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Re: BC BR Series Coilovers [Re: Trappy] #1546196
04/08/2015 12:36
04/08/2015 12:36
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Nigel,

Just a slight point to raise, Apex are the distributors for the kit. In the initial reply from James, he has forwarded on the reply from the factory which are based in Malaysia (IIRC), so there isn't much point stating about cars from the UK.


Originally Posted by Jonny - After being taken out at Spa
Your car is Usain Bolt with wellies
Re: BC BR Series Coilovers [Re: Trappy] #1546199
04/08/2015 13:06
04/08/2015 13:06
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Hi Alexis

Yes, I realised that, but if they are selling kit in the UK, they should take care to ensure that its suitable for UK cars, not on a single 93 car that they happened to look at sometime last year

I know that the topmounts for 20v cars have different part numbers to 16v variants - anyone know what the difference is?


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Re: BC BR Series Coilovers [Re: Trappy] #1546224
04/08/2015 16:29
04/08/2015 16:29
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Just had another reply - they are going to refer it to the factory


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Re: BC BR Series Coilovers [Re: Nigel] #1546622
08/08/2015 10:17
08/08/2015 10:17
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Having had the geometry sorted and been away for 5 days on holiday, it's time for an update.

I took the car to Elite last Saturday and the geometry was checked - these are the BEFORE results.

Camber
Front left 0o 19'
Front right 1o 07'
Rear left -1o 16'
Rear right -0o 44'

Caster
Front left 1o 54'
Front right 1o 42'

Toe
Front left -1o 40'
Front right -2o 37'
Rear left 0o 10'
Rear right 0o 25'

Once he'd gotten over the results, I told them about the issues with Castor to date and the chap said that less castor can help with steering response. He said that they offer a 14 day free alignment if not happy and so it would make sense to get it done now anyway. If I'm not happy, I can have the top mounts switched myself and then return to have it done again. So I had the full tidy up completed, asking for 1 degree of Camber on the front.

Front left -1o 01'
Front right -1o 01'
Rear left -1o 14'
Rear right -0o 46'

Caster
Front left 1o 54'
Front right 1o 42'

Toe
Front left 0o 08'
Front right 0o 08'
Rear left 0o 11'
Rear right 0o 24'

The rear settings are a bit wobbly, but will be fixed to a fair degree when I have the rear subframe refreshed, I'm sure.

All finished, I took it for a spin and... it is transformed. It's now handling very well indeed. Straight line stability is much improved, even a fair degree of self alignment has returned at speed. But it still feels very nervous; too edgy at motorway speeds. I will be having the top mounts switched and then take it back for another alignment for the higher Castor. More stability at speed and more favourable camber in corners sounds very good.

In terms of the car's ride, I'm pleased to report that it's actually rather good at 12/30 front and rear. Very composed over rough / jiggly surfaces on the sort of roads that sat navs love. On Motorways and flat A&B roads it feels amazing, save for the nervous steering. Really stable and planted. It's on bumpy b roads where it's suffered a little. Too bouncy for my liking, but they're hardly the roads you use for spirited driving.

One other problem I have is caused by the 235 section tyres. With a fair dose of steering lock and a little speed, it rubs the inner arches at the front. I haven't been able to explore the levels of grip properly because of this but it's already far better than it ever has been before when it starts to rub. I'll have the ride height increased again to alleviate this.
Would stronger ARBs front and rear help this? I have a 22mm whiteline on the rear but I'm thinking of going 24mm on the rear and 26mm on the front.

Oh, now that the tyres are well scrubbed in, I have full grip in 1st and 2nd gear - which is nice shocked


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1546633
08/08/2015 12:18
08/08/2015 12:18
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I struggle with toe settings in degrees - what is 0o 08' in mm (or where is it against the upper and lower limits)?

