Camber adjustment to Camber/Castor Adjustment

campbellju

Moderators
Staff member
Was looking at rotating my front top mount last night to do as the title says. Unfortunately the bolt positions are not symetrical, 2 pair are 10cm apart and 1 pair is 9.5cm.

I was thinking of drilling out the holes by 2 or 3mm to make it fit and position the adjustment plate at 45degs to the side of the car rather than 90degs. (This means as you move it back 45degs, you are changing camber and castor at the same time)

The reason for all this is I've got my camber set at -1.3degs front and there is still a little slack but I would like some more castor as I think it would help front end bite in slower corners.

The proper job is to buy some Ground control camber adjustment plates but these cost £200, lower the car a further 3/4" and only fit with certain strut braces so are far from easy.

The disadvantage of what I'm looking at is you will always have a compromise between getting an accurate camber and castor. I could buy another set of camber bolts though for the front instead that would solve that problem.

More importantly, I have to start drilling bigger holes through everything.

Anyone looked at this or tried this before?

Jim
 

CruiseGTi-R

Member
This is interesting. I really want to adjust my castor too even after the anti-lift/castor kit was fitted and had thought about elongating the holes in the top of the chassis tower to run 90 deg to the camber adjustment slots.

Its a question of space within the tower though, although with my D2 coilovers the head isn't too large. I reckon even a few mm of adjustment would yield castor angle change.

I'd think that you risk having quite a drastic change in castor angle at 45 deg. You'd have to work out the optimum angle for the top mount to sit at such that as you move through the whole range of camber, say -0.5deg to 3deg that you also move through your desired range of castor angles.

You need to draw it out in 3D to determine the best angle for the top mount.

What is it you don't like about the castor angle and why do you think its castor you want to adjust?
 

campbellju

Moderators
Staff member
It a little theoretical and a bit heath robinson at the moment which is why I thought I'd post.

Last question first, I want more castor as I think it will help the car bite more at the front. It should hopefuly reduce the amount of dive you get from the front out the outside point on a corner. Standard settings on a Sunny are 1.5 to 2.5 degs. The Whiteline kit reduces lift/dive by changing the lower arm position and in the process adds a degree of castor. this is why Whiteline state their caster setting as 2.5 to 3.5 degs. :D

IMO, this is still on the low side for a performance car, my daily driver the MR2 has adjustable castor and those in the know wind it up to the max at 5degs and it does improve the straight line stability and front end grip. The main downside is a heavier steering wheel but at this level of castor, the car still had a good "feel" and doesn't want to go straight a head all the time :wink:

I know an old rule of thumb is to run around 5degs castor on a road car and I know of race cars setup with twice that amount. For me, the problem is the Sunny suspension was originally designed for a 1.4LX shopping cart with manual steering where people want a nice light steering wheel so Nissan put virtually no caster in. The whiteline mod is a step in the right direction but in theory, I would like to add another couple of degrees to the front.

I've not really considered whether my idea will add 8degs rather than 2 and you raise a good point. Castor is a bit of a pain to measure accuratley too and my home made camber measurement kit won't cut it so I'd be going by eye and feel at the mo.

I'm tempted just to drill out all 3 holes an extra 2mm so I've got room to play a little either way. The 3D model is a nice idea but where do you start? I think I'll start by jacking it up, taking the wheel off and having a think before I start cutting drilling anything :wink:
 

CruiseGTi-R

Member
What about adding spacers to the rear bushes on the front arms.

Bit like exaggerting the anti-lift kit spacers/bushing. iirc the allen bolts were plently long enough.

or will that buggar up other geometry?

I'd also start by slotting/elongating the tower holes rather than making them larger altogether. At least then you can try to keep the camber unchanged as you adjust for castor.

what camber adjustment do you have? coilovers with adj top mounts?

You can't drill out the top mounts to give you longitudinal movement can you??? (can't picture it in my head without seeing my coilovers)

I do hate the self centring action nearer full lock on my car though, more castor would make it quite a handful.

I also hate the feeling around dead centre, dull as hell, but thats another issue altogether.
 

campbellju

Moderators
Staff member
Looked at not buying the kit at all and doing it myself at first as £65 for 1deg of castor isn't much :roll: :lol: Sucker that I am I went for it.

When you move the front arm down, you need to move it out as well or you start changing the toe under compression I think(?) This meant that using the standard bush I'd have had to start moving mounting points and wasn't sure I wanted to get into that.

