Author Topic: Spax initial settings  (Read 525 times)

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Offline Bryan Boyle

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Spax initial settings
« on: Tuesday,September 24, 2024, 06:58:09 AM »
Finally getting around to putting the new spax shockers on the car.  Tackling the rears first, since the bushings on the lower links are in pretty much toasted condition, and are the easiest to get to with the back up on stands. 

Anyway...running the perches on the shocks at the bottom, new springs from RD (along with the shocks...).  Road conditions here in MA (and to a lesser extent, PA) are pretty much what you'd see in photos of French towns in 1944...while the interstates (motorways) are ok, around town and the B roads are less than optimal.

Wondering what would be, from experience, suggestions for the initial settings of the adjustment for the Spax.  On the S2, I ran them with the perches down, and 4 clicks up from the bottom for the valve adjustment.   Thinking maybe the TC would be ok, maybe one or two more clicks of the adjuster to account for the heavier car? 

Not doing autocross...mostly around town, some B road work, and the motorway to eat up distances when needed.  Thoughts? 
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Clifton

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Re: Spax initial settings
« Reply #1 on: Tuesday,September 24, 2024, 08:12:52 AM »
I run adjustable front and rear but only Spax on the front. I run mine set the same for street and autox and that's for comfort. I set them to were I don't get the extra bounce. Set too stiff and it giggles your guts. On the rear with more weight and QA1 adj, I went to unconformable and backed off two clicks to what is comfortable on the street. Over damped it not fun or needed.

Offline BDA

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Re: Spax initial settings
« Reply #2 on: Tuesday,September 24, 2024, 09:40:11 AM »
I don't have Spax but rather Protech. I was surprised at how simple it was to get the shock's damping set and how narrow my choices seemed to be. It seemed that one click less was bouncy and one click more was obviously overdamped. I'm considering playing with that again to make sure my recollection was correct but I don't think there are more than two settings that make any sense at all. I suspect you'll find something similar.

Offline Bryan Boyle

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Re: Spax initial settings
« Reply #3 on: Tuesday,September 24, 2024, 11:03:52 AM »
I don't have Spax but rather Protech. I was surprised at how simple it was to get the shock's damping set and how narrow my choices seemed to be. It seemed that one click less was bouncy and one click more was obviously overdamped. I'm considering playing with that again to make sure my recollection was correct but I don't think there are more than two settings that make any sense at all. I suspect you'll find something similar.

I was counseled to run them all the way out for about 20 miles...then go three or 4 clicks in.  All the way out is almost no effect...from my seat of the pants feel.  Went 4 in (been busy not only putting the shooting match back together...in another post) and did another 20 miles.  That seems to be where she wants to be (at least for my somewhat 'James May-ish' driving style.)
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline BDA

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Re: Spax initial settings
« Reply #4 on: Tuesday,September 24, 2024, 11:41:20 AM »
I found fast highway driving was at least in part affected by shock stiffness. You might try a blast down an unmonitored stretch of highway useful for tuning your shocks. If they are set too light, the car will lack feel. Follows is a snippet from a section on handling  characteristics and causes in Carroll Smith's "Tune to Win":

Too little shock – overall
   Car floats a lot in ride and oscillates after bumps
   Response is slow and sloppy

Offline Bryan Boyle

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Re: Spax initial settings
« Reply #5 on: Tuesday,September 24, 2024, 06:15:18 PM »
I found fast highway driving was at least in part affected by shock stiffness. You might try a blast down an unmonitored stretch of highway useful for tuning your shocks. If they are set too light, the car will lack feel. Follows is a snippet from a section on handling  characteristics and causes in Carroll Smith's "Tune to Win":

Too little shock – overall
   Car floats a lot in ride and oscillates after bumps
   Response is slow and sloppy

Took it out on the roads and limited accesses again.  Brought the fronts up to 4 clicks, rear to 6.  Of course the fronts are out of Briggs Pletcher's toasted car from 2007...so they may be sketchy, too.  That's why I invested in brandy new ones for the front...but with the body on, I need to enlist the assistance of a willing compatriot to hold the spanner whilst I torque the inner pins and lower shock mount (at ride height).  Lot easier to do the fronts when the body is off...lol...as long as you load down the chassis with about 400 lbs of dead weight to compress the frame to the necessary height (6" under the cross box...).

I will say this...the rear doesn't bounce when given a push down now...and the only side to side movement is the sidewall flexing.  No more metalic knocking from perished rubber bushings.  Will take it out a few more times and settle the suspension a bit more and check the torques.  But, I'm pleased (chuffed?) with the result.

Photo post-drive...still love the look. 
« Last Edit: Tuesday,September 24, 2024, 06:29:32 PM by Bryan Boyle »
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline BDA

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Re: Spax initial settings
« Reply #6 on: Tuesday,September 24, 2024, 07:46:46 PM »
Congratulations on the upgrade! Those new shocks should make a big difference.

Re: torquing front suspension at ride height

When I got to where I was ready to put my car on the garage floor, I made up some blocks to put under the trunnions to put the corner at ride height so I could tighten the pivot pin nuts. Then it dawned on me that the important thing was sort of the relationship between the hub and the car. If the full weight of the corner was on the spring while the pivot nuts were loose. An inch or so higher or (not likely) lower wouldn’t make a noticeable difference in the deflection of the spring. Then I tighten the pivot pin nuts. No need to fiddle or worry. I was probably late too the party and everybody has already figured that out but I mention it here in the off chance somebody hasn’t it out yet.

Offline TurboFource

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Re: Spax initial settings
« Reply #7 on: Wednesday,September 25, 2024, 03:27:51 AM »
She looks great Bryan!
The more I do the more I find I need to do....remember your ABC’s …anything but chinesium!

Offline Bryan Boyle

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Re: Spax initial settings
« Reply #8 on: Wednesday,September 25, 2024, 04:44:49 AM »
Congratulations on the upgrade! Those new shocks should make a big difference.

Re: torquing front suspension at ride height

When I got to where I was ready to put my car on the garage floor, I made up some blocks to put under the trunnions to put the corner at ride height so I could tighten the pivot pin nuts. Then it dawned on me that the important thing was sort of the relationship between the hub and the car. If the full weight of the corner was on the spring while the pivot nuts were loose. An inch or so higher or (not likely) lower wouldn’t make a noticeable difference in the deflection of the spring. Then I tighten the pivot pin nuts. No need to fiddle or worry. I was probably late too the party and everybody has already figured that out but I mention it here in the off chance somebody hasn’t it out yet.

I did the same thing as you, in a way, when I put the used set of fronts in (a year ago?).  Probably more complicated though...put the wheels on the car, loaded up both seats with 170 lbs (FAA standard weight) of ballast (well, 4 bags of mulch on each side...close enough) measured from floor to center of axle to get tire compressed height...jacked back up, removed wheels, lowered onto 6" tall blocks under cross beam, put all the weight in front plenum, used jack to jack up wheel hub to previously measured height, torqued. Would be easy if I had an oil change trench I could drive over, but, there you go. 

Probably made it more complicated than needed to be, but it was a mental exercise.  And kept me busy. Keep reminding myself these cars are like comparing sundials to atomic clocks...
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline BDA

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Re: Spax initial settings
« Reply #9 on: Wednesday,September 25, 2024, 10:09:20 AM »
Quote
Keep reminding myself these cars are like comparing sundials to atomic clocks...

That's a very good thing because if we were talking about anything more complicated than sundials, I'd never have finished my car!!