lockout

[BigRed350x]

I too is a enganeer buts i choose nots to use my's knowledge all that very often. it are easier to just put the fuel in my's tank and go ride. thinking tooked two much time to doo in colidge. besides, i went to colidge to get edjamakated so's i cood be a engineer.

[McCoy's Performance]

An inertia brake Dyno in general is only as accurate or repeatable as the the control of the temperature of it's environment. DynoJets are particularly crappy as all of there DAQ software is based around the factory calibration and balance numbers for the flywheel. If you are outside the temperture of which the calibration occurred (I belive is 20 degrees C) then you really don't know what you have as far as results go. Beyond that the temperature of the wheel changes during a run, thus leading to their inaccuracy and lack of ability to repeat (granted they are probably still better than a friction brake dyno, but atleast you can recalibrate it's load cell to compensate for the condition of it's clutch pack) which also leads to their infamous nick name as "DynoGuess." As I discussed earlier, a DynoJet dyno has it's niche in the industry and you can't argue with their revenue generatikon potential, but a serious person probably wouldn't bother with them. The serious person thing was part of something someone, who is a far greater name in my industry than I am, to a group of college engineering students. The parting shot was that he likened doing serious work with a DynoJet to playing the lottery as an investment. The idea being both can work, but you'll spend alot of time and effort having it not work and winning a little here and there. I'm not sure if that was worth sharing, but I kind of liked it. :biggrin:

Absolutely worth sharing, even hilarious.

You made me laugh. Nothing like bringing up the foolishness of gambling to make a point. LOL

I understand that the Dynojet is the "poor boy" Dyno. However, my experience is that the repeatability is still rather amazing. Of course there is huge room for human error which I believe accounts for huge inconsistencies. But using the SAE correction factors, it is possible to produce back-up data on different days/ times of day/ temperatures/ atmospheric pressures, and so on. A decent motor will back up it's #s within 1% on a Dynojet once the air/fuel is matched, even when the environment is changed significantly. The only thing that seems to be a real problem with repeatability is atmospheric moisture (humidity variations). Our #s are slightly less on a rainy day: usually we see about a 2+% loss from a "dry" day baseline.

We can also, in most cases, get sufficient load to find clutch slip. On motors 150hp and less, when we cure clutch slip on the Dyno, it will hold in the field. If it slips on the Dyno, it will slip in the field. So the Data, though inferior to a comparable Superflow's, has some relevance.

The challenges of inertia-only testing is "loading the motor" to a level that has any relevance in to real-world application that it will run in. Gearing becomes crucial. And back up testing must be made at the same load rates (gearing), of course, to obtain meaningful data (which must include repeatability). The higher the HP, the greater the challenge. This is not a Dynojet commercial, by any means. They might be some of the worst dynos on the market. But with all of their inabilities and limitations, they are still a tool with enough repeatability to generate data that is useful. IMHO

Edited July 10, 2007 by McCoy's Performance

[FireHead]

I too is a enganeer buts i choose nots to use my's knowledge all that very often. it are easier to just put the fuel in my's tank and go ride. thinking tooked two much time to doo in colidge. besides, i went to colidge to get edjamakated so's i cood be a engineer.

Past a certain point edumacation is overrated. My best engineer at my current facility took 6 six years and three colleges across three states to get his bachelors degree. He is still learning alot about the engineering profession on the "office" side of things, but when it comes to the actual development of engines and making quick decisions the guy makes a few of these 40 year old guys that work for me look like crap.

 

Besides, when someone asks what I do for a living, I tell them I am this kind of engineer:

[Bansh-eman]

I too is a enganeer buts i choose nots to use my's knowledge all that very often. it are easier to just put the fuel in my's tank and go ride. thinking tooked two much time to doo in colidge. besides, i went to colidge to get edjamakated so's i cood be a engineer.

Jared,

 

i cant wait for you to finish medical school so i can get that lobotomy we have talked about

[GP racerX]

LOL the #1 reason I became an engineer is so I could drive a train!!

[GP racerX]

With regard to your Pike's Peak project (I am not really sure what you're working on for it), I would be happy to help if you need any. I have several 3D DAQ maps of this hill over the past 4-5 years. I can't really share much about what is going up the hill with my current employers venture this year (I have never put a Class 6 truck up that hill before, so it may be a learning experience), but I (and my group) at my old employer had several sucessful years at the venue, granted they were low budget compared to our other racing programs. They keep paving more and more of the hill which has been a challenge in the past to be able correlate that data to previous years.

 

The pavment sucks! :mad:

Tell me more about your Pikes Peak project There was some one working on a sim rally game a while back that needed the 3d maps I sent him some video fooage. I would love to have that as a training tool for the Peak. Do you guys have something like that?

Is this a new team in the class 6 trucks or some one whos race there before? I know of a few of those guys..

Edited July 10, 2007 by GP racerX

[FireHead]

Absolutely worth sharing, even hilarious.

You made me laugh. Nothing like bringing up the foolishness of gambling to make a point. LOL

I understand that the Dynojet is the "poor boy" Dyno. However, my experience is that the repeatability is still rather amazing. Of course there is huge room for human error which I believe accounts for huge inconsistencies. But using the SAE correction factors, it is possible to produce back-up data on different days/ times of day/ temperatures/ atmospheric pressures, and so on. A decent motor will back up it's #s within 1% on a Dynojet once the air/fuel is matched, even when the environment is changed significantly. The only thing that seems to be a real problem with repeatability is atmospheric moisture (humidity variations). Our #s are slightly less on a rainy day: usually we see about a 2+% loss from a "dry" day baseline.

