Shocks and Spring Rates

[DaveW]

Anybody had any experience with the Koni 8211 or 8212 shocks, price into oz ex US is about $550AU ea including freight, which i think is worth considering over the AVO's

Re: spring rates,
I've read the previous posts particularly around the Classic Revival setups, but most were awhile ago, what has everybody ended up settling on, Barry from Toperformance in Melb is suggesting based on his calcs of ratios, weights, etc tha the suggested 450 / 525 lb are too stiff, and suggests 375~400 fronts and 450's in the rear would be about right.

Whats the feel and satisfaction levels ?

Dave

[eschaider]

Originally Posted by DaveW

Anybody had any experience with the Koni 8211 or 8212 shocks, price into oz ex US is about $550AU ea including freight, which i think is worth considering over the AVO's

Re: spring rates,
I've read the previous posts particularly around the Classic Revival setups, but most were awhile ago, what has everybody ended up settling on, Barry from Toperformance in Melb is suggesting based on his calcs of ratios, weights, etc tha the suggested 450 / 525 lb are too stiff, and suggests 375~400 fronts and 450's in the rear would be about right.

Whats the feel and satisfaction levels ?

Dave

Dave,

Here's a pretty good tool I picked up some time ago. I either downloaded it or built it from formula's on a spring manufacturers site - don't remember which anymore.

It works amazingly well. Remember as you do your spring solution that these cars only have about 600 lbs per wheel they support so if you use a spring that produces a wheel rate of 600 lbs the car will feel like it has no suspension.

Be sensitive to the use/presence of sway bars. In general sway bars allow for a softer spring rate and gain vehicle control through the sway bay essentially using both springs to stabilize the car in turns.

The sway bar approach not only softens the boulevard ride but it also provides a suspension that absorbs and accommodates fairly significant imperfections in the road surface without the driver loosing control from a rigid non-compliant suspension set up. In general it goes something like stiff bar/soft spring or weak bar/stiff spring.

FWIW on a smooth racing surface (if there is such a thing) the car will want and can use to advantage, higher wheel rates.

Ed

Well it turns out the XL spread sheet is larger than 39KB so it is not uploadable. If you would like it, PM me with an email address and I'll send it to you.

[DaveW]

Ed.

PM Sent

[boxhead]

Dave is your CR a round chassis tube or square?

Mine is square (Jag front, Falcon rear)

I have (from memory) 425lb front and 450lb rear.
My front feels too stiff (I have a sway bar) but I can sit on the guard above the front wheel and car does not move (I am 120kg fat bastard)
Where as I can sit on the back guard and suspension goes down a couple of inches.

My car weighs 550kg front and 600kg rear.
I have also moved my rear lower shock mounting point inboard approx 20 - 30mm compared to build manual (making room for wider rims)

[DaveW]

Box,
Mine is new round chassis, not sure on finished weight, but Ian suggested it will be about 1150 with a 48/52 distribution, so similar, but i think the wheel travel to shock ratio is different.
Us fat bastards will have to get together, sounds like we could be called the ballast brothers.
Toperformance is pretty adament that 450 is way too stiff based on the dimensions and weights i gave him.
He is suggesting an eibach or kings sports single rate spring at about 375 to 400 lb, and rr at 450, which sounds similar too yours,

If i can ask so boldly, maybe i shouldn't, but whats your rear feel like........

Dave

[boxhead]

Originally Posted by DaveW

Box,
Mine is new round chassis, not sure on finished weight, but Ian suggested it will be about 1150 with a 48/52 distribution, so similar, but i think the wheel travel to shock ratio is different.
Us fat bastards will have to get together, sounds like we could be called the ballast brothers.
Toperformance is pretty adament that 450 is way too stiff based on the dimensions and weights i gave him.
He is suggesting an eibach or kings sports single rate spring at about 375 to 400 lb, and rr at 450, which sounds similar too yours,

If i can ask so boldly, maybe i shouldn't, but whats your rear feel like........

Dave

I already told you I am a fat bastard so it is round.

Oh do you mean ride wise in the Cobra?
I think it is too soft, it moves up and down alot on undulating roads.
I do also have a failed rear shock so will be looking to replace (Spax) may look at EVO or Koni.
My springs are single rate kings, when I get home I will take a look at invoice as I really cant remember exact spring rates.

I would like lighter front springs in mine and heavier rears (rears only 25 lb heavier I think) and add a sway bar to the back.

