for all of the "experts" giving out the 20mm offset bogus info
12-13-2002, 04:11 AM
#21
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ok let's get technical here:
Scrub Radius is the distance between the extended centerline of the steering axis and the centerline of the tire where the tread contacts the road. If the steering centerline is inboard of the tire centerline, the scrub radius is positive which increases "turn in" and cornering ability. If the steering centerline is outboard of the tire centerline, the scrub radius is negative which leads to understeer. Rear-wheel drive cars generally have a positive scrub radius. Using wheels with different offset/ wheel centerline than stock can alter the scrub radius. By changing the scrub radius to a negative angle you will increase understeer as seen in most front wheel drive cars ....
for the "king pin" comment ...you don't have "king pins" (google is your friend)
if you would like we can discuss vehicle and chassis dynamics in depth also
Scrub Radius is the distance between the extended centerline of the steering axis and the centerline of the tire where the tread contacts the road. If the steering centerline is inboard of the tire centerline, the scrub radius is positive which increases "turn in" and cornering ability. If the steering centerline is outboard of the tire centerline, the scrub radius is negative which leads to understeer. Rear-wheel drive cars generally have a positive scrub radius. Using wheels with different offset/ wheel centerline than stock can alter the scrub radius. By changing the scrub radius to a negative angle you will increase understeer as seen in most front wheel drive cars ....
for the "king pin" comment ...you don't have "king pins" (google is your friend)
if you would like we can discuss vehicle and chassis dynamics in depth also
12-13-2002, 04:19 AM
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Originally posted by Luke@tirerack
for the "king pin" comment ...you don't have "king pins" (google is your friend)
for the "king pin" comment ...you don't have "king pins" (google is your friend)
FWIW...
m
12-13-2002, 04:35 AM
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the angle that is referring to is the Steering Axxis Inclination ... I guess somethings don't translate from Japanese very well.
A "knig pin" was and is used on solid front axle equipt vehicles (remember Ford twin-I-Beam trucks and vans) The 350 suspension does not have king pins
here is a pic of what is being descibed the the specs
A "knig pin" was and is used on solid front axle equipt vehicles (remember Ford twin-I-Beam trucks and vans) The 350 suspension does not have king pins
here is a pic of what is being descibed the the specs
12-13-2002, 04:51 AM
#24
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You can call it whatever you like, the fact of the matter is that those of us who've been around racing long enough still call it the king pin inclination, as Nissan has as well. Until I see graphs, charts, data I'm calling BS. I haven't taken the time to get the information myself since I just got my Z so I don't have the answer yet either. Likewise, I don't think you have the data. If you do provide it otherwise remove your statement. I know suspension theory, design, dynamics, and everything else and I know when someone doesn't have the data to support their claims.
12-13-2002, 05:02 AM
#25
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the 350Z does not use kingpins, but does still measure the kingpin inclination angle.
i found this explaination on a model car site, but it should still apply to suspension geometry:
The term king pin inclination refers to the angle made between the centres of the axle block pivot points on your model car as viewed from the front of the car.
link: http://www.rctek.com/handling/king_pin_inclination.html
here is some more text i found on a racing webpage:
All suspensions have an angle referred to as the kingpin inclination (I know a strut doesn't have a kingpin, but the strut itself rotates on the same axis as the kingpin would if it were a double-wish bone and not a strut). This is the axis that the steering wheels turn upon to change the direction of the car. This angle interects the vertical axis of the wheel, but due to design restrictions it intersects well past where the tire meets the road. The distance between where these lines (the vertical axis of the wheel and the rotational axis of the strut - kingpin axle) is called steering offset.
that said, i can see where the confusion is coming from. nissan actually uses a special alignment tool called a CCK gauge (Camber, Castor, Kingpin) to measure these specs. there really is no kingpin.
m
i found this explaination on a model car site, but it should still apply to suspension geometry:
The term king pin inclination refers to the angle made between the centres of the axle block pivot points on your model car as viewed from the front of the car.
link: http://www.rctek.com/handling/king_pin_inclination.html
here is some more text i found on a racing webpage:
All suspensions have an angle referred to as the kingpin inclination (I know a strut doesn't have a kingpin, but the strut itself rotates on the same axis as the kingpin would if it were a double-wish bone and not a strut). This is the axis that the steering wheels turn upon to change the direction of the car. This angle interects the vertical axis of the wheel, but due to design restrictions it intersects well past where the tire meets the road. The distance between where these lines (the vertical axis of the wheel and the rotational axis of the strut - kingpin axle) is called steering offset.
that said, i can see where the confusion is coming from. nissan actually uses a special alignment tool called a CCK gauge (Camber, Castor, Kingpin) to measure these specs. there really is no kingpin.
m
12-13-2002, 05:08 AM
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Originally posted by rodH
Luke,
the site recommends 225/40/19 (f) and 245/40/19 (r), BUT nobody makes those 2 sizes. what to do???
