trhoppe

Below are the front and rear dyno charts of the Whiteline Group4 coilover shock that we were planning on putting on the ESP STi. We wanted to run a 12K front spring and 10K rear spring to start off with, and maybe revalve and go up from there. Will these shocks handle that spring rate?

I've read on here about the digressive valving of the Koni shocks and notice that these do not have that. What does the digressive valving do and why is it better? CRX_Lee, this is your opportinity to talk us into a set of Koni's with coilover sleeves instead of this setup

Front


Rear


Thanks for any help.
-Tom

MechE00

until Lee gets to this thread, I'll chime in with my understanding of the force/velocity curve.. basically, you want the shock to damp the oscillations of the chassis and the unsprung mass. Due to the high mass of the chassis it is unlikely to have any desire to oscillate at high frequency/speeds (the simple formula is resonant frequency = (spring rate/ mass)^.5.. the higher the mass, the lower the resonant frequency.. So gobs of force from the damper at high frequency isn't helping control the chassis -- it's mainly just transmitting more of the road's jolts through to the chassis.

As for also controlling the unsprung mass, even though that mass is usually quite a bit lower (so the frequencies you want to control are likely to be higher), the lower mass means you need less force to control it.

Someone let me know if I'm spewing crap.. or not making sense..

I don't know enough specifics to say whether that's enough damper for the rates you want.. and I'm too lazy/busy right now to check into that..

edit: fixed formula/smiley problem..

vtecvoodoo

From what I see, I`d get the Koni`s.

rice r0cket

[hijack]Does someone have a link to CRX Lee's other shock dynos that he performed earlier?[/hijack]

They'd be good for comparison...

Markus

Hey Tom -

Just to chime in with what I read elsewhere, CRX Lee has a busy couple of days. He just got done crewing at the 13 hour enduro and is going to SEMA. So - give him a day or two to respond and I'm sure he'll have a great analysis and some good info, seems like that guy always does.

- Markus

solo-x

just some wag's here, but i'd say that there is insufficient low speed damping (your handling damping) and WAY too much high speed damping (your ride damping). some revalved koni's would be better. some custom valved 3012's would be 'da b0mb, y0! personally, i'd be looking into either the koni's or some penske/jrz/moton setup. eh, i take that back. i wouldn't look past koni, but other people aren't quite as biased as i am.

the nice part about digressive valving is that you can have a LOT of low speed rebound/bump (relatively speaking here) to get the car to be responsive while at the same time have the shock "go soft" when you hit a big bump, letting the suspension deflect and absorb the bump, rather then transmit it all to the chassis. the dyno plot you show is not that inspiring in my book.

nate

trhoppe

I'm not in a hurry, so I'll be waiting for Lee's response. I love the support of Koni and would love to try Konis, but from what I have heard, the revalved 3012s would be cost prohibitive compared to these whitelines. What would a set of the 3012s run me?

I've been doing a little research today about the linear vs. digressive and I can see what you are saying Nate.

I guess what I want is enough compression dampening to handle the 12k/10k springs, which these might or might not have, but then a lot more low speed rebound and about the same high speed rebound, which I guess is what the digressive curve allows you to have. Am I right in saying that with the linear rebound curve, if I got enough low speed rebound to have a responsive transition car, the high speed rebound would be HUGE and the car would suck on bumps?

-Tom

TeamSlowdotOrg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trhoppe &raquo;</TD></TR><TR><TD CLASS="quote">Am I right in saying that with the linear rebound curve, if I got enough low speed rebound to have a responsive transition car, the high speed rebound would be HUGE and the car would suck on bumps?

-Tom</TD></TR></TABLE>That's how I see it. Have you talked to Mikey about his Konis lately?

bender

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stealthx32 &raquo;</TD></TR><TR><TD CLASS="quote">[hijack]Does someone have a link to CRX Lee's other shock dynos that he performed earlier?[/hijack]

They'd be good for comparison... </TD></TR></TABLE>

you mean civic & scca slide shows?
http://www.koni-na.com/tools/

trhoppe

So is this why the JIC's are **** on the street but good on track? They have enough low speed dampening to control transition, but a linear curve with too much high speed dampening gives them a crappy ride?

