Improving feel and handling on an F50

[StarPD]

I'd like to improve steering and handling on my new-to-me 2005 Q45 without making it too harsh. I'm thinking of minor tweaks,and would like some feedback from the experts.

After careful study of the tech articles on the Tire Rack web site, it seems that setting alignment to the maximum adjustments within the ranges provided by the manufacturer can improve these things. I'm wondering what other small things might aid further. I'm already putting on 18X8-40 TSW wheels and 245/45ZR18 100W RE050A Pole Position tires.

Can for example, the bushings securing the steering system (rack) be cinched down tighter to reduce movement in it?

Are there sway bar bushings for the rear sway bar that are more or less intermediate, i.e., not hard polyurethane, but somewhere between that and the stock ones, to bring the sway bar into action sooner without stiffening it's action up too much like the poly ones are reputed to?

I don't want to replace the tension rods, springs, or shocks, or engage in major surgery, just a few minor upgrades/improvements. It's been my experience that several very small changes are more effective in bringing out the best in a car than going to extremes.

I'm not trying to make the car stiff and harsh. I like the car, but it's not as performance oriented or as "European" as my '94 Q45t was. I'd like to get closer to that without giving up the good ride and smoothness. The ;94 Q45 was an excellent blend of ride/handling characteristics. I'd like to enjoy more of that than I have now.

Am I alone, or does anyone else with an F50 feel the same way?

[Q45tech]

The end link arm/bushings are more or less fixed by design, set the front camber for -0.8.

Probably the front isolation subframe creates some mushiness [no solution that wouldn't destroy the ride].

You might be able to stiifen the steering via the pinion preload or designing a circuit to SLIGHTLY reduce or limit the speed voltage to the steering pressure computer.

[mcrews]

Today I am driving an 07 M35 loaner car.My 02 Q45 is in for it's 90k service.

Man what a difference in ride!!!!!!! and responsiveness of the engine/transmission.granted it is two different engines and platforms.

But to be honest, I really do like the Q.YEAH, it could be a smidge tighter but I accept that to get a really sweet ride.I would recommend that you get the stickest tire you can buy.

I have also wondered if nylon bushing on the sway bar would help.

mark

[Q45tech]

Nylon? Urethane maybe, however the sway bar is coupled differently than the 90-96 or 97-01 so not much slop to tighten up.

Remember the front stock bar supplied by oem is always too stiff and leads to front tire wash out understeer........................always work on the rear first.

[mcrews]

good point Q45tech.

I quess I meant "non-rubber" on the bushings.I realizes the my 66 mustang is YEARS apart in technology but the instalation of poloyuethane bushings on the end links of the front and rear sway bars made a noticeable difference.

I haven't really gotten under the Q to take a look.Mark

[StarPD]

Nylon? Urethane maybe, however the sway bar is coupled differently than the 90-96 or 97-01 so not much slop to tighten up.

Remember the front stock bar supplied by oem is always too stiff and leads to front tire wash out understeer........................always work on the rear first.

You are of course, absolutely correct. I took my 2005 F50 in for a 4 wheel alignment after putting new tires and wheels on it. In talking with Ken, the Service Supervisor about this, I learned that the only adjustments are toe-in front and rear. It was good that I took it in, as toe was considerably out of spec on both ends. Everything else was within specs.

Apparently, sway bar and steering is all mounted with pivots rather than bushigns, and the rack is bolted solid to the car, not on rubber bushings.

I agree on workiing on front first, as this car does understeer, but there's no alternate sway bar, and no way to soften the connections on it. Same goes for the rear sway bar and tightening it. Considering the small amount of F50s built, the market for suspension upgrades is too small for anyone to make up new items. Only if someone can discover other Nissan parts that might interchange can anything be done to improve road feel and handling.

I might add however that changing from the previous 20x7.5 wheels and Sumitomo 245/35 20-91 tires to 18x8 wheels and 245/45 18-100W RE050A Pole Position tires did reduce the understeer considerably. Not as much as I'd like, but better.