Would this compliment Vishnu Ohlins?
Jan 3, 2007, 10:08 AM
#16
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so... i guess we're still waiting on sustainable, conclusive, and impartial test results as to whether or not these will stand the test of time and work with our many suspension, wheel, and tire combinations?
i'm running stock wheels and tires having only upgraded to the awesome vishnu/gerrard spec'd ohlins suspension-wise. would it help if i volunteered my car for a test bed or would some type of dyno be better suited for testing?
i'm running stock wheels and tires having only upgraded to the awesome vishnu/gerrard spec'd ohlins suspension-wise. would it help if i volunteered my car for a test bed or would some type of dyno be better suited for testing?
Last edited by malevlnt2; Jan 3, 2007 at 10:10 AM.
Jan 3, 2007, 10:34 AM
#17
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so... i guess we're still waiting on sustainable, conclusive, and impartial test results as to whether or not these will stand the test of time and work with our many suspension, wheel, and tire combinations?
i'm running stock wheels and tires having only upgraded to the awesome vishnu/gerrard spec'd ohlins suspension-wise. would it help if i volunteered my car for a test bed or would some type of dyno be better suited for testing?
i'm running stock wheels and tires having only upgraded to the awesome vishnu/gerrard spec'd ohlins suspension-wise. would it help if i volunteered my car for a test bed or would some type of dyno be better suited for testing?
If your application fits their testing criteria then you can get them right now however if you've got a "high g" car I'd wait FWIW.
Jan 3, 2007, 10:37 AM
#18
I was reading the link provided by Jim@Whiteline here: http://www.suspensionparts.info/showthread.php?t=272 and found it very interesting that the Whiteline guys are promoting soft springs with stiff anti-roll bars, which seems (somewhat) counter to what Joe Henry and Paulie G are promoting with the Ohlins. Both Whiteline and Vishnu are very clear that maximun grip is their priority (as opposed to making a car loose to get it to rotate easier).
Joe and Paul have said stiffer anti roll bars are great but only if they are BALANCED front and rear. Also, they don't promote super stiff springs, just stiffer in the rear than the front. But this little zinger written by Jim@Whiteline hit pretty close to home and I'd like to see how Paul and Joe respond:
Joe and Paul have said stiffer anti roll bars are great but only if they are BALANCED front and rear. Also, they don't promote super stiff springs, just stiffer in the rear than the front. But this little zinger written by Jim@Whiteline hit pretty close to home and I'd like to see how Paul and Joe respond:
Originally Posted by Jim@Whiteline
So how do we explain a 100 or 300% increase in the factory spring rate while leaving the roll resistance rate the same? For example, how could one justify using 400lb + springs on a road/race car while still using stock swaybars when the stock springs were only 200lb? We don’t, because it doesn’t make sense.
Jan 4, 2007, 05:10 PM
#19
Where's the freekin' whiteboard when you need one? Doesn't evom have everything??? j/k.
Paul, are you willing to talk a little (more) about roll center on the EVO?
The way Joe described this was a "bar" extending from CG to another point(s) RC. I've never seen this relationship officially pointed out to me. Is there a good picture or even animation you know about that would help me visualize this relationship?
Cheers,
~j.
Paul, are you willing to talk a little (more) about roll center on the EVO?
The way Joe described this was a "bar" extending from CG to another point(s) RC. I've never seen this relationship officially pointed out to me. Is there a good picture or even animation you know about that would help me visualize this relationship?
Cheers,
~j.
Pic 1 shows the front and rear Roll Centers
Pic 2 shows their relationship to the CG.
Pic 3 you can imagine as that torque wrench. Your hand on the CG(force) pushing against the RC.
Also look at the thread "Vishnu Ohlins are here". First pic computer animation is showing the RC movement.
Jan 4, 2007, 08:59 PM
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Sorry I haven't written any technical "white" papers for everyone, I just haven't had any time to commit to a well written tutorial that could get nit-picked if some stuff isn't clear. I usually write in fairly layman's terms here, just because it's meant for general consumption.
