Like the title says, I’m having trouble with my PIC Select R4 suspension.

The car is a 2000 Civic 2door coupe. I have a b18c motor and total weight with me in it is 2435lbs. In the Front I have Roll center adjusters, an ITR upper tie bar and Skunk2 pro+ Camber kit. In the rear I have Blox toe kits, PCI Trailing arm spherical bearings, Skunk2 camber kit and control arms, Blox Spherical end links, ASR Brace and 22mm type R sway bar….oh and a FIA ASN approved roll cage.

I have PIC Select R4 14-18kg/mm suspension. The rear was very bouncy so PIC sent me 16kg/mm springs for the rear and its still bouncy…is it the valving for rebound that is to fast or?

I generally set 6clicks front a 5 clicks rear…what would happen if I put a 32mm rear swaybar apart from adding oversteer???

My rake (front vs rear height) is ¼" higher in the rear then the front (measuring from the jacking points), could that be my problem or is it the shocks???

Before saying it’s the tracks…I was at Mosport last weekend and it did it going into turn 1.

Cheers!

 

A swaybar won't do anything for "bouncy."

I guess maybe you're finding this out, but...high spring rates tend to be "bouncy" on any kind of rough surface. I don't know Mosport at all, but it could just be the track surface. I'm running 16K/18K springs on Ohlins shocks, and on a rough track like Gingerman or Summit, I'm bouncing all over the friggin' place.

Welcome to tracking Hondas

 

Make sure you are not hitting bumpstops. If its bouncy to the point of loosing traction, your compression is too high.

Edit: or spring rates.

 

18kg/mm is only 1000lbs/in

16kg/mm is only 895lbs/in

You shouldn't have any problems running those spring rates if the shocks are valved right.

Mosport is a fairly smooth track right? It looks that way from WC TC in car footage at least.

With my limited knowledge of valving and spring rates, i'd say the shocks aren't in a workable range for the high speed compression and rebound. Now it could be that there is to much or to little, but i'd venture that there is too much high speed valving in compression and rebound.

I have ran 1,000lbs, 1,150lbs, and 1300lbs springs and my car does not "bounce". Pretty smooth ride actually

 

I'm the Only EM1 in my series but there is 5 or 6 Integras, they all run 1200 to 1600lbs rear spring rates but they all have Moton shocks!!!!

If I reduce the compression in the rear to like 3 or 4 clicks, its doesn't bounce any more but then I have roll in the back....which is why I'm thinking of the larger sway bar???

What's a good set up for the EM1 because I'm thinking of changing setup (2000 Civic Coupe)

 

1300 in the rear, and no bounciness? What shocks are you using dude?

 

There are different kinds of "bouncy", so you should find somebody who knows how to tune suspension to ride along with you, even on the street.

 

Koni 3011


Like beanbag said. I feel bumps, but they don't upset the car and one bump is controlled by the damper.


When i hear "bouncy" it means that the suspension hits one bump and then continues to oscillate.

 

When braking at high speed and perfoming my turn in, before a pivot the weight and start rolling on the throttle, if I get a slight bump it oscillates!

I was speaking to Andy from AMR Engineer, Good guy and knowlegable!!

Any feedback on his suspension?

 

This is a long shot, but when the original poster refers to bouncing, is he referring to the kind of bouncing that would be patently obvious to someone driving behind him?

 

I guess this is where we point out that there is a reason people are running Ohilins and race Konis.

 

like beanbag said and then 93slammed stated. bouncy is a generalized term. my daily driver which is slammed "bounces" due to no suspension travel but my hatch w 12/14 rates "bounces" on bumps. these 2 "bounces" are different types of bounces though because of the different reasons behind it.

and like stinkycheesesteak stated. the swaybar wont affect "bounciness" unless you ran over a 1ft bump on one side only. lol. and someone correct my if i am wrong but isnt that 32mm asr bar hollow and equal to ~18mm solid bar?

 

Yep, if you where behind my when I'm off the throttle entering a corner, you would see my rear end bounce.

 

then i would assume your low speed valving is off on the rear shocks. *assuming smooth surface*

 

Pardon me for asking this, but who adjusted the height of the car, and are you absolutely sure he knew how to do it? Are PIC aware that the car's visibly bouncing when it is being driven?

 

Track surface, burms- are high speed valving.

Braking, accelerating, cornering- are low speed valving


As to the question of "adjusting height and the person being aware".

This is on the rear of a honda there is plenty of travel. The whole preload thing isn't going to affect anything at all.

 

Well, I thought about it some more, and it turns out that you are in luck. Since your shocks are "only" 1 way adjustable, that means that there isn't a whole lot you can do about it, umm I mean, have to do about it. This makes tuning rather easy.

What I would do is find a smooth stretch of road with a very gradual and smooth speed bump. Failing that, find a smooth dip in the road. You don't want a sharp bump because that is more influenced by your compression damping, which you can't adjust. Umm, I mean, which you don't need to adjust.

Now drive over that speed bump, at varying speeds, and see how both ends of the car react. If you drive over it slowly, that is your low speed rebound at work, and if you go over it faster (like 30+ mph) that is your mid speed damping. Adjust the damping so that the car recovers quickly after coming off the bump, with only a small amount of overshoot. That is somewhere near the magical 70% number that people keep throwing around. Try way too much and way too little damping to see what it feels like.

Find a smooth and wide section of road and try swerving. That's also mostly low speed, and some mid speed.

Next, drive over a bumpy section of road (with sharp edged bumps) at moderate to high speeds. That is your high speed damping at work. Again, try turning the damping up and down to see how that feels. If you like different settings for the smooth bumps vs sharp bumps, then you should change the digression of your dyno plot. Looking at the PIC dyno plots, it looks like the **** pretty much only adjusts the low speed portion of the curve, so if you like more low speed damping, then you should get valving designed for softer springs and use the stiffer range of the adjusters, and vice versa.

