraper and windage tray “dyno” gain claims on the internet are outright fabrications? 80%? 95%? 99+%?
This must be a very frustrating industry for an honest person. If it’s not enough to show only a small power loss on stationary dyno and better oil pressure on track to sell the product, all honest operators will be driven out of scraper/windage tray business.
The Chrysler developed windage tray is the best horsepower-for dollar item available for your engine, and a real industry first. It will fit all the 361, 383, 400, 413, 426 and 440 wedges with complete interchangeability. Basically, the windage tray provides increased horsepower by reducinq oil friction on the crankshaft assembly at high speeds. It’s worth an extra 15 HP at 6000 rpm! Remember, you must use two pan gaskets - one below and one above the tray!
Like the Tea leaf paradox? You think investigating that led to any other insights about crank scrapers and windage trays beyond identifying you as charlatan?Kevin Johnson wrote: ↑Sun Jun 02, 2019 3:35 pmHey, your friends at Chrysler have led you down a garden path. I just looked up the part numbers for the OEM "Baffle, crankshaft oil scraper" for the big cross plane V8 engines, namely the LA and RB. The part numbers are 2531945 (since 1968) and 2863983 (since 1967).ptuomov wrote: ↑Sun Jun 02, 2019 1:48 pm Oh so they just designed the tray wrong, so that’s why no gains on a stationary dyno?
What fraction of scraper and windage tray “dyno” gain claims on the internet are outright fabrications? 80%? 95%? 99+%?
This must be a very frustrating industry for an honest person. If it’s not enough to show only a small power loss on stationary dyno and better oil pressure on track to sell the product, all honest operators will be driven out of scraper/windage tray business.
What percentage of what they are telling you is an outright fabrication? Are they good with Photoshop?
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You had better investigate this carefully and document it.