OK, I'll try to help clear up some things here. I've been following Whiteline's products for sometime. They do know what they're doing and they're very good at it. There may be some differences in philosophy about which path reaches the final goal, which is grip and lap times. Paul, myself, and many others, believe that larger sway bars make an independent suspension "less independent." If the sway bar were perfectly rigid, when one side compresses during a turn, the other must also compress. This will cancel each other meaning no roll, in theory. In reality, the outside tire will compress as much as it can, while rolling over on the side wall, and the inside tire will be lifted off the ground. Very stiffly sprung solid axle cars behave similar to this. Putting power to a lightly or unloaded wheel will just spin it. Sway bars certainly have their place, they reduce roll without having to increase spring rate, it's a great trick. Too much of anything is bad though. We prefer to use the sway bar as a fine tuning device, not depending on it as the major contributor of anti-roll.
Now geometry. I use the term torque arm because anyone who has used a wrench can understand leverage. The longer the arm, the more leverage. The engineering term is force-couple or moment, in vehicle dynamics it's roll-moment. This leverage works against the springs, sway bars, and shocks during cornering. The more leverage, the stiffer *everything* has to be to resist roll. Raise the roll center (RC) so that it's closer to the center of gravity (CG), and the roll-moment has been reduced. Softer springs, anti-roll bars, and dampers can now accomplish the same roll resisting effect. This has the extra benefit of allowing more compliance over bumps, and there are no race tracks that have no bumps, even super speedway ovals. Deciding how much spring, damping, and anti-roll depends on the roll-moment distance, static and dynamic, and this is constrained by the ultimate grip. An Evo that generates only 1g doesn't need 1000lb/in springs, it's overkill and it will wear the tires down too fast. The softest values you can "get away with" for any suspension component will produce the most grip and yield the best tire temps and wear. That is just plain fact. Ok, getting slightly off topic, but geometry definitely matters. The balance does as well.
A neutral car by definition makes the same grip, front and rear. Understeer has less front grip and oversteer has less rear grip. All things being equal, raising the front roll center will stiffen the front, causing more weight transfer percentage across the front (vs. the rear). This will lead to understeer. On the plus side, the camber curve is improved, meaning less positive camber gain during roll, meaning more contact patch on the ground at all times, and more grip. It might be a wash. If it's not, you will have to use softer front springs to regain the front grip. The other problem with the Evo front roll center is how quickly it migrates outward during roll, meaning the roll-moment grows exponentially. This causes the front end roll resistance to decrease exponentially as well. You see this in situations where initial corner entry is good, but towards the apex, the front just flops over. You then lose grip because of excessive camber and toe changes. The stock roll center position is horrible, it migrates to infinity in around 2 degrees of roll. I think this might be some built in understeer from Mitsu. Either raise the car or lower it, but don't leave it there. Lower too much and the roll center dives undergound at an exponential rate, but doesn't migrate much during roll. Now, with chosen tires (grip level), you can pick RC height, spring, and anti-roll rates finding the best compromise out of all situations, but it takes a lot of time and testing. All of this info is a bit dumbed down for easy reading and only covers the basics. If we talk about the geometric roll axis versus the actual then you'll be wishing you took the blue pill.
We've worked very hard to find the best compromise point with ride height, spring rate, sway bar rate, and matched damping for corner entry/exit and bump control. I can't say that adding this piece to our existing setup will make it better, it may be worse, because remember the suspension is a system. If anyone still wants to try one, I'd say lower the front even more, because the Whiteline ball joints will recover the RC and camber curves. Unfortunately the bumpsteer will be worse, unless someone makes a longer tie-rod outer ball joint. Anyone who tries one of these is free to PM me for advice, because I'd like to know how it works out.
Lastly, safety. Calculating the "real" loads that go thru the ball joint are nearly impossible, to do it right, you have to measure using strain gauges. Anything else is an estimate and a sizable safety margin needs to be used. The stock ball joint is incredibly strong, I've seen proof in crash photos, and from force measurements from similar ball joints. Everthing else will bend before that does, but if it shears you will have no control over that wheel, steering or otherwise. Whiteline is smart to use an OEM type manufacturer for this. It reduces their liability because they don't actually produce the part. The OEM also has experience in this area. Based on everything else they do, I would trust it.
