16"s on willy track

[Slithers]

Anyone on here ever run 16"s on a willy track?

If so how do they compare to 15"s run on a willy track?

Obviously theyre gonna have a speed difference in favour of the 15"s but iirc the tarmc spec maxi's ran 16"s on a willy track.

So i guess my question is: Is there a grip/handling benefit that 16"s give over 15"s on a willy track?

[Winston]

I try'd some 16" on mine yesterday and it wouldn't move lol

They rubbed on standard ride height iirc with 45's

16" allowed them to fit bigger brakes....so not for handling

[Slithers]

I try'd some 16" on mine yesterday and it wouldn't move lol

They rubbed on standard ride height iirc with 45's

16" allowed them to fit bigger brakes....so not for handling

But surely if 16" alloys compromised the handling and speed as much as people say they do on a valver/willy, the works team would never have considered fitting them to the maxi, as what would have be gained in the braking areas would be eventually lose time in acceleration/speed and cornering?

[u33db]

Maxi, well grp A ran 7.5" (instead of 7" willy wheel) 16s so more grip. Can't remember if it was TB'd (that was only the 17" shod monster they did??) but i'd expect it to be tweaked so any performance drop the 16s cause would be outweighed or compensated for.

Those 16s were also a different offset from the road cars...

[Slithers]

Maxi, well grp A ran 7.5" (instead of 7" willy wheel) 16s so more grip. Can't remember if it was TB'd (that was only the 17" shod monster they did??) but i'd expect it to be tweaked so any performance drop the 16s cause would be outweighed or compensated for.

Those 16s were also a different offset from the road cars...

Yeah i get where your coming from but what im saying is that wouldn't it have been easier to run 15" wheels and be able to achieve a higher level of performance/handling, than you could on doint the similar tweaks and getting a lower level of performance/handling from 16" wheels, just for the sake of fitting bigger brakes?

I think that there must have been a characteristic of the 16" wheels that made it more suitable for tarmac use than the 15".

[clowo16v]

The diameter of a wheel makes no difference to handling just the width. With road wheels the difference in weight between a 15" and 16" wheel of the same style is quite noticeable and would probably make a slight handling difference due to the higher unsprung weight. However the Maxi wheels were probably very light anyway so this wouldn't matter.

See ya

Matt

[Slithers]

The diameter of a wheel makes no difference to handling just the width. With road wheels the difference in weight between a 15" and 16" wheel of the same style is quite noticeable and would probably make a slight handling difference due to the higher unsprung weight. However the Maxi wheels were probably very light anyway so this wouldn't matter.

See ya

Matt

Alright point taken but it still doesn't answer the question, cos a 15" wheel would have been lighter still than a lightened 16" wheel and would have had better handling charateristics.

So the question still remains........why did they use a 16" rim as opposed to a 15" on the maxi tarmac rally cars?

[Martin]

I thought they used 17s on tarmac.....I guess is was to get 260 bhp down better?

[u33db]

Theres a bit of confusion here;

- The maxi ran was wide bodied and ran 17s all the time,
- The grp A ran 16s and had the same (shell) appearance as a road going willy.

Both were TB'd altho i believe the maxi got quite a hike in power.

As for why the 16s over 15s, i have to side with Martin about the power...16s would be a better choice. However, last time i looked a 16" maxi wheel, the tyre profile was bit bigger than a 195/45...maybe some kind of gearing/top speed issue comes into it too (i.e. larger circumference = less work for the engine to travel faster).

[Mark_Ritchspeed]

16's and 17's will give you more grip in general, but will not improve handling. When your going for times though, the handling balance is not as important as outright grip.

[Slithers]

Theres a bit of confusion here;

- The maxi ran was wide bodied and ran 17s all the time,
- The grp A ran 16s and had the same (shell) appearance as a road going willy.

Both were TB'd altho i believe the maxi got quite a hike in power.

As for why the 16s over 15s, i have to side with Martin about the power...16s would be a better choice. However, last time i looked a 16" maxi wheel, the tyre profile was bit bigger than a 195/45...maybe some kind of gearing/top speed issue comes into it too (i.e. larger circumference = less work for the engine to travel faster).

Cheers dougal

So its feasible, that a 16" wheel has advantages over a 15" wheel in the traction and grip when on the willy chassis and delivering high power?

But loses out in the acceleration area?

[u33db]

But loses out in the acceleration area?

Yes, but that assuming you don't get wheelspin. I think once you reach a significant level of power, 15" wheels (well the rotating mass of) could be 'too' light to make best use of the power for the above reason. I mean, if 15's were always better, all these scoobys/evos/ferraris etc (i.e big bhp) wouldn't be running 17s...

[Zollo]

16's and 17's will give you more grip in general, but will not improve handling. When your going for times though, the handling balance is not as important as outright grip.

Would have said exactly the same thing. Chassis balance, predictability and progressive brake-away, are all things that make for a good handling car and things that road drivers need in abundance for a fun drive.

However, they're not top priority for rally drivers trying to shaved thousandths off their stage times. 16-17 inch wheels will give them their slight performance gains, at the expensive of anything else. World class rally drivers tend to be a little talented, so can cope with the hoping, skipping, snatchy, aggressive nature of bigger wheels.

They also have a car with coilovers, poly bushes, a roll cage and a seam welded chassis, which is set up precisely by pretty well qualified mechanics, that will help them make the bigger wheels work.

I like 15s :D