I've got the tein top mounts on the front. I did consider moving the bolts on the mounts but during fitting originally, I snapped 1 of the bolts whilst trying to torque it up :oops: :oops: (I blame the bolt :wink: ) I then had to drill out the bolt and fit a new one. After going through 3 drill bits :shock: I don't fancy doing that again.

The "ground control" camber castor plates provide X-Y adjustment with in the hub but sacrafice the max camber you have against camber due to the hole for mounting the strut. This is bascially what I'm trying to replicate on the cheap.

http://www.ground-control-store.com/products/description.php/II=146/CA=93

Through a few sketches I've worked out by drilling one new 8mm hole, 5mm offset from the front inside hole, then I can rotate the plate 45degs and try it out. This would look like a slot rather than a big hole and be structurally stronger as you imply. The position would be in the wrong place to rotate though as your more subtle plan.

My thinking is I can use a combination of my modded camber/castor plate to set the castor and if I need anymore fine tuning on the camber, I can use camber bolts (Which I still think are yuk but would work.)

I'm mid new driveway at the moment so my garage, house and everything in the vicinty seem to be covered in sand so now is not a good time to start playing :cry:

Totally agree with everything you've said on castor. I actually like the self centring action :lol: whilst my wife already thinks my car's handling is too slow and heavy so it goes to show how subjective handling is.
 

CruiseGTi-R

Member
Looks like a trick bit of kit, but looking at where the three bolts are and thinking about the R's tower holes, it looks like it wouldn't fit without cutting out loads more of the centre hole in the tower top.

Been tempted to cut out a couple of nicks in the tower top just to allow my camber plates/bolts to slide further in, but I think the flange around the hole is probably good at keeping things stiff.

The 45 deg placement sounds like its worth trying, particularly if its only drilling one extra hole.

I can get almost 1 deg camber from the bottom slotted hole of the coilover clamp to the hub, makes installation a pain but useful for adjustment.

Let me know how it works out, I'll be getting the drill out too if it makes a big difference.

Ultimately need someone to replicate that kit, or a design like it, although I still think it needs the hole in the tower top enlarging and so re-strengthening.

Have you ever tried running big camber, 5+ deg say, oz V8 supercars style?

Do you use the uprated steering bushes, wondering whether they help to get rid of some of the fluffiness around dead centre, its one of my current bugbears with the handling.
 

campbellju

Moderators
Staff member
Well I've done it, One hole extra, rotate top mount 45 degs. Then found the top mount was not designed to work the opposite way round so needed to shamfer an edge or two with the angle grinder to be able to move the top mount to its limit in reverse. I then had to take an angle grinder to my strut brace to get that to fit again.

By calculation I've added between 1.5-2 degs of castor. I can't tell you if its done any good as my clucth is still awaiting to be fixed but it is done at least. My camber will probably not be matched anymore but I've not had chance to measure it yet.

We'll see if it was worth the effort once the car is working again. If its rubbish then I might just by the ground control kit instead that has greater adjustment :D
 

campbellju

Moderators
Staff member
Well I've tested the mod and all seems good so far but its too ealy to understand precisley what effect its had whilst I'm still getting used to the car.

Has a good solid feel to the helm (Wooden ;-) :D ) but no sign of torque steer.

Will take some photos and watch this space
 

campbellju

Moderators
Staff member
This is an old thread but I thought I'd post up where I finished on this.

By calulation it adds around 2degs of castor. It improves stability, helps turn in and helps -ve camber gain whilst turning.

You move the strut as close in board as possible and adjust your camber at the bottom. (D2, Camber bolt or my coarse camber mod) The disadvantages are you need to drill and cut a few things and get a re-alignment done. I revesred the sides on my whitleine ARB and went from 3 holes to 2 so it would fit again.

Whiteline have started selling something they call a Max-C camber/castor plate. This does the same thing but with more bling. The marketing is nonsense about taking a car to a track and move the plate to the max position as you will find your toe out and your wheels pointing in funny directions. You will need a re-alignment whenever you change your camber or your castor.

I've since cut my towers to bits and fabricated some plates to add a further 2 degs of castor but the average owner will find this too extreme to do and IMHO may not like the results.

For most people I think this extra hole mod is simple enough and gives sufficient improvement to recommend to others.
 

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fubar andy

Moderator & N/W Rep
Staff member
I’d like to add to this if I may. :-D

As for all that’s been posted above I would like to add to this information about the modification and the actual overall improvements.

A couple of weeks ago I spent my bank holiday in a workshop with Jim and Stu as they offered their advice (and some tools) to allow my attempt with adding some caster to my suspension.