With an uprated rear ARB, I'd suggest going for a bit more toe-in to get the motorway stability

Also, play with your rear tyre pressures - I found that dropping the rear pressures tended to help the stability

Will be interesting to hear your findings with the top mounts switched for more caster - suggest you don't do much more playing around until this is sorted, as it will make quite a difference. High speed stability will be improved, as will "feel" and (hopefully) the twitchiness on turn-in will be reduced

I'd recommend you refrain from uprating ARBs at both ends unless you're going out on track - as soon as you uprate the front, you'd need 23mm or 24mm at the rear and (IMHO) its a bit much for the road


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Re: BC BR Series Coilovers [Re: Nigel] #1546640
08/08/2015 14:45
08/08/2015 14:45
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Trappy Offline OP
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According to their machine's guidelines, the toe range for a
Fiat: Coupé: Rest of World: 2.0 Turbo: 1994-2001 is 0o 13' to 0o 04'. I don't have Excel on my home laptop so can't work it out using formulae I've found on the internet.

It's more how responsive the steering is than the car wandering around on the motorway. It's too edgy.

Like you say, I'll get the top mounts switched before playing with anything else but the ride height will have to go up too - I can't have this rubbing any longer.

Once I have degrees converted to mm, what would you recommend I get them to set it too?


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1546644
08/08/2015 15:11
08/08/2015 15:11
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I'd start at the most stable setting (full toe-in) and then work back from there

If its still turning in too rapidly and the back is feeling loose, you may have to back off the camber a bit

I spent ages trying to get the balance back on mine, before I twigged that it was a tyre mis-match, which clearly doesn't apply in your case

Before then though, try firming up the front damping a little (or softening the rear) - should help

If its still diving into corners, an ARB might be the only answer - suggest you search for a Lancia Dedra front ARB - slight upgrade on the OE 20vt

On another note, but related - keep a very close eye on your oil pressure gauge - I found that with trackday tyres on, it was easy to get enough lateral G through a roundabout to cause the oil pickup to starve - not a good idea, especially on an expensive forged build


[Linked Image]
Re: BC BR Series Coilovers [Re: Trappy] #1546660
08/08/2015 22:53
08/08/2015 22:53

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click to enlarge
click to enlarge

Re: BC BR Series Coilovers [Re: Trappy] #1546923
12/08/2015 18:47
12/08/2015 18:47
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Originally Posted By: Trappy
I took a few snaps this morning on my way out of the house.

click to enlarge



Quick snap of the same side now they've been swapped over.

click to enlarge

I'm off for a realignment on Saturday morning so will report on the Castor status then.

No idea if it handles any better yet as the shoreline ARB has snapped a bracket bolt and that now needsremoving but has to wait until next week.


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1546934
12/08/2015 20:48
12/08/2015 20:48
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Looks a lot better, although you might want to back off from max camber.....


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Re: BC BR Series Coilovers [Re: Nigel] #1546943
12/08/2015 22:32
12/08/2015 22:32
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I asked Rog to do that because the middle setting gave me 1o of positive camber on one side and half a degree of positive on the other side. 1o negative was 90% of the travel so I figured it's better in the short term. Clearly, BC didn't do a very good job on the top mount design with the asymmetric versions...


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1546962
13/08/2015 07:26
13/08/2015 07:26

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So I'm assuming that when facing the engine of the car, the coilovers are labeled correctly? Like mine are overe here

Re: BC BR Series Coilovers [Re: ] #1546969
13/08/2015 08:57
13/08/2015 08:57
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Trappy Offline OP
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Originally Posted By: mihai7645
So I'm assuming that when facing the engine of the car, the coilovers are labeled correctly? Like mine are overe here


Yes, that's how they should be fitted for more Castor.


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1546984
13/08/2015 12:24
13/08/2015 12:24
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Originally Posted By: Trappy
I asked Rog to do that because the middle setting gave me 1o of positive camber on one side and half a degree of positive on the other side. 1o negative was 90% of the travel so I figured it's better in the short term. Clearly, BC didn't do a very good job on the top mount design with the asymmetric versions...


