Luxurious turning circle

[SPQR]

Does anyone know why the Luxury with 17" wheels has a larger turning circle than the Standard?

I found a previous post about fitting the Honda Luxury/Sport 17" wheels to the Standard that mentions the turning circle but nothing really illuminating on the subject.

http://www.ozhonda.com/forum/showthr...turning+circle

My car is a 2004 Standard to which I have fitted Luxury 17" wheels. It tramlines badly. The 17" wheels have the same offset as the 16" wheel. I wonder if the front suspension geometry is different? It might explaining the different turning circle and the tramlining.

Does anyone know?

[yfin]

Tramlining is caused mostly by the width of the tyre and the tyre tread. I also moved to 17" rims from the standard tyres and found it followed the road too easily with 225 wide tyres and directional tread.

The thing is changing to a 235 wide tyre and a non-directional tread significantly reduced the tramlining.

[Merlin086]

Does anyone know why the Luxury with 17" wheels has a larger turning circle than the Standard?

I found a previous post about fitting the Honda Luxury/Sport 17" wheels to the Standard that mentions the turning circle but nothing really illuminating on the subject.

http://www.ozhonda.com/forum/showthr...turning+circle

My car is a 2004 Standard to which I have fitted Luxury 17" wheels. It tramlines badly. The 17" wheels have the same offset as the 16" wheel. I wonder if the front suspension geometry is different? It might explaining the different turning circle and the tramlining.

Does anyone know?

I would have thought maybe a larger rolling diameter for the increase in turning circle.......

Damn, are those wheels still tramlining SPQR!.......

Only ever noticed a slight tramlining in the first month when new before you bought them, and the Avanti 17" that replaced them have a offset of 45mm.

Still a very slight tramlining effect, but then after lowering 45mm on Tein coilovers a month later I have found in almost a year now that the car goes wherever I point it with no tramlining except a couple of times on extremely grooved roads, but only then minor.

I have only just replaced the Bridgstone RE040 with Pirelli Dragons, and it seems even more direct.

Is it possible the steering geometry was altered between the 03-05 and the 06 on?
I had heard their was some suspension mods between models

[EuroDude]

The rolling diameter of the wheel between the stock 16" size and 17" size is only about 0.36% (17" uses lower profile tyre to near-match the 16" tyre), so the turning circle would be virtually identical.

The original 17" bridgestones have a drifting problem, so when its time to change, get some Pirelli Dragons or Yokohama C-Drives (Ive had both on my euro and they dont tramline or drift)

I dont think the suspension changed between the 03-05 and 06-08, but I know that the suspension of the Base model is different to the Luxury/Sport model.

[Merlin086]

The rolling diameter of the wheel between the stock 16" size and 17" size is only about 0.36% (17" uses lower profile tyre to near-match the 16" tyre), so the turning circle would be virtually identical.

The original 17" bridgestones have a drifting problem, so when its time to change, get some Pirelli Dragons or Yokohama C-Drives (Ive had both on my euro and they dont tramline or drift)

I dont think the suspension changed between the 03-05 and 06-08, but I know that the suspension of the Base model is different to the Luxury/Sport model.

As I stated above, I've been running the stock Bridgestones on my 06, and tramlining is almost non-existant, and reduced after increasing the track 20mm and lowering.

I don't think SPQR was running stock Bridgestone after purchasing the rims for his 04 and did so in a attempt to stop the tramlining, and is still getting severe tramlining.

That says to me it isn't the tyres at fault......

[SPQR]

I would have thought maybe a larger rolling diameter for the increase in turning circle.......


Is it possible the steering geometry was altered between the 03-05 and the 06 on?
I had heard their was some suspension mods between models

Hello Merlin086!

The 225/45R17 tyres of the Luxury and the 205/55R16 tyres of the Standard have virtually the same rolling diameter and the the 17" wheels and the 16" wheel have the same 55mm offset.

The Honda Australia website specification lists a turning circle of 10.8m for the Standard and 11.2m for the Luxury. Check the "Dimensions" tab at the following page:

http://www.honda.com.au/wps/wcm/conn...pecifications/

This to me suggests a difference in suspension geometry between the Standard and Luxury.

I remember that when the Luxury came out standard with 17" wheels, Honda said that the Luxury suspension was changed to suit the 17" wheels. I thought this was only to make the suspension softer to compensate for the reduced sidewall height but it might also have included a geometry change; perhaps to reduce tramlining.

I did try 17" wheels with the stock Bridgestone RE030 tyres. These were aftermarket with 45mm offset. The tramlining was quite evident. I did not think that Honda 17" wheels would have the problem.

The thread that I quoted in the first post (above) talked about a Honda Dealer telling a member that the 17" wheels would not fit the Euro with 16" wheels. Maybe there was a good reason for this.

I don't think the tramlining is such a problem on the Luxury as it is with the Standard fitted with 17" wheels.

[Merlin086]

Hmm, as the theory goes the main factor is supposedly the tyre width, so you should have noticed a increase in tramlining going from 205/16 to 225/17?

[SPQR]

I did not experience any tramlining with the standard 16" wheels and 205/55R16 tyres.

What I am suggesting is that the Luxury with 17" wheels has a larger turning circle resulting from a different front suspension geometry that might be so designed to counteract what would otherwise be the severe tramlining that would be experienced if the 17" and 225 section tyres (with straighter sidewalls) were fitted to the Luxury without any suspension changes. The tramlining is thus more evident on Standard Euros fitted with 17" and 225 section tyres because they were not designed for the wider section tyres.