So, bottom line. The suspension is a system. A poorly setup car may certainly improve from this, a well sorted car may need to get resorted, but don't quote me. This is also a major safety item, but Whiteline is very reputable.
OK, I'll try to help clear up some things here. I've been following Whiteline's products for sometime. They do know what they're doing and they're very good at it. There may be some differences in philosophy about which path reaches the final goal, which is grip and lap times. Paul, myself, and many others, believe that larger sway bars make an independent suspension "less independent." If the sway bar were perfectly rigid, when one side compresses during a turn, the other must also compress. This will cancel each other meaning no roll, in theory. In reality, the outside tire will compress as much as it can, while rolling over on the side wall, and the inside tire will be lifted off the ground. Very stiffly sprung solid axle cars behave similar to this. Putting power to a lightly or unloaded wheel will just spin it. Sway bars certainly have their place, they reduce roll without having to increase spring rate, it's a great trick. Too much of anything is bad though. We prefer to use the sway bar as a fine tuning device, not depending on it as the major contributor of anti-roll.
Now geometry. I use the term torque arm because anyone who has used a wrench can understand leverage. The longer the arm, the more leverage. The engineering term is force-couple or moment, in vehicle dynamics it's roll-moment. This leverage works against the springs, sway bars, and shocks during cornering. The more leverage, the stiffer *everything* has to be to resist roll. Raise the roll center (RC) so that it's closer to the center of gravity (CG), and the roll-moment has been reduced. Softer springs, anti-roll bars, and dampers can now accomplish the same roll resisting effect. This has the extra benefit of allowing more compliance over bumps, and there are no race tracks that have no bumps, even super speedway ovals. Deciding how much spring, damping, and anti-roll depends on the roll-moment distance, static and dynamic, and this is constrained by the ultimate grip. An Evo that generates only 1g doesn't need 1000lb/in springs, it's overkill and it will wear the tires down too fast. The softest values you can "get away with" for any suspension component will produce the most grip and yield the best tire temps and wear. That is just plain fact. Ok, getting slightly off topic, but geometry definitely matters. The balance does as well.
A neutral car by definition makes the same grip, front and rear. Understeer has less front grip and oversteer has less rear grip. All things being equal, raising the front roll center will stiffen the front, causing more weight transfer percentage across the front (vs. the rear). This will lead to understeer. On the plus side, the camber curve is improved, meaning less positive camber gain during roll, meaning more contact patch on the ground at all times, and more grip. It might be a wash. If it's not, you will have to use softer front springs to regain the front grip. The other problem with the Evo front roll center is how quickly it migrates outward during roll, meaning the roll-moment grows exponentially. This causes the front end roll resistance to decrease exponentially as well. You see this in situations where initial corner entry is good, but towards the apex, the front just flops over. You then lose grip because of excessive camber and toe changes. The stock roll center position is horrible, it migrates to infinity in around 2 degrees of roll. I think this might be some built in understeer from Mitsu. Either raise the car or lower it, but don't leave it there. Lower too much and the roll center dives undergound at an exponential rate, but doesn't migrate much during roll. Now, with chosen tires (grip level), you can pick RC height, spring, and anti-roll rates finding the best compromise out of all situations, but it takes a lot of time and testing. All of this info is a bit dumbed down for easy reading and only covers the basics. If we talk about the geometric roll axis versus the actual then you'll be wishing you took the blue pill.
We've worked very hard to find the best compromise point with ride height, spring rate, sway bar rate, and matched damping for corner entry/exit and bump control. I can't say that adding this piece to our existing setup will make it better, it may be worse, because remember the suspension is a system. If anyone still wants to try one, I'd say lower the front even more, because the Whiteline ball joints will recover the RC and camber curves. Unfortunately the bumpsteer will be worse, unless someone makes a longer tie-rod outer ball joint. Anyone who tries one of these is free to PM me for advice, because I'd like to know how it works out.
