Picture request on staggered rims for X sedan
Here is a recent thread with a X on a staggered setup:
https://g35driver.com/forums/picture...lots-pics.html
https://g35driver.com/forums/picture...lots-pics.html
Here is a recent thread with a X on a staggered setup:
https://g35driver.com/forums/picture...lots-pics.html
https://g35driver.com/forums/picture...lots-pics.html
I looked around for some additional details, and it looks like 5% is the slip threshold where power would be sent to the front wheels. As I stated earlier, the only thing monitoring slip is the wheel speed sensors (some people call them ABS sensors). The feedback from these sensors is processed 100 times per second by the ECU, and then the vehicle makes any changes by engaging the front wheels. I just fail to see how a half percent is going to throw the system off when the threshold is 10x of that.
There is one additional sensor used to calculate slip, VDC, and ABS activation. Apparently there is a 3-axis "G" sensor that also provides input on lateral and longitudinal movements, but it looks like it is mostly tied to the ABS system and vehicle dynamic controls.
The system seems pretty simple-
**100% of power goes to the rear wheels
**If more than 5% slip is detected on the rear wheels vs. the front it sends 0-50% of the power to the front wheels (based on some sliding scale for the amount of slip)
Not to be the Naysayer, but I would like for someone to explain in a more technical way that it won't work. Not what someone said or thinks....
Last edited by jran76; Apr 9, 2009 at 07:48 PM.
There's a reason Infiniti/other manufacturers put same size all around on AWD.
I'm sure it won't harm the system immediately but if you want to brave, go for it. Every expert and mechanic I asked on the topic (when I was shopping for my wheels) said DO NOT DO IT!
So to simplify your math, I'll give you my equation...
OEM Inifniti (same size all around)
+
Other manufacturers OEM (same size all arund)
+
Experts/mechanics/dealership's/wheel dealer's opinion (same size all around)
=
Me buying a set of rims that are the same size all around.
And to add to that, someone suggested wider rims in the rear with the same diameter rubber all around...to this i say...WHY?
That would look retarded. The whole point of going staggered is so you can throw some fatties on the rear, have some taste and do it right.
Same size all around on an X... FTW!
I'm sure it won't harm the system immediately but if you want to brave, go for it. Every expert and mechanic I asked on the topic (when I was shopping for my wheels) said DO NOT DO IT!
So to simplify your math, I'll give you my equation...
OEM Inifniti (same size all around)
+
Other manufacturers OEM (same size all arund)
+
Experts/mechanics/dealership's/wheel dealer's opinion (same size all around)
=
Me buying a set of rims that are the same size all around.
And to add to that, someone suggested wider rims in the rear with the same diameter rubber all around...to this i say...WHY?
That would look retarded. The whole point of going staggered is so you can throw some fatties on the rear, have some taste and do it right.
Same size all around on an X... FTW!
If you want to be a smart a$$, at least get your facts strait. Last time I checked all top end cars with AWD used staggered setups.
Nissan GTR
Porsche 911 turbo
All Lambo's
Audi R8
Do I need to go on?
Guys, I am not trying to be difficult, just pointing out the facts. Many AWD cars run staggered setups. The system in the G35 (ATTESA ETS) is much less advanced than those cars. The GTR uses an advanced version and has no issues. I think if you really research the facts on the ATTESA ETS system you will change your minds. I have no doubt that someone that works for Infiniti or a mechanic will tell you not to do it. They are not engineers, and know little to nothing about the actual engineering that goes into these cars.
I am not saying you have to run staggered tires (I actually think a non-staggered setup is better for all around performance, but that is a different argument for a different day). All I am saying is that it is possible, and I DON'T think it will cause major issues. I am open to changing my mind, but until someone can come up with a more technical reason that it won't work, I am sticking to my theory. You guys don't have to buy into it....
Nissan GTR
Porsche 911 turbo
All Lambo's
Audi R8
Do I need to go on?
Guys, I am not trying to be difficult, just pointing out the facts. Many AWD cars run staggered setups. The system in the G35 (ATTESA ETS) is much less advanced than those cars. The GTR uses an advanced version and has no issues. I think if you really research the facts on the ATTESA ETS system you will change your minds. I have no doubt that someone that works for Infiniti or a mechanic will tell you not to do it. They are not engineers, and know little to nothing about the actual engineering that goes into these cars.
