SDGenius

iTrader: (1)

4SHIZZIL

iTrader: (10)

305s on 370z 19x10 for now...345s to come. Fronts running 275

Waiz

iTrader: (57)

You can blame the wacky engineers at XXR for the weird sizing.

scotts300

iTrader: (46)

Looks like a G with 370 wheels. ? . ? I assume your 345-wish is with different wheels, as they are too big for the 370 wheel.

805350z

iTrader: (7)

yeah 5mm in rear. might go 8, but im not 100% sure yet.

Yessir.

jarrodh77

iTrader: (20)

Alright, I've got the itch to go all out with my autocross setup once my current tires wear out. I'm going for 295F 315R x18 Hoosier A6, and I want the widest contact patch possible (widest wheels). I'm considering a 18x11 +28 front, 18x12 +36 rear. I'd rather overestimate the offset and use spacers to get it perfect. I used some of the setups in this thread and an online calculator to come up with what I think will work. Has anyone tried something similar? I have rolled fenders and will pull them slightly if I have to, but I want to avoid any major fender work for now.

BTW - I'm looking at the Forgestar F14. They're available in 18x10, 18x11, and 18x12, in a wide range of offsets. Similar weight to a RPF1, and less $$ than CCW, etc.

KingBaby

iTrader: (3)

^^^

Do it man!

I like the F14s weight and the offsets they come in...dunno but can someone chime in on the qaulity of them compared to Enkeis as a track wheel.

terrasmak

iTrader: (8)

With an 11 you will need it at +15 up front to clear the spindle. Easy way to check is off the offset calc , 9.5 +35 clears only by a few MM , 11 +15 has 1mm extra clearance. I would do 10.5 +20 up front if i was having custom made for widest tires.

Rear i would go 11.5 +25 , which is also going on know rear offsets to a close to clearing the inside.

SoCal07HR

iTrader: (17)

I'd go 18x10 +25 front and 18x11 +30 rear and fit those tires under the fender. Your wheel idea isnt going to put all the tire under the fender anyway so why not run those sizes with 305 f 335 r?

The 18x11 +30 inner clearance



The 18x10 +25 inner clearance

03threefiftyz

iTrader: (25)

Worth mentioning....every Forgestar F14 I have ever seen has been over the listed weight. I'd expect an 18x11 to be in the 22-23lb range. That's a good 4lbs heavier than the cheaper 18x10.5" RPF1.

jarrodh77

iTrader: (20)

Thanks SoCal07HR for the pics and measurements. That is extremely helpful.

I think the magic number for inner clearance on an 11" wheel up front is +16. The wheel would extend outward 1" more than the 18x10 +28(with spacers) RPF1 that has been used with a 305/30 tire. However, the 295/30 tire would be shorter and bulge much less on the 11" rim. Another calculator I used shows the 295 tire on an 11" rim extends 7mm more than the 305 on 10". I think that could be made to fit with only a slight fender pull, if even that.

In the rear, maximum offset for inner clearance of a 12" wheel looks like about +26. According to the calculator, the 315 tire on a 12" wheel will extend 17mm farther than the one in the below pic (315 on 18x10.5 +43). There is some space leftover there, and the rest could be handled by rolling flat and a slight pull. 2 degrees of camber will help too.


I know the safe bet would be a 10/11" stagger, but I don't think I will be satisfied unless I know the envelope has been thoroughly pushed to the limits. I'd probably end up spending money down the road on a wider setup. I've looked all over, and the only Zs I've seen with 11-12+ widths are the hardparking hellaflushers with 90 degrees camber and 225 tires.

jarrodh77

iTrader: (20)

I'm sure you have more experience than I do, but I based my statement on the weights from this link: http://www.forgestar.com/blog/?p=374. The weights listed are very comparable to advertised RPF1 weights in the same sizes. The 8.5 is actually lighter, and the rest are within 1 pound. I'm a big RPF1 fan, but they don't offer anything over 10.5", and the +15 offset isn't ideal for stuffing maximum rubber.

I talked to a vendor tonight who can get them for $1400 shipped. Wait time is 8-12 weeks, but they only require $700 down at the time the order is placed. I'm close to pulling the trigger.

graffkid732

iTrader: (44)

I'm running a 19x11.5 with a 305 in the rear. Not gonna be hard parked at all 19x10 285 up front.

SoCal07HR

iTrader: (17)

Looks like you've done your homework and this is what you want so I say go for it. It is gonna be a tight fit. I will be running the same setup eventually on my 10 and 11 inch staggered setup. good luck, post pics!

scotts300

iTrader: (46)

That's good data (about the 10" +28 with the 305) and a good picture (with data) - wonder where you got it? Glad it could all be useful. . .

Useless info without offsets! ! !

graffkid732

iTrader: (44)

Rear:
19x11.5 +18 305/30/19

Front:
19x10 +19 285/30/19

Have Seibon CF front fenders which are +10mm wider than stock. Will be rolling/cutting rear fenders. Looking to run as little camber as ppossible.

scotts300

iTrader: (46)

I don't have any issue with the sizing in the front - even without the wider front fenders. I imagine you may even want to space the fronts out a bit with that front fender.

I am concerned about how you've made the rears fit, as I've had many sets of 10.5" wheels in various offsets rub with a smaller tire - even with rolled fenders and camber. Any pics of how it sits now?

graffkid732

iTrader: (44)

In pieces. Going to body shop soon. A lot of changes this winter. Friend is running his Track purpose Z with 305s in the Rear and not running into big issues that I know of.

scotts300

iTrader: (46)

305 even 315 (like the picture above) are no biggie on the rear with the right offset. I was just surprised that your 11.5 +18 would work without some pull. Cheers.

graffkid732

iTrader: (44)

If I searched and read correctly, I believe a +22 would have been an almost perfect offset with no more than -1.0 camber. I figured I would be close to -1 to -1.5.

What are your thoughts on this?