I saw in one of your posts that you were using damping to control roll. That is what a sway bar is for. It sounds to me, then, that you have the "overdamped" bounce, which comes from jacking down. Maybe you should stop caring about roll so much and tune your dampers for traction and chassis control.

 

How/why does the speed of the car have any effect on if the valving issue is high, mid or low speed?

 

I just wanted to make sure that the height adjustment had been performed by someone who knew how to do it. If this is someone's first chassis adjustment then it's possible to adjust them so incorrectly that the car will be bouncing even in normal driving on the street.

I've seen this happen, and I know it's a remote possibility.

But having seen it, my mind went there.

This writer was not referring to preload as much as he was referring to the remote possibility that the rear spring and height adjustment was performed entirely incorrectly. Neither did I want to come out and say that directly.

I'm not pretending to be any kind of expert. :-)

 

I am a private team with some sponsors backing me up. I have a decent Engine tuner, a great mechanic but no one for my suspension tuning. My Mechanic does the alinment to what ever I tell him. (Generally Front camber -3.0 to -2.7 toe open 0.20 Rear cmaber -2.0 to -1.7 with neutral toe in the back) As for height, we never played with the rear hieght....how do you set it properly???

I spoke to my crew, the bouncing is when I performe hard braking (I guess the *** gets light) and the bouncing countinues into my turn it but it stops when I get on the throttle and set the car!!! Could that be the rake of my car (rear being slightly higher the the front) or is it the shocks??? I'm using GSR Brakes, brembo rotors, hp Blue or 14s for the front and hpplus in the rear (Type R master and booster...I'm not allowed bigger brakes)

 

Mosport is bumpy and thus "bouncy". It is old and in need of re-paving. That doesn't stop the ALMS cars from running stupid fast though. When I run there with my ITR and 850F/1100R springs, car is quite a bit less settled than with same setups on smooth tracks. I would guess it is the dampers, and might actually have to soften the springs as well.

Optimal setup varies a lot depending on track smoothness. On a smooth track you can run very stiff springs and dampers, but when things get bumpy, you might need a little less support from the dampers. It is a lot harder to get a good setup on a bumpy track.

 

I just spoke with the boys from PIC and they are sending me the proper shock to go along with the 16kg/mm springs that they sent me last year!!! (I hope the valving of the shock that was made for their 18kg/mm that I was using was the problem)

I will also remove the ITR 22mm sway bar and install the 32mm ASR bar!

I'm not using any front sway bar but I do have the 99-00SIR one (SI model in the U.S.)
Is it 24 or 26mm??? I'm not sure if I want to put it on because I like a little more oversteer?

I am very curious on how to properly set ride height?

Thanks to everyone!!!

 

Because the faster you go, the faster the suspension needs to move to follow the road. In the case of the smooth speedbump, the faster you go over it, the harder the car gets "slammed" into the ground when you come off of it, and thus the suspension gets compressed more, and thus springs back harder, thus going to higher velocities.

 

Shocks do not change your amout of roll, only the rate of roll. That is controled by the rebound setting if the inside dampers. Your springs and bars adjust your amount of roll. You are using the shocks wrong, you are probably "jacking the rear down" with to stiff a setting.

 

Both bump and rebound affect the rate of roll in and out of a corner, and it is the low speed part of bump and rebound that are in action.

At the entry of most corners, the nose has come down due to braking, and thus both front dampers are compressed and both rear dampers are extended at corner entry. Once you start cornering, the inside front begins to extend (low speed rebound) while at the exact same time the outside rear begins to compress (low speed bump) until you get to steady state cornering, with both outside dampers compressed and both inside dampers extended. So weight first transfers to the nose making it go down under braking (low speed bump for both front dampers and low speed rebound for both rear dampers), and then weight transfers diagonally from the inside front to the outside rear until the dampers stop moving and thus stop controlling rate of roll, since roll is controlled by the springs and anti-roll bars, and not the dampers, as said above. After the apex, since the outside front is already fully compressed, it must extend (low speed rebound) and the inside rear must start to compress since it was fully extended. and thus on corner exit weight transfers across the diagonal from outside front to inside rear. A while after the apex, as lateral g's come down and longitudinal g's go up, weight again transfers diagonally but this time along the original corner entry diagonal, in the opposite direction to corner entry, and slightly delayed to the weight transfer across the diagonal for corner exit weight transfer (outside front to inside rear) In order to get the car back out onto the next straight and to a flat attitude, the outside corners have to compress (low speed bump) and the inside corners have to extend (low speed rebound), and the car will squat some due to acceleration and weight transfer to the rear, and thus the rear dampers will be compressing more at corner exit while the fronts extend a bit. However unlike under braking where the nose goes full down every time due to 1g braking regardless of corner apex speed, the apex speed of the corner determines the amount of squat under acceleration since you cannot accelerate quickly out of a high speed corner compared to a low speed corner. So the dampers will be moving at different speeds depending on whether you are coming out of a slow (fast damper squat) or fast corner (slow damper squat). It is a common fallacy to think that only one direction of damper motion (bump or rebound) is involved in cornering.

At corner entry, with the nose already down, only two dampers are moving, while at corner exit all four dampers are moving.

Charts below were made from data generated by Lapsim for a relatively fast right hand corner at the end of a long straight, and show the various phases of the corner with damper shaft position and damper shaft velocities, assuming perfectly smooth track. Notice that there is no damper velocity above 50 mm/sec or 2.0 in/s, and most of the action is below about 30 mm/sec. If you double the roll stiffness with bars and springs, the damper velocities will drop by half since the damper travel will be half as much in about the same time for the corner.