GMS - 2017 Alfa Romeo - 4C Coupe

As expected car was tramlining quite bad, so I did wheel alignment.

Before:

Front:

• Camber: -1*04' and -0*52'
• Caster: +2*09' and +2*02'
• Toe: -0*12' and -0*09'

Rear:

• Camber: -1*52' and -1*55'
• Toe: +0*17' and +0*12'

After:

Front:

• Camber: -1*05' and -0*51'
• Caster: +2*09' and +2*02'
• Toe: -0*04' and -0*04'

Rear:

• Camber: -1*52' and -2*04'
• Toe: +0*20' and +0*20'

Now conclusion is that this was a brand new car but alignment was quite out of specs, so it drove bad. There was too much front toe out. I reduced by more than half and turn in response is just as good as it was. No need to run more than about -0*5' toe out for good turn in response, but I would appreciate about -1*30' front camber for better midcorner grip and at least +4*0' of caster for straight line stability. I suggest everyone who didn't had alignment done yet, that they should do it. This is the cheapest and best mod you can do.

I'm still not happy with the results so I'm waiting for adjustment blocks to arrive for the front end, so I'll be able to add more caster which shall significantly improve tramlining. I'm also planing to run wider and stickier tires so a bit more front camber will be added.

That's it for now. I'm planing to go for a local time attack event this weekend, to see how car performs in comparison with my old BMW Z3M Coupe.

Hello,

Did the alignment yesterday after work. I took me about 4h to get blocks and shims installed and matched to get proper camber and caster.

I have installed "race" version of Jamie's blocks.

Before:

Front:
Camber: -1*05' and -0*51'
Caster: +2*09' and +2*02'
Toe: -0*04' and -0*04'

Rear:
Camber: -1*52' and -2*04'
Toe: +0*20' and +0*20'

After:

Front:
Camber: -1*43' and -1*31'
Caster: +4*28' and +4*08'
Toe: -0*04' and -0*04'

Rear:
Camber: -1*52' and -1*59'
Toe: +0*20' and +0*20'

In stock configuration I had 4x1mm shim under each left, lower wishbone and 3x1mm shim under each right, lower wishbone. I kept it this way, I've only added Jamie's "race" blocks. This gave me about additional -40' of camber.

As you can see alignment is still not perfect and it would take me a bit more time to sort it out with adding another 1mm shim under correct wishbone mount (in my case lower right rear wishbone - this would give me a bit more camber and caster on front right side), but I was happy with the results for now so I didn't bother, as I am planing to change the wheels with 17' and 18' setup with semislick tires, soon. I'll try to make it perfect then.

You also need to know that car is very light and therefore also very sensitive to the load. My measurement was done with me in a car (cca. 70kg). If I had a passenger, or the car was empty, alignment specs were almost identical left/right side.

After modification, steering effort is higher, you better feel response when you're getting towards the limit, there is much less tramlining and therefore car feels much more stable and gives you more confidence when pushing it. However you do loose some low speed turn in response because of higher caster, but it's not really a big deal as turn in response is still good enough. Honestly I didn't really understand the logic of stock 4C suspension geometry, so I was really looking forward to do this mod. Geometry specifications with this mod are quite similar to Lotus Elise/Exige now, which is somehow a synonym of perfect handling car. It's something Alfa should have done to 4C before handing over the cars to journalist and final customers. I believe this is a major flaw and reason for journalist bashing on handling of this car. But this is good for us customers, because we got a decent discount on a car no one wanted, because of a bad reviews. :grin2:

I went on a trackday, honestly more like an autox than a trackday, but it was a good time anyway.

Trunk is just big enough to put in 2 pairs of racing shoes and helmets, perfect!

I was suprised how much body roll car has, given its weight and not very grippy stock tires. I was expecting it to be more planted, but otherwise car was handling good and predictable for a stock setup, with a bit too much understeer. Good coilovers with adjustable swaybars and stickier tires should fix that. The most disappointing thing were stock seats. They offer almost no lateral support so you spend most of time dealing with not getting thrown around the car, which is really tiring and distracts you from focusing on a driving. I also disliked ABS interruption, which even in race mode felt too sensitive.

If I compare 4C to my BMW Z3M Coupe with well prepared, road legal trackday setup (300hp, 1300kg), 4C is much slower in current stock form. With Z3M Coupe, my best time was 52.xxx and it was among the fastest road legal cars on this track. My 4C best time was 56.xxx. Honestly, I was expecting it to be about second faster than this. I was pushing it as hard as I could, but I guess for a stock setup, that's it. However 4C was still fast enough for 4th overall time of a day, but competition wasn't strong that day.

Fuel consumption on a way to autox was about 6l / 100 km and on a track it was 34l / 100 km. :grin2:

Which suspension do you have, Gale?
That seems like an unusual amount of roll for that part of a curve. Perhaps the standard, not the optional track suspension?

Yes, a good set of coilovers and heavier roll bars will help.

Also as to the seats, I found that this helped me a lot:



http://www.cg-lock.com