mark kibort

As many of you know, Ive been running the Devek Level II suspension on the Holbert car. There is a chance that the shocks are shot , but with stiff spring set ups, its hard to say. it doesnt bounce around much at the track, but it has always been a little soft on quick inputs like braking and hard quick cornering.
They might be fine, and that would be almost as amazing as the engine has been reliable over 6 full race seasons and 91 hours on the track! Most of the racers seem to think shocks need to be rebuilt every few years, at a min.
come to think of it, my Devek suspension is older than the holbert car, except for one shock that got blown out in the '84 racer crash in 2001. So, i think the suspension has 9 years on it and 150 racing hours!

Anyway, they are not leaking, but when the car is on the hoist, i can push up the wheels and have them move up pretty easiliy until it starts to compress the spring. one side is different than the other.

The shocks have also been maxed out since day one back in 1998. it also might be good to have what ever setting the shocks were at from day one, as a mid point, and have the shocks revalved accordingly.

Anyone have experience with shocks or the koni 2 way adjustable coilovers?
Marc?? I remember i had the one bad shock set out to be replaced, is there a company that does this? was it a Koni dealer that does this ?

The interesting thing is that the car is running some of its fastest times and doesnt seem to be that bad. I do like the feel of other race cars ive driven, but its really hard to say. when you drive a car as long as i have driven mine, i would guess you learn to drive around problems that the car might have.

anyone have a real bad shock? what does it feel like?

thoughts??? info?

Thanks,

Mark

Jim bailey - 928 International

"OTHER KONI AUTHORIZED REBUILD FACILITIES
In addition to the KONI Service Center in Hebron, KY, there are three KONI authorized rebuild facilities in North America. They are TrueChoice in Hilliard, OH (800-388-8783), Pro Parts West in Canoga Park, CA (818-888-8904), and Performance Shock Inc. @ Infineon Raceway in Sonoma, CA(800-965-5664). "

mark kibort

Thanks Jim?? any experience with these. Infinion sounds good, pretty close by, but do they just send things out to koni, or do they do the work themselves.

Do you think sending it back to the koni service center might be the best choice?

mk

Jim bailey - 928 International

No experience , we do not sell or have Koni shocks rebuilt.

Bill Ball

Mark:

I had my Konis dyno'd by Performance Shock at Infineon - great guy. He can rebuild your shocks any way you want. He can even convert them to 2-way external adjustment, although I don't think you need that if he dials in the damping properly. He may have even better ideas. I'm sure when he hears the spring rates you have and the application, he will get the shocks to work far better than they ever did with the standard Koni/DEVEK valving.

Mako 928

Mark
When/if you do this what will you do re: ride hight? and will you corner balance the car? Reason I ask is my car felt good when I replaced springs to Eibach/Boge. The front was lower than stock W/ the drivers front aprox. 1/2" lower. Then I adjusted the ride height and it never felt as good and now I have just gotten used to it.

IcemanG17

2nd for Performance shock at Infineon....great honest guy...ask for Bruce.....I got a quote from him for a koni-hypercoil kit like carl sells....but Bruce told me just buy them from Carl since he couldn't match the price!! Now thats an honest guy...he also said he can rebuild or custom valve any koni shock!! He can even dyno the shocks for ya to make sure they will work with the springs correctly!!

Bruce also said he is working on a race 928 shock-spring package.....I can't think of a better "demo" vehicle than the holbert 928...maybe you can work out a deal??

mark kibort

I do race the car quite extensively, so the ride hight is pretty set now, evolving over 6 years and 91 race days. Right now, the ride hight is 110mm up front and about 135mm in the rear. corner weight cross weights are+/- 10lbs, which is one of the most imporatant elements. front to rear is about 54/46%, and the is not much you can do about this. over 6 years, ive made small adjustments, getting the cornerweight where it is today. Scots car that was eye-balled for ride hight with the adjusters and even cutting a loop out of the eibach springs is not bad. probably a turn and a half on one rear corner from being almost perfect .

when you replace shocks, that will have no bearing on ride hight. (at least it shouldnt) The shocks are the dampers that allow for rebound and compression rates of movement based on how fast a force on the chassis is applied. (ie quick turn in, or hard braking where how much dive you get is the compression of the front and rebound of the rears. )

I wish i could see where the suspension is really at, because actually, based on the feel at the track, it feels quite good, but like i said, i could be driving around some major shock issues. Putting on new shocks could change everything, and i might need to take quite a bit of testing to get it back where i luckily was before. Then again, i might create a car that handles MUCH better and be thankful i changed them all out.

