I've been thinking about these Koni sports, and from research here I see that a 4gen rear will fit my 89 and are externally ajustable.

In reading the specs, the Konis for the 3rd gen rears are high pressure twin tube where the 4th gens are low pressure twin tube ?

Why the difference ? .... is it because of the external ajustment ?

Anyone with the 4th gen ajustable Koni's .... did they raise you ride height ?

I've also considering the Bilsteins HD's but I'm leaning towards the Koni's

Koni's on tire rack
http://www.tirerack.com/upgrade_gara...?markdowns=yes

 

Both Tirerack and Summitracing are often wrong in their description of products.

I can gaurantee you that 3rd gen Koni Yellows are a high pressure MONOtube shock. The 4th gen top adjustment units are a low pressure Twintube shock. THe koni setup with the base valve being the separate compression disc in a Koni rather than a pressure stabilizing valve enables the low presure oil in Koni;s twin tube to use two separate portions of the chamber for individual compression and Rebound flow through dual discs acordingly. When the potential aeration of the oil is separated with the opposing strokes , the same oil is not disrupted and heated and thus will stay cooler and disapate heat better then a conventional twin tube design. A koni twin tube is very comproble to a Koni Monotube with two main exceptions 1) they are heavier ( when considering unsprung weight), and 2) a twin tube low pressure shock can not be run inverted to save on unsprung weight whereas of course a monotube can (mute point on a 3rd gen proprietory shock mount setup- both are close enough in performance). So basically you are paying almost twice the price for a shock that is 9/10th the Monotube is but is extenally adjustable WITHOUT removing it from the mount to adjust rebound.

 

Thank's, STG

So the koni 3rd's fronts are monotube high pressure ? I'll have to go to Koni's site for info.

 

No- if a shock or strut from Koni extenally adjustable from a top dial then they are Twintube design from Koni.. Koni oniy makes the 3rd gen fronts twin tube. The 3rd gen rear is Monotube, the 4th gen rear is twintube.

 

Thanks again,
Do you like this combo ? 4ths in the rear. The price was about 45. bucks more than the mono tubes per shock. I'm trying to keep the car close to stock and yet have it perform better than stock without doing a lot of mods, like lowering etc.

 

It is worth not hassling for most people to use the 4th gens. I am a suspension nut and always seek the best, not the easiest (I have monotubes on all my cars- but the Camaro I was stuck with the twintube strut fronts of course when I had that car. You are not giving up much at all so if you want to be able to experiment alot then go with the 4th gen rears.

 

Thank's for your help ^ I appreciate it.

 

I considered the very same question when I bought my Konis. Pay the extra for the **** adjusting 4th gen rears or save a few bucks and get the gotta take them out to adjust them 3rd gen rears.

I went with the 3rd gen rears (hey, it's expensive for a set of 4 struts/shocks). In fact, I bought the rears first and waited about 5 months before I got around to buying the fronts.

I think I've had them for about 3 years now. The fronts, I adjust about once every 3 months or so. Most of the time they're set at 1/2 turn from full soft. Occasionally I'll crank them down to full soft. Occasionally I'll put them on 1 full turn. I rarely to never go higher than that. Maybe I'll fiddle with it and go 3/4 turn.

The rears, I installed at full soft (0 clicks) and have had them there since day one. One of these days I might take them out and go to click 1 on them. But I'm not in a hurry to do it. I find that it's the fronts that seem to control the front end and the center of the car. The back shocks just seems to control the back end. And with all the weight up front, you get more feel by changing the front settings.

What I've found with the rear setting choices is that if you're the type of person that might take a 90° turn at 40-45 mph while NOT on the gas pedal. The 0 click works fine. It's only if you're going to be on the gas pedal in the same situation, that the weight transfer sends the weight out back and in that situation, you wish you had it set on 1 click (or possibly 2 clicks if you have everything else done suspension wise). Because on 0 clicks, you'll feel the rear start to squat down in one corner when on the gas (Front end is still level)

 

Excellent info! Thanks again STG! I'm the opposite of Reid, i bought the fronts and am waiting to afford the rears. I've been trying to decide between 3rd or 4th gen koni rears but this thread has definitely helped me make a decision.

