Author Topic: Wheel combinations  (Read 655 times)

0 Members and 1 Guest are viewing this topic.

alfa duk

  • Full Member
  • ***
  • Posts: 223
  • AROCA Member #: 6530
Wheel combinations
« on: August 14, 2019, 07:44:53 PM »
Looking for comment about the ultimate wheel size for track use only. Consider that brakes will be upgraded from the standard bremboís, the car is an Alfetta 6 weighted at 1050 kgs. I have pondered the thought of wider rears like a Porsche but donít see it done so assume it doesnít work.
85 gtv6 dead, cant let go
84 gtv6 24 valve VRA spec
84 gtv6 andalusia
80 gtv group s

julianB

  • Full Member
  • ***
  • Posts: 169
Re: Wheel combinations
« Reply #1 on: August 15, 2019, 09:07:45 AM »
Having seen 17x9Ē and 18x9Ē under the back of GTV6s and 75s, I can say that it looks fantastic.
These cars have all have coilvers and the best front suspension tricks out there, so understeer isnít an issue.
I guess thatís what I would be worried about- too much rear traction. Having said that, Alfettas do tend to rotate well, when provoked!
They also had outboard rear brakes.
Given that a 911 has all of its weight hanging over the rear axle, the pendulum effect of that moment arm when traction is lost is massive (having spun a 930 turbo and nearly collected a barrier, im speaking from my one experience!). The tyres also help take advantage of the torque and help them with the amazing traction out of corners.

Althoigh mine is a road car (track-biased), Iíll definitely be running staggered 17x8F 17x9R.
I donít have a race class to satisfy.
Well, it appears that the VRA restriction on 15Ē wheels is the 105 mafia hanging on to the idea that they can be competitive against a serious 116/119/162. Which, with a 24v and all the suspension tricks out there, is never going to be possible.
So that has held back the development of  NSW Alfetta racers, big time.
Looking at what the Dutvh GTV6 and 75 racers have done, and others in Europe, youíre getting towards ultimate Alfetta chassis stuff and they all have big bore 24v, or turbo TS engines making north of 400hp, straight cut boxes with coolers,  running staggered setups.
Itís a pity we canít get to that stage in australia and have a class to run in competitively outside - for example, minimum weight for improved production is too high.
Anyway, my $0.02
85 GTV6 Zender "Juliet"
Ex GpA 2.5 screamer, soon to be GTA..
17" Zender Milanos
RSR kit
PACE knuckle risers
Restored tan pin stripe interior with Recaros
330mm Brembo conversion underway

'68 step nose Junior "Romeo"
bare metal project

GTVeloce

  • Hero Member
  • *****
  • Posts: 651
  • AROCA Member #: 4050
Re: Wheel combinations
« Reply #2 on: August 15, 2019, 12:07:37 PM »
Interestingly the Alfa SZ had bigger tyres on the rear (225 v 205) on 16in rims which is the same size as on my brothers 911 SC.

Colin Edwards

  • Hero Member
  • *****
  • Posts: 514
  • AROCA Member #: 5065
Re: Wheel combinations
« Reply #3 on: August 15, 2019, 12:48:01 PM »
Hi alfa duk,

Probably need to decide how far you are going with the proposed brake upgrade.  Wheel diameter permitting, its possible to fit 295mm dia, 310mm dia, 318mm dia and 330mm dia rotors to the front.  295mm or larger will require 16" wheels, while 318mm or larger will require 17" wheels.  No point whatsoever for running bigger diameter wheels than necessary - just increasing unsprung weight and burning $'s.

Choice of wheel diameter will also have significant impact on choice of tyres.

Given the Alfetta has near perfect weight distribution, a bit of extra capacity on the rear brakes is worth considering - especially if the car is lowered all round.  A fair bit of weight will remain on the rear end under braking.  The rear brakes will still contribute a fair bit to the overall package, so no need to go over the top with the front.  I fitted SZ spec rear braking to my 75 and improved the package heaps.  Going down this path doesn't increase unsprung weight - actually improves it as the sprung weight on the rear increases a tad!
« Last Edit: August 15, 2019, 12:50:53 PM by Colin Edwards »
Present
2018 Abarth 124 Spider
2015 Giulietta QV
1987 75 3.0