I am not saying you have to run staggered tires (I actually think a non-staggered setup is better for all around performance, but that is a different argument for a different day). All I am saying is that it is possible, and I DON'T think it will cause major issues. I am open to changing my mind, but until someone can come up with a more technical reason that it won't work, I am sticking to my theory. You guys don't have to buy into it....
^whatever man, I don't want to even start typing my list of "top end" cars that run non-staggered (same all around). It would be a long one and not worth the effort.
Was I aware that some AWD cars run staggered? Yes, in fact I was. Congrats on pointing that out to me.
"Less advanced" AWD doesn't mean it runs staggered properly. The AWD should run what it was engineered to do.
And further, this argument is useless as both of us don't know $hit about the AWD on the G. All we're doing is generalizing, and I hate generalizing:
You say because other manufacturers run staggered AWD, it should be OK,
I say because other manufactures don't run staggered AWD, neither should we.
So instead of generalizing to get to my answer, all I did was take a step further and ask for expert's opinions:
When I don't know something, I ask people who do know, and I even get more than one opinion. It's a system that's worked well for me my entire life.
It is in my dealer's and mechanic's financial interest to have me screw up my car and both heavily advised me not to. The feedback on these forums and others all told me to stick to the same size all around.
I like my car and I don't feel like screwing it up intentionally. Maybe it won't...I don't care, but at least I tried to do it right.
And to answer your statement:
Sure it's possible, it's a wheel, it turns, it bolts up the same. That says absolutely nothing in a technical sense that you DON'T think it will cause issues. Really, how credible are your thoughts? Why would tell people that they "don't have to run same size all around" and they "don't have to buy into that" when you have no research done yourself and other than generalizing, have no backup with info?
I don't mean disrespect, don't take it wrong, I love a good debate, and love learning new things. I'm not trying to be a smart a$$, I just wouldn't recommend something (on this scale) to someone unless I really knew what I was talking about.
Prove me wrong.
Was I aware that some AWD cars run staggered? Yes, in fact I was. Congrats on pointing that out to me.
"Less advanced" AWD doesn't mean it runs staggered properly. The AWD should run what it was engineered to do.
And further, this argument is useless as both of us don't know $hit about the AWD on the G. All we're doing is generalizing, and I hate generalizing:
You say because other manufacturers run staggered AWD, it should be OK,
I say because other manufactures don't run staggered AWD, neither should we.
So instead of generalizing to get to my answer, all I did was take a step further and ask for expert's opinions:
When I don't know something, I ask people who do know, and I even get more than one opinion. It's a system that's worked well for me my entire life.
It is in my dealer's and mechanic's financial interest to have me screw up my car and both heavily advised me not to. The feedback on these forums and others all told me to stick to the same size all around.
I like my car and I don't feel like screwing it up intentionally. Maybe it won't...I don't care, but at least I tried to do it right.
And to answer your statement:
All I am saying is that it is possible, and I DON'T think it will cause major issues
I don't mean disrespect, don't take it wrong, I love a good debate, and love learning new things. I'm not trying to be a smart a$$, I just wouldn't recommend something (on this scale) to someone unless I really knew what I was talking about.
Prove me wrong.
I don't have time to go through the research I have done, or all of my credentials. I'll just leave it as is. I am pretty sure I know as much, or more, about the ATTESA system used in these cars than most on here. I think I pretty clearly explained the way the system works in basic terms for you (and others) to understand. Re-read what I said about the way the system works. I don't want to re-hash it again.... My argument goes a lot deeper than saying other manufacturers do it, so it "should" work on these cars.
I have no problem with a healthy debate either, but insinuating that I have no facts to back up what I am saying vs. the "experts" you talked to is bogus. You know nothing about me, or what I do. My specialty in life if figuring out complex machines that involve many complex mechanical, electrical and software components-- I do this on machines that cost between $200k and $40 million dollars, and I run a global support organization that does just this. These aren't cars, these are machines that are infinitely more complex. I'll leave it at that for now.
You are right, I don't know specifically how this system works, and other than an engineer at Nissan, no one really does. With that said, I think other than the engineers that really know, I trust my ability to figure it out as much as I do the "experts" you talked to (yet, could offer no details on why it actually will not work). I freely admit this is my opinion, and you can freely choose to disregard it if you so choose (and it sounds like you have).