Now that I checked out some of penske's material, it seems like these would not be good for autox or track. They would work on the street where they would have a softer ride, but not control enough on transition for something like autox, where low speed rebound is important to keep the transitions good, but you can't have too much high speed as the car will be skittery on bumps....

-Tom
getting smart4r on shocks

solo-x

yeah, 3012's are not cheap. major :drool: factor though.

i forgot about mike's car. rich has a good idea there. find out what superman was using for valving in his shocks and work with koni from there. mike's car definitely was very composed over the bumps in topeka.

nate

solo-x

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trhoppe &raquo;</TD></TR><TR><TD CLASS="quote">So is this why the JIC's are **** on the street but good on track? They have enough low speed dampening to control transition, but a linear curve with too much high speed dampening gives them a crappy ride?

Now that I checked out some of penske's material, it seems like these would not be good for autox or track. They would work on the street where they would have a softer ride, but not control enough on transition for something like autox, where low speed rebound is important to keep the transitions good, but you can't have too much high speed as the car will be skittery on bumps....

-Tom
getting smart4r on shocks</TD></TR></TABLE>

yes, and yes.

nate

ryan12321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">yeah, 3012's are not cheap. major :drool: factor though.
</TD></TR></TABLE>

You can find them just have to look in the right places. Just last week I saw 2 on ebay for $400 and there are still 2 more on scca forums for $500. Also saw a pair of 28 series on ebay for $500.

trhoppe

Ok. so what is "not cheap"

Another idea I came up with after IMing chris hartman was to run cheaper SA's on the front and go for the DA's on the rear.

Valve the SA's on the front with enough compression to control a 12K spring, and a good digressive curve with lots of low speed rebound but not as much high speed. Then I can adjust the rebound for the cars attitutude on turn in or the front wheel attitute on turn out.

The rear would be DA with the correct compression to control a 10K spring set as the middle of the compression adjustment. Then I could set it softer or stiffer to adjust the car's attitude on turn out, as the STi is more like a RWD car on corner exit. The rebound adjustment would be the same style as the front, with good low speed rebound and not much high speed, but a good low speed adjustment range to let me adjust the car's attitude on turn in.

Hmmmmmmm...

-Tom
learning more every minute

trhoppe

Oh, something like that is totally within my price range.

I don't want to pay more then $400 a corner for SA's or $700 a corner for DA's. Thats why the SA front, DA rear idea might work as we wanted to have a $2500 budget for the shocks + springs. Is that feasable?

-Tom

krshultz

Tom, I paid I think $100 a shock to get my singles revalved. Assuming a street price of 150 for the new shock you're at $250 a corner, well within your budget and I'd say you now have one of the best shocks you can get for anywhere near that price.

As to getting them converted to doubles in the back, I wouldn't think more than a couple hundred bucks tops per shock. But I'll let our man Lee talk to that.

solo-x

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ryan12321 &raquo;</TD></TR><TR><TD CLASS="quote">

You can find them just have to look in the right places. Just last week I saw 2 on ebay for $400 and there are still 2 more on scca forums for $500. Also saw a pair of 28 series on ebay for $500.</TD></TR></TABLE>
the ones i saw on sccaforums.com were just a bare shock with generic shock mounts like what you'd see on a formula type car. i'm not sure how accurate my price information is, but i beleive the 3012's are roughly $500 a corner PLUS fabrication work to fit them to your car. take that with a huge grain of salt though. obvsiously lee will have a more accurate idea of pricing.

the cost to get my rear shocks converted to DA according to lee out at nationals was roughly $375/corner. there is a lot of machine work that goes into it. koni does make an insert that is already DA, the 8612 i beleive. i was under the impression that superman was using revalved 8612's on his car, but i could be wrong.

nate - hopes to be SA front/DA rear next year...

trhoppe

According to their catalog thats the 8611. The external double adjustable insert. I was under the impression that mikey was using a fully built strut, as he had to sent his in to get measured. In the motorsports catalog there is the 87 series, which is a full strut housing. There is no subaru application for that, but I guess thats what they could have done for mike. Hopefully, they will be able to replicate that for this car.

