Improved Stance With Wheel Spacers
#16
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#17
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Just using a 1 to 10 scale, cars from the factory are going to be set at level 5 if that is going to be the most successfull formula for mass production with the least amount of problems. Making changes to a design that push it to level 8 or 9 may give you better results in one area but will likely have adverse effects in another. The more you push, the more you give up.
Going spacers would not be the first or optimal option to achieve better handling, just the cheapest. And least effective unless you went extreme.
Lowering the vehicle
Staggered rim setup with wider rim/tire combo
upgrading suspension components
Front/Rear Strut bars
Any one of the above will provide a real difference in changing the handling characteristics (notice that I did not say improve, just changing) for street application. But lets say you do put on a spacer that is large enough to where you notice less rolling. It's an SUV and designed to have roll to avoid flipping, that stress is going somewhere and the only upgrade you've added is ?...
I am not knocking spacers at all as I run them on my GS, but if adding them for looks, just add them for looks and leave it at that, drive the SUV like an SUV. There are pros to adding spacers, but there are cons as well and my point is that the conversation should not be simplified to where someone is just going to pick a number (5mm, 10mm, 20mm) out of thin air, slap them on a vehicle and declare it 'better' than before.
"Never enough time to do it right, but always enough to do it over"
Going spacers would not be the first or optimal option to achieve better handling, just the cheapest. And least effective unless you went extreme.
Lowering the vehicle
Staggered rim setup with wider rim/tire combo
upgrading suspension components
Front/Rear Strut bars
Any one of the above will provide a real difference in changing the handling characteristics (notice that I did not say improve, just changing) for street application. But lets say you do put on a spacer that is large enough to where you notice less rolling. It's an SUV and designed to have roll to avoid flipping, that stress is going somewhere and the only upgrade you've added is ?...
I am not knocking spacers at all as I run them on my GS, but if adding them for looks, just add them for looks and leave it at that, drive the SUV like an SUV. There are pros to adding spacers, but there are cons as well and my point is that the conversation should not be simplified to where someone is just going to pick a number (5mm, 10mm, 20mm) out of thin air, slap them on a vehicle and declare it 'better' than before.
"Never enough time to do it right, but always enough to do it over"
You would expect a person to properly measure the fender gap on their particular vehicle, who would randomly pick a spacer size out of thin air and risk the tires protruding past the fenders!
Check out this site it does a much better job of the advantages of using quality spacers than me. It also states that the reason manufacturer's build the clearance between the tire and fenders are to accommodate snow chains www.trakplus.com (I'm not an employee nor have stock option there. LOL)
Last edited by tak06; 09-28-13 at 01:33 AM.
#18
Pit Crew
Thanks for this very useful sharing. I have waited for the information for a long time.
I have 2 quick questions.
Do you need to cut the O.E. studs a little bit when using the 20mm spacer?
Since the fender is high and impossible to touch the tire, what is the reason you chose 20mm instead of 25 mm?
I appreciate your help.
I have 2 quick questions.
Do you need to cut the O.E. studs a little bit when using the 20mm spacer?
Since the fender is high and impossible to touch the tire, what is the reason you chose 20mm instead of 25 mm?
I appreciate your help.
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Thanks for this very useful sharing. I have waited for the information for a long time.
I have 2 quick questions.
Do you need to cut the O.E. studs a little bit when using the 20mm spacer?
Since the fender is high and impossible to touch the tire, what is the reason you chose 20mm instead of 25 mm?
I appreciate your help.
I have 2 quick questions.
Do you need to cut the O.E. studs a little bit when using the 20mm spacer?
Since the fender is high and impossible to touch the tire, what is the reason you chose 20mm instead of 25 mm?
I appreciate your help.
OE studs, so you will have no problems there. (In the case of my son's Mustang, I had to cut the
protruding portion of the studs)
I used a flat edge against the center portion of the tire and measured with a mm ruler, the distance from the sidewall to the outer edge of the fender lip and chose 20mm., 25 mm would have the tire extended approx. 3mm past the fender, with the 20mm., the tires sits approx. 2mm inboard of the fender's outer edge.
If you go to www.trakplus.com. it will explain the above in detail., these are German made quality
hubcentric spacers, which I've had absolutely no problems.
Hope this helps.
