Anyone ever see an axle like this before?
Aug 31, 2007 | 01:48 AM
#21
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From: Kingston, WA
Oh, and from what I can tell, these types of axles don't "rob clearance between your axle and your rig" unless you change how your suspension is setup to get the axle closer to the rest of the truck.
And, I think there wouldn't be much of a difference (in COG) between a rig that has 5 inches of lift from a portal axle setup, and one the has 5 inches of lift from a suspension. If there is any advantage, it would probably be on the one with the portals, as stated in 4mogger's response.
All that being said, I would definately have to throw back quite a few adult beverages before I threw $3k-$5k down on a set of axles
And, I think there wouldn't be much of a difference (in COG) between a rig that has 5 inches of lift from a portal axle setup, and one the has 5 inches of lift from a suspension. If there is any advantage, it would probably be on the one with the portals, as stated in 4mogger's response.
All that being said, I would definately have to throw back quite a few adult beverages before I threw $3k-$5k down on a set of axles
Aug 31, 2007 | 08:56 AM
#22
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From: Mount Pleasant, SC
I agree with part of your statement but the C.O.G. statement is technically incorrect.
The easiest swap would be into a solid axle'd stock rig with the front output of the transfer case already offset to the driver's side.
To actually fab up a 4 link suspension and reroute all of the brake lines, fuel lines and exhaust is difficult to some extent, but not much more difficult to accomodate the portal axle.
The portal axle swap does not raise the C.O.G. There have been scientific studies (Land Rover with lift and standard axles, same Rover fitted with Volvo portal axles--same wheels/tires in both configurations--portal axle rig had lower C.O.G.) that have proved that the C.O.G. assumption you state is incorrect.
I can understand the misconception. That is a helluvalot of daylight under a portal swapped rig and it does *seem* to have the result of an increased C.O.G. but that is just an illusion.
The easiest swap would be into a solid axle'd stock rig with the front output of the transfer case already offset to the driver's side.
To actually fab up a 4 link suspension and reroute all of the brake lines, fuel lines and exhaust is difficult to some extent, but not much more difficult to accomodate the portal axle.
The portal axle swap does not raise the C.O.G. There have been scientific studies (Land Rover with lift and standard axles, same Rover fitted with Volvo portal axles--same wheels/tires in both configurations--portal axle rig had lower C.O.G.) that have proved that the C.O.G. assumption you state is incorrect.
I can understand the misconception. That is a helluvalot of daylight under a portal swapped rig and it does *seem* to have the result of an increased C.O.G. but that is just an illusion.
If I used portals on my rig as it sits right now the whole rig would be raised the length of the portal and thus raising the COG of my rig. Now if I were to lower my suspension to get it to sit where is was before I have now decreased the distance between the axle tubes and the frame taking away some uptravel. I my case the front axle is located directly below the very front of the oil pan and the crank pulley so to clearing a portal with my setup and maintaining the same travel would be a nightmare.
Now travel aside two exact same rigs height-wise one with portals and one without, the portal axled rig would still have a higher COG. Thats just common sense. It wouldn't be much and it would be totally worth the trade off for the clearance but your thinking on COG is off...
Aug 31, 2007 | 09:45 AM
#23
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From: Thornton, Colorado
If I used portals on my rig as it sits right now the whole rig would be raised the length of the portal and thus raising the COG of my rig. Now if I were to lower my suspension to get it to sit where is was before I have now decreased the distance between the axle tubes and the frame taking away some uptravel. I my case the front axle is located directly below the very front of the oil pan and the crank pulley so to clearing a portal with my setup and maintaining the same travel would be a nightmare.
Now travel aside two exact same rigs height-wise one with portals and one without, the portal axled rig would still have a higher COG. Thats just common sense. It wouldn't be much and it would be totally worth the trade off for the clearance but your thinking on COG is off...
Now travel aside two exact same rigs height-wise one with portals and one without, the portal axled rig would still have a higher COG. Thats just common sense. It wouldn't be much and it would be totally worth the trade off for the clearance but your thinking on COG is off...
Aug 31, 2007 | 04:22 PM
#24
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From: Oregon City, OR
I agree with part of your statement but the C.O.G. statement is technically incorrect.
The easiest swap would be into a solid axle'd stock rig with the front output of the transfer case already offset to the driver's side.
To actually fab up a 4 link suspension and reroute all of the brake lines, fuel lines and exhaust is difficult to some extent, but not much more difficult to accomodate the portal axle.
The portal axle swap does not raise the C.O.G. There have been scientific studies (Land Rover with lift and standard axles, same Rover fitted with Volvo portal axles--same wheels/tires in both configurations--portal axle rig had lower C.O.G.) that have proved that the C.O.G. assumption you state is incorrect.