Edit: Spoke to Bill from Sojax. Mike definetly received 4 fully built ready to go DA struts with threaded coilover sleeves from Koni. The "guess" was $2000 for all 4. We'll see the real #s when Lee chimes in. I would still like to get his opinion on this whole thing.

Thanks for the help so far guys!

-Tom


Modified by trhoppe at 9:45 PM 10/27/2004

solo-x

in this thread lee mentions being at SEMA for the next week, so it might be a little bit before he chimes in like some others already mentioned.

nate - no catalog, working from very poor memory, sorry!

WRXRacer111

I don't remember the exact number, but I believe Truechoice was quoting around $3000 and 2 months lead time on a set of DAs with custom valving . Did you try plotting the dyno curves against the Teins?

CRX Lee

Greetings all. I am actually still in town for a few days pre-SEMA but am hosting Dutch bigwigs so I am getting little time to breathe or really accomplish anything.

Looking at the graphs you have posted, my intial thought is that you need to make sure which part you are looking at to keep it in perspective because the piston speeds shown get pretty high into speed ranges where the car may rarely get, especailly in autocross. We normally run our graphs with .33 meters or 13 inches per second as the high ends whereas this graph has that point (300 mms) down in the bottom half. At that point, it has about 700ish N of bump and rebound range of about 1700-2300 N. Of note as mentioned is that this is an extremely linear valving on both bump and rebound with no low speed at all to speak of. In this case, in the really lower piston speeds that an autocross car would be, I would think this car is going to roll quite a bit as the dampers will have little control at low speed on rebound and minimal support on bump. It may be a bit wallowey and not sharp in subtle motion so it may need extra support from springs and bars there. In short, it isn't really adding much for the cause and is pretty much just along for the ride. Those numbers aren't very high either for spring rate control either to speak of but without more info and no driving I wouldn't go as far as to say that they won't "handle" the spring rate. Just that they aren't really contributing much and generally could be likened to a low tech, not particulalry sophisticated internal. There is no effort at all to make low speed motion control which is really what an exercise like autocross is all about.

Also, it is rebound and not bump that is needed to be increased when the spring rate goes up. Mike King is indeed on custom double adjustable struts that we made out of factory strut housings. The problem is that to make them, it takes so much time and effort that even at a quite high price, we really can't charge enough to cover our efforts. As much as I hate the situation, we have been forced to stop doing there "wet kit" strut conversions because of their inefficiency. It might take one man 30+ hours to build one set of wet DAs and we just can't charge for all that time. I think Truechoice will continue doing wet kit struts but we have had to suspend doing them in our shop as it just really slows down productivity on all orders. I don't like it but it just doesn't make business senseto clog the shop up with orders that you can't really charge properly for based on time invested. We are looking for options including making changes to our 8611 DA insert line to pick up the slack.

We can revalve the Koni Sport insert offering for the WRX but -ea-strut installation retaining bolt eliminates the opportunity to make the double adjustable. I was just talking with the Dutch today about wishing to have a more flexible option on struts and specifically mentioned the WRX as a hot topic but that one is a definate uphill climb.

BTW, great shock that the 3011/3012 is, there is no strut version of it although I would love to make a way to do one and it will be one of tomorrow's topics for the Dutch meetings.

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">yeah, 3012's are not cheap. major :drool: factor though.
</TD></TR></TABLE>

3011's are cheaper

If you add up what you spent on your Koni Yellows..... compare to 3011's...

whitney

Is rebound on the bottom and compression on the top of those graphs? If not, it seems crazy to me for compression to be higher than rebound.

I believe the convention is that negative force is rebound, no?

But I, just like Tom, am not a guru and I am learning.

whitney

These two charts from the KONI site are very informative. Doesn't give any insight to the curve shape, but it did help me to better understand the difference between compression and rebound and how to use them:

From "SCCA Shock Seminar" on http://www.koni-na.com/tools/:
(CRXLee - if it is verboten to be linking these pictures let me know and I will remove them)

PseudoRealityX

Tom, you can do whatever fancy shocks you want, but I'll tell you one thing...

You're mine in the SuperChallenge Final

Will the 8611 DA inserts work with the WRX strut bodies? Seems like a good solution, and not terribly expensive if you want to go that route.