Mk

mark kibort

Ill have to call up bruce and have a discussion. thanks for the lead.

Im thinking of having the suspension set up a little stiffer, but the softness might be one of the keys of it being such a great handling car as it is. my damping might all be in the rubber bushings right now! the shocks sure feel pretty dead by using the old "push on the bumper" technique.

mk

IcemanG17

MK
Didn't Anderson go back to lighter springs......since the car was to jittery with the super stiff springs..... If I remember right your running 750-400's....Bruce said the Koni's were valved for up to a 750lb spring.....Maybe custom valving with 1000-500 or so.....

I wonder what worn out suspension costs you in terms of time....1 second a lap.......that plus the bigger motor should gain you a few seconds a lap easy.....maybe turn up the wing and splitter....you should be 1:35's at Laguna...under 2:00 at Thunder and mid 1:40's at Sears

BTW did you see the results for the 25 hours of Thunderhill.....the Daytona prototypes were running as fast as 1:40......damm thats moving....basically everyone else was above 2:00 except for the trick 993 which pulled just under 1:55.......I bet Anderson or Fan could run low 1:50's at Thunderhill

adrian928se

Mark, I found that my car (with worn shocks), performed OK on most corners still, except for tight slow turns like Druids at Brands Hatch circuit. If yours are shot, it will be costing you time on that type of corner. You should get your shocks dynoed by someone with the equipment, and they will soon be able to tell you for sure (it shouldn't cost much), and then you can keep the results for future reference.

Adrian

mark kibort

Yep, anderson and I talked about it when his car was really skatey.. he went softer with the springs, and took out a lot of camber. after that, he was pretty happy.

Im at 750 front and 475 rear with the rear sway bar stiffener, and the pretty thick front devek swaybar front. I think the bigger motor will require me to crank down some of the rebound and compression. dont know, as i havent done ANY adjustments due to being maxed out, in 8 years!!

Ill probably send the rears in first and see what they say based on my spring rates.

however, i spoke to Bruce and he said the these koni coil overs are near $800 each and are very good shocks. Probably one of the reasons my car has done so well. also, he said its not that unusual that they would still be ok, as usualy they leak when they start to go bad. (thanks for his name. he seems to know his stuff)

None the less, I will send the rears in and have them valved so that the current setting is more like a middle setting to have some adjustability. Then, ill send the fronts in, if i can get them off easy enough. I have never removed the front konis, only replaced the old stuff with the new stuff, and that required a disassembly of the front alignment components

Yes, i saw those Thunderhill times. 1:40 is REALLY smoking fast! generally , 20 seconds off thunderhill equals Laguna. (ie 1:20 laguna!)
They were running the bypass, which is 2 seconds faster, so i already run near 2:00 at thunderhill now. however, with the big motor, it would probably be in the 1:56 to 57 range and 1:58-59 with the new motor,(hopefully faster) . certainly, 1:36-37 at Laguna easily, as right now, im stuck at a best of 1:38.9 and mostly low 1:39s. Sears, 1:47.9, but havent been below 1:49 in a while now. (and that was before the wing and new splitter). Im hoping with the new power, as you say, to crank up that wing and put some bigger tires up front!


mk

Bill Ball

Hi Mark:

$800 each? What Konis are these? Koni red shocks are less than $200 per corner. Do the springs cost $600 each? My Koni reds turned to mush w/o leaking. Bruce does know his stuff. Either you have some other shocks or he thinks you do.

The worst you may have to do to get the fronts off is unfasten the lower control arm at the body. The alignment eccentrics are not touched. Last time I did a set, I managed to get the shock tops to clear the wheel well and out of the car w/o touching the lower or upper control arms.

Mike Simard

Mark, I agree with Adrian about getting your shocks dynoed.

What's up with the serious spring rates you guys are running? Do you know if your suspension is moving much or is it mostly sidewalls and rubber bushings?

I may be seeking you out for advice soon, I'm fitting my car with 400/250 springs as a baseline. I like the idea of a lighter spring along with a bump stop that acts like a variable rate spring and is in effect for 1/2 or 1/3 of the wheel travel.

BC

Devek's Koni/Hypercoil kits in the 90s and early 2000s were always a 600/400 set, and they moved up from there. Your 400/250 is not too far off the stock rates (or at least the rates Porsche intended - I think people forget springs wear out).