Luke,
the site recommends 225/40/19 (f) and 245/40/19 (r), BUT nobody makes those 2 sizes. what to do???
Dunlop Sport 9000
Michelin Pilot Sport
Continental Sport Contact 2
Last edited by Luke@tirerack; 12-13-2002 at 05:10 AM.
12-13-2002, 05:10 AM
#27
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kingpin inclination and steering axis inclination are the same things anyway...
KINGPIN INCLINATION (KPI)
Definition: The angle formed by a line that runs through the king pin in the steering knuckle on a truck with an I-Beam axle. It's the same as the steering axis inclination (SAI).
http://autorepair.about.com/library/.../bldef-404.htm
KINGPIN INCLINATION (KPI)
Definition: The angle formed by a line that runs through the king pin in the steering knuckle on a truck with an I-Beam axle. It's the same as the steering axis inclination (SAI).
http://autorepair.about.com/library/.../bldef-404.htm
12-13-2002, 05:37 AM
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Bogus!?!?
Originally posted by LS350Z
You can call it whatever you like, the fact of the matter is that those of us who've been around racing long enough still call it the king pin inclination, as Nissan has as well. Until I see graphs, charts, data I'm calling BS. I haven't taken the time to get the information myself since I just got my Z so I don't have the answer yet either. Likewise, I don't think you have the data. If you do provide it otherwise remove your statement. I know suspension theory, design, dynamics, and everything else and I know when someone doesn't have the data to support their claims.
You can call it whatever you like, the fact of the matter is that those of us who've been around racing long enough still call it the king pin inclination, as Nissan has as well. Until I see graphs, charts, data I'm calling BS. I haven't taken the time to get the information myself since I just got my Z so I don't have the answer yet either. Likewise, I don't think you have the data. If you do provide it otherwise remove your statement. I know suspension theory, design, dynamics, and everything else and I know when someone doesn't have the data to support their claims.
12-13-2002, 07:38 AM
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Wow!
All this and I still don't know why 19x8.5(+22) and 19x9.5(+22) are bad.
Skid, I desperately want to know how your new wheels fit and an estimate of the room available. I want to order my wheels.
All this and I still don't know why 19x8.5(+22) and 19x9.5(+22) are bad.
Skid, I desperately want to know how your new wheels fit and an estimate of the room available. I want to order my wheels.
What are you guys talking about???
12-13-2002, 10:42 AM
#31
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Originally posted by z461
Actually... skyline specs demand +12mm for front and rear for the R34-GTR, the Skyline GT-Turbo R34 uses +30mm and +35mm front and rear. So in other words, you're wrong.
http://www.rayswheels.co.jp/cgi-bin/...modelName=TE37
BTW, maybe Tirerack will get on the ball and start getting some wheels in for the Z. It's been nearly 4 months and all you guys have are winter wheels. Come on now.. And what happened to the SSR? All that are available are bogus offsets like +37 and +41... Looks tucked. Even stock 8.5's are +30mm offset on the Z. So going to +22mm offset on front 8.5's isn't bad at all.
Actually... skyline specs demand +12mm for front and rear for the R34-GTR, the Skyline GT-Turbo R34 uses +30mm and +35mm front and rear. So in other words, you're wrong.
http://www.rayswheels.co.jp/cgi-bin/...modelName=TE37
BTW, maybe Tirerack will get on the ball and start getting some wheels in for the Z. It's been nearly 4 months and all you guys have are winter wheels. Come on now.. And what happened to the SSR? All that are available are bogus offsets like +37 and +41... Looks tucked. Even stock 8.5's are +30mm offset on the Z. So going to +22mm offset on front 8.5's isn't bad at all.
well I'm wrong am I ...
R33 and R34 Skylines use very low offsets .... like the 12mm you mention but the Skyline GT-r R32 uses low 20mm offsets which is the wheel dimensions that are being sold as 350 fitments.
do you actually think you could drive this car without rubbing issues
the fender lips have been completely removed and still the tires have no clearance .... (yes it is extremely low but when your suspension compresses you will get the same effect)
Have I said that they can not be installed on the car ... no
what I have said is that it is not a correct fitment and will mostlikely rub under suspension compression unless you use a narrow enough tire. The GTR offsets will limit the tire size selection because of the incorrect offset .... stay tuned I have some pictures to prove my point which are being uploaded to supply everybody with visual proof.
