superlubricity

Forgestar F14 Gun Metal Wheels (18x8.5" ET46, 18x9.5" ET55)

First off, a big thank you to James@ACGSD. James had the best price on the wheels. James was very patient with me as I huffed and puffed for 15+ weeks waiting on these damn things. I do appreciate the constant updates and sense of humor throughout this whole ordeal.

Overview:
So I wanted lightweight (sub-20 lb.) wheels but didn't want to spend a small fortune on them. All the buzz around the new 18" size Forgestars got me hooked. The price sounded too good to be true. I placed an order and custom-picked my own offsets. Center caps and hub-centering rings (Poly Carbon Plastic, P/N HR74-6660 from Custom Wheel Accessories, Inc.) were included.

Offset:
I wanted the fitment to be a little more aggressive than stock but I didn't want the wheel to stick out too far like the infamous Forgestar 19x10" ET50 wheel. The offsets I chose absolutely nailed the look I wanted.

Both the 18x8.5" ET46 and 18x9.5" ET55 offsets are 5mm more aggressive than stock (they stick out 5mm further than the stock wheel) while only impacting suspension clearance by 7mm. There are zero fitment issues with the 245/40 and 275/35 tire combo I chose.

Weight:
18x8.5" ET46 = 17.90 lbs. (18.08 lbs. w/ hardware)
18x9.5" ET55 = 20.33 lbs. (20.51 lbs. w/ hardware)
Hardware (TPMS, hub-centering ring and center cap) = 0.175 lbs.

Brake caliper clearance:
Because there is no lip and the spokes run to the edge of the rim, there is no issue with brake caliper clearance.

Finish:
The color is just a hair lighter than Steel Grey. I'd say it has a little less blue and a bit more of an earthy tone. I like the contrast of the Black/CF center caps as well. All in all, I really like the appearance.

Bolts:
You can't run the OEM radius seat (ball seat) bolts with these or many other aftermarket wheels. You have to run cone seat bolts. I picked up the Gorilla Automotive 17018SD-20 Locking Lug Bolt Kit. (14mm x 1.50 RH, 1.0 inch length). Each bolt is also a lock and the set of 20 is 0.12 lbs. lighter than the OEM bolts. Nifty.

TPMS:
I picked up (4) AirAware TPMS (P/N 28214) from Tirerack. I drove around for 5-mins and they worked perfectly. No adapters were needed.

Load rating:
I saved the best for last. The 1,200 lb. elephant in the room.

This is a bit of an issue and I admit, I'm concerned. Never before have I seen so much attention dedicated to one wheel spec. Apparently this all started on one of the BMW message forums where a competitor of Forgestar called them out for making a wheel with such a low Load rating (1,200 lbs.). This high-profile and public argument was probably the first time I've ever heard folks discussing Wheel Load Rating online. The competitor did a great job of drumming up fear in the community. You got me thinking about it. Nice work.

The big question is, "Will this actually be a problem?"
The answer I'm afraid is, "Maybe."

I've always used the general rule of thumb that says 1/2 your highest GAWR = your minimum wheel load rating. This is the guideline I used back in the late-90's when I bought Weld Racing PROSTAR wheels for my Blown Trans Am. It was a 3,700 lb. car and the PROSTARs were also rated at 1,200 lbs. I never road raced that car but I cut some ultra-low 1.69 60' times in it. Never had an issue.

BTW, the GAWR for the C63 is 2,469 lbs. per axle. 1/2 of that would be 1,235 lbs. We're certainly in the ball park but I'm still a little concerned.

Anyhow, I'm only going to run these wheels on the street and they'll likely get some winter tires mounted on them in November. Given the concern around load rating, I won't be taking them road racing or auto-xing. I will however use the fronts @ the drag strip because of the weight savings.

I'm shopping for another set of wheels specifically for the track. James and I have been discussing options over the past few weeks. In fact, I believe someone still owes me a quote.

Note: It was posted in January that Vince from Forgestar had the 18" F14s retested at 1,350 lbs. and the wheel passed. I haven't seen any documentation other than forum chatter so who knows. I'd feel a lot more comfortable if this testing information was published.

Nitto NT05 Tires (245/40-18, 275/35-18)

After reading many positive reviews online I pulled the trigger on the NT05. I wanted a street tire that could double-duty at the local road course. I don't have enough seat time with them to give a formal review but you know I threw them on the scale. Like most reinforced tires designed for extreme performance, they are a bit heavy. I actually gained some weight going with wider/stiffer tires.

Specs:
245/40-18 = 25.59" Diameter, 9.65" Width
275/35-18 = 25.63" Diameter, 10.79" Width

Weight:
245/40-18 = 25.09 lbs.
275/35-18 = 27.38 lbs.