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#22
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I agree that it's a compromise and I drive the RX like a SUV not a race car, for that purpose I have a Z06, lowered on coilovers, larger sway bars, 7mm spacers, light weight TSW's, staggered wheel setup 9.5x19", 10.5x19"'s, 275/30/19"'s, 305/30/19"'s., it's loud, fast and pulls over 1g's in corners. Incidently, the GS is a luxury 4 dr family sedan much like the RX, it has built in understeer and body roll, they are basically built for the same purpose, one happens to sit higher and who would really want to lower the suspension, install sway bars etc. on a RX, defeats it's purpose. According to you, one should slap on spacers and drive a SUV like a SUV and leave it at that, wouldn't that apply to the GS too, just drive it like a 4 dr sedan because that's what it is. When one increases the width of a vehicle by an inch and a half, the law of physics dictates better stability and less roll, which is the upgrade in question. There may perhaps be slightly more stress on the bearings as do wider aftermarket rims. I've never experienced any suspension or bearing issues & I've installed quite a few, all were less than 25mm. The use of hubcentric spacers is not a CHEAP method to increase handling and appearance but an intelligent way. One keeps the quality Lexus wheels, maintains the OE ride with improved appearance & handling. When purchasing low offset aftermarket wheels & tires one usually opts for larger diameter lower profile tires with plastic or metal hub rings risking the possibility of shimming or vibrations at higher speeds, not to mention the quality of the wheels and the expense. When installing spacers, they should be properly torqued not just slapped on, and the studs should accommodate at least 7 full turns of thread engagement, if not ET nuts or longer studs should be installed to maintain safety.
You would expect a person to properly measure the fender gap on their particular vehicle, who would randomly pick a spacer size out of thin air and risk the tires protruding past the fenders!
Check out this site it does a much better job of the advantages of using quality spacers than me. It also states that the reason manufacturer's build the clearance between the tire and fenders are to accommodate snow chains www.trakplus.com (I'm not an employee nor have stock option there. LOL)
You would expect a person to properly measure the fender gap on their particular vehicle, who would randomly pick a spacer size out of thin air and risk the tires protruding past the fenders!
Check out this site it does a much better job of the advantages of using quality spacers than me. It also states that the reason manufacturer's build the clearance between the tire and fenders are to accommodate snow chains www.trakplus.com (I'm not an employee nor have stock option there. LOL)
Thanks for the clarification on the website info as I was beginning to wonder. But I'm not sure of the wisdom of receiving your information from a website who's sole purpose is to sell you something. Pretty easy for the website to say:
2. Will installing TRAK+ Wheel Spacers wear out my wheel bearings faster than normal?
No. TRAK+ Wheel Spacers will not cause premature wear of your wheel bearings. Inspect your bearings to make sure they are in good working condition before installing TRAK+ Wheel Spacers.
No. TRAK+ Wheel Spacers will not cause premature wear of your wheel bearings. Inspect your bearings to make sure they are in good working condition before installing TRAK+ Wheel Spacers.
3. Can I test fit TRAK+ and exchange them if needed?
Once spacers have been installed, H&R can no longer accept them for return. To ensure you get the correct spacer the first time, view How To Buy
Once spacers have been installed, H&R can no longer accept them for return. To ensure you get the correct spacer the first time, view How To Buy
With regards to my GS, it stopped be a 'luxury sedan' a long time ago, it rides 1.5" off the ground, has f/r strut bars, improved sway bars, coilvers, engine goodies and matches a good deal of the Krauts on the road with its handling as she gets driven hard. My spacers were installed only to clear my BBK setup.
Like i said, I'm not against spacers and yes they do improve looks. Nor am I saying the negatives outweigh the positives (in your setup specifically), but for those looking to install, don't just grab a (MM) number out of thin air. Do so with a purpose and realize what you are doing when making changes to your suspension.
Here is some good information for those wishing to install spacers for 'handling and the effects associated within:
Scrub Radius. by Roger Jackman.
This man walks into a bar... "NORM!" He proceeds to belly up to the bar and begins to talk about the daily grind and the latest in his relationship with his wife. The bartender, a former sports icon, talks to a patron at the other end of the bar about the specifics of modifying the suspension on his Corvette. He was told that after changing to an aftermarket wheel and tire combination, he needs to modify the scrub radius a bit and wants to know what in the world they were talking about. Cliff is trying to explain that scrub has been in use since early man invented the wheel. He claims, "in order to get the perfect lateral friction to rolling resistance ratio, you must periodically 'scrub' the tires to expose the unused material."
Does this scenario sound like you and your car buddies at the local watering hole after a club meet or romp through the countryside? I know I have heard it somewhere before. Now, I was able to get through school with a little intuition and a lot of B.S., but these qualities do not always work when I am dealing with inanimate objects that are not humored by my B.S. and theory. When dealing with suspension design and dynamics, little things that are easily overlooked like scrub radius can make a greater difference in your car's handling and feel than all your theory and fervent tuning can accomplish.