Also, speaking with the Ray's engineering folks at SEMA in November they are the ones who told us that they are using the R32 GT-r wheels on the 350
12-13-2002, 10:46 AM
#32
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I am also curious why nobody has even mentioned the mounting of the pressure sensors and how that effects wheel selection ...
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
12-13-2002, 11:10 AM
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Originally posted by roberto350z
uh oh. Luke warns that 25+ is bayd, then the same company ships 24+ to a customer. Something has to give!
uh oh. Luke warns that 25+ is bayd, then the same company ships 24+ to a customer. Something has to give!
why havent you addressed this yet??? grrrrr..
12-13-2002, 11:15 AM
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Originally posted by Luke@tirerack
I am also curious why nobody has even mentioned the mounting of the pressure sensors and how that effects wheel selection ...
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
I am also curious why nobody has even mentioned the mounting of the pressure sensors and how that effects wheel selection ...
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
12-13-2002, 11:33 AM
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Luke, maybe we need to be more specific about what we are talking about.
Will the TE37's in 19x8.5f and 19x9.5r (both with +22 offset) fit the 350z?
If they will fit but have issues, what specific issues? (handling? rubbing? other? all?)
Then please provide some facts to back up your opinion. The pictures you mentioned would be a good start. But the picture you posted from the Rays site is not good because I don't know what size wheels those are (I only see the size of the wheels they are promoting).
Again, don't take this personal. I value your info but everyone on this site has info (including me). I need to weed out the facts from the opinions.
Will the TE37's in 19x8.5f and 19x9.5r (both with +22 offset) fit the 350z?
If they will fit but have issues, what specific issues? (handling? rubbing? other? all?)
Then please provide some facts to back up your opinion. The pictures you mentioned would be a good start. But the picture you posted from the Rays site is not good because I don't know what size wheels those are (I only see the size of the wheels they are promoting).
Again, don't take this personal. I value your info but everyone on this site has info (including me). I need to weed out the facts from the opinions.
12-13-2002, 11:38 AM
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Originally posted by Luke@tirerack
I am also curious why nobody has even mentioned the mounting of the pressure sensors and how that effects wheel selection ...
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
I am also curious why nobody has even mentioned the mounting of the pressure sensors and how that effects wheel selection ...
has anybody even given any thought to that or, will any wheel accept the sensores or did you not know that there a specific angle at which the valve hole should machined in the wheel to allow for proper sensor installation .... any thoughts
1) live without them...
2) epoxy the flat part of the sensor to the inside of the wheel.
both of these have been done, and all parties have been happy.
i chose #1... i will keep the sensor on my stock track wheel... now my racing wheel.
txstyle chose #2, and it works flawlessly.
m
12-13-2002, 12:31 PM
#38
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ok ... here are some facts ....
the OE wheel postions the center line of the wheel 1.25" inboard the mounting surface ... with 3.0" outboard and 5.5" inboard
9.5" 22mm offset postions the centerline .9" inboard of the
mounting surface ... with 3.85" outboard and 5.65" inboard
10" 40mm offset positions the centerline if the wheel 1.5" inboard the mounting surface ... with 3.5 out board and 6.5 inboard
as you can see with the 22mm offset wheel a large majority of the additional width is going to the out board side of the mounting surface (which will add undue torsional force on the bearings and change the scrub radius of the suspension) as opposed to the 10" 40mm offset which has a much better balance for the added width and will offer more tire/fender clearance.
the OE wheel postions the center line of the wheel 1.25" inboard the mounting surface ... with 3.0" outboard and 5.5" inboard
9.5" 22mm offset postions the centerline .9" inboard of the
mounting surface ... with 3.85" outboard and 5.65" inboard
10" 40mm offset positions the centerline if the wheel 1.5" inboard the mounting surface ... with 3.5 out board and 6.5 inboard
as you can see with the 22mm offset wheel a large majority of the additional width is going to the out board side of the mounting surface (which will add undue torsional force on the bearings and change the scrub radius of the suspension) as opposed to the 10" 40mm offset which has a much better balance for the added width and will offer more tire/fender clearance.
12-13-2002, 01:05 PM
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You're right must have been thinking about my 300ZX TT (which has 4 wheel steering) ... the term scrub radius is used to describe turning tires actually, I had started to post some front wheel info also but changed my mind at the last second ....
but the roll center for the rear wheels is affected with the wheel measurements mentioned above
but the roll center for the rear wheels is affected with the wheel measurements mentioned above