For something that’s free over a whiteline kit that offers less but charges you your hard earned cash – it’s a no brainier really. :doh: :lol:

So I set out and drilled the holes in my car as well as my strut brace and within 20mins I had done one, 15mins on the other side and that was done.
So easy it was it to do I felt like I could do it again just to feel like I’ve spent long enough doing something on the car, as we know most jobs on the GTiR take about 6 months!

Anyway – once everything was reconnected we set my cambers:
o/s -1.9 and n/s -1.9 deg camber, Toe was also set at 0.0 and that was it!

Granted not everyone has a the tools for a camber and toe, but any garage can sort that out for you ;-)

The Conclusion

With my camber correctly set-up and the caster mod complete I can honestly say that the handling is more improved.
I have a specific road section that I use that helps me test my car and see/feel any improvements; whether new products or settings have helped or changed the way the car works.
The difference is noticeable when cornering at lower speeds. 20-70mph is where the real gains are. I could carry more speed into the corners without having to worry about understeer. On the exit again I could comfortably put the power down earlier and the car felt more stable. The only area that I could feel to be on any issue was the tyres. I had to push them to understeer, but the actual handling grip and stability has improved to my delight.

Granted, I had to build up myself up slowly, nor have I tried changing my ARB settings as yet, they are still on medium. Roundabouts used to be more of an inconvenience but now I can’t get enough of them, fast in and fast out and the car doesn’t even break out in a sweat. :thumbsup:

Would I recommend this, yes I would.
I think Jims work has been lost/overlooked here and something so simple and CHEAP could help our cars handle better.
I’ve really appreciated both Jim and Stu’s help and I would seriously consider looking into performing this action if you’re a keen driver down the B roads or trackday enthusiast. 8)

However, if you’re just going to rev your car on McDonalds restaurant car park all night for the little girlies then ignore all the posts above!
:yawn:
 

campbellju

Moderators
Staff member
Thanks Andy, I but still no one listens because its not yellow or silver :doh:

fubar andy said:
IHowever, if you’re just going to rev your car on McDonalds restaurant car park all night for the little girlies then ignore all the posts above! :yawn:
:lol::lol::lol::lol: Very true


@Animal, it depends how much camber you are getting with the adjustable top mounts. You might be alright but proceed with caution
Jim
 
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fubar andy

Moderator & N/W Rep
Staff member
campbellju said:
Thanks Andy, I but still no one listens because its not yellow or silver :doh:
At least we know whose pay out eh? ;-) :roll: :lol:

Anyway, it can be a bit daunting drilling into your pride and joy, but I can assure you if you take your time and read what’s been posted correctly then it should be no difficult than fitting a fmic.

This is my driver’s side strut, here it has been rotated clockwise.





And this is my passenger’s side strut, which has been rotated anti-clockwise.





But don’t be fooled here, I’ve not tuned them about 5-10mm they have tuned so that the threads on the coilovers have rotated to the next hole round, therefore requiring the drilling of a new hole :)

I'll shut up anyway, as Jim's posts are more detailed but you get the idea and the finished product 8)
 

davey red.r

New Member
just had all my toe alligment, camber, laser wheel alighment ,today,ill echo andys comments,the car is unbelivable the handling side of it just by getting it set up correctly:-D has made all the differance.
 

azboy

New Member
when i fitted my whitline caster bush kit i did notice it would turn in much better to a corner, the only bad thing is u have to turn the wheel more for the same turning then before but certainly notice the difference, i personally find the middle setting on the rear anti roll bar too hard so going to try the softest setting as the backend doesnt grip as well as with the standard antiroll bar, or maybe its just the front end gripping better now.
 

fubar andy

Moderator & N/W Rep
Staff member
I want to bring this up again, but more to do with the rear.

I was at a rally garage the other week when. I noticed a WRC focus with its rear wheel off. I noticed that the rear coilover had quite a few degrees of caster and it got me thinking.

Example:

image.jpg

I removed the rear wheel of my dub bus and low and behold that too was the same albeit with less castor angle.

Looking at the shed I can't see any angle on that, my question is would Jim's orginal idea for the front also work for the rear, adding more caster to aid turn in and stability?

I've done the front and noticed better turn in at 40-70mph, however I'm curious what and how the car would react if I did the same at the rear?

Front Caster on WRC Polo
image.jpg
 

PobodY

Moderators
Staff member
Clearly it does have a point or they wouldn't do it... but it might not be turn-in; perhaps it's ride related instead?

If it was turn-in, could it be that as the suspension compresses that side of the wheel-base becomes shorter, thus affecting a bias in drive? - That might make no sense to someone with more understanding than me, but I'm just trying to think about the mechanics of it.
 
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