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Low grip tires... a better way to improve?

2 and 3 are more likely.. I tracked the z1 with almost to the cord in wet/dry condition before... I didn't noticed any loss of grip when the track is dry.... it was quite scary on my 6 hour drive back in freezing rain though.

I agree. Z1s will wear to a harder compound right before they cord, and they aren't as grippy then, but if you can still see any hint of tread pattern, they're fine. In fact, the "greasiness" might even happen less when they are at the wear bars vs. when they are new due to less tread squirm (i.e. the tread blocks themselves deflecting under load).
 
I've got an ae86 corolla gts with a 2-way clutch type LSD as my daily driver and every one in a while track car. I will say that getting the back out between one to the other are as polar opposite as can be. Im used to steering with the throttle but its a whole different feeling in my NSX. Lift off oversteer is the obvious killer in this car. There have been circumstances where Ive found myself going to fast into a corner and lift, not all the way off but just enough to lighten the rear and feel the car start to rotate. And as CL65 said its all about feeling the unloading and catching it early and quickly. On the other hand power with power oversteer its pretty similar to any other rwd car but you've got to work in a much shallower angle to maintain it and not have to deal with the severe 'crack back' of the mid engine.

You can see in this video theres a bunch of circumstances where I am getting power on oversteer. (0:50, 1:51, 2:00-2:07 3:46 4:53) and then liftoff oversteer at 1:33 and 2:18

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Also here at 1:46 is a perfect example of the load induced oversteer that the rear non comp stuff helps to eliminate. This was before I installed mine and was running on r888's that being said ive never actually gone around.

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Oh hell if you want to pick up a ton of terrifying experience, definitely throw some crap tires on. Make sure it's at a track with no walls or obstacles to hit.

For entertainment factor I did this with DZ101's. They have really weak sidewall and very low grip. Felt like I was carrying a swimming pool in the trunk. I spent 3/4's of the time correcting. That was fun and scary at the same time.

Just don't run them on the street, it's too dangerous.
 
greatly increased rear chassis stiffness (which I believe may had a similar effect as having a larger rear sway bar??).



not completely similar.. the beefier the rear sway.. the less independence your suspension has...

think about how a sway bar connects to your spindle...
 
not completely similar.. the beefier the rear sway.. the less independence your suspension has...

think about how a sway bar connects to your spindle...

I understand that the way & method a rear swaybar contributes to oversteer would be different than how a rear strut bar would. However I guess what I'm asking is: "is the effect of a slight increase in oversteer to be expected from installing a STMPO RSTB?"

I mean, I understand that the main purpose of the RSTB is to increase rigidity in the overall body (not so much affect handling), but since it's over the rear towers it would seem it would increase rigidity in the rear of the vehicle. Therefore, I was theorizing that the increase in rear rigidity would have a secondary effect on the handling (namely, slightly increasing oversteer).

Just wanted to get your thoughts on this Ross, since I have your RTSB and love it so far!
 
not completely similar.. the beefier the rear sway.. the less independence your suspension has...

think about how a sway bar connects to your spindle...

I understand that the way & method a rear swaybar contributes to oversteer would be different than how a rear strut bar would. However I guess what I'm asking is: "is the effect of a slight increase in oversteer to be expected from installing a STMPO RSTB?"

I mean, I understand that the main purpose of the RSTB is to increase rigidity in the overall body (not so much affect handling), but since it's over the rear towers it would seem it would increase rigidity in the rear of the vehicle. Therefore, I was theorizing that the increase in rear rigidity would have a secondary effect on the handling (namely, slightly increasing oversteer).

Just wanted to get your thoughts on this Ross, since I have your RTSB and love it so far!

My nose doesn't belong in this conversation but it's a slow work afternoon.

I think you're comparing apples to oranges when thinking about stiffness of the chassis vs. tortional rigidity of the sway bar. A stiffer chassis will make the behavior of your sway bar more predictable. If you incorporate chassis flex into the equation then it's another dimension of uncertainty and it may or may not contribute to increase or decrease of oversteer - I think it will simply make it less predictable where high chassis flex = high unpredictability. A stiffer chassis cuts down your unknown variables in terms of what you're suspension is doing.

I think of it this way. Imagine if the top of your coilover mount is floating (because of a loose chassis). For every inch of compression the shock incurs you have say 1/8" of movement on that top mounting point. This may be 1/4" of movement at higher loads in a turn and less while hitting bumps. Let's now incorporate the twist the chassis experiences between the front and rear axles. The harder this twist the harder it will want to snap back into place while it unloads on itself. It's a mess. So stiffer chassis should lessen the amount of flex to such things.

