Wheel advice (again!)

[riverflyer]

Hey all,
Could someone explain to me how wheels with the following specs would fit the Z8?
Fr 19x8.5 +32
Rear: 19x11+25

My car came with 20"HRE's and although I like them, I keep thinking 19's would be lighter, handle better and ride better.

Anyone with a direct comparison bewtween 19" and 20" in a short period of time who could offer their observations?

Damn, I love my Z. I even take people out to the garage who have never seen one just to show them how beautiful a design it is!

[Scott Pettit]

Screw the cars... I like the garage!

[macfly]

I'd suggest that you'd get less understeer and better balance following GM's 19" rim sizes, which I think are 19x9 and 19x10 rather than the 8.5 & 11 you noted above.
The tire sizes he uses are 65/35/19 f - 285/35/19 r

I'd only run 20" rims on a Z8 if it has the complementing Alpina suspension, with either stock, or Dinan suspension I'd do 19" with Michelin Pilot Sport 2's.

[riverflyer]

thanks Andrew. I think thats the setup that dinan also recommends for the e46 m3 to combat understeer and offer the best handling.


I know you have spent a lot of time dialing in wheels, what are your thoughts on using spacers.
I have a factory fresh set of HRE wheels that I really like and are 19x9 and 19x10 but i think would require a small spacer in the rear. I have not mounted one yet to be sure it clears the brembos but with the correct spacer it will.

[macfly]

There is no problem using spacers so long as you use long lug bolts and make sure that your rims don't contact the body panels on the outside. The guys at Bimmerworld supply spacers with bolts - link (http://store.bimmerworld.com/shared/StoreFront/default.asp?CS=bimmerworl&StoreType=BtoC&Count1=338146388&Count2=255286812) in the Wheels section of their site.

[RRZ8]

Hey all,
Could someone explain to me how wheels with the following specs would fit the Z8?
Fr 19x8.5 +32
Rear: 19x11+25

My car came with 20"HRE's and although I like them, I keep thinking 19's would be lighter, handle better and ride better.

Anyone with a direct comparison bewtween 19" and 20" in a short period of time who could offer their observations?

Damn, I love my Z. I even take people out to the garage who have never seen one just to show them how beautiful a design it is!



Great cars Riverflyer!

[riverflyer]

Great cars Riverflyer!

Thanks.
Thats only half of them! Its a sickness!
I thought the tightening up with regard to our new economy would save me but there are so many really good deals out there the temptations are brutal.:eek:

I do know the Z8 is one of the keepers for sure.

[Scott Pettit]

Where is the lift in your garage. Damn, I'm still drooling.

[riverflyer]

Hi Scott, no lift yet, just another garage. I used to use the argument (with my self) that it was a good investment. Well of course, almost everything was a good investment over the recent past! Now I have felt fortunate to be able to change some things up and sell a couple of good cars and am feeling pretty reasonable right now!!;)

[Scott Pettit]

Where are you located?

Scott

[Scott Pettit]

Just FYI, BMW highly advises against spacers since their rims are hub centric and I agree with them.

I know that a lot of folks use them but I don't recommend it.

Scott

[macfly]

I have used them on some cars, but only with extended bolts.

[riverflyer]

I thought that there were hubcentric spacers available. No??

Scott, I live on the north coast of California. Lovely, wild and some very fun roads although road surface conditions are deteriorating with the economy!!

[macfly]

There are, you should find them at these places...
http://www.dinancars.com/
http://www.bimmerworld.com/
http://www.bavauto.com/

[riverflyer]

thanks for the links Andrew. I would think with the correct hubcentric spacers that they would work fine with no loss of suspension efficiency. Was that your experience?

[macfly]

Yes, with the extended bolts it should be no problem. I know Dinan recommend front spacers for our car, to lessen the understeer, while they say leave the rears alone. I like little spaciing on the rears to fill the wheel wells visually, but beware of hitting the inside fender lining. On my BMW 20" rims there is no room to space the rears, but a bit to space the fronts - however I haven't bothered to do that as I simply don't drive the Z8 that fast anymore!

[Grease Monkey]

I agree with Mac on the use of spacers. As long as you use longer lug bolts to compensate for the spacing out from the hub, and use hub centric spacers, there is no problem using them on a Z8. In fact, Porsche has used hub centric spacers for years on their cars to allow different style wheels to be fitted to different models. I would look for T.U.V. approved spacers to insure the highest quality. When installing them on the rear of a Z8, be careful not to use lug bolts that are too long. If they penetrate inside the hub, they can interfere with the parking brake mechanism and stop the hubs from turning. Hub centric spacers of 10mm or more should have their own extended flange which duplicates the hub centric mounting feature of the hubs themselves and insures perfect centering of the wheel. Thinner spacers, while still being hub centric, will lack the extended flange due to a lack of material thickness to work with. Fortunately, on a Z8, a 5mm spacer is thin enough to allow the hub's flange to protrude through the spacer and this can be used to center the wheels on the spacer. 8mm is too thick and I don't recommend using them. In my experience, 5mm up front and 10mm in the back works very nicely. Another thing to consider, particularly if you want to experiment with different sizes of spacers, is to add wheel studs to your hubs and use lug nuts, instead of bolts, to fasten your wheels. This allows you to try a variety of spacers without having to have multiple lengths of lug bolts on hand plus it makes it easier to mount your wheels since the studs act as supporting guides during the installation process. My favorite spacers are the ones made by H&R which are carried by BMP Design (http://www.bmpdesign.com/). They can also supply the correct length lug bolts or wheel studs and lug nuts. One other point: Dinan recommends the use of spacers up front because their wheels will not fit on the Z8 without them, while their wheels will fit on the rear without spacers. Dinan uses a reduction in front to rear tire stagger, not spacers, to reduce understeer.