Forgestar F14 17x10, data thread
02-19-2014, 10:46 PM
#16
Parts getter 
K, got them home, getting down to business. I'll get the brake clearance info posted tomorrow.
stukay--they're all 17x10 +55, wearing 255 40 17 R888s.
Basics: Forgestar F14, 17x10, +55 offset. Tires, Toyo R88 255-40-17
Weight: 17.75lb, measured by Modbargains prior to tire mounting
Weight with tires: 44.4lbs - sanity check on Modbargains' measurement, confirms wheel weight!
Lower ball joint clearance, Buddy Club: I had previously clearanced my front balljoints to fit Enkei PF01SS, but there is ample clearance now. It appears no clearancing would be necessary to fit BC balljoints with these wheels. Plenty of room in either direction as well, so any offset will work.
Attachment 190490
Rear Koni V3 clearance: Plenty of clearance to the reservoir with this offset. The reservoir in fact is within the diameter of the wheel, but just barely. An offset higher than ~+70 well be hugging the reservoir, but there is still ~3mm clearance.
Lugnuts holes: Lugnut holes could be deeper. I can only get 5 rotations before the lugnuts are torqued. I would prefer 8+. Distance between the lugnut face (engaged in with the cone) is 12.3mm, while on my Enkei PF01SS, this distance is 9.2mm.
I calculated out the minimum ISO thread engagement--comes down to 6.5 turns. I'm getting 5. Hrmph. The ISO minimum engagement is the minimum engagement necessary for the bolt to fail before the threads. So likely, the threads will fail first with this few threads. That isn't to say it will fail in use however, but it isn't ideal.
Additionally, pretty heavy powdercoating in the lugnut holes--torque and remove the lugnuts a couple times, blowing out the lugnuts holes in between cycles. The coating will flake off the aluminum until it's all gone and you can get proper torque to the aluminum.
Balancing: These seem remarkably well balanced--wheel weights used are as follows:
Outboard weight [oz] / Inboard weight [oz]
1.25 / 0.00
1.00 / 0.50
0.75 / 0.00
1.00 / 0.00
Much better than my Enkeis. I haven't driven on them yet, so this may be the result of a very optimistic balancing...
Offset accuracy: Measured to 53mm with tape measure and straightedge. This is close enough that I'm comfortable saying no one fat-fingered the machining center. That being said, I will assume from this point forward that these wheels are +55mm, as ordered from Forgestar (meaning, if I can stick a brake caliper forward 10 more mm, I'll say +65mm will clear). This assumes Forgestar cuts the offsets reasonably accurately.
K, got them home, getting down to business. I'll get the brake clearance info posted tomorrow.
stukay--they're all 17x10 +55, wearing 255 40 17 R888s.
Basics: Forgestar F14, 17x10, +55 offset. Tires, Toyo R88 255-40-17
Weight: 17.75lb, measured by Modbargains prior to tire mounting
Weight with tires: 44.4lbs - sanity check on Modbargains' measurement, confirms wheel weight!
Lower ball joint clearance, Buddy Club: I had previously clearanced my front balljoints to fit Enkei PF01SS, but there is ample clearance now. It appears no clearancing would be necessary to fit BC balljoints with these wheels. Plenty of room in either direction as well, so any offset will work.
Attachment 190490
Rear Koni V3 clearance: Plenty of clearance to the reservoir with this offset. The reservoir in fact is within the diameter of the wheel, but just barely. An offset higher than ~+70 well be hugging the reservoir, but there is still ~3mm clearance.
Lugnuts holes: Lugnut holes could be deeper. I can only get 5 rotations before the lugnuts are torqued. I would prefer 8+. Distance between the lugnut face (engaged in with the cone) is 12.3mm, while on my Enkei PF01SS, this distance is 9.2mm.
I calculated out the minimum ISO thread engagement--comes down to 6.5 turns. I'm getting 5. Hrmph. The ISO minimum engagement is the minimum engagement necessary for the bolt to fail before the threads. So likely, the threads will fail first with this few threads. That isn't to say it will fail in use however, but it isn't ideal.
Additionally, pretty heavy powdercoating in the lugnut holes--torque and remove the lugnuts a couple times, blowing out the lugnuts holes in between cycles. The coating will flake off the aluminum until it's all gone and you can get proper torque to the aluminum.
Balancing: These seem remarkably well balanced--wheel weights used are as follows:
Outboard weight [oz] / Inboard weight [oz]
1.25 / 0.00
1.00 / 0.50
0.75 / 0.00
1.00 / 0.00
Much better than my Enkeis. I haven't driven on them yet, so this may be the result of a very optimistic balancing...