We can also, in most cases, get sufficient load to find clutch slip. On motors 150hp and less, when we cure clutch slip on the Dyno, it will hold in the field. If it slips on the Dyno, it will slip in the field. So the Data, though inferior to a comparable Superflow's, has some relevance.

The challenges of inertia-only testing is "loading the motor" to a level that has any relevance in to real-world application that it will run in. Gearing becomes crucial. And back up testing must be made at the same load rates (gearing), of course, to obtain meaningful data (which must include repeatability). The higher the HP, the greater the challenge. This is not a Dynojet commercial, by any means. They might be some of the worst dynos on the market. But with all of their inabilities and limitations, they are still a tool with enough repeatability to generate data that is useful. IMHO

I disagree, I belive that a poor boy dyno is a fish scale hooked to a disc brake..........., but that's another story.

 

The SAE correction factors are a way of standardizing data different days, time, locations, planets, but that doesn't help you much when the calibration of the dyno's flywheel is off (which really doesn't have anything to do with the SAE Correction Standards at all).

 

The worst commercially available dyno's on the market in my opinion are made by Go-Power. The dyno's were originaly marketed to repair shops in the '60's, but for some reason people continue to buy them. They are typically inertia or friction brake pieces, and when you approached one, you could tell it was a pile of crap from about 35 yards away. :biggrin:

[FireHead]

The pavment sucks! :mad:

Tell me more about your Pikes Peak project There was some one working on a sim rally game a while back that needed the 3d maps I sent him some video fooage. I would love to have that as a training tool for the Peak. Do you guys have something like that?

Is this a new team in the class 6 trucks or some one whos race there before? I know of a few of those guys..

Mike Ryan is who is taking the Pike's Peak porject up the hill for my current employer. It's a modified Freightliner chassis with a Detroit Series 60 engine. My facility did some of the engine development, but I came in fairly late to that project.

 

My facility at my previous employer did several of Rod Millen's engines (the 4 cylinder GP engines). I believe Rod still holds the all time record on the hill. Of coarse I was only involved with that going back about 5 years. Our mapping of the hill was done in several differents manners, but we were always looking for load vs. time vs. altitude or BP. The trick always was to control the turbo(s) in such a fashion that you could all but remove BP, temp., and air density from the equation.

 

If you can come up with a copy of the CarSim software, I'd be happy to send you a non-cofidential copy of some stuff we did a couple years ago.

[BigRed350x]

I like to build lego cars, does that give me any credit in this conversation? :biggrin:

[GP racerX]

I like to build lego cars, does that give me any credit in this conversation? :biggrin:

 

 

HaHa I grew building lego cars...one of the best time we had as a kid was building long rocket powered lego dragsters :biggrin: we used the estes model rockets enginesand 2stage them and then blast the off down the street!

[GP racerX]

Mike Ryan is who is taking the Pike's Peak porject up the hill for my current employer. It's a modified Freightliner chassis with a Detroit Series 60 engine. My facility did some of the engine development, but I came in fairly late to that project.

 

My facility at my previous employer did several of Rod Millen's engines (the 4 cylinder GP engines). I believe Rod still holds the all time record on the hill. Of coarse I was only involved with that going back about 5 years. Our mapping of the hill was done in several differents manners, but we were always looking for load vs. time vs. altitude or BP. The trick always was to control the turbo(s) in such a fashion that you could all but remove BP, temp., and air density from the equation.

 

If you can come up with a copy of the CarSim software, I'd be happy to send you a non-cofidential copy of some stuff we did a couple years ago.

 

Out of all the cool stuff at Pike Peak i would have to say Millen's car and Ryan's truck is the most impressive rigs I have seen go up the hill!!

Infact Mike ran a faster time than me on my quad 2 years ago when he broke into the 12min.! Damn he was haulin' :ohmy:

[FireHead]

HaHa I grew building lego cars...one of the best time we had as a kid was building long rocket powered lego dragsters :biggrin: we used the estes model rockets enginesand 2stage them and then blast the off down the street!

My parents did not let me have model rockets until I was 14 and they never let me have video games of any kind. Look how messed up I turned out.

[FireHead]

Out of all the cool stuff at Pike Peak i would have to say Millen's car and Ryan's truck is the most impressive rigs I have seen go up the hill!!

Infact Mike ran a faster time than me on my quad 2 years ago when he broke into the 12min.! Damn he was haulin' :ohmy:

Rod does the hill climb, Rally, and Desert stuf better than anyone one I have ever seen or ridden with, plus he is one of the nicest folks you will ever meet.

 

Mike Ryan is fast and will certainly be faster this year at the hill. We are also putting a Bonneville project together for him for 2008'ish. Mike is a bit weird per my taste in folks, but I am probably quite nerdy compared to most folks. A couple of my folks that were with me for our recent three week trip to Las Vegas couldn't believe that I just wanted to go read a book in my rooom after about the first week there............I mean naked chicks, beer, gambling...........I have seen it, if there is more out there, the guys could tell me about it later. :biggrin:

[shee rips]

Past a certain point edumacation is overrated. My best engineer at my current facility took 6 six years and three colleges across three states to get his bachelors degree. He is still learning alot about the engineering profession on the "office" side of things, but when it comes to the actual development of engines and making quick decisions the guy makes a few of these 40 year old guys that work for me look like crap.

 

Besides, when someone asks what I do for a living, I tell them I am this kind of engineer:

i wanted to be that kind of engineer when i was little :biggrin:

[korndawg]

i wanted to be that kind of engineer when i was little

 

 

I still would like to be that kind of engineer. It seems like it would be a pretty decent job. You either go forward or backwards, no real steering involved. Would be pretty tough to get lost, and you ALWAYS have the right of way. I'm sure there's got to be more to it than that, but it sounds pretty good.