Past
2009 159 3.2 Ti Q4
2012 Giulietta TCT Veloce
2006 147 Ti 2 door Selespeed
1979 Alfasud Ti 1.5

vin sharp

  • Full Member
  • ***
  • Posts: 189
Re: Wheel combinations
« Reply #4 on: August 15, 2019, 10:16:59 PM »
It might more depend on what sizes the best tyres are available in or what you are allowed to run.
I used to run 8s on front & 9s on rear on improved production GTV6, but these were 15" & control A008r Yokos which were relatively short on grip anyway. Rear tyres were a management job anyway as lap 3 was best they got,  then deteriorated from there...
In any case, I do see that even these days there are not many more modern & modded Alfas that go much faster than the best of the Historic class Gp N & S cars running 14 X 195s, so sometimes I do wonder what all the fuss is about..... ::)

giulia_veloce

  • Sr. Member
  • ****
  • Posts: 402
  • AROCA Member #: 1500
Re: Wheel combinations
« Reply #5 on: August 16, 2019, 06:48:04 AM »
Julian B

The VRA rules at the beginning was for CAMS log Booked cars Group S + N and improved production Alfas.
Group S cars used 6 inch wide wheels and group N used 7 inch wide wheels.
The idea was to have an all Alfa Race with these 3 groups as per Log book.
The series ran for 15 great years with one meeting at Wakefield Park having 38 Group S + N + improved production CAMS Log Booked cars.
The series was very close racing.
Times have changed and Turbo 4 and 24 valve V6s joining the stable which is allowed now.
Anyone can spend money and build 400 + HP race cars,but that was not intended for when this VRA series started.
VRA will hopefully survive and race with these updated Alfas.
Hopefully the TS cup guys with 147,,156 + GTV coupe can keep the rules regulated as it seems the way to go for cost effective racing,,to get a car on track for under $10,000.
As for the the 105 mafia (your Words)..105s Log booked cars were very competitive for 15 years in VRA.winning many races to the VRA rules.

Julian B..maybe you can leed the way and build a 400+HP  Alfa monster.
You can not stop people spending money with the new rules.
Waiting for a TCR Giulietta to join the VRA series.
15 good years have gone,,so hopefully it will continue and encourage people to build cars.
As for me,,the TS cup rules (147,,,156 etc) is attractive now, and affordable for most people.


alfa duk

  • Full Member
  • ***
  • Posts: 223
  • AROCA Member #: 6530
Re: Wheel combinations
« Reply #6 on: August 17, 2019, 08:41:04 AM »
As I suspected, I would receive a variation of answers, but was hoping for more to establish a common size. The wheel size then dictates where you go with the brakes, upgrades are limited on 15s and expand as you go up in size. Me, I was looking at 16s, tyres are limited but available today however it is not the most popular size and would hate to do all the work and then tyres NLA, so 17s seem to be the way. Vin, you are right about the 15s going off early, with the vra racing, when the tyre rules were being discussed, it was thought that the late model fwd would cook their 17s mid race, but they never seem to have a problem with them.
Julian, you are probably right about the vra rules stemming the development in this area however I have a feeling things will change in the not too distant future. Just briefly, 18 years ago there was a lot 2 litre cars about fast forward to today, not so many as have seen a number of them destroyed, few new cars have been built, difficultly of parts location as well as specialist labour. But the issue is the competitors, number 1 age, 2 cost.
85 gtv6 dead, cant let go
84 gtv6 24 valve VRA spec
84 gtv6 andalusia
80 gtv group s

martym00se72

  • Full Member
  • ***
  • Posts: 210
  • AROCA Member #: 1152 (SA)
Re: Wheel combinations
« Reply #7 on: August 28, 2019, 12:38:10 PM »
The TS Cup sounds (on the surface anyway with no real knowledge) the same as our Formula 98 series - FWD 2 litre NA Alfa's built from 1998 on - road std car with exceptions of harness, pads (and this year slotted discs), cat back exhaust and minor suspension (Eibach red springs and Koni adjustable shocks). I got into it with a prepped car for $4k. The series is expanding and is great fun. You don't need a monster of a car to have fun on the track.
'83 GTV6 - 3.0 is in! Ohhh yeah!
'99 156 T-spark - Formula 98 ready!

What do people do with their old 2.5...?