I have no problem with a healthy debate either, but insinuating that I have no facts to back up what I am saying vs. the "experts" you talked to is bogus. You know nothing about me, or what I do. My specialty in life if figuring out complex machines that involve many complex mechanical, electrical and software components-- I do this on machines that cost between $200k and $40 million dollars, and I run a global support organization that does just this. These aren't cars, these are machines that are infinitely more complex. I'll leave it at that for now.
You are right, I don't know specifically how this system works, and other than an engineer at Nissan, no one really does. With that said, I think other than the engineers that really know, I trust my ability to figure it out as much as I do the "experts" you talked to (yet, could offer no details on why it actually will not work). I freely admit this is my opinion, and you can freely choose to disregard it if you so choose (and it sounds like you have).
And to add to that, someone suggested wider rims in the rear with the same diameter rubber all around...to this i say...WHY?
That would look retarded. The whole point of going staggered is so you can throw some fatties on the rear, have some taste and do it right.
Same size all around on an X... FTW!
That would look retarded. The whole point of going staggered is so you can throw some fatties on the rear, have some taste and do it right.
Same size all around on an X... FTW!
You do know that the rear and front tires can have different widths but have the same diameter right?
Let me add.... jonnyzee, you are taking the right "cautious" approach, and I don't blame you for doing so. I would feel the same way if I was unsure about it working or not. Don't think I am attacking your position, I just don't think the facts indicate there would be a problem. I have no issues with you being reluctant to do so. Lucky for me, I don't have an X, so it is easy for me to sit on the sidelines and say this.
I am only playing the devil's advocate here, and take it for what you want. I do think I understand the way the system works. Can I say without a doubt that I really know, no I can't. So, I don't blame you for questioning me.... I just don't think your "experts" are any different.
Maybe this should be moved to the TECH section? Sorry to the OP for jacking the thread to debate this.
I am only playing the devil's advocate here, and take it for what you want. I do think I understand the way the system works. Can I say without a doubt that I really know, no I can't. So, I don't blame you for questioning me.... I just don't think your "experts" are any different.
Maybe this should be moved to the TECH section? Sorry to the OP for jacking the thread to debate this.
I finished some things I was working on, so let me better explain the way the ATTESA ETS system works as clearly as I can.
*There is a speed/ABS sensor inside each hub assembly. The purpose of these sensors is to detect the moving speed of the wheel.
*The data from the sensors is fed back to the ECU. From everything I have seen the system looks for some pre-defined amount of wheel slip to determine if AWD is needed--this means the back wheels turning and the fronts not moving at the same speed.
*The threshold for activating the AWD system is listed as 5%.
*When slip is detected, 0-50% of the power (torque based) is sent to the front wheels by injecting pressurized oil into the differential depending on how much wheel slip is detected. The ECU sends a signal to a selenoid, that then injects oil at a certain pressure (something between 0-300 psi-- the higher the PSI the more torque it sends to the front wheels).
There is one additional 3 axis "G" sensor that feeds lateral and longitudinal data back to the ECU for processing. This has some impact on the AWD system, but looks to mostly effect the ABS and VDC systems. Going with a staggered setup will increase understeer, which in theory could have some impact on the "G" sensor and AWD.
So, to sum this up..... Running a staggered setup of 245/40/19 and 275/35/19 will result in a 0.5% difference in rolling diameter (or slip). This is 0.2" in diameter. The system allows up to 5% of slip before it kicks in the front wheels. The only time I could see an issue is at the extreme limits if the car has a higher amount of understeer and this confuses the G sensor. (albeit, not a good time to have an "issue"). I think if you get to that point, the AWD system is not going to help you out anyway.
I can get even more technical and provide more details if it is really needed. I think this should give you a good idea of what goes into the AWD system....
*There is a speed/ABS sensor inside each hub assembly. The purpose of these sensors is to detect the moving speed of the wheel.
*The data from the sensors is fed back to the ECU. From everything I have seen the system looks for some pre-defined amount of wheel slip to determine if AWD is needed--this means the back wheels turning and the fronts not moving at the same speed.
*The threshold for activating the AWD system is listed as 5%.
*When slip is detected, 0-50% of the power (torque based) is sent to the front wheels by injecting pressurized oil into the differential depending on how much wheel slip is detected. The ECU sends a signal to a selenoid, that then injects oil at a certain pressure (something between 0-300 psi-- the higher the PSI the more torque it sends to the front wheels).
There is one additional 3 axis "G" sensor that feeds lateral and longitudinal data back to the ECU for processing. This has some impact on the AWD system, but looks to mostly effect the ABS and VDC systems. Going with a staggered setup will increase understeer, which in theory could have some impact on the "G" sensor and AWD.
