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4C Steering geometry

96K views 371 replies 62 participants last post by  Chris1712 
#1 ·
I've owned my 4C Spider for 4 weeks and love everything about it, well almost everything. :frown2:I have a few local roads (narrow lanes to be precise) that I use to exercise all of my five Alfas. However, I have found that the 4C, and don't forget this has the latest steering upgrade, still tends to wander a bit too much on some surfaces and can also tramline if you encounter lorry ruts on the motorway. My attention was recently drawn to an article in the AROC-UK magazine written by Jamie Porter, the Alfa specialist in Royston, who has done some work on the steering geometry. There was also a report by the club chairman who posted his opinion on these changes to the geometry on the AROC forum having driven the car a few days ago. This led me to contact Jamie who invited me down to drive the car and give my opinion on the changes he's made. I'll not go too deep into the 40 bhp increase, the custom exhaust, or the rear suspension bushes, but I'm happy to report that the revised steering geometry is a revelation. I drove Jamie's 4C Coupe on all types of road surfaces around Royston, many of which replicated those I encounter in my local area and I have to say that the changes make a big difference. Apparently the changes to the camber and toe are quite small and have been arrived at by a lot of trial and error, they certainly make driving the car so much more relaxing. I'll be making arrangements to get mine done very soon. :smile2:

Arnold
 
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#2 ·
Care to post the toe and camber alignment settings when you get them? I'd love to be able to dial this out with an alignment.
 
#4 ·
Ditto, if Jamie is willing to share. Obviously, it is his effort, and his option.
I'm guessing that the bushing changes are an issue only at hard cornering, so the improvements you noted are solely from the alignment.
I have forgotten - is the car still running on stock rubber?
 
#5 · (Edited)
Stock rubber and original more extreme sport pack, I avoided the pitstop! There are two issues with the suspension which we have managed to sort out. The changes work just as well with all tyres and the bushes at the rear do allow more grip to be extracted. We have tested the new settings on our own car extensively and they work very well. We have also shared them with a couple of members of the forum to try, but just for the moment I have asked them to keep it to themselves. The mods on the front suspension are not expensive we are working on the production process for the rear today, at the moment the rear wishbone machining is done by hand
 
#6 ·
Hi Guys, below is my latest report on my 4C Spider just posted on the AROC-UK forum regarding the revised steering geometry.

After a horrendous drive this morning down to Jamie Porter's at Royston (A14 congestion was terrible) I finally arrived at the 'Alfa Workshop' for Jamie Porter to work his magic on the steering geometry of my 4C Spider. Having already clocked up about 1200 miles I was really getting into the spirit of things with the car and beginning to push on a bit more than usual. The 4C really is a great car but needed this particular geometry tweak to make it brilliant. I have not been so happy with the behaviour of the car on some road surfaces and, having test driven Jamie's 4C which had had the geometry sorted, I was keen to get mine done.
There are still some local 'problem' roads around here that I still have to test the car on, but I'm confident that the new geometry settings have cured what can be an unsettling experience, certainly first impressions are great. On the journey home I found the car to be so much so much more pleasant and relaxing to drive than before. This vast improvement is down to a lot of deveolpment work by Jamie involving the addition of shims in the right places and a lot, and I mean a lot, of fine tuning on the toe in/out by Jamie and Ben who are perfectionists when it comes to doing the job. I am well pleased.

Updates later.

Arnold S. (AKA AlfaArnold)
 
#7 ·
Hi AlfaArnold,

Nice review, I too had my 4C set up by Jamie and the results are night and day in my opinion. I'm thinking about stiffer springs in the front though to dial out the remaining understeer and a set of lightweight OZ Ultraleggera's with some stickier rubber so may need further fine tuning. Did you go for the ECU upgrade?

Will77
 
#8 ·
Jamie - a question about shims. While I wait for you to release your recipe, I have 16 shims waiting for me at the dealer. I ordered these before learning of your improved shims. Will I have any issues using them? Because, well, they want me to pay for them.
 
