mark kibort

when i mentioned they were dual adjustable, he said, "oh yes, my mistake" i though you were talking about the other konis (and he rattled off some part number) i told him they were the devek level II shocks and he understood that they were modified from the same style housing as the normal konis, but were much more expensive. springs are cheap. i think less than 80bucks a corner for hypercoils.

when you removed the shocks, were they the stock spring diameters or the ones like i have , small diameter hypercoils? if i could remove them without touching the suspension, that would be nice. otherwise, sounds like there is a way to unbolt something down there and leave the eccentrics untouched.

mk

mark kibort

The springs are really not that stiff, especially considering the car's purpose now. actually, its one of the few race cars that is actually nice to drive on the street. with all the traveling weight, the car is even softer. one data point is that the eibach set ups are between stock and what i have. by cutting one coil out of scots racer's koni eibach springs, it became right around as stiff as my devek level II spring set up.

what do you mean about the suspension moving? Its pretty solid. the race tires dont have much sidewall flex, but i have noticed i am hitting the bumpstops in extreme situations on the track (corkscrew, Laguna)

MK

bernard farquart

Isn't that likely a function of your shocks being too soft?

Lizard928

Bernard, simple answer No.

Bill Ball

Oh, DUAL adjustables! I missed that in your original post. That's DEVEK Level 3 and was $3k+.

I was able to get stock coilovers out the top. The tight spot is clearing the shock tower lip. A little compression (just with a prybar at the top of the shock) may be needed. Hypercoils would make it even easier to maneuver after the top tip clears. If I encounter shocks that just won't clear, I undo the inner lower control arm mounts. That only has a slight effect on alignment due to a bit of slop in the mount point locators.

SwayBar

Mike, those rates are way too low! Start out with 600/400 as that's what Ronn at 928 International sold me his GT racecar with; the car weighs 2850 lbs. I am very happy with the rates and Eibach's.

No, Lizard is correct. The shocks job are to 'dampen' spring harmonics and disapate kinetic energy, and why they are corretly called 'dampers' in Europe.

First guess would be the spring rates are too soft; but if the spring rates are okay, then tighten-up the swaybar a bit if that part of the track is too problematic. Suspension setup is all about compromise.

Mark, that's a great picture!

Mike Simard

I meant 'is the suspension moving or is it mostly sidewall flex with stiff springs?'
That's something I've wondered since reading the Porsche letters circa 1994 where they recommend unholy spring rates for 928s racing on various tracks.

Your picture is worth a thousand words and I'm listening as though you're EF Hutton. Are your "bump stops" those nice conical things? Those aren't bump stops, they're variable rate springs!

mark kibort

actually, its not really fair to post this picture of the corkscrew. However, the bump stops (those conical things you mention) for me, are part of the suspension! Most all race cars look like this here . after all, we are dropping 17 stories from the top to the bottom of the corkscrew !

I think most cars in the 90s were over sprung. I think now, most racers get it. That camaro i race with, was for years, 2-3 seconds slower than me. one day, a pro told him to remove his rear swaybar. reluctantly, he did and he shaved 2 seconds off his time at t-hill that next session. he has been real fast ever since.
So many components to think about. Bars, shocks, springs all need to be matched up well.

I think 600 to 400 would be a good high performance street set up. Im debating going to 800 and 500 like anderson, just slightly stiffening up the front as it does feel a little soft on hard turn ins and quick right , left turns like at Sears point. (bar is full stiff on the race car now)

check out the tire flex at turn 2 at laguna . I think this is at 45mph.

Mk

F451

Not having any experience with racing and auto suspension, but having lots with dirt bikes, I would highly recommend having your shocks looked at. And your whole suspension setup reviewed. Especially since they've been on their so long.

We have a recurring occurance where we think our dirt bike suspension is great (after sending it out for custom setups - valving and springs), only to ride someone else's bike the next year, and realizing how far we are behind, in just one year! Holy cow.

We often refuse to ride each others bikes because once you ride one of the newer ones, you don't want to get back on yours. The suspension improvements year to year are a big part of that.

Ok, I'm actually kidding about not riding each others bikes, we always jump at the chance to trade off bikes, but it is true that riding a newly suspended bike spoils you.

And these are bikes that are highly maintained, fork oil changed regularly, etc.

Anyway, sounds like you're already on the way to reviewing your whole setup. Keep us posted. The wanna be track boys are watching and learning. -Ed

mark kibort

Ill have to get a G-meter reading on that turn 2 at the apex, but you can see from the additional picture i posted, the tire rolling off the rim due to the grip. the suspension doesnt look that bad for the type of loading the car is going through. Its about 4000rpm in 2nd gear right there. (50mph?)
check out the smaller BMW tires at the same speed but a lighter weight car by 200lbs

IcemanG17

MK
A g-meter would be very interesting......a cheapo G-tech pro like mine is only $40 on ebay.....I managed a 1.15g last week at thunderhill in my 20 year old stock suspension full weight S4..... Of course I don't know which corner I did it in either...just the peak number in a left hand turn?

Dennis K

Re: spring rates - remember that MA has different motion ratio from stock. His wheel rate for a 800 lb/in spring is higher than our wheel rate would be. For my car (3250 lb), I don't think 800 lb/in is enough. I want to try 1000's. I'd rather gain roll stiffness without using an undamped spring (anti rollbar). At a certain point though, I think the rubber bushings need to be eliminated.

Re: g-meter - You might like this Brian. Lateral g plot of Thunderhill, comparing street tires to R-compounds. Street tires are the black line, R-compounds in red. 2:10.xx on streets, 2:07.xx on R's.

IcemanG17

Dennis
VERY cool data...I gotta get one of those......it seems about 1.15-1.2G is the max for street tires...but your getting peak transitions of probably 1.5G with the R compounds....that plus 3 seconds a lap is nice!!

We gotta get together for some track days.....my last instructor looked at things quite a bit differently than you did.....he liked to enter the corner MUCH slower than I felt the car could handle and accelerate through it more....I guess it worked since my lap times were slightly better....but it really felt like ai was parking the car before 5-11-14......

BC

That description smacks of a driver of an ***-dragger. Slow in, fast out.

"Regular" cars are supposed to be able to carry more speed at entry.

mark kibort

That slow in technique can be nice for making the tires quiet, but is not really the fastest way around the track. trail braking around most turns alows you to use the tires and the turn to slow the car down to speed you need to get a fast exit.

The data from a high end aquisition system that the Evo driver had at Thunderhill and Laguna, when we were much closer in times, showed 1.6gs for most of the turns.

mk