Lastly, safety. Calculating the "real" loads that go thru the ball joint are nearly impossible, to do it right, you have to measure using strain gauges. Anything else is an estimate and a sizable safety margin needs to be used. The stock ball joint is incredibly strong, I've seen proof in crash photos, and from force measurements from similar ball joints. Everthing else will bend before that does, but if it shears you will have no control over that wheel, steering or otherwise. Whiteline is smart to use an OEM type manufacturer for this. It reduces their liability because they don't actually produce the part. The OEM also has experience in this area. Based on everything else they do, I would trust it.
So, bottom line. The suspension is a system. A poorly setup car may certainly improve from this, a well sorted car may need to get resorted, but don't quote me. This is also a major safety item, but Whiteline is very reputable.
Jan 5, 2007, 09:20 PM
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G'day everyone,
I didn't realise that this thread was also going, I'll post an answer here and copy on the other.
I'd like to say that we very much enjoy participating in these technical discussions. One of our new slogans is "we don't do bling" so we really appreciate being able to discuss the technical basis of our products
Joe, thanks for the positive words about the Whiteline brand. I suspect that like so many other topics, suspension setup discussion can sometime fall into the same category as religion and politics, something that should not be discussed in polite conversation. Once you get past the science, physics and maths it seems that all you're left with is faith in your own perspective and experience. There are many ways to achieve the same outcome and I am very happy to support anything that moves us to more total grip, that's where good suspension setup starts and ends in our view.
I would like to study the other posts a little more before commenting in detail but at the moment I'd like to clarify a comment re soft springs and hard swaybars. Its not that we don't like increasing spring rate, its just that we prefer a more holistic approach and try to increase the relative rate of all "springs" in the system as we move toward higher performance levels and stickier tyres. That of course includes swaybars and springs but also involves chassis stiffness through extra bracing etc. Hence my earlier point about our recipe for springs varying between caged and non-caged cars even when using the same tyres. We continue to increase swaybar rate along with spring rate but it is fair to say that physical spring rate increases disproportionately more the closer we get to the level of slicks. However, any Whiteline balanced performance setup will always include stiff swaybars front and rear fromt he beginning. The other key aspect of the Whiteline philosophy is to always use as little total or overall spring rate as you can, where ever it may be while remembering that the actual rate at the tyre contact patch is all that matters.
Speaking of tyres, we saw a mention of Hoosiers and high lateral G's relative to our G-plot. In Australia the Hoosiers are treated as "slicks" in the class structure and are not allowed in the intermediate or "semi-slick" tyre class where most of our work is done. This also relates to the swaybar/spring argument as we push bigger bars very heavily for amateur and enthusiast upgrades as we find its the easiest and most cost effective way to increase grip on a road car thanks to the reserve grip capacities of most road tyres, even stock. Very early in our WRX development our skid pan logs showed we could increase lateral G's by a couple of points just by increasing rear swaybar size with no other changes. This is often overlooked on modern cars and people are quite surprised when they experience it.
Joe, one thing that has not really been teased out by anyone else so far is the issue of front to rear roll axis and its affect in this equation. One of the reasons why we keep the change down to under 10mm is to keep the balance with the rear, we don't want to invert the roll axis to a nose-up stance. The rear end is not a classic strut config and roll centre change is much more contained. Balance is the key.
The KCA395 kit includes modified tie rod ends so the bump steer curve is also addressed. Anyone wanting to try the kit is welcome to contact our US distributor Global Performance Parts and see if they can do a deal, don't quote me but they might be interested.
Will study the other stuff a little more and come back if we have something more to add.
Best regards
Jim
Whiteline Automotive
PS. Joe, isn't it also fair to say that a physically stiffer spring will also "make an independent suspension less independent" when you consider the body and the law of equal and opposite reactions?
I didn't realise that this thread was also going, I'll post an answer here and copy on the other.
I'd like to say that we very much enjoy participating in these technical discussions. One of our new slogans is "we don't do bling" so we really appreciate being able to discuss the technical basis of our products
Joe, thanks for the positive words about the Whiteline brand. I suspect that like so many other topics, suspension setup discussion can sometime fall into the same category as religion and politics, something that should not be discussed in polite conversation. Once you get past the science, physics and maths it seems that all you're left with is faith in your own perspective and experience. There are many ways to achieve the same outcome and I am very happy to support anything that moves us to more total grip, that's where good suspension setup starts and ends in our view.