Offset accuracy: Measured to 53mm with tape measure and straightedge. This is close enough that I'm comfortable saying no one fat-fingered the machining center. That being said, I will assume from this point forward that these wheels are +55mm, as ordered from Forgestar (meaning, if I can stick a brake caliper forward 10 more mm, I'll say +65mm will clear). This assumes Forgestar cuts the offsets reasonably accurately.
02-19-2014, 11:39 PM
#17
This is good stuff 
I'm eagerly anticipating your measurements on the StopTech ST40 BBK. I doubt the +55 offset will clear, but i'm hoping something slightly lower, but not lower than +45 will clear. Mid to high 40s offset will be perfect.
I'm eagerly anticipating your measurements on the StopTech ST40 BBK. I doubt the +55 offset will clear, but i'm hoping something slightly lower, but not lower than +45 will clear. Mid to high 40s offset will be perfect.
02-21-2014, 12:23 AM
#18
K, the only thing anyone really cares about, big brake clearances.
My methodology:
Using the available templates for the Urge/Essex AP racing kit, the StopTech ST40 kit, and Paul Reineck's Spoon template, I made some new templates that incorporate a 3mm clearance area. Here is what that clearance looks like for the three:
And just for grins, here are those profiles overlaid:
From these, I made some new cutout template guides that incorporated some guidelines so I could trim the template to offset from my wheels to determine the actual offset requirements. I trimmed these down until I found the transition from clearing to interference.
These represent the minimum offset required to just create interference, using a 3mm clearance area, based on the assumption that the wheels I have are what you'd get if you ordered a "+55mm" offset wheel.
Minimum offset requirements for brake kits:
Urge/Essex AP Racing kit: +52mm
StopTech ST40: +64mm
Spoon: +52mm
Some detail, starting with the AP racing kit:
Attachment 190480
The angled part of the caliper is almost exactly parallel to the section of the wheel that it interferes with.
Spoon:
Attachment 190481
This is really strange actually, ending up with the same minimum offset as the AP racing, but whatever. If the caliper stuck out a few more mm, you this could run a pretty high offset, too bad! But +52 is still pretty good...
StopTech ST40:
Attachment 190482
So this is kinda neat--I think at +64 you could almost get away with not flaring the fenders at all, just rolling the lip. I'd imagine there'd be a good bit of lower control arm interference at full lock though, so you'd probably want to add some steering limiters. I have no idea why you would do this though, because +50-55 looks super badass. Also--the caliper come pretty close to the wheel weights if they're stuck on top of the "ridge" in the wheel. Nothing to really worry about, as you still have a good 6-8mm of clearance.
So ya, this weekend, I'll put them on the car, roll the fenders and do the rear bumper tabs, and see what kind of control arm clearance there is (although I don't expect it to be much different than what we already know regarding 17x10!)
My methodology:
Using the available templates for the Urge/Essex AP racing kit, the StopTech ST40 kit, and Paul Reineck's Spoon template, I made some new templates that incorporate a 3mm clearance area. Here is what that clearance looks like for the three:
And just for grins, here are those profiles overlaid:
From these, I made some new cutout template guides that incorporated some guidelines so I could trim the template to offset from my wheels to determine the actual offset requirements. I trimmed these down until I found the transition from clearing to interference.
These represent the minimum offset required to just create interference, using a 3mm clearance area, based on the assumption that the wheels I have are what you'd get if you ordered a "+55mm" offset wheel.
Minimum offset requirements for brake kits:
Urge/Essex AP Racing kit: +52mm
StopTech ST40: +64mm
Spoon: +52mm
Some detail, starting with the AP racing kit:
Attachment 190480
The angled part of the caliper is almost exactly parallel to the section of the wheel that it interferes with.
Spoon:
Attachment 190481
This is really strange actually, ending up with the same minimum offset as the AP racing, but whatever. If the caliper stuck out a few more mm, you this could run a pretty high offset, too bad! But +52 is still pretty good...
StopTech ST40:
Attachment 190482
So this is kinda neat--I think at +64 you could almost get away with not flaring the fenders at all, just rolling the lip. I'd imagine there'd be a good bit of lower control arm interference at full lock though, so you'd probably want to add some steering limiters. I have no idea why you would do this though, because +50-55 looks super badass. Also--the caliper come pretty close to the wheel weights if they're stuck on top of the "ridge" in the wheel. Nothing to really worry about, as you still have a good 6-8mm of clearance.
So ya, this weekend, I'll put them on the car, roll the fenders and do the rear bumper tabs, and see what kind of control arm clearance there is (although I don't expect it to be much different than what we already know regarding 17x10!)
02-21-2014, 02:20 AM
#19
Excellent!!!! Great work - good methodology. It looks like I just found my next set of wheels.