So, to sum this up..... Running a staggered setup of 245/40/19 and 275/35/19 will result in a 0.5% difference in rolling diameter (or slip). This is 0.2" in diameter. The system allows up to 5% of slip before it kicks in the front wheels. The only time I could see an issue is at the extreme limits if the car has a higher amount of understeer and this confuses the G sensor. (albeit, not a good time to have an "issue"). I think if you get to that point, the AWD system is not going to help you out anyway.
I can get even more technical and provide more details if it is really needed. I think this should give you a good idea of what goes into the AWD system....
To jran76
I guess we share the same specialty in life
...I'm also figuring out complex systems for a living (airport air surveillance and ground radar systems, various xrays, bomb and metal detectors)....Although I don't run a global support organization...which is just pimpin'!!!!
: You definitely take me on that one!
I'm just playing around man, good for you, seriously. you sound like a proud and successful guy there (no sarcasm intended at all)
Anyways....
I appreciate the info on the AWD, I understand your conclusions, you did a good and very thorough job explaining yourself and I commend you on getting the details. As I have $hit for details at this moment to make an argument, I'll give this one to you.
In all honesty, I never really challenged my mechanic's or the dealer's opinions on this topic nor did I really get into details with them about why it would be bad.
The potential issues given to me were: throwing sensors out, running out of spec, possible damage and void warranty on AWD powertrain and system, possible malfunctions with AWD engagement, and generally the AWD would not perform the way it was meant to and its reactions couldn't be relied on.... was enough to win me over on keeping them the rims/tires the same size.
All that said, I feel I did the right move with my setup and I sleep easier at night because of it...you know, they say poor sleep decreases lifespan!
AND:
Between yours and antons posts, I completely misunderstood/misread it.
My bad on that one 100%.
What I thought you meant skimming through the posts was that one of you thought wider rims in the rear with the same size tire (for ex: 245/40 on front with 245/40 on the wider rear rim)-and yeah, that would look retarded, but obviously not what you meant now that i re-read it.
and yes, i know different widths can have the same diameter, thanks!
Later boys.
I guess we share the same specialty in life
...I'm also figuring out complex systems for a living (airport air surveillance and ground radar systems, various xrays, bomb and metal detectors)....Although I don't run a global support organization...which is just pimpin'!!!!: You definitely take me on that one!I'm just playing around man, good for you, seriously. you sound like a proud and successful guy there (no sarcasm intended at all)
Anyways....
I appreciate the info on the AWD, I understand your conclusions, you did a good and very thorough job explaining yourself and I commend you on getting the details. As I have $hit for details at this moment to make an argument, I'll give this one to you.
In all honesty, I never really challenged my mechanic's or the dealer's opinions on this topic nor did I really get into details with them about why it would be bad.
The potential issues given to me were: throwing sensors out, running out of spec, possible damage and void warranty on AWD powertrain and system, possible malfunctions with AWD engagement, and generally the AWD would not perform the way it was meant to and its reactions couldn't be relied on.... was enough to win me over on keeping them the rims/tires the same size.
All that said, I feel I did the right move with my setup and I sleep easier at night because of it...you know, they say poor sleep decreases lifespan!
AND:
My bad on that one 100%.
What I thought you meant skimming through the posts was that one of you thought wider rims in the rear with the same size tire (for ex: 245/40 on front with 245/40 on the wider rear rim)-and yeah, that would look retarded, but obviously not what you meant now that i re-read it.
and yes, i know different widths can have the same diameter, thanks!
Later boys.
Registered User
Joined: Nov 2007
Posts: 4,636
Likes: 42
From: Omaha
You want pics? Just look at any other G sedan with staggered wheels. Nothing is diffrent except the front bumper (i think) in terms of looks.
You want to run them? The do it, but keep in mind that any damage that is cuased you will be responible for fixing it.
Best of luck.
You want to run them? The do it, but keep in mind that any damage that is cuased you will be responible for fixing it.
Best of luck.
Registered User
Joined: Dec 2008
Posts: 989
Likes: 0
From: Columbus, Ohio
I must chime in here. Studies now show that not only is this true, but having too little sleep AND HAVING TOO MUCH SLEEP is also associated with a decreased lifespan. It's hard to win in this game called life. lol.
And now back to the thread. Thanks both of you guys for posting an intense, well-thought out debate. It was very informative.
Doc