I would like to study the other posts a little more before commenting in detail but at the moment I'd like to clarify a comment re soft springs and hard swaybars. Its not that we don't like increasing spring rate, its just that we prefer a more holistic approach and try to increase the relative rate of all "springs" in the system as we move toward higher performance levels and stickier tyres. That of course includes swaybars and springs but also involves chassis stiffness through extra bracing etc. Hence my earlier point about our recipe for springs varying between caged and non-caged cars even when using the same tyres. We continue to increase swaybar rate along with spring rate but it is fair to say that physical spring rate increases disproportionately more the closer we get to the level of slicks. However, any Whiteline balanced performance setup will always include stiff swaybars front and rear fromt he beginning. The other key aspect of the Whiteline philosophy is to always use as little total or overall spring rate as you can, where ever it may be while remembering that the actual rate at the tyre contact patch is all that matters.
Speaking of tyres, we saw a mention of Hoosiers and high lateral G's relative to our G-plot. In Australia the Hoosiers are treated as "slicks" in the class structure and are not allowed in the intermediate or "semi-slick" tyre class where most of our work is done. This also relates to the swaybar/spring argument as we push bigger bars very heavily for amateur and enthusiast upgrades as we find its the easiest and most cost effective way to increase grip on a road car thanks to the reserve grip capacities of most road tyres, even stock. Very early in our WRX development our skid pan logs showed we could increase lateral G's by a couple of points just by increasing rear swaybar size with no other changes. This is often overlooked on modern cars and people are quite surprised when they experience it.
Joe, one thing that has not really been teased out by anyone else so far is the issue of front to rear roll axis and its affect in this equation. One of the reasons why we keep the change down to under 10mm is to keep the balance with the rear, we don't want to invert the roll axis to a nose-up stance. The rear end is not a classic strut config and roll centre change is much more contained. Balance is the key.
The KCA395 kit includes modified tie rod ends so the bump steer curve is also addressed. Anyone wanting to try the kit is welcome to contact our US distributor Global Performance Parts and see if they can do a deal, don't quote me but they might be interested.
Will study the other stuff a little more and come back if we have something more to add.
Best regards
Jim
Whiteline Automotive
PS. Joe, isn't it also fair to say that a physically stiffer spring will also "make an independent suspension less independent" when you consider the body and the law of equal and opposite reactions?
Jan 5, 2007, 09:28 PM
#22
I was never even considering these till I read this thread.
Posts like the last few above are why I love evom, when a vendor, manufacturer, or tuner will go out of there way to fully explain a product, its development, and how and why it works, it's nice.
I learned something today......I thought............dogs.......laid eggs.-Burgendy
Scorke
Posts like the last few above are why I love evom, when a vendor, manufacturer, or tuner will go out of there way to fully explain a product, its development, and how and why it works, it's nice.
I learned something today......I thought............dogs.......laid eggs.-Burgendy
Scorke
Jan 6, 2007, 04:41 AM
#24
And like scorke said, this is why evom can be a great place at times
It's also a fine example of how experts converse and debate
Smoggie is right Joe should have guru status
I think Ali will be updating his status shortly!
Last edited by meanmud; Jan 6, 2007 at 04:03 PM. Reason: Djazair comment
Jan 6, 2007, 05:35 PM
#25
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I concur(+1 )...good responses all around, to Jim at Whiteline I appreciate a manufacturer that take the time to explain their philosophy, it really does help promote the brand and shows that you are passionate about what you do (these are all things that help people bust out their credit cards ).
We (Joe and I) do sometimes spec larger bars for some customers but the focus of those people is the street/track compromise. It does give you more flexibility for the dual purpose car (where street ride more of a priority). For the more "no compromise" approach to absolute lap time the propotionally stiffer spring combo just plain makes more grip especially over several flying laps. They simply use more of the inside tires promoting more inside tire temp (due to the increased usage of the inside tires) and proportionally cooler outside temps (reality of course says we can just push the car/tires harder due to this and that's why it's ultimately faster longer). We also prefer having pitch dive and roll all at the same "rates" because it can be more precisely controlled by the dampers ( and we love tuning dampers and have done over 27 re-valving refinements just for the EVO!).