[DaveW]

Box, The bouncing around on undulating roads would be ineffective compression and rebound damping ?, ie the shock and not the spring, Maybe the shocks are stuffed.

[gjkrv8]

Dave, I've got 450 front and 400 rears.

I dont have much at all preload on the springs to get 120mm (measured at round tube main rails) ride height.

Front could be a fraction softer. Rear feels ok.

Dont bother with AVO's though. I have already had to replace a leaking rear shock and now just noticed on the weekend a leaking front shock. Not happy Jan.

This should not happen to a vehicle thats only done 3000 Klm's. 12 month warranty is useless.

Anyone know a place in melb that reconditions AVOs?

Rgds

gregg

[Merv and Sharon]

I had all my AVOs leaking after 12 months. They re-conditioned all of them for free and now seems fine. Seems that they had a "bad batch", as others have had them for years without problems.

[eschaider]

Originally Posted by DaveW

Ed.

PM Sent

It's in your mail Dave.

Ed

[DaveW]

Greg,
Did you get the 400lb rears from Ian, he suggested 525lb rears for me, or are your fronts 400 and rears 450, i'm sure he definitely had higher rate rears

Dave

[Philm]

HI Dave,
I have 450 front and 400 rears. I also run the Koni 8211 shocks.

Go for a good set of springs, eibach or King you wont be dissappointed.

With the konis you dont get as much adjustment on the spring saddle so I would go for a 230mm rear spring plus the keepers springs.


Phil

[Mando]

I'd rather have a case of clap than a case of AVO's. DaveW is on the right track, there are much better shocks available out there.

Regards.

[gjkrv8]

Originally Posted by DaveW

Greg,
Did you get the 400lb rears from Ian, he suggested 525lb rears for me, or are your fronts 400 and rears 450, i'm sure he definitely had higher rate rears

Dave

Dave, I double checked my invoice (from TOP Performance bye the way) and they were Eibach 400lb's for the rear and the front have 450lb marked on them (they were from Ian).

I think originally my rears were 350.

Rgds Gregg

Mando, you crack me up.

[DaveW]

Philm, Are you happy with the feel of your springs as a street car, or track car ?

Gregg, Sounds like your pretty happy, maybe could go a bit softer on the front, i'm thinking maybe somewhere around the 400/425 fronts and similar rear.

Phil, do you remember what valving was in your 8211, suggested to me was B4 front and B6 rear

[Philm]

HI Dave,
The car is a pretty good track car with all the shock settings in the middle and then on the street set at the softest for a very comfy ride.

Not sure of the valving as I got them thru Neil Streeting at Street and Track.

Phil

[gjkrv8]

Originally Posted by Philm

HI Dave,
The car is a pretty good track car with all the shock settings in the middle and then on the street set at the softest for a very comfy ride.

Not sure of the valving as I got them thru Neil Streeting at Street and Track.

Phil

Hmmm, Phil you have me thinking. I have mine set on middle, maybe I'll adjust them to soft for the fronts for a better cruise ride. When driven hard on the middle setting I feel like it handles really well. So maybe like you I'll leave the middle setting for track (If I ever get on one).

Dave, yes I think maybe 425 on front may have been the go.

Rgds

Gregg

[Rob. Smith]

Originally Posted by Philm

HI Dave,
I have 450 front and 400 rears. I also run the Koni 8211 shocks.

Go for a good set of springs, eibach or King you wont be dissappointed.

With the konis you dont get as much adjustment on the spring saddle so I would go for a 230mm rear spring plus the keepers springs.


Phil

King Springs ? I needed a particular length of a 400lb rate so I rang the King Springs mob and they couldn't answer my questions so they put me through to the boss. He explained to me that they do not make custom springs and do not know how to ! I asked about their lowered springs and the raised ones as well. He said that they just use the factory OEM specs and just make them shorter or longer. They had no idea about spring frequencies or rates....you decide.
Currently (sadly)I have King Springs in my car but they have major spacers on top to make them work. This is not good. I will replace these with some custom springs made by Jubilee Springs in Gosford. NSW.

[Rog246]

Hey try Kevin Mcintyre from KMac. He's still around and he does custom springs etc
here are some details off his web site


118 Hattersley St
Rockdale NSW 2216
Sydney Australia
(Cnr. Princes Hwy - Behind Nissan)
Phone +612 9556 1799
Fax +612 9556 1507

[Rog246]

Then again this might help some of us too.
http://www.box.net/shared/gcuutlsgbd
Its a link to a spring rate calculator
Rog