I'm not an engineer so my terminology is likely incorrect. Anyway, now back to my crack pipe!...
 
I think of it this way. Imagine if the top of your coilover mount is floating (because of a loose chassis). For every inch of compression the shock incurs you have say 1/8" of movement on that top mounting point. This may be 1/4" of movement at higher loads in a turn and less while hitting bumps. Let's now incorporate the twist the chassis experiences between the front and rear axles. The harder this twist the harder it will want to snap back into place while it unloads on itself. It's a mess. So stiffer chassis should lessen the amount of flex to such things.

I'm not an engineer so my terminology is likely incorrect. Anyway, now back to my crack pipe!...

This all makes sense to me and is exactly what I've been saying. What I believe is happening is that the increased strutural rigidity in the rear allows the forces on one side of the car to be more easily transfered to the opposite side of the car. A sway bar does this by directly tying the suspension components on one side to the other. My theory would be that the rear strut tower bar (specifically the STMPO RTSB, which is significantly stiffer than the OEM one) would do something similar by not allowing the rear chassis to "flex" where instead of the forces causing the car to flex, they would be transferred to the opposite side of the vehicle to be absorbed by the suspension. Of course this would be just a "secondary" (or for some and "unintended") effect of the bar and not it's primary purpose.

I found a few animated gifs from here that show the role of Strut bars:
http://www.ultraracing.my/template.asp?menuid=30

strut-bar-before.gif
strut-bar-after.gif


Then going into corners:
strut-bar-corner-before.gif
strut-bar-corner-after.gif


The website states this about their "rear strut bars"
http://www.ultraracing.my/template.asp?menuid=03
UltraRacing said:
The Rear Strut Bar is particularly useful for an FF vehicle. The Understeer behavior can be corrected by stiffening the rear chassis by installing a Rear Bar.
^I am assuming the understeer correction effect would be similar in the case of the STMPO RTSB.


In contrast & for reference, here's the Anti-Roll bars:
anti-roll-bar-before.gif
anti-roll-bar-after.gif
 
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your both correct and thats a pretty cool way to explain it... the jpegs I mean

I wouls add.. a sway bar pulls from the side with load = why I said the beefier the bar - less independance on the suspension
 
I just had my first drive in my car since I installed my KW competitions, 1000 front springs and 600 rears. I was expecting a VERY harsh ride. Frankly, I am in shock. I think at least on the highway, the car rides BETTER than stock. I know that sounds nuts, but it is very very smooth. I have not yet played with the compression and rebound settings, but as is (definitely not full soft) the ride is incredibly compliant. Took a few turns and twists, and the car is just not the same NSX. I was FLYING around corners and it felt incredibly stable and unstressed, felt like the car was laughing at me... saying "is that all you have?". I am so surprised. BUT...

Now I feel the chassis flex more. I have the STMPO FCB, but I really need to so something fairly significant to tighten things up. In all my readings about people upgrading to coilovers, etc... no one mentioned that at least on targa cars, the chassis flex increases as the suspension stiffens. Doesn't anyone else notice this? :confused: The car still feels amazing but I can see the weak point has shifted.

I am still on stock rear sway and R front sway bar. I waited on going to thicker track bars, although billy recommended a 1.25" dali trophy bar. I really like the car now... and am afraid I might lose some independence and ride comfort. That's a massively thick bar. Is that going to make the chassis flex more?

Ross I am going to need your help with some chassis work.
 
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For the street, try leaving the compression where it is and just reducing the rebound on all four and go for a drive. :wink:
 
I don't have any personal experience but in all my bench racing/reading it takes special equipment or a professional driver to be able to adjust both the rebound and compression properly. If Billy gave you a baseline on compression leave that be and only mess with the rebound as the Captain said.
 
I don't have any personal experience but in all my bench racing/reading it takes special equipment or a professional driver to be able to adjust both the rebound and compression properly. If Billy gave you a baseline on compression leave that be and only mess with the rebound as the Captain said.

The only special equipment needed is a stopwatch. :p

sent from my crappy cell phone.
 