Bars are a simple, cheap upgrade for the budget minded enthusiast and a great tuning tool at the track (if they are adjustable) but in my world not used for serious roll control.
anyway, enough babbling but you have an idea what's behind our tuning philosophy. I have several Whiteline products on my EVO and we spec them on all the suspension kits we (Vishnu) sell. Whiteline=Good stuff
)...good responses all around, to Jim at Whiteline I appreciate a manufacturer that take the time to explain their philosophy, it really does help promote the brand and shows that you are passionate about what you do (these are all things that help people bust out their credit cards ). We (Joe and I) do sometimes spec larger bars for some customers but the focus of those people is the street/track compromise. It does give you more flexibility for the dual purpose car (where street ride more of a priority). For the more "no compromise" approach to absolute lap time the propotionally stiffer spring combo just plain makes more grip especially over several flying laps. They simply use more of the inside tires promoting more inside tire temp (due to the increased usage of the inside tires) and proportionally cooler outside temps (reality of course says we can just push the car/tires harder due to this and that's why it's ultimately faster longer). We also prefer having pitch dive and roll all at the same "rates" because it can be more precisely controlled by the dampers ( and we love tuning dampers and have done over 27 re-valving refinements just for the EVO!).
Bars are a simple, cheap upgrade for the budget minded enthusiast and a great tuning tool at the track (if they are adjustable) but in my world not used for serious roll control.
anyway, enough babbling but you have an idea what's behind our tuning philosophy. I have several Whiteline products on my EVO and we spec them on all the suspension kits we (Vishnu) sell. Whiteline=Good stuff
Jan 6, 2007, 09:02 PM
#26
I wish Vishnu would have come up with a COMPLETE Whiteline suspension setup. Of course, I don't know if Whiteline struts measure up to Ohlins, but I truly wish Ohlins people would have EVER just ONCE dropped in to say BOO to us, like the Whiteline folks have over just a minor product. Thumbs up to Whiteline....
Jan 7, 2007, 11:47 AM
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Paul (Chrono) is spot on in elaborating my previous post, I think we're all on the same trend here. The suspension is a system and balance (in all modes) is essential. Part of goal behind the Vishnu Ohlins kit is to allow use of stock sway bars, it doesn't stricty prohibit them, but we address each customer individually as to their uses and needs. I just love showing people how I can do pull-ups on sway bars (with disconnected end links) to illustrate what a dramatic effect lubricating (or lack of) the bushings has and the overall effect of the swaybar itself. Still, we believe the best way to promote a product is thru consumer education, help them make the best decision for themselves.
I'm glad to hear that the Whiteline ball joint kit does not drastically change the RC position, makes me more comfortable telling people it will probably work fine, without much other adjustment. It also includes the bumpsteer correction, so hey, you guys thought of everything. Still, out of a matter of principle I can't blindly endorse a product I haven't tested, but I wouldn't mind helping out someone else who will.
I doubt Ohlins will ever come on to these forums, or any for that matter. Ohlins USA is so wrapped up in Nascrap that their priorities descend from the highest paying customers. I call them relatively frequently and saw them 2 years in row now at PRI, and it's obvious that the big leagues have their attention. These dampers were only made possible by Ohlins Japan (Carrozerria) putting together a lower price set by using all Swedish internals and manufacturing their own housings. We're fortunate to have such a product from these guys and I'm reminded of that each time I deal with them. At least there is support in terms of rebuild parts and local tuners that are familiar with their product, unlike many products that come from Japan, mainly because of distance and the langauge barrier.
Thanks for the Guru status guys
Jim, yes I definitely agree, but anything in excess isn't good. I've worked on many other cars as well. On a certain nameless sports racer, the springs AND antiroll on the front were so stiff that I decided to constrain the car measure the front bulkhead deflection. Turns out that was the piece giving compliance for grip.