 

Thanks for your input Reid......... I placed the order with Tire Rack and went for the 4th gens for the rear. I Live at the foot of some nice mountain roads... so while I'll start with full soft all around.... we'll see what some **** twisting does.

I know I saw a post with instructions on how to set them up here someplace... I think you posted it ?

I've owned a couple of 911's before with Bilsteins so know the quality of the metal work from that part of the world. I think I read Koni was started in the Netherlands ?

Thank's again

 

We you adjust a shock rebound, what youa re feeling for is body roll. As youa re traveling fore and aft as in accelerating and braking, the rear rebound contriol the body weight from motioning forward under braking- and the fronts control the car from lifting as you accelerate.

Now as you have these set individual front and rear (make sure side to side is equal) what you will feel for is the car skipping over the pavement as you are hard on the brakes over bumps. You want to make sure the tires are returning fast enough not to be causing a traction loss. The higher the rebound setting the more likely to skip over the pavement and skid the tires. Note thought hat on flat smooth ground a high rebound setting will reduce the roll rate of the chasiss into a hard corner. You can steer into and off much faster into and out of steady state with better chassis control....but what out for bumpy surfaces. This is why setting are changed for different race tracks.

 

To take this a little fuirther so you can see how shock adjustments can be really defined in circle trackracing, we use no symetrical setups. What this means is there can and usually is different spring rates on all 4 corners of the car. We also use solid live axles (spools- due to rule resrictions) so we use stagger on the tires to create both camber aid as well as counter cross weight or "wedge" What the car is doing in essense is driving dwn the straight on the two rears and RF, then under braking into steadystate it rocks forward onto both fronts and the RR. The spring rates are set so as to balance this dynamci motion and create balance in corner entry, steady state, and corner exit.

That was a very basic rundown, but getting to the point of how we use shock setting to help a car struggling at a certain part of the racetrack. lets say the car is blanced wel at steady state, and is coming off the corner very well- yet it struggle with a tight understeer condition under hard braking going in. What is happening is the weight transfer is leaning on both front wheels and the dynaimc cross (usually about 54% on the LR-RF wheels (46% on the other two diagonally) will cause the RF to overweight and plow up the racetrack in a tight condition. If both compression settings are 4 (1-12, 12 being firmest valving) I can increase the LF compression setting to 6 so the car will lean on that tire a little more than the RF under braking weight trasfer for that 1 to 2 seconds as get the car to rotate into the corner better. Same would go for using a little more Rrebound int he inside rear (LR shock) but in circletrack we generally already have that inside rear rebound already maxed out to "hold down" the rear diagonal transfer of weight from going onto the RF. In this case the LF conporession is the way to go to fix a turn-in problem.

keep in mind that the left front tire (inside tirein circle track) is what steers the car. The outside right is merely for lateral grip, not so much the direction or path the car is headed. So basically upping the dynamic load upon braking forces to load the inside from more firmly get the car to turn.

Koni's are not all valved the same for different applications either. I Use to run them on #2 click on my rears (V6 car with EXTREMELY )built suspension) Most V8s are better on #1 (settings soft to firm are 0,1,2, &3). The front dial would run at about 7/8 full turn up front for street use, and then about 1/3 turn back from mxed on smooth track use. bumby tracks were a little inbetween based on roughness of pavement. I have them on a little Mercedes Cclass I own and they have only 3 setting, not 4. That car I have them maxed on both front and rear. My truck is custom valved. My Vette racecar I run old old orange/red shocks (prior to them having reds and yellows) that have been custom valved many times over the years

 

Very interesting information, thank you for taking the time to share it. I have a Koni Sports question as well. I recently installed a full set of Yellows (third gen style in rear). As I have read in other posts the rear Koni shocks have raised the back of my car by almost an inch. This confused me because I have always read that the Koni shocks were designed for "lowered" cars. Note that these shocks have less than 200 miles on them now.

