Spax lowering kit

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rrrs
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Spax lowering kit

Post by rrrs »

Hi, is there someone with experience on Spax lowering kit

https://www.demon-tweeks.com/us/spax-ps ... spxtap099/

It is much better priced than typical B9/HnR kit; about $300 less including shipping and it offers adjustable damper.
I seen many very favorable reviews on Spax springs in E28 forums, but most of them seem to be used with B9 shocks; not much feedback on Spax shocks.

I realize they are quite low (35mm lowering) which might be good considering I would like to add IE upper camber plates which should add back about 5mm of height.

Is there option to adjust the rear height on Spax setup; something like on Bielstein where one can move the spring seat height?

Anything else to consider/be aware of before deciding for this?
rrrs
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Re: Spax lowering kit

Post by rrrs »

So, seems not many have this kit installed; I think I will go ahead and post back the report....but it will take some months before they will be on the car.
Thinking to pair them with IE sway bar kit https://www.iemotorsport.com/product/sw ... r-e24-e28/
And their fixed upper camber plates.
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jps635
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Re: Spax lowering kit

Post by jps635 »

Type spax into the search box at the top. Haven't read them but a number of posts.
'85 635csi JPS (RA2-66)
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Re: Spax lowering kit

Post by rrrs »

Thanks for the tip, I actually did this first and although there come number of post there is no report from someone that has the whole kit (springs and shocks)'
Much more useful info I did find on E28 forum with lots of very positive posts, but I am not sure if E28 setup would translate directly to E24.
I will go ahead and report how I like them once I get them installed.
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Re: Spax lowering kit

Post by bpoliakoff »

Which chassis do you have? E28 suspension will not cross over to an E12 suspension(pre82) and the drop is 1.35 Most lowering springs offered usually state a drop of 1.25-1.35 as they allow themselves some wiggle room based on weight etc Plus what they are showing in the link you provided states it will not fit a pre 82 car

If interested I have a set of proper ST springs and an adjustable 24mm rear sway bar
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
rrrs
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Re: Spax lowering kit

Post by rrrs »

Hi, it is '85 car, so yes, 28 based.
I already ordered the Spax lowering kit that includes springs and shocks, but am still looking for a swaybar setup.

Based on reading some posts on this forum, seems that preferred setup is 22mm front (ST makes this) combined with 18mm rear (from E28 M5).
Other option that seem to work well from the feedback is 25mm front and 19 rear (I think this is no longer available ST setup).

Please let me know what swaybars you got, would be very interested if they suit.
I guess you meant 24mm front, not the rear?

Since my front will be a bit heavier than standard (it is getting turbo-setup from 745i) thicker bar could be good.
I realize it will require new mounts, but that should be OK to get weld-in.
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Re: Spax lowering kit

Post by bpoliakoff »

My 81 Euro has a 25mm front stock from factory 18mm rear
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
rrrs
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Re: Spax lowering kit

Post by rrrs »

My Spax kit arrived; looks like a really nice quality, adjustable shocks front and rear.

Hoping to install over the weekend, but just wondering about two points, if someone could help:

1) I got new bump stops; the kit does not include the bump stops with it. Should I use the OEM once and should I use them as they are or cut them shorter?

2) I read that one should fill the strut housing with oil, but not to do it with Bielsteins. Should I use any oil or grease when inserting front struts in the housings?

Thanks a lot, will post the pictures once done!
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hornhospital
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Re: Spax lowering kit

Post by hornhospital »

If they're stock length bump stops you'll need to shorten them by the amount of drop from stock.

I don't know about the oil. I believe it was intended to help cool the shocks, but I'd never heard you don't add oil with Bilsteins.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
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Re: Spax lowering kit

Post by bpoliakoff »

The Bils fit slip fit tight in the strut housings so if any oil, it will be minimal
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
rrrs
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Re: Spax lowering kit

Post by rrrs »

Hi, thanks for the feedback; got all front components off and am going to re-fresh (clean and paint) the strut housings while they are off the car.

I am still wondering about the oil and if I should use it or not; in my Bentley E28 manual stands : "if using gas filled strut inserts do NOT use the oil in the strut housings"; Spax are Krypton gas filled, so I guess that would mean no oil.....probably best to leave them without oil and maybe just spray some white lithium grease inside as the future rust prevention?

Regarding the bump stops, on Spax page I found following:
"What should I do with my original bump stops when I fit lowered springs?
You should always keep the original bump stops. If they are not in good condition, replace them."

