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Joe Ricard |
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#1
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CUMONIWANNARACEU ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 ![]() |
So now I see the MAJOR difference from Koni red externally adjustables versus the new Koni yellow sports.
Both are only adjustable in rebound. So what is it that is actually happening and what is the theory behind slower (firmer) shock dampening on handeling of the car. The way I see it acceleration causes weight transfer to the rear of the car (if it gets to sliding mash the gas) squats the rear end and compresses the shock. mash the brake and weight transfers to the front compressing the front and lifting the rear. Does the more dampening you have slow the weight transfer? I know spring rates further complicate the whole thing. So what I noticed/discovered was the effect that moving from 17mm to 21mm torsion bars and new Koni's in front reduced the nose dive under braking and somehow reduced the unloading of the rear wheels. Rear shocks Koni reds externally adjustable were full firm as always. fronts we set to 1/4 from full soft. seemed pretty good so we just left it alone. |
SLITS |
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#2
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"This Utah shit is HARSH!" ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None ![]() ![]() |
Ok Joe....Think of it as this way....as you roll into a corner, the suspension takes a "set".....as long as this "set" is controlled, the car is easier to drive thru the corner. If the car rolls in (suspension on the loaded side) compresses and on rebound the spring is allowed to extend rapidly, the car will feel uncontrolable in the corner (rapid camber changes)...twitchy....kinda like bad shocks. In reality, it is the rate of rebound you want to really control, 'cause the compression is taken car of by weight and force counteracted by the "springs".
How was that for bullshit? |
Aaron Cox |
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#3
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Professional Lawn Dart ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Retired Admin Posts: 24,542 Joined: 1-February 03 From: Corona, CA Member No.: 219 Region Association: Southern California ![]() |
smells like bullshit ron (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)
i havent a clue about such questions. i just drive the dumb things (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) |
SLITS |
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#4
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"This Utah shit is HARSH!" ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None ![]() ![]() |
And badly, I might add (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) Is this time for your picture? |
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J P Stein |
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#5
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Irrelevant old fart ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None ![]() |
Damned if I know. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
I do know that mongo serious AXers spend what it takes to get the best shocks available....double adjustables at minimun...Penske, Moton, JRZ....whut ever. 4k is entry level. I also know that if I had all them knobs to fool with I'd fuck it up. I just had Bil. West revalve mine to whatever they thought best. I have enuff trouble with tiar pressures. |
Joe Ricard |
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#6
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CUMONIWANNARACEU ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 ![]() |
I'm with ya JP.... as always it seems.
I guess the reason for the techy "howz that shit really work" question is If I'm going to screw around with something I want to know what it is that I'm intending to accomplish. Espeacially if I'm going to throw money at it. Nearly fell over when I priced a set of Koni Sports for the rear. How much is "No Longer Available" each Plus shipping? (IMG:http://www.914world.com/bbs2/html/emoticons/flipa.gif) Found AJR stocks them and shipping is free. Found the QA-1 brand aluminum rebound adjustables from JEG's and then thought Hmm what's up wit DAT. No graphs to compare rebound rates. Which I believe should be valved to match or be able to control the spring rate. My head hurts ... Thats what I get for thinkin into stuff and squeazing a dollar bill till the eagle screams "uncle". Ron your Bull shit seems about what I thought too. (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif) |
phantom914 |
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#7
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non-914-owner non-club member ![]() ![]() ![]() Group: Benefactors Posts: 1,013 Joined: 24-February 04 From: Covina,CA(North ofWest Covina) Member No.: 1,708 ![]() ![]() |
Oversimplified: As far as turns, damping will affect handling balance at the moment you turn into a corner. As the car takes a set, the springs and swaybars affect the handling balance. So on an AX course, if you make the rear dampening very stiff, the car will oversteer more on quick direction changes.
Put another way, the handling balance on a skidpad (i.e. steady state cornering) can be tuned with springs and swaybars, but not shocks. Handling balance in quick directional changes are tuned with shock dampening. The realtionship is the same as with springs and swaybars, stiffer dampening in the rear means balance towards more oversteer in quick transitions and vice-versa. OK. I'm too lazy to type more, but if you want more confusion, I can probably arrange that. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) Andrew |
Joe Ricard |
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#8
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CUMONIWANNARACEU ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 ![]() |
I also know that if you are screaming into a corner and the rear rebound is not firm enough you will get tail happy as the rear tires unload.
Dampening in rebound keeps the suspension from extending...... I guess. which 1 keeps the rear tires on the ground during breakng and once you start to change direction. |
Don Wohlfarth |
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#9
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Member ![]() ![]() Group: Members Posts: 104 Joined: 8-January 03 From: Fairfax, VA Member No.: 117 ![]() |
I agree with JP. I installed single adjustable JRZ's front and back on my 2.8, semi tube 914 and made no other changes. I chased settings for a little over a year, maybe 15 track days. Got it to handle OK but always felt there had to be more. No, I didn't fiddle with shocks after ever session but a couple times over a weekend. I'm a de inst so I'd always have at least 1 student and maybe a checkout ride for others. Add in a little discouragement with lack of "real" improvement. Finally hit the right settings. Only realistic comment is Night and Day. (IMG:http://www.914world.com/bbs2/html/emoticons/boldblue.gif) Picked up over 2.5 seconds on home track where I've got over 100 days. JP's starting price may be a little low but well worth the investment. |
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Joe Ricard |
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#10
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CUMONIWANNARACEU ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 ![]() |
That will leave a mark. on my frigging head if the wife knows I spent that much on my cars shocks. Need new Hoosiers more than JRZ's DAMN!!!!!!!!!!!!! (IMG:http://www.914world.com/bbs2/html/emoticons/drooley.gif) |
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groot |
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#11
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Dis member ![]() ![]() ![]() Group: Members Posts: 897 Joined: 17-December 03 From: Michigan Member No.: 1,444 ![]() |
I'm in the middle of doing some damper tuning for an upcoming product. It's amazing what a little change will do to a vehicle's steering, handling and ride. We use take-aparts and re-valve them for each change.
Damping controls the transitions only! It can cause entry oversteer or understeer because it controls the loading of the contact patches. It will not fix any inherent imbalance in steady state cornering. Rebound controls the vehicle's sprung mass and compression (jounce/bump... whatever) control the unsprung mass. With rebound adjustable dampers you can have too much or too little damping... more is not always better. For ride, ff you have too much damping, the vehicle will feel tuggy... it will pull down on the driver. For handling, too much rebound control will not load up the outside wheel as fast as the other end of the vehicle.... causing oversteer. After typing this I realize it's best to let Koni tell you they're recommendation (from the Koni website):
I use Koni double adjustables on my race car... 8611s on the front and 30 series on the rear. Total cost for all 4 of the dampers <$1200. You don't have to get Motons or JRZs. There are other options that are far less expensive. |
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Joe Ricard |
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#12
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CUMONIWANNARACEU ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 ![]() |
Nice thanks Kevin.
always value the teachings of someone who is out there doing it and succeeding. Not to say some of the bench racers don't have valued input (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif) |
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