HotBits coilovers

Everything seems good, no leak at all, not even a tiny drop, the shafts are "dry" but don't have the slip/stick effect. Very happy so far.
 
Back from a trip with 100km offroad with corrugations, a lot of dust and all is still good. I think that I finaly found the right springs, oil and seals :)
 
My original suspension is properly sagged out now - 2 inch spacers and rear is sitting at about stock height and the front is not much higher.

So now I'm considering going down a similar path to jf1sf5 and just want to get some questions out the way before I contact some coilover places.

Background
I have a 2006 SG Forester. I want to have about 2 inches of lift, no body lift, stock axles/CV's and the most safe articulation possible without ripping out a CV or damaging stuff. I travel light weight, major camping trips are an esky and sleeping bag. I'm more interested in crawling over stuff then rallying around, so I need springs with a light enough rate to get full travel when the car is empty. I have Whiteline swaybars that I disconnect offroad and I am really happy with the current handling on road when the swaybars are connected, I'd like to keep the onroad handling similar.

Questions
Earlier it was said that you can get 240mm front and 260mm rear stroke with Heri axles, but if you want to keep oem axles you'll be limited to 220/230mm stroke. I believe I can safely have:
Front - Coilovers that compress to 385mm (OEM shocks compressed length) and extend to 568mm (OEM shocks extended + 2inch lift blocks) = 183mm stroke
Rear - Coilovers that compress to 448mm (OEM shocks compressed length) and extend to 672mm (OEM shocks extended + 2inch lift blocks) = 224mm stroke
How much further can I go in either direction?

What spring rates should I go for? I was thinking around the 25N/mm mark. Should I have a slightly heavier rate in the front due to the car being front heavy? I usually run 2-3psi more in the tyres when airing down offroad as the front is noticeably heavier.
 
Red XS, the first thing to do is to weigh your Forester front/rear. From there, you can choose the spring rates but you are probably right with the 25N/mm mark for the intended use.

I came from straight spings to barrel type springs like Jeremiah because of rubbing on the strut housings since Eibach has them in 16" length, shorter like 14" didn't allow full stroke.

Front : you could probably gain 10mm compressed compared to OEM (375 vs 385), 183mm OEM stroke and add 50mm/2" stroke from there. (OEM SG5 front have 190mm stroke, thought that SG9 were the same ?). As the front A-arms are 1cm longer on SG vs SF, you won't have any issues with the CV axles (my next upgrade !)

Rear : 25mm of the shaft is lost in the top mount, so you "only" have 200mm stroke ! You will have to modify the rear top mounts to receive the springs (https://offroadsubarus.com/showpost.php?p=94834&postcount=27).
OEM SG shafts 225mm + 60mm = 285mm shaft/260mm stroke.
 
Just received the SG front A-arms :)

Should have time to do the job tomorrow.
 
Job done !

SVX cv axles work perfectly with SG A-arms and Hotbits coilovers :)

Front track is now 2cm wider.
 
My Hotbits coilovers :ebiggrin:
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kbrRAuc
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Overall length is only slightly longer then the standard strut with 2 inch lift, but quite similar.
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Which means slightly more down travel
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But a heap more uptravel
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kbrRAuc
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This is currently with the Hotbits supplied 250mm long springs 4.5Kg/mm front and 3Kg/mm rear and helper springs. I have ordered some 350mm 3.5Kg/mm front and 430mm 2.5Kg/mm rear springs locally which will give even more uptravel. Plus I still need to modify the rear top hats.

Currently the ride is incredibly good! The stiff springs and my Whiteline swaybars mean theres hardly any body roll and the dampening can be set up to give a far smoother ride then I thought possible.
m3bhM
 
Cool :)

What's the length of the front and rear shafts ?

35N/mm for the front is maybe a bit too firm, why not try 30N/mm unless you want to add a winch ? ( I actually have 22N/mm front and rear but your SG9 is probably a bit heavier than my SF5)
 
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Nice

Congrats RedXS,
nice new set!!!!
I'm saving up some $ for a setup like that it seems to get really good results especially on jf1sf5 SF5,

I'm joining jf1sf5's question what specs did u get (travel and shaft length)?
 
Stroke - I went 210mm Front and 300mm rear. I think the front is perfect, but I probably should have gone 285mm stroke rear as the combination of the longer housing and bulky top hat mounting will cost a little uptravel. But I'll see how it turns out when I mod the top hat.

I was weighing up between 35N/mm and 30N/mm springs for the front and wasn't really sure. My SG with a bullbar is very front heavy, weight distribution ratio is closer to the 35:25 spring ratio and I have calculated the 35N/mm springs will give me full articulation on the front, plus they will be better handling on road and less likely to bottom out if I take a sand dune too enthusiastically. But I know the 30N/mm will still be better for traction. Would be nice to try both and there's always a chance that might happen.

jf1sf5 - Do your 22N/mm springs bottom out at all? For example when taking a run up to get over a dune?
 
I would go with 30N/mm (but I don't know the weight of your front bullbar) to be able to have full flex when driving slowly over ruts. And if you drive on dunes or on bumpy tracks, just turn the compression knobs a few clicks.

I very rarely bottom out because I drive slowly but if I was more of a rally driver, I would probably go for the 30N/mm spring ratio. But its always possible to turn the compression knobs...
 
The front weight is about 790Kg and rear about 610Kg under what I am taking as the lightest driving situation. I'm guessing my rear would be close to yours but the front is a fair bit heavier. A little over 10Kg would be bullbar and extra lights hanging so far forward over the front axle and the rest would be EJ253 and extra chassis strengthening in the SG.

Under full articulation I figure I'm going from 395Kg to 790Kg of weight on the compression front corner, with 35N/mm springs this gives me (790-395)*9.81/35=110.7mm of up-travel. I will reach bump stops before this happens. But let me know if I'm doing anything wrong, I've already had a lot to learn.
 
I did a calculation for Jeremiah22 two years ago, here it is :



Weight front : 845 kg - 100 kg (unsprung weight) = 745 kg - 40 kg (strut spring force at ride height, 20 kg per side) = 705 kg

Spring rates : 1x 254 mm x 50 N/mm + 1x 254 mm x 40 N/mm = 1x 508 mm x 22,2 N/mm ((50 x 40) : (50 + 40) = 22,2)

[FONT=Calibri, Arial, Helvetica, sans-serif]705 kg : 22,2 N/mm = 31,7 cm (amount of compression of the springs at full load like when diagonal spin occurs)[/FONT]

[FONT=Calibri, Arial, Helvetica, sans-serif]Spring length at ride height : 508 mm - (317 : 2 = 158) = 350 mm (divided because the weight is on both front wheels) [/FONT]

Ride height : 350 mm - 165 mm (thread height) = 185 mm (rod length)


Weight rear : 710 kg - 100 kg = 610 kg - 40 kg = 570 kg

Spring rates : 2x 280 mm x 40N/mm = 1x 560 mm x 20 N/mm

570 kg : 20 N/mm = 28,5 cm

Spring length at ride height : 560 mm - (285 : 2 = 142) = 418 mm

Ride height : 418 - 165 = 253 mm

I did this calculation if you want to have maximum stroke (what I did to mine).

Your hydraulic settings are quite hard I think but its easier to change the oil than the settings. HotBits uses ATF Dexron III (viscosity 34 cst@40°C). I changed for Motorex Fork Oil 7.5W because it works much smoother (no stick-slip) but has the same viscosity because my settings are like oem Subaru struts and I can harden the compression with the knobs (DT2)

Et voilà ! Hope it helps you !
 
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