I wouldn't worry too much about having less static camber, if you're running more positive caster then you will get extra camber as the wheel turns. That's exactly how you want it, full tyre contact with the wheels pointing straight ahead and negative camber as the wheel turns in so the body roll and suspension compression will still have full tyre contact in the turn.
Should handle nicely.

Re: BC BR Series Coilovers [Re: Jimbo] #1547000
13/08/2015 16:46
13/08/2015 16:46
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Originally Posted By: Jimbo


I wouldn't worry too much about having less static camber, if you're running more positive caster then you will get extra camber as the wheel turns. That's exactly how you want it, full tyre contact with the wheels pointing straight ahead and negative camber as the wheel turns in so the body roll and suspension compression will still have full tyre contact in the turn.
Should handle nicely.


It's funny you should say that Jimbo, because I was thinking along the same lines yesterday. More specifically, I was considering asking the chaps in the alignment shop if they could measure the camber on full lock. Is that possible?

If it was, then what sort of settings should I be looking at? If, say, 3 degrees was ideal in a corner and in a straight line that meant 1 degrees, would it still be worth backing off to 0 degrees and taking 2 degrees at full lock? As far as I know, it might increase it by a factor of two or more… In that case, you’d need some to get any increase!

I have no idea how much extra camber I’ll get, but how much at full lock is good?


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1547015
13/08/2015 18:30
13/08/2015 18:30
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It's way more complicated than just saying you'll have 3' of camber with the wheels turned Trappy.
In a corner, the outside damper will be compressed so the geometry will change from the static condition.
Just get them to measure the caster angle, if you're running a little more than standard then you'll be fine, if not then pull in some negative camber.

Re: BC BR Series Coilovers [Re: Jimbo] #1547062
14/08/2015 11:50
14/08/2015 11:50
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Originally Posted By: Jimbo
It's way more complicated than just saying you'll have 3' of camber with the wheels turned Trappy.
In a corner, the outside damper will be compressed so the geometry will change from the static condition.
Just get them to measure the caster angle, if you're running a little more than standard then you'll be fine, if not then pull in some negative camber.


Go on then Jimbo, what’s “a little more than standard”?

Book would appear to say -0o13’ to -1o13’. Go for good old -1 degree?


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1547109
15/08/2015 09:43
15/08/2015 09:43
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Just got back from Elite. Settings are now the same as before but with 2o 47' of castor on the left and 2o 30' on the right.

Feels a lot more stable and surrfooted at speed but with the rear left ARB bracket not in place, I can't really push on yet.

Almost there!


F****** b****** thing...
Re: BC BR Series Coilovers [Re: Trappy] #1547187
16/08/2015 12:17
16/08/2015 12:17
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Hmmm, you're still almost 1 degree of positive caster short of a standard coupe.

Re: BC BR Series Coilovers [Re: Jimbo] #1547216
16/08/2015 18:43
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Originally Posted By: Jimbo
Hmmm, you're still almost 1 degree of positive caster short of a standard coupe.


I've just checked one of my geometry printouts - with Osrav shocks and standard topmounts, I have 3.13 (L) and 3.37 (R) degrees of caster

Either Trappy has something fundamentally different going on with his car (wishbones?) or the BC coilovers are all wrong somewhere


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Re: BC BR Series Coilovers [Re: Trappy] #1547217
16/08/2015 18:44
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PS - I'm only guessing, but with the BC top mounts on the other way, the caster must have been around 1 degree - no wonder it felt a bit weird to drive....

EDIT - just remembered that Trappy listed the caster earlier on - 1.50-ish - not sure I understand why flipping the mounts has added such a small amount

Last edited by Nigel; 16/08/2015 18:47.

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Re: BC BR Series Coilovers [Re: Trappy] #1547227
16/08/2015 21:03
16/08/2015 21:03
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On my report I have 2,55 and 2,54 (degrees of caster) on both sides and values should be between 2 and 3 degrees according to the report.
I have aftermarket standard top mounts (febi bilstein).

EDIT : Fiat documentation says 3°30' +/-30'
I have Eibach springs -30mm. Can this explain the difference?