I kind of baseline tuned my suspension at the street just by driving around. drive some bumpy roads vs highway, n make some turns.. you should be able to tell if you are comfortable with the compression (generally harsher as you stiffening up) but rebound will take a little bit more patience.

other than that, Koni website has a good read and I found it very useful.

copy and paste from there:
Suggested Adjustment Procedure for Road Course Use

Adjusting the Compression (Bump) Damping Control



Bump damping controls the unsprung weight of the vehicle (wheels, axles, etc.). It controls the upward movement of the suspension such as hitting a bump in the track. It should not be used to control the downward movement of the vehicle when it encounters dips. Also, it should not be used to control roll or bottoming.



Depending on the vehicle, the ideal bump setting can occur at any point within the adjustment range. This setting will be reached when "side-hop" or "walking" in a bumpy turn is minimal and the ride is not uncomfortably harsh. At any point other than this ideal setting, the "side-hopping" condition will be more pronounced and the ride may be too harsh.



1. Set all four dampers on minimum bump and minimum rebound settings.

2. Drive one or two laps to get the feel of the car.
NOTE: When driving the car during the bump adjustment phase, disregard body lean or roll and concentrate solely on how the car feels over bumps. Also, try to notice if the car "walks" or "side-hops" on a rough turn.

3. Increase bump adjustment clockwise 3 clicks on all four dampers. Drive the car one or two laps. Repeat this step until a point is reached where the car starts to feel hard over bumpy surfaces.

4. Back off the bump adjustment two clicks. The bump control is now set.

NOTE: The back off point will likely be reached sooner on one end of the vehicle than the other. If this occurs, keep increasing the bump on the soft end until it too feels too hard. Then back that side off two clicks. The bump control is now set.



Adjusting the Rebound Damping Control
Once you have found what you feel to be the best bump setting on all four wheels, you are now ready to proceed with adjusting the rebound damping. The rebound damping controls the transitional roll (lean) as when entering a turn. It does not limit the total amount of roll; it does limit how fast this total roll angle is achieved. How much the vehicle actually leans is determined by other things such as spring rate, sway bars, roll center heights, etc.



It should be noted that too much rebound damping on either end of the vehicle will cause an initial loss of lateral acceleration (cornering power) at that end which will cause the vehicle to oversteer or understeer excessively when entering a turn. Too much rebound control in relation to spring rate will cause a condition known as "jacking down." This is a condition where, after hitting a bump and compressing the spring, the damper does not allow the spring to return to a neutral position before the next bump is encountered. This repeats with each subsequent bump until the car is actually lowered onto the bump stops. Contact with the bump stops causes a drastic increase in roll stiffness. If this condition occurs on the front, the car will understeer; if it occurs on the rear, the car will oversteer.





1. With the rebound set on full soft and the bump control set from your testing, drive the car one or two laps, paying attention to how the car rolls when entering a turn.


2. Increase rebound damping three sweeps or 3/4 of a turn on all four dampers and drive the car one or two laps. Repeat this step until the car enters the turns smoothly (no drastic attitude changes) and without leaning excessively. Any increase in the rebound stiffness beyond this point is unnecessary and may in fact be detrimental.

EXCEPTION: It may be desirable to have a car that assumes an oversteering or understeering attitude when entering a turn. This preference, of course, will vary from one driver to another depending on the individual driving style.
 
Well I have two compression settings, and most stuff I have seen only talks about one. I have high speed and low speed. I'm going to have to do a lot of reading, I am not sure I quite understand the difference between the two. I read somewhere to throw a 4th element in, you can even play with the PSI in the cannisters. Thank God for Billy's baseline or else I would screwed right now. LOL... I will play with rebound and not mess with low or high compression per your recommendations. I can always go back. Got some reading to do first. :tongue:
 
NSXDreamer2 - What suspension setup are you running anyway? Just curios..

Koni 2812 with comptech pro hardware... I loved the setup except the knocking noise from the ball bearings on highway joints. I personally have not driven JRZ or moton setup on nsx so I can't really compare.
 
I'm not sure all the folks posting know that your setup is a triple adjustable uber expensive competition version.....you will need to do some reading and befriend a good race shop.
 
I'm not sure all the folks posting know that your setup is a triple adjustable uber expensive competition version.....you will need to do some reading and befriend a good race shop.

This is exactly why I'm very happy with my KW V3's...no race shop needed, just Billy, Coz, you guys and my driving skills.
 
This is exactly why I'm very happy with my KW V3's...no race shop needed, just Billy, Coz, you guys and my driving skills.

V3's are for wussies... :biggrin:
 
Well now...I don't post all over Prime about being scared about tracking my car...:wink:

I wrote you a nasty reply then saw that you had a silverstone and I deleted it. I'll let you have one... :tongue:
 
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