I need to know what people think is the best wheel offset is for a S/C Z. I am getting 19x9.5 fronts and 19x11 in the rear. I will be rolling the rear fenders if needed. I think that offsets are sometimes different when you are running FI. I am getting the Work Meister S-1 wheels and found some people here with them but no FI setup. Soooo what offset would be the best looking and aggressive. +25front +29rear? Please help!!!

 

+29

+25 would stick out further and be harder to deal with

what size tire you putting on?

 

What does NA or FI have to do with wheel offsets?

 

it doesn't

 

i been asking myself the same questions... but look at his other threads in this Forum... he is being EXTRA carefull with EVERYTHING..

i guess next will be what parking light bulbs with FI

 

I guess everyone is playing extra nice. This should be in the wheel section.

 

well in a round about way..............................
he wants to run super wide tires on his 11" wide rims to put as much power on the ground as possible

 

That is true aritrackk. I guess wheel offset has nothing to do with FI. I will head to the wheel and tire forum. Sorry for bothering everyone with a bad question in a wrong forum.

 

Yeah, but if you stagger it too much, you'll get a lot of understeer.
If I were you, I'd try to stuff as much tyre as I could in front well and not exceed it by more then 10-20 mm in the rear...
A good reference would be the Project 350Z from Sport Compact Car mag...
These guys broke 1.0g on skidpad by only changing wheels, say bars and LSD...
Try to source the mag. Contact me if you cannot and I'll see if I have that issue, then I'll either scan that article, or send you the info...

 

Article you're referring to is right here:

http://www.sportcompactcarweb.com/tech/0404scc_350z/

I used this as the pattern for my setup, works great!

 

^WOW that was alot of info that I did not understand. Sorry. I just need to know what tire size is good for the +24front and +23rear with 19" rims. I want a decent amount of tire with no rubbing. I feel unsmart right now. Tire sizes are confusing.

 

+23 offset on the rear isn't going to leave you much room to to really wide with tires I don't think. You might be limited to 285 or maybe 295

 

265/35 front and 285/35 rear is the tire size people are telling me to get for the +24 and +23 offset. I dont know if this is wide enough for FI. I want a wide tire for FI. I guess there is no simple anwser seeing most of the guys in the Wheel and Tire forum are not FI.

 

My rears are 10" wheels with 15mm spacers. The offsets weren't that great, but the lip in the rear sits at about where a +19 volk 10.5" wheel would. I also have camber arms which correct it to -.08 deg camber, which lessens the clearance. I have 285/35's on them with cut fenders, and the spacing is about perfect.

My car understeers a bit at the moment, but I'm not sure if the wheels are the contributing factor. I need to put some sways and other suspension mods in before I consider changing them.

 

also make sure you can fit a BBK, in case you ever want to add that later

 

Like others have said, your tire size has nothing to do with how your engine breathes. From what you've said, you want wide tires in the back to get the most traction in the rear end. So FI/NA makes no difference. Just ask that simple question, "What is the widest tire/wheel combo I can run in the rear end".

To answer that question, do some searching, but I'd say a 285 is the best you're going to get without getting into body work of some kind. A 285 can generally be mounted on a 10"-11" wide wheel. I personally don't like the "stretched" look so I'd mount it on a 10 or 10.5, but to each their own. A wider wheel WILL give you a slightly larger contact patch with the same tire, so if you don't care about what the sidewall looks like, go with the 11" wheel. An offset in the +25 to +30 range will work, from what I've seen of various setups.

I don't actually run this fitment, so don't take that as gospel. Check to find someone running the exact wheel/tire combo you want to make sure. Yes, there is a lot to look at when changing your wheels and tires, when you start pushing the bounds of "what will fit?"

-E

 

yeah i kinda wonder about the 315/30/18 people run on 9.5 inch rims if in the end, it ends up having the same contact patch as a 295/35/18 on a 10.5 inch rim since there'd be less bulge and more reinforcement from the rim and also larger diameter which means more length touching the ground

28-35mm offset is probably the ideal offset to get the widest tire.

 

+23 285/35 will rub on bumpy roads or with 2 heavy passengers, even on stock suspension. Friend of mine has this set up and it rubbed on a bumpy road BAD-was cutting into the top of the sidewall. I rolled his fenders last night, he shouldnt have problems anymore If you want to go BIG like 305+ find something around +30-33 offset and run a 10-10.5" wheel. People with Nismo rims are running 315's on them and its only a 9.5" rim-I wouldnt do it but they dont seem to have issues.

 

I definitely wouldn't vary from the manufacturer's specs on what size wheel to mount a tire on. You're just asking for irregular tire wear, less traction, and possible safety issues such as seperation, popping a bead, etc. I imagine most of the guys who do this don't track their car and introduce serious side-loads.

One thing to remember is that bigger tires aren't the only thing to consider here. For one, most of the stickiest tires don't come in 19s. So right away you're limiting your traction by specifying a 19" wheel. Secondly, the right suspension setup for your intended purpose will make more of a difference than 20mm more tire tread. If you want max straight line acceleration, you'll need a different setup than someone who wants max cornering. Getting 285s flat on the pavement will work far better than 305s with a lot of camber. Spring rates and tire pressure affect this too.

I don't mean to sound harsh, but when you decide to run larger horsepower numbers, the cost and complexity go up quickly. Research, research, research. There are no simple answers, and no one knows it all. Questions are welcome, but you'd better be prepared for some serious skull sweat to get into this.

Places to learn more:

www.tirerack.com (read every article in their tech section till you understand them)
www.1010tires.com (play with their tire size calculator till you understand the math involved on tire sizing, and read all their tech articles)
http://www.familycar.com/alignment.htm (read and understand every aspect of basic suspension geometry and how they affect your driving, so you know what changing your tire sizes and offsets will do)

-E

 

Thanks to all.