The section width is the cause of the tramlining but, I suggest, Honda has counteracted this by changing the front suspension geometry of the Luxury to suit.

The 235 section tyres mentioned in a post above would ameliorate the problem because if fitted to the Honda 17" x 7" wheels, the sidewalls would be more rounded. This section tyre is not designed to fit a 7" wide rim.

I think that fitting 225/50R16 tyres to the 16" rim (correct rolling diameter) might also cause tramlining.

[JohnL]

Hello Merlin086!

The 225/45R17 tyres of the Luxury and the 205/55R16 tyres of the Standard have virtually the same rolling diameter and the the 17" wheels and the 16" wheel have the same 55mm offset.

The Honda Australia website specification lists a turning circle of 10.8m for the Standard and 11.2m for the Luxury. Check the "Dimensions" tab at the following page:

This to me suggests a difference in suspension geometry between the Standard and Luxury.

I remember that when the Luxury came out standard with 17" wheels, Honda said that the Luxury suspension was changed to suit the 17" wheels. I thought this was only to make the suspension softer to compensate for the reduced sidewall height but it might also have included a geometry change; perhaps to reduce tramlining.

I did try 17" wheels with the stock Bridgestone RE030 tyres. These were aftermarket with 45mm offset. The tramlining was quite evident. I did not think that Honda 17" wheels would have the problem.

The thread that I quoted in the first post (above) talked about a Honda Dealer telling a member that the 17" wheels would not fit the Euro with 16" wheels. Maybe there was a good reason for this.

It suggests at least a steering change to me. Assuming that the 17" wheels (fitted with wider tyres) are also wider in the rim than the 16" wheels fitted with the narrower tyre, or even only because the only tyres are wider, if the larger wheels have the same offset as the smaller wheels then the larger wheel and wider tyre will extend farther inward into the wheel well. This could mean interference problems with either bodywork or suspension components at full lock.

To address this Honda may have simply decreased the limits of lateral rack motion (?), thus a bigger turning circle.

[SPQR]

It suggests at least a steering change to me. Assuming that the 17" wheels (fitted with wider tyres) are also wider in the rim than the 16" wheels fitted with the narrower tyre, or even only because the only tyres are wider, if the larger wheels have the same offset as the smaller wheels then the larger wheel and wider tyre will extend farther inward into the wheel well. This could mean interference problems with either bodywork or suspension components at full lock.

To address this Honda may have simply decreased the limits of lateral rack motion (?), thus a bigger turning circle.

I don't know if Honda reduced the limits of lateral rack motion/full lock position of the Luxury: The 17" wheels fit the Standard Euro without interfering/touching with the suspension or other internal wheel-well objects. I have never encountered this even in hard cornering with the suspension fully loaded.

I still think the geometry change and larger turning circle might be so to address the tramlining that would otherwise happen.

[Exar Kun]

I don't know if Honda reduced the limits of lateral rack motion/full lock position of the Luxury: The 17" wheels fit the Standard Euro without interfering/touching with the suspension or other internal wheel-well objects. I have never encountered this even in hard cornering with the suspension fully loaded.

I still think the geometry change and larger turning circle might be so to address the tramlining that would otherwise happen.

Almost every review I've ever read has had the particular models in a range with a larger wheel/tyre package having a larger turning circle too. I'd always assumed this to be because of the reason above - i.e. the wheel extending further in towards the car.

[JohnL]

I don't know if Honda reduced the limits of lateral rack motion/full lock position of the Luxury: The 17" wheels fit the Standard Euro without interfering/touching with the suspension or other internal wheel-well objects. I have never encountered this even in hard cornering with the suspension fully loaded.

I still think the geometry change and larger turning circle might be so to address the tramlining that would otherwise happen.

You may be correct, but keep in mind that hard cornering doesn't necessarily mean hard cornering at full lock. Just because the tyre may never actually touch anything on full lock in practice (or when you've been cornering hard) doesn't necessarily mean that Honda may not have increased the clearance just to be absolutely certain it never happens. The design engineers may have a minimum clearance they never go under as a matter of principle or policy (?).

If other geometries have been altered to address any tramlining issues, I do wonder just what they might be. The only thing that springs to mind might be decreasing scrub radius (associated with wheel offset relative to the steering axis, so could be changed more easily with offset than suspension component alteration), but I'd imagine scrub radius would probably be minimal in the first place (?).

If you fit wider tyres then an increase in tramlining would be to be expected, the most practical way to address this to whatever degree would be to use tyres with a softer sidewall, even if in handling dynamic terms this might mean you take one step forward and one step back (or maybe two steps forward and one back as the wider rubber will give slightly improved grip levels).

Keep in mind the probable main reason for Honda to fit wider rubber (or offer it as a more expensive option) will likely be percieved customer demand for wider rubber, i.e. most people assume wider will be better (true or not, depending on the application, less so for front drivers not driven on baby bottom smooth race tracks), and also tend to just like the way it looks.

Honda may then choose a wider tyre with a relatively soft sidewall to pre-empt complaints about excessive tramlining, even if this might mean the OEM wider tyre offers relatively little dynamic improvement over the narrower OEM tyre with the taller but stiffer sidewall (??).