I can understand the misconception. That is a helluvalot of daylight under a portal swapped rig and it does *seem* to have the result of an increased C.O.G. but that is just an illusion.
The easiest swap would be into a solid axle'd stock rig with the front output of the transfer case already offset to the driver's side.
To actually fab up a 4 link suspension and reroute all of the brake lines, fuel lines and exhaust is difficult to some extent, but not much more difficult to accomodate the portal axle.
The portal axle swap does not raise the C.O.G. There have been scientific studies (Land Rover with lift and standard axles, same Rover fitted with Volvo portal axles--same wheels/tires in both configurations--portal axle rig had lower C.O.G.) that have proved that the C.O.G. assumption you state is incorrect.
I can understand the misconception. That is a helluvalot of daylight under a portal swapped rig and it does *seem* to have the result of an increased C.O.G. but that is just an illusion.
Aug 31, 2007 | 08:39 PM
#25
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From: Montrose, CO
If I used portals on my rig as it sits right now the whole rig would be raised the length of the portal and thus raising the COG of my rig. Now if I were to lower my suspension to get it to sit where is was before I have now decreased the distance between the axle tubes and the frame taking away some uptravel. I my case the front axle is located directly below the very front of the oil pan and the crank pulley so to clearing a portal with my setup and maintaining the same travel would be a nightmare.
Now travel aside two exact same rigs height-wise one with portals and one without, the portal axled rig would still have a higher COG. Thats just common sense. It wouldn't be much and it would be totally worth the trade off for the clearance but your thinking on COG is off...
Now travel aside two exact same rigs height-wise one with portals and one without, the portal axled rig would still have a higher COG. Thats just common sense. It wouldn't be much and it would be totally worth the trade off for the clearance but your thinking on COG is off...
I understand your reservations but your opinion is based upon untested assumptions.
I can send you pictues of the vehicle to post and I will try to find a link to the test itself which I believe was done in Russia.
Aug 31, 2007 | 08:56 PM
#26
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From: Montrose, CO
How is your Russian?:
http://www.off-road-drive.ru/index.php?link=152217
That is the link to the study that concluded portals provide a LOWER COG.
More discussion here:
http://www.pirate4x4.com/forum/showt...01#post4605701
http://www.off-road-drive.ru/index.php?link=152217
That is the link to the study that concluded portals provide a LOWER COG.
More discussion here:
http://www.pirate4x4.com/forum/showt...01#post4605701
Last edited by 4Mogger; Aug 31, 2007 at 09:15 PM.
Aug 31, 2007 | 09:22 PM
#28
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From: Mount Pleasant, SC
How is you Russian?:
http://www.off-road-drive.ru/index.php?link=152217
That is the link to the study that concluded portals provide a LOWER COG.
More discussion here:
http://www.pirate4x4.com/forum/showt...01#post4605701
http://www.off-road-drive.ru/index.php?link=152217
That is the link to the study that concluded portals provide a LOWER COG.
More discussion here:
http://www.pirate4x4.com/forum/showt...01#post4605701
Wow dude. I just don't know what to say other than you are still totally wrong.
Look at the article you posted. The two test vehicles are FAR from that same which makes the test total BS. The guy even states that one of the reasons the portal axle has a greater roll angle is because its wider. Well no crap?!?!
A widened stance is going to lower the effective COG. Near as I can tell they didn't do an actual measure for the true COG. The only way it could be lowered by raising a component in the vehicle is if its new location was still below the original COG and if its weight was increased enough to pull the COG down. I doubt volvo portals are that heavy, but hey, what do I know. If they were I doubt anyone would want to use them...
Aug 31, 2007 | 09:25 PM
#29
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From: Montrose, CO
Wow dude. I just don't know what to say other than you are still totally wrong.
Look at the article you posted. The two test vehicles are FAR from that same which makes the test total BS. The guy even states that one of the reasons the portal axle has a greater roll angle is because its wider. Well no crap?!?!
A widened stance is going to lower the effective COG. Near as I can tell they didn't do an actual measure for the true COG. The only way it could be lowered by raising a component in the vehicle is if its new location was still below the original COG and if its weight was increased enough to pull the COG down. I doubt volvo portals are that heavy, but hey, what do I know. If they were I doubt anyone would want to use them...
Look at the article you posted. The two test vehicles are FAR from that same which makes the test total BS. The guy even states that one of the reasons the portal axle has a greater roll angle is because its wider. Well no crap?!?!
