Curious about offset effect on steering

pwblacklock · Postby **pwblacklock** » Tue Feb 02, 2010 5:16 pm

Hi Guys,
I have an NA 6 for which I am getting some Watanabe 14x6 plus 14.5mm offset.
I have been trawling through the JDM site and drooling at the NA's with big dish wheels but can't help wondering what effect that sort of offset will have on steering (tramlining, bumpsteer, steering effort etc). I have power steering.
Any body wish to share their experience, make recommendations ?

Thanks

devolutio · Postby **devolutio** » Tue Feb 02, 2010 8:26 pm

should be related, on my ae86 with running stock castor, when i changed from stockish wheels to relatively low offset (+20mm) i lost all self centering. applying as much castor as i could with the stock suspension fixed the issue and i got my self centering steering back. very important on a drift car.

I assume the mx5 is probably better set up from stock so this may not be an issue... but keep it in mind. only other thing i could comment on would be wheel bearing wear - but thats a small price to pay.

talk to wazman he has a powersteering nb8a with pretty beefy offset wheels.

Adam_NAclubman · Postby **Adam_NAclubman** » Wed Feb 03, 2010 1:15 am

My 15x7 +17 Buddyclub P1's made my car feel like the wheels went from sitting flat to on an edge to flat again at around 80% lock... Grip, slip, grip, and you could feel it pull the wheel around.

The 14x6.5 +14.5 Watanabes (pwblacklock's new wheels) didn't do this though, and they werent really sitting that much further inboard than the outer edge of the P1's.

I don't know if maybe it was more to do with the tyres, 195/50 Yoko A539's on the P1's and 185/60 shopping trolley tyres on the Watanabes whick didn't have shoulders as squared off as the A539's had, or maybe it was the difference in grip between them. I'd always thought it was just the offset that made the P1's feel strange but the realisation that the Watanabes sat in pretty much the same position and the US guys that run 8 +0 wheels don't seem to complain about weird feel through the steering

pwblacklock · Postby **pwblacklock** » Wed Feb 03, 2010 11:27 am

Hi Adam,
That's reassuring. However, I would expect their to be some deterioration in steering with a significant change in wheel offset.
I suspect your experience with the larger wheel/tyre combo might be fairly common and I wonder if others have managed to regain steering feel with suspension geometry changes and if so, what those changes were.
Any experience out there with this ?

Phillip

Adam_NAclubman · Postby **Adam_NAclubman** » Wed Feb 03, 2010 5:34 pm

I'll let you know on the weekend if it feels any different with the stock wheels on compared to the Watanabes, I'm going for a drive on Saturday night

pwblacklock · Postby **pwblacklock** » Sat Feb 06, 2010 5:22 pm

Well, I fitted the Watanabe wheels with standard tyres and no noticeable deterioration in steering (with power steering fitted) was experienced.
Car is now cornering slightly flatter (60mm increase in track) and riding slightly firmer.Steering feels, if anything, sharper-probably due to the increased tension in the sidewallls of the 185/60 tyres on the 6.5" rim.
Overall, all seems positive, however to complete the "look",it needs lowering- and then run the risk of clearance problems, loss of supple ride, ground clearance issues and ingress and egress difficulties (for senior cit such as myself anyway)

Phillip