Last edited by crazyf1; 16/08/2015 21:17. Reason: Comparison with Fiat data

Re: BC BR Series Coilovers [Re: Trappy] #1547249
17/08/2015 08:34
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Yes - the amount of lowering will affect the caster - the lower you go, the more caster you will have


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Re: BC BR Series Coilovers [Re: Trappy] #1547250
17/08/2015 08:37
17/08/2015 08:37
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.

Last edited by Nigel; 17/08/2015 08:37. Reason: double-post

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Re: BC BR Series Coilovers [Re: Trappy] #1547302
17/08/2015 17:52
17/08/2015 17:52
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Are you sure Nigel? Camber alters with lowering due to the suspension moving in an arc which is hinged inboard to outboard, I'm not sure the caster angle adjusts with lowering?

The BC top mounts are at fault, they just haven't done their homework on them. Take a look at an OE top mount and look how much the spring mount and damper mounting is mounted to the rear of the mount, these BC have almost gone for a central mounting point, it's only ever so slightly aft if you fit them in the wrong positions (that's how poor the engineering is).

Re: BC BR Series Coilovers [Re: Trappy] #1547303
17/08/2015 17:54
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I just used the word "mount" 6 times in one sentence, is this a record?

Re: BC BR Series Coilovers [Re: Jimbo] #1547342
18/08/2015 08:31
18/08/2015 08:31
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Originally Posted By: Jimbo
Are you sure Nigel? Camber alters with lowering due to the suspension moving in an arc which is hinged inboard to outboard, I'm not sure the caster angle adjusts with lowering?


No, I'm not 100% sure, but here's my rationale:-

Let's say that the bottom ball joint is 25mm forward of the centre of the shock top mount (both are clearly fixed points, so cannot vary)

At standard ride height, let's say there's 400mm (wild guess) between the bottom ball joint and the top mount - this creates an angle of (say) 3 degrees

Now, we shorten the distance between the bottom ball joint and the top mount (by fitting lowered suspension). The fore and aft distance (25mm) cannot change, so the angle of the line between the bottom ball joint and the top mount MUST get a little steeper, as the vertical distance has shortened.

The arc prescribed by the bottom ball joint with movement of the wishbone will make the bottom ball joint move away from, or closer to the centre line of the car (thus increasing or decreasing camber) but it cannot move the bottom ball joint fore and aft, so the arc will not affect caster

EDIT - contrived diagram to explain my thoughs

click to enlarge

Left-hand line is the standard suspension (as viewed as though you're looking into the wheelarch with the wheel removed)

Right hand line is lowered suspension - the fore and aft distance of the top and bottom points is the same, but the height is reduced, which increases the caster angle

Last edited by Nigel; 18/08/2015 08:40. Reason: added diagram

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Re: BC BR Series Coilovers [Re: Trappy] #1547360
18/08/2015 12:11
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Ok I agree there will be some altering but the ammount is minuscule in the 20mm of lowering we are talking about, certainly much less than he camber created by lowering so probably not enough to recover the 1' of caster we are missing here.

I think those top mounts need a redesign to at least match the OE parts and add a little extra for good measure.

Re: BC BR Series Coilovers [Re: Trappy] #1547372
18/08/2015 13:18
18/08/2015 13:18
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Are there any piccies of the Gaz "max caster" topmounts that are available as an option on their coilovers?

Edit - Gaz coilovers with Max-caster topmounts

Just look at the extra offset on the topmounts to create the additional caster - its massively different to the BC topmounts


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Re: BC BR Series Coilovers [Re: Jimbo] #1547374
18/08/2015 13:38
18/08/2015 13:38
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Originally Posted By: Jimbo
Ok I agree there will be some altering but the ammount is minuscule in the 20mm of lowering we are talking about, certainly much less than he camber created by lowering so probably not enough to recover the 1' of caster we are missing here.


I agree - any increase is there, but very minimal (and probably not detectable by the driver)


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