More Weight Data:

Front OEM Wheel (18x8 ET45) & Front OEM Tire (Pirelli PZero 235/40-18) w/ TPMS and 5,000 miles of use = 49.75 lbs.
Rear OEM Wheel (18x9 ET54) w/ TPMS = 26.00 lbs.
Rear OEM Wheel (18x9 ET54) & Rear Tire (Nitto NT555R 285/35-18) w/ TPMS and 400 miles of use = 51.77 lbs.
Front Forgestar F14 Wheel (18x8.5 ET46) & Front Tire (Nitto NT05 245/40-18) w/ TPMS and 25 miles of use = 41.52 lbs.
Rear Forgestar F14 Wheel (18x9.5 ET55) & Rear Tire (Nitto NT05 275/35-18) w/ TPMS and 25 miles of use = 48.27 lbs.
Spare tire, Jack, Styrofoam Pad and First Aid Kit = 39.50 lbs.
Rear Headrests (All 3 Combined) = 4.51 lbs.

Net unsprung weight savings from wheels/tires:
Front = 16.46 lbs.
Rear = 7.00 lbs.
Total = 23.46 lbs.

Net unsprung weight savings from wheels/tires/rotors:
Front = 40.88 lbs.
Rear = 21.00 lbs.
Total = 61.88 lbs.

Well that's all I got. Here are a bunch of photos. A rainy Sunday in the PNW today so nothing fancy . . . just some shots from my steep-*** driveway.

Enjoy!













18x8.5" ET44 Weight


18x9.5" ET53 Weight


Cap, TPMS and Ring


Back of 8.5" w/ Stamps & Certs


Back of 9.5" w/ Stamps & Certs


Nitto NT05 Tires


Nitto NT05 245/40-18


Nitto NT05 275/35-18

Sincity

Another great writeup from The Master. Time for a new avatar?

FYI: Kleemann wheels uses ball seats as well.

ZephyrAMG

Man they look goooood! I would say excellent choice for the look you wanted. Sharp contrast and great replacement...

Looks like you did your homework to make sure you clear the calipers...
Thanks for nice write up and congrats!!!!

superlubricity

Thanks and done.
Thank you. I really like the new look.

bhamg

Yep, a great look, stylish and classy.

Alex396ss

Looking good!

Alex

avengerboater

Very nice, Super!!! I'm sure they look even better in person!!

hhughes1

Mission accomplished!!!

Fill the wheel wells with agressive looking rubber that looks at home on a race track without rubbing........Check

Great looking wheels that compliment the sinister aura of the C63 with a finish that is perfect for the color of your car.........Check

Now about the track package

superlubricity

Thanks! They actually look a little darker in person.

You know it!

I'll keep you in the loop regarding the track wheels. I know you are looking for something similar.

Mort

The wait is over.......AT LAST!

It was worth it, congrats and I think you made some great choices. Going to help me out a lot down the road.

Thanks for taking the time and putting the effort into yet another great review!

14cue

wow, that looks great.
goes perfect with the colour of the car

what kind of bolts are you using? i like the look.

black-clk500

they look sweet
They look like they belong on the car; some aftermarket wheels don't IMHO.
Personally, I'd like em better in 19" in a perfect world and we may as well make em have a higher load limit too if we're creating a utopia
nice improvement, especially the weight savings!

AMGC60-3

Well now that you shaved all that weight off do you notice a difference on the butt dyno?

superlubricity

Thank you.
Thanks! I'm using Gorilla locking bolts. More details up top.
Thanks. The 19" F14s do have a higher load rating but they are a bit heavier and are not available in a 9.5" rear wheel. In my opinion, their 10" rear wheel is overkill and it doesn't come in the right offset for this car.

I noticed the difference right away with the rotors. Night and day. I feel the difference in steering and front suspension with the new wheels/tires as well. It is hard to gauge acceleration improvements considering I've been driving around on Drag Radials the past few weeks.

Kjellster

Wayne, Great looking wheels and as always a killer write up. You put in all the info anybody could ask for, THANK YOU.... You have one of the nicests tuned C63's I have seen, Great Job... Enjoy

superlubricity

Thanks, Kjell.

chief63

Awesome write up and set up, please keep me in the loop, I'm currently looking for 18" track wheels (something affordable under 2K). thanks

Boost Gomez

Perfect.

BenzoBoi

Looks great!

I'm pretty sure you'll love the NT05's. I have them on my stockies at the moment and used them at a track event about a month ago. They were EXCELLENT!

superlubricity

Thanks, guys. I appreciate the kind words.

It's still raining but I did get a chance to snap this photo . . .

alqamzi

^^ It looks very nice in this picture..

JM

Sick! I will have a write up soon too but it will be a few sentences still thinking what tires to go with my 19's I hate how they don't have star spec for 19's

Sincity

Do you mean "overkill" and "offset" in the sense that you cannot properly fit a 285 and not have it rub? More functional than cosmetic?

BerBer63

Just ordered my tires, thanks. I knew about the different lugs needed, but hadn't heard about the hubcentric ring. Where did you pick that up? Thanks

Sincity

Is there a difference between using plastic or aluminum rings?