Possibly quite firm for road use but it'll be nice for track days. That said others on here have fitted even heavier springs to prevent the rear wheels rubbing on the rear arches.Originally Posted by Lancialulu
Possibly quite firm for road use but it'll be nice for track days. That said others on here have fitted even heavier springs to prevent the rear wheels rubbing on the rear arches.
Reading into that, track is wrong and a stronger arb is what's in order?
John, not sure of point re ARB??? Please explain. Track was right when checked last week. I am sorting out this play identified at the MOT, It is minuscule hence no advisories. I have tracked down to a not tight outer wishbone bush and miniscule play on the inboard rose joint. All these have done less than 3000miles. I am getting a replacement high performance two part inner rose joint as we speak.
Craig - unless I have got it wrong the Stratos tech data indicates a standard spring rating of 330lb/in (when converting from kg/mm). I seem to read in various parts of this forum 325 is a good standard for the Hawk but I understand for an Alfa V6 Hawk nowadays folk have gone up to 350. We shall see!?
There will be no real difference in the rear spring rates whatever the kit manufacturer provided the car is fitted with strut type rear suspension. The ratio of wheel movement to damper movement will always be all but 1:1 & a car with an Alfa V6 will always have roughly the same axle weights. The front end on the other hand varies considerably due to damper angle & mounting positions.
I can obviously only speak from my personal experience and IMHO I find that 275lb is more than adequate for a the rear of a Stratos replica on the road, I have run the 325lb rate spring rate and it will work perfectly well but it is slightly stiffer than it needs to be for a road car but will offer a good compromise between a road car & a track day car.
Last edited by Strat Fan; 15-12-2016 at 16:18.
Thanks Craig. We will see. At the moment Shades had run 200lb in. so I will surely see some difference. I have some roads to exercise the suspension in a controlled way so am looking forward to getting back out.
If I read it correctly the Stratos manual / tech data states that the stock spring compresses 142mm under a load of 300 - 330kg that's a spring rate of 22kg/cm or 120/130lb/in - which from my calculations is a compliant sports car ride stiffness on a strut. - so sounds about correct.
325lb/in at near 3 times the standard stiffness seems a bit on the high side - For a 1000kg car with 40/60 distribution my calculator throws out 250-275 as being in the firm sporting area.
350 lb will only have 1.75" of coil crush so if you have more than 2" of droop in roll or bounce the spring will be unrestrained. Stiff springs are all well and good but you also need to take into account the suspension travel you have on the strut and the bounce and droop you want to have. Having a wheel in roll unsupported and just bouncing against a loose spring is not good.
I always want to have at least 3" of bounce and droop with the spring restrained in that movement - for 3" of coil crush - and no preload on the strut - assuming adjustable platform of course - you need a spring of 220lb/in range - the coil free length etc will depend on the open and closed lengths of the strut and position of the bump stop.
Big subject
Last edited by Darkspeed; 15-12-2016 at 19:45.
Hi Andrew. Yes I got the wrong page - how irritating is that! Calculated for front ARGHHHH. Having said that looking at the Stratos rear spec the spring is c12" whereas the LEDA strut takes a 9". The Factory spring is as you say c 125lb in....
Strange thing is the LEDA guy thought the 325 spring was in the right area and said other Hawk users were going a little bit higher.
I calculate I will get 2+inches of crush (625+kg rear axle when loaded) if I set the spring with zero preload. (Wonder what the ride height will go to...Need to aim for 175mm). The LEDA strut has 7 inches of travel. Looking at the Stratos tech book it seems the rear damper only has 5.75" travel. Not sure what to make of this other than wheels will dangle as early as my set up??? The setup I got for a Gp4 ashphalt Stratos works car (from Gianni Tonti) had a spec for "Molle" of 17 to 14 % for the rear and 40 to 35% for the front. Can anyone interpret this??
I am aiming to set the car up as sporting rather than comfort (I have other Lancias that fit that GTouring bill!!!) We will see but if I have to go softer its not big deal. The debate goes on.
Last edited by Lancialulu; 16-12-2016 at 09:39.
A long time since I posted but another hurdle navigated.
Last edited by Lancialulu; 05-04-2019 at 21:34.
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