A widened stance is going to lower the effective COG. Near as I can tell they didn't do an actual measure for the true COG. The only way it could be lowered by raising a component in the vehicle is if its new location was still below the original COG and if its weight was increased enough to pull the COG down. I doubt volvo portals are that heavy, but hey, what do I know. If they were I doubt anyone would want to use them...
The portal rig has a lower COG and it is quite a bit taller too. There is a pic that shows exact dimentions of both rigs.
On second look, both rigs are 2050 wide. Look at the exact specs.
Post the pics.
Last edited by 4Mogger; Aug 31, 2007 at 09:30 PM.
Sep 1, 2007 | 04:50 AM
#33
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From: Mount Pleasant, SC
Did you look at the other measurement you posted? I don't know if that is the WMS to WMS measurement but it is wider on the portals. Regular axle - 1615 vs portal axle - 1688. I mean look at the darn pictures. The trucks are totally different and you want to call this a scientific test producing FACTS??? The regular axled truck has a full exo cage and completely different suspension. Different tires, hell are they even running the same air pressure? The portal truck also has a stripped interior and other looks like it added 200 pounds of interior crap. This is crazy talk. I said all things being equal a portal will raise your COG, that my friend is a fact and as near as I can tell its the only one that has been produced in this thread. Is it a large increase in COG? NO. Is it worth it, yes, I think so. If I had some blingin portals I would rock them. I would have to build a new chassis so I could use them and still stay low and keep the travel I have now. But most of us build on a budget and I already had a pair of 8"s so that's what's in the buggy. With my 8"s with a 55" WMS-WMS and 39.5s I doubt there will be many times were I wish I had portals but time will tell...
Sep 1, 2007 | 04:53 AM
#34
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From: El Paso, TX
The only vehicle that I have come across that had portals was the the FJ80 that I saw on Pirate. He is using 38" tires I believe. Obviously portals are not for someone who wants to run a more common tire size. Going with portals gave him the option of just having to use a small set of lift springs and he kept all the stock Toyota geometry since he welded all those mounts to the Volvo axle. To lift enough to clear those tires with his stock axle would have meant extended drive shafts and probably a switch to a four link system if he wanted to keep coils. He planned his build out meticulously and was done in two weeks so that shows that portals have a definate use if you are going to go 35" or above.
Sep 1, 2007 | 05:51 AM
#35
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From: Montrose, CO
Did you look at the other measurement you posted? I don't know if that is the WMS to WMS measurement but it is wider on the portals. Regular axle - 1615 vs portal axle - 1688. I mean look at the darn pictures. The trucks are totally different and you want to call this a scientific test producing FACTS??? The regular axled truck has a full exo cage and completely different suspension. Different tires, hell are they even running the same air pressure? The portal truck also has a stripped interior and other looks like it added 200 pounds of interior crap. This is crazy talk. I said all things being equal a portal will raise your COG, that my friend is a fact and as near as I can tell its the only one that has been produced in this thread. Is it a large increase in COG? NO. Is it worth it, yes, I think so. If I had some blingin portals I would rock them. I would have to build a new chassis so I could use them and still stay low and keep the travel I have now. But most of us build on a budget and I already had a pair of 8"s so that's what's in the buggy. With my 8"s with a 55" WMS-WMS and 39.5s I doubt there will be many times were I wish I had portals but time will tell...
The wheel measurement that counts is not the WMS but the overall width. And that figure for both is 2050. The wheelbase is different and so is the overall height. In fact most of the other measurements ARE different. Of course, they would be considering that portal axles and the mods needed to fit them will subtantially change all of those measurements.
Point being...if you would post those pics--particularly the first of both rigs side by side and ask yourself which rig has a lower COG--it would appear to be the yellow rover on stock axles. But that would be false. The white rover on Volvo portals has the lower COG and to me that is an amazing FACT.
Sep 6, 2007 | 02:49 PM
#38
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From: Longmont, CO
there's a portal axle Jeep in the issue too
I kinda have mixed reviews of "Crawl". It's great that it's devoted to rockcrawling, but the pictures are only OK and the stories/text are pretty lame.
I kinda have mixed reviews of "Crawl". It's great that it's devoted to rockcrawling, but the pictures are only OK and the stories/text are pretty lame.
Sep 6, 2007 | 06:47 PM
#39
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From: Fort Collins, CO
With respect to physics, how can you keep the weight the same, the width the same, increase height and not impact COG?
I imagine there is some axle weight value and width that would off set the height gain, but how much is that value and could it get past the original COG?
I still love your truck TiredIron. You got'er done when told it was impossible.
I imagine there is some axle weight value and width that would off set the height gain, but how much is that value and could it get past the original COG?
I still love your truck TiredIron. You got'er done when told it was impossible.
