Wheather or not a shock is on a race track or a street ....it acts the same. Bump and rebound arel about controlling the timing timing.slowing donw or speeding up the allowable spped of a shock. It doesnt matter if it is at Silverstone or highway 71 North.
A bump in the road is a bump in the road.

High speed and low speed bump are two differnt settings but in the same direction...compression..it just relates to how fast it lets the shock travel when compressed.

EXAMLE
high speed bump= the shock body moving at 1000 mps per inch
low speed bump= anything under that

Koni softened the compression for two reasons.....they are trying to generate less inside rear wheel spin in cornering by giving the rear more grip by transfering more weight to the rear quicker.....2nd there is too much wind up in the OEM rear upper control arms bushings....this excesive wind up in the bushings acts like spring rate...combined with the valving found in the OEM shocks= Bounce

If you have a shock with softer compression and softer rebound you will can have the same effect= no shock control and it will fell like your just riding around on springs.
The theory behind the Konis where they are now is a little softer compression= letting the car compress a little quicker and more rebound which keeps the rear from popping back up so quick.

 

Low speed damping controls the chassis (high mass).
High speed damping controls the wheel (low mass).

Lots of low-speed compression damping will help with transients (like fast turns) because it'll help hold up the car. Too much will make the car jittery (what we're seeing). Too much high-speed damping will make the tires skittish over rough pavement.

I believe a 2-way adjustable shock will have compression and rebound adjustability. High- and low-speed damping will be adjusted together. A 4-way shock has low- and high-speed adjustability for both bump and rebound. Don't ask me about 6-way...

I have a vague memory that the Koni yellows on my Supra are adjustable for bump, but I could be wrong.

At least that's what I think.

Asterix

 

BJ,

What were the changes Koni recommended you try to further eliminate the bounce? Have you had a chance to do this? I know you've been sick. Just thought I'd ask. My personal perference would be that you get the handling right & take care as much of the bounce as possible with just the Konis, 350Evo sways & maybe the bushings. Many people that buy this setup will not be changing springs too. Springs will just add another piece to the puzzle as well as lower the car which many here don't want to do. I won't lower the car any more than what the NISMO S-Tune lowers the Z. Just my 2 cents......

 

We are looking at doing a performance spring package with the Konis or the SACHS when they come in. This would be with new spring rates....not progressive springs. Its just on the drawing board. Been too busy taking orders and all the other stuff around here and plus we are super busy trying to get the race car ready for Daytona in 3.5 weeks.

 

BJ and others, thanks for defining the meaning of low-speed and high-speed. Very helpful. I love these forums. So much to be learned.

BJ, from your quote up above, you say EVO is considering putting together a full suspension package? Would it be safe to assume the package would have these features:

1) shocks
2) springs
3) front and rear swaybars
4) stiffer bushings
5) all of this properly tuned and set to EVO's recommended settings

That last bit is complicated, of course. As you said earlier, different tracks/courses/roads might require different setups.

This brings up a neat idea. When/if EVO finally releases an adjustable kit like this, how about you guys have a section on your website (or this website, or anywhere) where you post the settings you have found to be optimum on different tracks, situations, etc. For example:
1) Buttonwillow settings
2) daily street driving settings
3) autocross settings
4) Thunderhill settings
5) drag racing settings (not my thing, but it appears lots of people here are into that)
6) etc, etc, etc


I like the idea of this. Even though I don't want to figure out my own tuning, I wouldn't mind making adjustments for different situations provided the adjustments are relatively easy to do and have already been tested and determined to be good settings. I only say "easy to do" because I don't have a garage to work in. While I'm perfectly happy to work on my car, I'm limited by where I live, so adjustments need to be doable without a garage. Something I can do out on the street in front of my apartment.

 

Now Koni themselves lets it be known what they feel a given strut aplication can be run up to when increasing spring rates. You reach a certain level of deminishing returns since they don't have compression adjustability, rebound adjustments only work things to a certain degree. It has been my personal experience that Koni SA's are happiest at levels below Koni's peak spring rate allowances, I found springs around 25% stiffer worked best and any higher could not offer proper control levels with simple increases in rebound control. I know you'll test and test things, I'm urging that proper dampener control issues are watched like a hawk. That being said, I LOVE the idea that your looking to market linear sport springs. Please look into slightly taller versions for G35 sedan owners so you can hit the sedan market to, as coupe and Z spirngs applied to the sedan lower the sedan more and would likely find the sedan running to low. To help you, stock Z springs lower the sedan 7/8" front and 1 1/8" rear, keeping that would be great. If their is any data or demension info that I can provide in that respect please ask, I'll try my best to provide.

Regards,

Jim C.

 

Good explanation BJ. That's why the Z rides better with a full tank of fuel. What other things did Koni recommend you try to take more bounce out? Had a chance to play with any of settings?

 

no but i got ballpark pricing!!!!!!!!!!!!!!!!!

and i think you will be happy!

 

Well out with it!

Stock suspension -

Konis or S-Tune -

 

BJ,

Got any pics yet of the Konis installed?

 

 

BJ, How about some pics of the Konis installed.

 

BJ, Did the part every come in from Koni?

 

If you have a shock with softer compression and softer rebound you will can have the same effect= no shock control and it will fell like your just riding around on springs.
[/B][/QUOTE]

Is this why the stockers feel like they bounce/travel about 6 inches on an newly laid asphalt highway thats a little wavy? Any decent shock/strut should just even out the ride, right? My car bounces in what feels like a very short travel that is both irritating and uncomfortable. It does not stop until you get on another surface and then I get crash, bounce(big) and crash some more. The Konis need to correct this behavior, first and foremost. If they do this, I will buy them and consider other upgrades later.

BTW, my wife and I just broke in her new Acura TL on a 3 day trip to NW Arkansas. I bought the 5AT w/o Nav and everything else, incuding DVD-Audio and XM radio is part of the basic pkg. What has this to do w/shocks/struts? Sport Sedan firm, but excellent ride on all surfaces from Central OK to NW ARK and down state to I40 and west toward OKC. When we crossed into OK., the ride began to deteriorate on several sections on a county by county basis going west, even with the Touring setting on the TL. The Konis have their work cut out for them on our roads, but anything is better than stock, IMO.

 

Well, I am going with the S-Tune. Thanks for the useful info on this thread though!

 

Give us a full report once it is installed.

 

But if course! Jan 2nd.

 

How much will you be paying for the S-Tune, parts and labor?

 

 

Boomer,

My best price is $1750 parts + $509 install = $2259. I can do the Konis + 350Evo sways + 350Evo install = for a lot less!