Is J2807 worthless?
A recent thread was locked due to brand bickering. Before I got a chance to respond to the latest turn of the conversation. It was stated that J2807 a worthless standard by a few people... Primaril...
Forum Discussion
Shiner,
Glad you got posted, I just sent you a pm back with a "I've been using trailerlife.com to post" when I have been having some issues the last few days. For all, I have reported my issues to the upper folks I report to in a forum we talk to ea other on about issues etc. It may very well be a server issues, along with what will hopefully be an improvement on the way......wait until you "I'll see it, to believe it" if it shows up....
Back to shiners thoughts.
I understand your thoughts. Issues with your grade options. An interstate per federal law, for the most part has a max of 6% with short bursts to 8%. So from the towing up a grade standpoint at a minimum speed of X mph....5% is adequate in my book. Not real sure a 45 at 6% or 55 at 5% is going to make that big of a deal. One could end up with too much cooling on lessor roads and environments in such a manner that rigs will not due as well from an mpg etc standpoint.
You do not get into the 15+% range until on city or at best typically county roads. Sometimes a state road, or for sure forest service, driveways etc. So can a person go 45+ mph on these types of roads? maybe, do I need to, not! in reality, a max 35 on a 15% grade is plenty in my book based on the types of roads I have seen, most of not all I have driven up, the max speed limit has been 25-35 mph. With this in mind, the HP/ability to go faster than this is not needed. From my bases, its being able to stay going! having burned up an auto trans or three do to lack of gearing in trans, not axels!
Grade braking would be good, say 25 mph max on a 10+% grade in low gear or maybe 2nd......max 35-40 on a typical 5% freeway grade I just went up meeting the uphill performance spec in min 2nd, maybe 3rd or max gear below direct!
Adding a few more thoughts on what should be included.
3 frontal area figures, for a full size 60, 90, and 120 sq ft. With these broken down to 3 other figures, aerodynamic setup, say an airostream/boat. moderate, typical boxy trailer, and a very unaerodynamic setup. Some of you have probably seen contractors with pipe rack etc on trailers, along with some kinds of construction equipment that are not aerodynamic in nature. As an example, some figures I've worked out in the past. A 15K rig with 70# of FA, takes about 105hp to go down the road at 60 mph. Same weight at 90#, 135HP! same hp as a 26K/70# setup!
Another reality is, no matter what minimum spec is chosen, SOMEONE is not going to like the specs. For some of the same reasons I do not. I go up way steeper grades locally than the specs call for. With no deduct in specs for wt reduction of i am going up these grades. I'm not in a mode to buy $3K trannies like 30K mile clock work as I have done in the past with trucks.
There are a lot of factors that go into how well or will not your rig work. Even tire types, 60 vs 85 series, radial vs bias, traction vs hwy will effect who well, fast etc you rig will do towing. Most of these things are also somewhat predictable with formulas that engineers have worked out throught the years. so literal testing is not needed per say, but yet still testing needs to be done.
Marty
ps, I had to copy and past into TL to get this to work......grrrrrrrr!
Glad you got posted, I just sent you a pm back with a "I've been using trailerlife.com to post" when I have been having some issues the last few days. For all, I have reported my issues to the upper folks I report to in a forum we talk to ea other on about issues etc. It may very well be a server issues, along with what will hopefully be an improvement on the way......wait until you "I'll see it, to believe it" if it shows up....
Back to shiners thoughts.
I understand your thoughts. Issues with your grade options. An interstate per federal law, for the most part has a max of 6% with short bursts to 8%. So from the towing up a grade standpoint at a minimum speed of X mph....5% is adequate in my book. Not real sure a 45 at 6% or 55 at 5% is going to make that big of a deal. One could end up with too much cooling on lessor roads and environments in such a manner that rigs will not due as well from an mpg etc standpoint.
You do not get into the 15+% range until on city or at best typically county roads. Sometimes a state road, or for sure forest service, driveways etc. So can a person go 45+ mph on these types of roads? maybe, do I need to, not! in reality, a max 35 on a 15% grade is plenty in my book based on the types of roads I have seen, most of not all I have driven up, the max speed limit has been 25-35 mph. With this in mind, the HP/ability to go faster than this is not needed. From my bases, its being able to stay going! having burned up an auto trans or three do to lack of gearing in trans, not axels!
Grade braking would be good, say 25 mph max on a 10+% grade in low gear or maybe 2nd......max 35-40 on a typical 5% freeway grade I just went up meeting the uphill performance spec in min 2nd, maybe 3rd or max gear below direct!
Adding a few more thoughts on what should be included.
3 frontal area figures, for a full size 60, 90, and 120 sq ft. With these broken down to 3 other figures, aerodynamic setup, say an airostream/boat. moderate, typical boxy trailer, and a very unaerodynamic setup. Some of you have probably seen contractors with pipe rack etc on trailers, along with some kinds of construction equipment that are not aerodynamic in nature. As an example, some figures I've worked out in the past. A 15K rig with 70# of FA, takes about 105hp to go down the road at 60 mph. Same weight at 90#, 135HP! same hp as a 26K/70# setup!
Another reality is, no matter what minimum spec is chosen, SOMEONE is not going to like the specs. For some of the same reasons I do not. I go up way steeper grades locally than the specs call for. With no deduct in specs for wt reduction of i am going up these grades. I'm not in a mode to buy $3K trannies like 30K mile clock work as I have done in the past with trucks.
There are a lot of factors that go into how well or will not your rig work. Even tire types, 60 vs 85 series, radial vs bias, traction vs hwy will effect who well, fast etc you rig will do towing. Most of these things are also somewhat predictable with formulas that engineers have worked out throught the years. so literal testing is not needed per say, but yet still testing needs to be done.
Marty
ps, I had to copy and past into TL to get this to work......grrrrrrrr!
