ALFAGTV6.COM

Although I understand the point regarding inertia, the issue must be more than simply inertia, otherwise you would be worried about the mass of the tires too. This would lead you to the most narrow wheel possible. So in reality it is traction and inertia right? Maximum traction with the least amount of mass possible.

That is the goal Glenn, you got it.

-Brian

So other than cosmetics, the only advantage of 17 inch wheels versus 16 (assume the same tire tread pattern and tire width) is the minor additional amount of rubber on the road?

Uhh, 16" to 17" has no impact on the contact surface. A 17" will fit larger rotors and calibers than a 16" wheel, but that is somewhat academic (in most cases). Given same circumference of the wheel+tire combo the 17" wheel will typically give you a slightly rougher ride. Side walls are obviously lower on the 17" potentially affecting handling.

Jes

First you need to see what sizes are available for the tire you are going to use. That usually ruins every dream you have because our cars have pahtetically small tires to begin with (hence, less tires available outside 15")

You should look into the rulebook for your class to if you're going to race, sometimes there are stuff there that can give you an edge. Example: In the Supertouring rules you must have enough ground clearance to be able to drive the car without air in the tires on one side without scraping the body on the asphalt...
Thats why they all have 19" rims with VERY low profile tires, that way they can have very low cars.

Sidewall stability is naturally something you gain with low profile tires (i.e. bigger rims) but he tire is less forgiving usually, higher definition but less forgiving.

Usually 17" tires are twice as expensive as 15" too...

Also, if you go too big with the wheels and tyres, when you set the car to the required lower ride height, the front wishbones and steering arms will be at crap angle.

You will also give the rear driveshaft joints a hard time as they'll be angled up also.

I had purchased Ronal rims a year and half ago and about after six months the clear coat finish started to crack and haze. I have been emailing the co. back and forth for a year now insisting that the finish is defective. However they insist that it is not. The rims have only ever been washed with armoral car soap and then they get mothers carnuba wax. So far all they can offer me is a $175 cost to reclear coat each wheel and i have to pay shipping to and fro California. Has anyone had a bad experience with these rims or any Ronal rim? If you could pm me or post that would be fantastic.
I thought the site was lost.. Thank god it is not,
Vittorio

What is Ronal saying to you, something like: "you must have driven through some type of caustic, or acidic liquid? The one picture sure looks like Aluminum oxidation under the clear coat, but it is difficult to tell.

I just ordered a set of rims earlier this week from Ronal. I hope we do not end up with the same sort of problem.

Good luck!

Hey guys. I have just had these compomotives refurbished to there original condition as they were one of original three types of rims that were fitted to our South African GTV 3.0l's. Pitty they are only 7jx15''. Im going to fit them on the 3.3 24v for our Alfa Romeo day at Kyalami on 23 April. I would love to get a set of these in 17".

Here's a coupe of pictures with the 18" Mille Miglia wheels on the Milano with the spacers. The spacers are a little hard to see in the pictures but you get the idea.

The wheels are 18x8 35ET, tires are 215/35-18. Don't think I could go any larger than that without rubbing.

-Peter

Brian, Mats help me out here. What would technically be the best size rim and tire for the GTV for racing(smooth track surface- less effect from unsprung mass)) with the max size rim of 17'' min size 15'' and max width of 235mm for tire. In this instance dont worry about brakes and ratios. All the rims are 'lightweight' with the 15'' being 'only' 3kg lighter than the 17''. Would a 17'' with 235/40 be better than 15'' with235/40s' relating to suspension ride heights.

Hmm, several things to bring into the eqation.

What gearings can you choose from, speed needed, what tyres are available, minimum ride height, rims available....

A friend of mine uses ETCC rims on his GTV, seems to work well, 235mm on 9x17 rims.
Can be difficult to find wide enough rims in smaller sizes (and tyres too).
From what I can get here I would have to say that 17" rims is the only option för 235 wide tyres.

235 on 17"? Is this the "Morberg" GTV? Damn that car looks awesome! I had 225/50/16 on my car and it really made the car slower (straightline acceleration) However due to the fact that there were R comp. tires, the car just flew through the turns.

Here in the US 16" wheel means very limited R comp. tire choices. In Europe and Asia you can get R comp. tires in sizes like 225/45/16 which would be ideal.

May as well stick with 15" or take the jump to 17" wheels.

Yes, that is Moberg's GTV.
Did you measure the acceleration (ET or similar) or was it the old seat-of-pants dyno? I'm sticking to 205's because the 225/50-15 is too large diameter, and you went an inch larger? Merde...

16" is really not the best choise for a track car, seriously difficult to get the right diameter tires (yes here too).
I still haven't used fifth gear in anger and larger tires wouldn't be beneficial in any way right now.

Hi Mats, ratios are not a problem at all as I have quite few gearboxes with an asorment of ratios to choose from(compliments of Julian) and im limiting top end to +- 200km/h . Brakes are AP and fit in 15'' so no problem with braking. Ride is limited to 80-100mm clearance under sump. (not to low as got to drive home from track).
I have various sets of 17'' rims with 235/40 and 15'' with 205/50's.
We run on semi slicks and can also go 235 on the 15'' rims. The question is what would you go for in these circumstances if only road handling was to be considered for GTV with 'standard 'suspension(no coil overs but 28mm torsion bars and Bilstein shocks). thanks