I guess this would mean that I should not shorten them?
Problem I see with shortening bum stops is that if I cut the bottom off then I loose the dust protector locating groove and if I cut the top then the narrow ID part that keeps them in place is lost?
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Re: Spax lowering kit

Post by jps635 »

'85 635csi JPS (RA2-66)
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Re: Spax lowering kit

Post by rrrs »

OK, thanks, so will go ahead and trim the top of the bump stops by one groove (this makes it about 35mm shorter, so should match Spax sprigs).
To hold them on the top of the strut insert rod probably my best bet will be just a very small amount of gorilla glue, since the narrower part of the bump stop that holds it in place will have to get cut off.
Will dispose the oil from the strut housings, as Bruce suggested.
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Re: Spax lowering kit

Post by rrrs »

Hi, I am still in process of suspension rebuild; it is taking longer than expected since I am trying to clean and repaint most of the components....

I am also using Meyle HD rear sub frame mount bushing but fill them with liquid Polyurethane, 80 hardness before installing.

I also wanted to do the same with front upper control arm (trust arm) bushing, to tape it off and fill with Polyurethane, but I am worried if this could create a problems there.
I fail to understand how is this arm articulating in up-down direction as it seems that it is not designed to rotate around the large mounting bolt; is it the give/flex in the rubber of the bushing that is critical to let this move up and down as suspension travels?
This would mean that filling the large voids in this bushing could really cause problems and maybe even break something?

I realize they sell Poly bushings for this location, but they make them totally without rubber and are probably made to rotate around the polyurethane insert; rubber ones are not made to rotate but just flex within the bushing, if I understand correct?

I will eventually get the mossehead ones in the future, but at the moment they are not available and would like to experiment with poly filled rubber bushings, as long as this is something that could be OK to try and not cause other problems?
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Re: Spax lowering kit

Post by 86_6series »

Don't forget to pre-load before torquing.
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rrrs
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Re: Spax lowering kit

Post by rrrs »

Thanks for reminder, will definitely make sure to pre-load the suspension before tightening control arms.
Finished pouring the 2-part Urethane into the bushings and they came out really nice; now hope the extra stiffness this ads to normally very open bushings will not cause some unexpected problems...

Here are couple of photos of both, Rear sub frame and trust arm bushings filled with 80 hardness polyurethane.

I poured the urethane to be flush with arm mount so it should be held in place/squeezed with the trust arm bracket.
IMG_0423.jpg
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IMG_0424.jpg
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rrrs
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Re: Spax lowering kit

Post by rrrs »

So, finally all installed, drop was as advertised, about 35mm; it does seam like the front drooped slightly more than rear which is nice as it gives me the place to add front fixed camber plates to the top of the struts.
I checked the wheel camber after lowering and it is 2-3 degree on the rear (one side is 2, other 3) while it remained near 0 on the front (0 on driver side and 0.5 on passenger).
I will be adding camber and tow adjustment brackets to the rear, but am wondering the best way to get the correct front geometry.
I am thinking of adding the bump-steer correction blocks that also increase the camber at the same time, similar to this:
Bumpsteer.jpg
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There are few questions I have:
1) What would be the optimum camber on the front; using sticky modern "track-day" and autocross tires?
2) Same question in the rear; with sticky tires is something around 2 degree negative camber OK?
3) Should I also look into increasing the front Caster when making the bump steer spacers by moving the strut bottom not just out but also forward?
4) Same for the camber plates; would it be good to shift the strut top mounting point in and back to increase both, camber and caster?
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Re: Spax lowering kit

Post by bpoliakoff »

Where did you get the bump steer spacers??
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
rrrs
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Re: Spax lowering kit

Post by rrrs »

Hi, I did not get any yet, but am planning to get a set machined.
The ready ones are available from AKG, but unfortunately they do not offer any additional camber.

https://www.akgmotorsport.com/product/b ... -1983-e24/

The once I posted picture from are not for E28/E24, but this is the idea on how they should be made.
I got a drawing already made but want to check on how much camber I should try to dial in and whether I should add also some caster or not.

Once I get to order them I am happy to make extra at my cost if someone needs, but would not like to take responsibilities for any problems with them :-?
bpoliakoff
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Re: Spax lowering kit

Post by bpoliakoff »

Unfortunately no one seems to have them for an E12 suspension. I was not under the impression that they are supposed to add camber just restore proper steering geometry on a lowered car
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
rrrs
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Re: Spax lowering kit

Post by rrrs »

So, as promised, here are the pictures and photos with Spax kit installed.
image005.jpg
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image001.jpg
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I feel that rear is maybe slightly high; seems front dropped a bit more, but this is now with empty fuel tank.
Somehow, the right side of the car is little bit (8mm) higher than left.
Springs and shocks feel great; tested first at 4 clicks from softest and this is plenty soft (can's really compare to stock as my old shocks ware totally gone).
Then changed to 12 clicks from soft (close to medium of the settings) on front and this felt really nice; maybe just slightly stiff when taking the speed bumps a bit faster; still have to play more with the rear.
All in all really happy with the kit, looks like quality of component is good, like the on-car adjust-ability of the dampers, height is perfect for me (might add front camber plates which should add few mm and level better front to rear) and cost shipped was around 30% lower than HnR/Bielstein.
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