To understand scrub, you must first know about Steering Axis Inclination (SAI). The steering axis is the line between the top pivot point of your hub and the lower ball joint of your hub. On a MacPherson strut, the top pivot point is the strut bearing, and the bottom point is the lower ball joint. On a suspension using upper and lower control arms, the pivot points are where the upright connects to the control arms. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel, so if your camber is adjustable within the pivot points (i.e. Volkswagen) you can change the SAI.
Now back to the subject at hand. The scrub radius is the distance on the ground between the centerline of the tire contact patch and the point at which the SAI intersects the ground. If these two lines intersect at ground level, then you are said to have zero scrub. If the SAI intersects the ground at a point inside or outside of the centerline of the contact patch, you are said to have positive or negative scrub respectively.
You now know what elements make up scrub, now you may ask what it has to do with the price of tea in China? Well, the point at which the steering axis line contacts the ground is the fulcrum pivot point on which the tire turns. The location of this point within the contact patch has a great effect on steering effort, feel, and stability. If you have not already guessed, the easiest way to change scrub is by changing your offset with either new wheels, or hub centric wheel spacers.
If the scrub is zero, the scrubbing action of the contact patch is equal on either side of the pivot point causing the tire to act like a car with a welded differential, inducing a condition called 'squirm'. In a straight line the tire tends to be stable and tracks well. As you turn though, the portion of the contact patch on the outside of the pivot point moves faster than the portion on the inside of the contact patch. Since the scrubbing area is equal on each side of the pivot point, yet the forces are different, the tire tends to fight itself and it becomes 'grabby' causing tire wear to increase and the steering to become unstable.
Positive and negative scrub radii have benefits in different types of suspension. A MacPherson strut assembly typically performs well with a lot of SAI and caster, a system negative scrub works well in. Because both SAI and caster increase the amount of camber on the outside wheel when steering, the fulcrum pivot point is at a point that has more leverage, requiring less steering effort. Negative scrub also helps reduce torque steer in front wheel drive cars. Positive scrub radius works well with suspensions that use dual control arms that use less caster and SAI to optimize geometry.
As with anything else, a little of a good thing is great, but lot of a good thing is not necessarily better. When you have excessive scrub, whether it be positive or negative, steering effort increases and road 'feel' increases, as the steering is more susceptible to road shock. Additionally, if you plan on doing some homework on, and modifying your scrub radius, you must take into account the amount of sidewall flex your tire will encounter under hard cornering. When the sidewall flexes, the contact patch moves in relation to the SAI and can make a slightly negative scrub radius become zero.
Well, now you know all about scrub, so the next time it comes up at the watering hole you have the confidence in knowing that your drunken compatriot is having more fun with creative banter than tuning and driving his car. That is not such a bad thing though. Order another beer and go with it. I will bet you can come up with something better.
This man walks into a bar... "NORM!" He proceeds to belly up to the bar and begins to talk about the daily grind and the latest in his relationship with his wife. The bartender, a former sports icon, talks to a patron at the other end of the bar about the specifics of modifying the suspension on his Corvette. He was told that after changing to an aftermarket wheel and tire combination, he needs to modify the scrub radius a bit and wants to know what in the world they were talking about. Cliff is trying to explain that scrub has been in use since early man invented the wheel. He claims, "in order to get the perfect lateral friction to rolling resistance ratio, you must periodically 'scrub' the tires to expose the unused material."
Does this scenario sound like you and your car buddies at the local watering hole after a club meet or romp through the countryside? I know I have heard it somewhere before. Now, I was able to get through school with a little intuition and a lot of B.S., but these qualities do not always work when I am dealing with inanimate objects that are not humored by my B.S. and theory. When dealing with suspension design and dynamics, little things that are easily overlooked like scrub radius can make a greater difference in your car's handling and feel than all your theory and fervent tuning can accomplish.
To understand scrub, you must first know about Steering Axis Inclination (SAI). The steering axis is the line between the top pivot point of your hub and the lower ball joint of your hub. On a MacPherson strut, the top pivot point is the strut bearing, and the bottom point is the lower ball joint. On a suspension using upper and lower control arms, the pivot points are where the upright connects to the control arms. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel, so if your camber is adjustable within the pivot points (i.e. Volkswagen) you can change the SAI.
Now back to the subject at hand. The scrub radius is the distance on the ground between the centerline of the tire contact patch and the point at which the SAI intersects the ground. If these two lines intersect at ground level, then you are said to have zero scrub. If the SAI intersects the ground at a point inside or outside of the centerline of the contact patch, you are said to have positive or negative scrub respectively.