I'm glad to hear that the Whiteline ball joint kit does not drastically change the RC position, makes me more comfortable telling people it will probably work fine, without much other adjustment. It also includes the bumpsteer correction, so hey, you guys thought of everything. Still, out of a matter of principle I can't blindly endorse a product I haven't tested, but I wouldn't mind helping out someone else who will.
I doubt Ohlins will ever come on to these forums, or any for that matter. Ohlins USA is so wrapped up in Nascrap that their priorities descend from the highest paying customers. I call them relatively frequently and saw them 2 years in row now at PRI, and it's obvious that the big leagues have their attention. These dampers were only made possible by Ohlins Japan (Carrozerria) putting together a lower price set by using all Swedish internals and manufacturing their own housings. We're fortunate to have such a product from these guys and I'm reminded of that each time I deal with them. At least there is support in terms of rebuild parts and local tuners that are familiar with their product, unlike many products that come from Japan, mainly because of distance and the langauge barrier.
Thanks for the Guru status guys
Jim, yes I definitely agree, but anything in excess isn't good. I've worked on many other cars as well. On a certain nameless sports racer, the springs AND antiroll on the front were so stiff that I decided to constrain the car measure the front bulkhead deflection. Turns out that was the piece giving compliance for grip.
Jan 8, 2007, 07:54 AM
#29
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Thank you all VERY much for this discussion!
At first I was rather critical of the Whiteline product, but after understanding a bit more about roll center (more importantly roll center migration) I'm starting to see where all parties are coming from.
There are always some compromises with the EVO suspension setup in a lot of areas. I'm glad I got a hold of Paul and Joe (and Robbie) for an Vishnu Ohlins valving as I think that alone allows for a very large range of street vs. track usage.
One thing I always note is that the EVO is meant to have some oversteer built in, in order to help rotate the car up to its optimum yaw angle. (Help me Paul if I say this incorrectly.) The point at which oversteer starts to occur I believe Paul and team always wanted a "catchable, modifiable, and correctable" oversteer type setup for fastest lap times. I believe they have done this development very well. Of course a nice compliment to this idea is that your front end doesn't play games with you during an oversteer moment because of perhaps a front roll center problem. If the Whiteline product helps here, GREAT!
I'd be overly excited if I could see some results on this product in terms of its wearability, installation, and tuning help.
Cheers,
~j.
At first I was rather critical of the Whiteline product, but after understanding a bit more about roll center (more importantly roll center migration) I'm starting to see where all parties are coming from.
There are always some compromises with the EVO suspension setup in a lot of areas. I'm glad I got a hold of Paul and Joe (and Robbie) for an Vishnu Ohlins valving as I think that alone allows for a very large range of street vs. track usage.
One thing I always note is that the EVO is meant to have some oversteer built in, in order to help rotate the car up to its optimum yaw angle. (Help me Paul if I say this incorrectly.) The point at which oversteer starts to occur I believe Paul and team always wanted a "catchable, modifiable, and correctable" oversteer type setup for fastest lap times. I believe they have done this development very well. Of course a nice compliment to this idea is that your front end doesn't play games with you during an oversteer moment because of perhaps a front roll center problem. If the Whiteline product helps here, GREAT!
I'd be overly excited if I could see some results on this product in terms of its wearability, installation, and tuning help.
Cheers,
~j.
Jan 10, 2007, 07:16 AM
#30
A neutral car by definition makes the same grip, front and rear. Understeer has less front grip and oversteer has less rear grip. All things being equal, raising the front roll center will stiffen the front, causing more weight transfer percentage across the front (vs. the rear). This will lead to understeer. On the plus side, the camber curve is improved, meaning less positive camber gain during roll, meaning more contact patch on the ground at all times, and more grip. It might be a wash. If it's not, you will have to use softer front springs to regain the front grip. .
Would you mind giving an example of a ride height that is too low? What would be the accurate way to measure this? From the center of the wheel to the top of the fender arch, from the ground to the top of the fender arch, or from side skirts down to the ground. I've seen all methods used.