I was wondering since you guys are familiar with the 4th gen shocks being run on the rear of third gens if the twin tube design lift the rear the same amount? I wouldn't mind purchasing a rear 4th gen set if I knew I could get at least 1/2" lower in the rear.

 

I cant answer your question about twin-tube vs mono-tube; but I had the exact same change in ride height happen to my iroc when I installed Koni yellows. If I'm not mistaken it's because they are gas charged.

When I mentioned the lift I experienced on this forum I had some tgo member on here act like I was an idiot and installed them wrong lol. I'm glad to see I'm not the only one who experienced lift.

You will just have to trim your springs; or remove the rear isolator.

 

I just read your thread prior to posting here, you are no alone. I measured about a 7/8" change after the install and my springs are not "out of place".

Unfortunately I had already removed the isolators prior to the installation. That along with the new springs put it where I wanted it. If you look at the photo of my car in the garage here that was prior to isolator removal. After installing the Koni shocks it's back to about the same level or slightly higher.

I'll leave it as is, the ride quality and handling improvements of the Konis far outweigh the slight change in aesthetics.

 

Agreed. I think any well built gas charged shock will have the tendency to cause some lift. It' best to spend the money and get weight jacks so you can readjust your ride height as you please.

 

The ride height is another reason I went with the 4 gen twin tube, their low pressure from what I've read. I'm hoping they don't lift the rear.
I just put 6 new gas shocks on my Kenworth and it raised it up... I didn't check how much... So no reference point , and i think it's settling down now after a couple of months.
It depends on what was one their before... If the shocks were shot, new gas charged shocks will lift a bit in my experience.

 

Please report back and let us know what if any difference they make on the rear. I would greatly appreciate it.

 

Will do .... it will probable be a couple of weeks. I'll measure before and after and then after some miles.

 

I'd advise leaving everything on full soft for a month or so. Learn to get used to the way the car feels like that. It really was totally different from stock.

https://www.thirdgen.org/forums/susp...og-5662-a.html

My review of Konis at the link above along with ride height differences (shocks and spring replacement) as well as Norm Peterson's "how to" guide on how to set them up

 

Monotubes will raise the car more than twintubes do for two reasons.

Lets first look at why a gas charged shock raises the car. The gas pressure is put into the bottom of the shock to pressurize the fuild chamber so as to prevent foaming. Just like a radiator cap will increase pressure in a radiator- every psi the cap builds the boiling point of the coolant will raise 3*. Take that same somewhat format to shock oil and add presure and it help prevent foaming of the oil that would occur without pressure.

Now a twintube shock has about an outer and an inner chamber. The inner chamber is the full length of the shock so the stroke can travel the length of it (a monotube only travels about 2/3rd the length). The outer tube holds mostly gas pressure (Nitrogen) at about 160psi. The monotube holds about twice that but both vary on the applications.

Since the nitrogen is filled with the piston shaft at the top of the stroke, when the piston goes downward into the tube the volume of the shaft takes up space. THis space taken up will increase the PSI of the nitrogen because it compresses it it's chamber so it will want to release back by forcing the piston/ and rod back out. This is what raises the car with a gas charged shock.
Now since the monotube is a single chamber, the fluid is contained in the top 3/4 of the tube and the gas on the bottom 1/4 with a disc separating the two. It will compress less but starts with a higher psi. The Twintube has a longer stroke and will generally build PSI a little higher in ratio than the monotube but remember it starts out much lower at half the static psi.

If the Monotube will raise a car about 1/2", the twintube should only raise the same application about 1/4- 3/8" depending on application and depth of ride stroke. note the lower the car, the less the ride stroke so the more PSI build and more raising.

 

Thanks for the in-depth explanation!

 

I was checking the tracking on the Konis I bought, and the Struts are coming from Illinois ( Next Tuesday on them ).... and the rears were out of Nevada... and it said delivered on the rears. Yep, they were on the porch.
Shipped on the 2nd.

Nicely packed too.

 

hey there,
any updates on this?