You now know what elements make up scrub, now you may ask what it has to do with the price of tea in China? Well, the point at which the steering axis line contacts the ground is the fulcrum pivot point on which the tire turns. The location of this point within the contact patch has a great effect on steering effort, feel, and stability. If you have not already guessed, the easiest way to change scrub is by changing your offset with either new wheels, or hub centric wheel spacers.
If the scrub is zero, the scrubbing action of the contact patch is equal on either side of the pivot point causing the tire to act like a car with a welded differential, inducing a condition called 'squirm'. In a straight line the tire tends to be stable and tracks well. As you turn though, the portion of the contact patch on the outside of the pivot point moves faster than the portion on the inside of the contact patch. Since the scrubbing area is equal on each side of the pivot point, yet the forces are different, the tire tends to fight itself and it becomes 'grabby' causing tire wear to increase and the steering to become unstable.
Positive and negative scrub radii have benefits in different types of suspension. A MacPherson strut assembly typically performs well with a lot of SAI and caster, a system negative scrub works well in. Because both SAI and caster increase the amount of camber on the outside wheel when steering, the fulcrum pivot point is at a point that has more leverage, requiring less steering effort. Negative scrub also helps reduce torque steer in front wheel drive cars. Positive scrub radius works well with suspensions that use dual control arms that use less caster and SAI to optimize geometry.
As with anything else, a little of a good thing is great, but lot of a good thing is not necessarily better. When you have excessive scrub, whether it be positive or negative, steering effort increases and road 'feel' increases, as the steering is more susceptible to road shock. Additionally, if you plan on doing some homework on, and modifying your scrub radius, you must take into account the amount of sidewall flex your tire will encounter under hard cornering. When the sidewall flexes, the contact patch moves in relation to the SAI and can make a slightly negative scrub radius become zero.
Well, now you know all about scrub, so the next time it comes up at the watering hole you have the confidence in knowing that your drunken compatriot is having more fun with creative banter than tuning and driving his car. That is not such a bad thing though. Order another beer and go with it. I will bet you can come up with something better.
All in all, as stated, your vehicle looks much improved in stance.
#23
Moderator
Did you get part number 40656000? That is the number for the DRM type 20mm spacers? It is funny that the web site lists the models as RX335 or RX400h for model years 2010 and up.
#24
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Try Ichiba as an alternative, they are a much more well known brand. Their version comes with extended lugs if needed.
http://www.ichibausa.com/searchresults.asp?cat=1157
http://www.ichibausa.com/searchresults.asp?cat=1157
#25
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RX 350.
#26
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Try Ichiba as an alternative, they are a much more well known brand. Their version comes with extended lugs if needed.
http://www.ichibausa.com/searchresults.asp?cat=1157
http://www.ichibausa.com/searchresults.asp?cat=1157
On another note, I don't think you read my response, no one picks a spacer out of thin air as you suggest, obviously the gap has to be measured.
Why would H&R accept a return on a product that has been installed, would you accept a return on a tire that's been mounted.
No offense but I don't wish to continue a p*****g contest with you, my intentions were merely to share a simple mod to enhance the appearance and provide a little more stability for our RX's, if you don't agree with the means that's your prerogative, I don't think many RX 350's owners plan to track the RX, like you said drive a SUV like a SUV, and no matter what you do to a luxury 4 dr family sedan it's still a family sedan, slammed or not, what's a relevance of "Scrub Radius to a RX" perhaps it is to a IS series and sport sedans out there planning on tracking same.
Last edited by tak06; 09-30-13 at 11:19 PM.
#27
The pursuit of F
tak06 - I've always been conservative when it came to spacers due to the negatives I've heard over time like those pointed out above. So I always stuck with 3mm or 5mm and never had any issues. Latest project is with my IS https://www.clublexus.com/forums/is-...-thread-4.html
However, I really like the way your wheels are nearly flush with the fenders. Looks good! This look would really suit my RX F-Sport.... hmmm....
Oh and nice exhaust tip
However, I really like the way your wheels are nearly flush with the fenders. Looks good! This look would really suit my RX F-Sport.... hmmm....
Oh and nice exhaust tip
#28
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tak06 - I've always been conservative when it came to spacers due to the negatives I've heard over time like those pointed out above. So I always stuck with 3mm or 5mm and never had any issues. Latest project is with my IS https://www.clublexus.com/forums/is-...-thread-4.html
However, I really like the way your wheels are nearly flush with the fenders. Looks good! This look would really suit my RX F-Sport.... hmmm....