#10 ·
Jamie, i appreciated much you gave an insight of what the rear arms modifications do, did you write anywhere what the front ones do also? Are the front and rear arms planned to be changed together and at the same time or are they indipendent.
I have some other four people here in italy interested (well.. i'm the fifth but i don't have the car yet), for track use.. at this time we have done some setup work by adding negative camber and changing the from caster using shims, but what we are looking is modified arms for a "cleaner" caster management and more negative camber.. it would be useful to understand if the suspension arms you made address this or not, and if they add more.. thanks :)
 
#11 ·
To make this car handle properly you need to sort out the front suspension geometry which we will release around christmas. The rear wishbone then becomes the issue and once you have replaced that a set of front springs and you will be the fasted car on the track!!!! The front arms we supply dont change anything yet but we are working on that.
 
#12 ·
Oh, ok.. so let me see if i get it right.. the front for now is "just" geometry work, and the arms on the site have no changes from the standard ones, for now... there is no hardware modification involved yet. Rear whishbone, you already explained. Springs and geometry improve and match with the work done at the back, so if someone wants to go with your setup needs to wait for the setup to be finalized, buy the springs and just the rear arms.. no need of the front ones..
 
#13 · (Edited)
The front is instability is just a geometry issue, the rear is a problem with the bush causing rear steer, then any of the after market set-ups from KW Bilstien etc will work with the car it well as they all use a stiffer front springs, all my modifications do is show up the inherent chassis behaviour and allow you to push the limits of the car. They make absolutely no difference to ride quality as that is down to springs and dampers
 
#17 ·
All I've had done is the steering geometry, after the fun I had in the 4C yesterday it's highly unlikely I would want a bhp increase. There's an outside chance I might have the rear suspension revised but I reckon the car is doing everything I want at the moment. I'm getting on in years and, although I drive quite 'briskly', tend not to take the car to too close to its' current handling limits. I've done quite a few track days in my Alfas but tend to err on the side of caution on the public roads.

Arnold S.
 
#20 · (Edited)
Just picked up my 4C this week and I'm in LOVE... except for the wandering steering that constantly needs correction, especially at high speeds and rough roads.

@jamiealfa Any updates on the release of your fix for this instability? Thank you.
The front geometry modification is now available, go to our web site (link below) go to 4C parts then performance parts and scroll down until you see the anodised blocks.
www.alfaworkshop.co.uk
 
#22 · (Edited)
Am I the only person that finds this thread incompressible? I don't mean to be gruff, but it's all a bit cloak and dagger for an enthusiast forum. I can find no real data on what exactly is being changed.

Is there a direct link? Has anyone found an actual direct link to a product or information? I have found one to a jammed pack website, but no link to a specific product. I did find another bunch of glowing reviews, but for what, I can't tell.

Please share if you have.

Thx
 
#23 · (Edited)
Hi Penquinn,
You've obviously found the Alfaworkshop website. Look across to the far right of the horizontal menu near the top of the page and you'll find "parts". Click or tap on that. The page that appears has a list of cars Alfa workshop supplies parts for. Click or tap on "4C". The page that appears has a list of parts. On the far right hand side click on "performance parts" and you'll arrive. The only trouble is Jamie is disclosing the front settings only to those who purchase his suspension blocks, I assume. Understandable, since he's done the development work. The modified rear arms are there too. Hope this helps. Regards
 
#24 · (Edited)
Sorry BlackPenquin, you are right I have kept the settings quiet until I had extensively tested them, I am sure you appreciate that we have made quite a number of changes and each one has been thoroughly tested, some have been good and some have been discarded until we have got to this solution. The solution we have come up with changes both camber, castor and toe and is simple to fit, you leave all the thin shims that Alfa have used to achieve the factory geometry set up in place and you change the mounting blocks between the shims and the wishbone, the blocks we supply are all different sizes and are color coded to denote the position they go in on the car, these blocks change the geometry for you. Once these blocks are fitted all you have to do is change the toe and the car is transformed, the nervousness goes the dead spot in the straight ahead position disappears and the steering becomes very precise. here is a link to our performance parts page If you need further info please contact me using the details below
 
#33 · (Edited)
Thanks guys. I was trying to follow the thread, but could not make head nor tail of it.

I'd love to see some track times before and after, or a real driving review from a hot shoe that can explain.

I don't find the current car setup a chore, but I always put the GT3 setup on my Porsches, with monoballs and a proper alignment. Of course info in the Porsche world is abundant. Same goes for Lotus (less people but rabid and friendly).

I will have my shop call you in the spring to discuss. Looking forward to hearing more.

Thanks!!
 
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