Oh and nice exhaust tip
However, I really like the way your wheels are nearly flush with the fenders. Looks good! This look would really suit my RX F-Sport.... hmmm....
Oh and nice exhaust tip
My son & I both have 7mm spacers on our Z06's., non hubcentric, however, much like your set up on your IS-F, there appears to be just enough hub bore lip to stabilize the rim to the hub, in our case we had to use ET wheel nuts as the 7mm spacer shortened the wheel studs to just 4 turns
of thread engagement, with the ET nuts we were able to achieve 11 full turns.
I'm not an automotive engineer but 20mm represents .79" not really all that much to worry
about regarding the bearings/suspension IMHO. I've owned over 50 vehicles and used spacers
on many, so far have not experienced any problems, if hubcentric spacers were used. Appearance is enhanced and the ride seems more planted and secure.
In the past I've used non hubcentric spacers (Stud centric), plastic hub rings and experienced
shimming at higher speeds. Just my experience, others may differ.
#29
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The questions was, what are the negative consequences, if any? You want to challenge my response at every turn because you've had 'no issues' Not a problem. others have and others will depending on what size they choose to go with.
To answer your specifc question above and I'm going to be done with the topic completely: relevant enough for the SAE to publish a paper on it: "The Impact of Scrub Radius on Sport Utility Vehicle Handling" http://papers.sae.org/982834/
Scrub radius and SUV handling
A new wheel end concept was designed and tested at Dana Corporation to offer sport utility vehicles and light trucks the possibility of achieving a negative scrub radius. Computer analysis and performance data from instrumented vehicles determine its effects.
Scrub radius is defined by SAE as kingpin offset, which is the distance between the two points created by the inter- section of the wheel centerline (centerline of tire patch) and the steering axis with the ground plane. The steering axis is determined by the kingpin index angle, which is the plane projected through the upper and lower ball joints and the wheel shaft joint. A zero scrub radius exists when the wheel centerline and the kingpin index intersect exactly at ground level. Positive offset occurs when the wheel centerline is located laterally inboard from the steering axis at the ground plane, while negative offset occurs when the steering plane intersects the wheel centerline above the ground plane.
Choosing a negative or positive scrub radius for a vehicle's suspension has emerged in recent years as a philosophical debate. For a passenger car strut suspension, achieving a negative scrub radius is at least a viable option. However, on SUVs and light trucks with 4WD and short long-arm (SLA) suspensions, packaging the wheel end components and achieving a negative scrub radius has been difficult or impossible. Demand for off-road capability, working payload capacity, and the required brake component size needed, makes achieving even a small positive scrub radius difficult or requires compromising brakes, steering linkages, or other suspension components.
Configuring the CV Hub wheel end design with several scrub radius settings was an attempt to show that it is feasible to achieve even a negative scrub radius in an SUV. Opinions about whether negative scrub in a light truck is what the average driver wants are mixed. However, there is a trend to provide improved vehicle-handling dynamics, which has increased the focus on reducing scrub radius to a small positive number.
A new wheel end concept was designed and tested at Dana Corporation to offer sport utility vehicles and light trucks the possibility of achieving a negative scrub radius. Computer analysis and performance data from instrumented vehicles determine its effects.
Scrub radius is defined by SAE as kingpin offset, which is the distance between the two points created by the inter- section of the wheel centerline (centerline of tire patch) and the steering axis with the ground plane. The steering axis is determined by the kingpin index angle, which is the plane projected through the upper and lower ball joints and the wheel shaft joint. A zero scrub radius exists when the wheel centerline and the kingpin index intersect exactly at ground level. Positive offset occurs when the wheel centerline is located laterally inboard from the steering axis at the ground plane, while negative offset occurs when the steering plane intersects the wheel centerline above the ground plane.
Choosing a negative or positive scrub radius for a vehicle's suspension has emerged in recent years as a philosophical debate. For a passenger car strut suspension, achieving a negative scrub radius is at least a viable option. However, on SUVs and light trucks with 4WD and short long-arm (SLA) suspensions, packaging the wheel end components and achieving a negative scrub radius has been difficult or impossible. Demand for off-road capability, working payload capacity, and the required brake component size needed, makes achieving even a small positive scrub radius difficult or requires compromising brakes, steering linkages, or other suspension components.
Configuring the CV Hub wheel end design with several scrub radius settings was an attempt to show that it is feasible to achieve even a negative scrub radius in an SUV. Opinions about whether negative scrub in a light truck is what the average driver wants are mixed. However, there is a trend to provide improved vehicle-handling dynamics, which has increased the focus on reducing scrub radius to a small positive number.
For those still unclear about scrub radius:
#30
Pole Position