exgr

i am in the doodling stages of a brand new wheel designed specifically for motorsports use. i already have fairly detail number calculated and i believe it is a highly feasible project so i will be forging (ha) ahead. the idea is to make a light weight cast 14x7 wheel that will have flow formed barrel for the strength. the Enkei RPF1 is exactly this, a gravity cast wheel disc with flow formed barrel except they give a fancy name call MAT most advanced technologies to their process. Enkei was an early adapter of this technology more than 10 years ago. but now this process is widely used.

Enkei RPF1 14x7 et38 weights 9 lbs (some say as light as 8.6 lbs), 6 split spoke design.







my design will be form follows function. my initial thought is to do a 8 spoke design similar to the Mugen MF8. i like how that wheel looks. i know MF8 is forged. i will take casting into consideration. it will be 3D modeled and FEA'ed anyway. other design consideration is max wheel caliper clearance. i'm not sure if it is possible but i will try to clear 11" NSX brake setups. at the minimum it will clear 10.3" GSR brakes for sure. i will also have a secondary design that is purely function driven. i will have to talk to few wheel designer friends to see which spoke configuration gives the best weight to strength ratio.



i will target the 14x7 to be max weight of 9.5 lbs. i'm willing to allow it to be up to 10 lbs if it means extra strength for road racing abuse (such as hard curb running). but no more than 10 lbs. the wheels will be VIA and JWL certified.

to save cost on tooling, the wheel face will have to taken into account of be widened to 14x8. so it will be slightly compromised. the best lightweight design would feature 2 unique wheel disc tooling but i do not think it is worth the expense. the weight penalty will be minimum.

as far as i know there are currently no flow formed 13" wheels out there. *current factory i'm working with already surprised that i'm making 14"... *all the factory want to do min. size of 15 and up, and especially the larger 17+" wheels due to higher profit margin. *i'm trying to go the opposite direction from the norm and produce parts that no one else makes.

i know hardcore racers prefer 13" over 14" actually, 14" is the odd ball size and has fewer tire selection than 13" and 15"...

13" has lot of slick options... *14" is limited to width 205, and 225. *that's why i'm only building 14x8 and 14x7. *actually i might build only 14x8 initial batch. *and if there is demand i will build the 7" version.

if you guys are interested in this rim please give me some feedback.

the wheel center is optimized for 4x100. should i bother to do 4x114.3 or no? any people with 4x114.3 better speak up now or forever hold your peace.

why do this wheel? although tire selection is limited in 14", there is actually still few solid options for track days.

Falken Azenis RT615 195/60/14
Hoosier R7/A7 205/60/14
Hoosier R7/A7 225/50/14
Toyo R888 205/55/14
Toyo R888 225/50/14
Toyo R888R 185/60/14
Hankook VENTUS Z214 205/55/14 and 225/50/14
Yokohama A050 G/2S Compound and GS compound 185/60/14

Maxxis RC1 no 14" tires
Federal RSRR no 14" tires
Yokohama AD08 no 14" tires
Toyo RA1 no longer has 14" now, used to have i think
BFGoodrich G-Force R1 Sizes: 15-18" (35 sizes)
Michelin Pilot Sport Cup Sizes: 18-19" (20 sizes)
Yokohama A048 Sizes: 15-18" (22 sizes)

my idea of the wheel will be eight split spokes design so 16 spokes, looks something like:

exgr

hmm after i give it some thought i think it makes most sense to do 14x7 first. since that's all the road cars will need due to street tires not being available wider than 205. if i can make it clear 11.0 ITR/NSX brakes i think it could do very well.

KoRn_vIRuZ

Nice idea but it will be a struggle. Most people want 15" wheels.

.one lane

Need more options in 15x10. My 245 on 9 feels slightly "squishy."

Btw, Maxxis released a 245/40/15 tire a few months back. Hankook and BFG will be releasing theirs sometime next year.

Caoboy

i think you need 15" minimum to clear ITR brakes.

dirty19

iTrader: (1)

I believe this is correct!

exgr

It's a tight fit but physically it should be possible to clear. I just have to do some accurate measurements. You guys do know that 13" can be made to clear 10.3" GSR brakes right? My old set of Keizer 3 piece 13x9 cleared GSR brakes no problem. So if ITR 11.0" rotors is only 0.7" taller, then we are up sizing to 14" certainly in theory there could be enough room. I'm 95% sure I can make it fit.

I guess 949 is the only one doing 15x10 and 15x11. But his fitment is Miata prioritized. I suppose I can do a Honda EG focused 15x10.

exgr

Is that a fact or just rumor? More extra wide 15" options... this is good news. Now the next question I would ask you guys is should I do the 15x10 in cast or forged? I'm leaning towards forged because nobody else does it. It won't be the silly expensive *** forged magnesium. It'll be good old forged 6061 or if maybe I will one up it and do forged 7075. that'll be super strong. Price wise I should be able to match Volk at most. So say $550 a piece for 15x10. Construction would be forged 1 piece monoblock with flow formed barrels. Or possible 3D forged barrel, depending on if I want to make multiple widths or not.

Chuck629

No one's going to want to spend more than 6ul money on a 15x10. $200 a piece. Less if you really wanted to be competitive. $550 a piece for 15" track wheels is just stupid.

exgr

Clearly you have reading comprehension issues. I can do 15x10 cast wheels for $200 no problem. But if people want really strong forged wheels it will be $550 a piece. While 6UL sells well, I've heard decent amount of stories where people have cracked them from heavy track use. Since now days there are plenty of people spending $2200 buying a set of 15" Volks, it would appear that there is a market for them. Most SCCA road racers are Solo people are more budget minded and you do not see them running Volks as much.

The problem I see with most rrax folks is they are very narrow minded... But over the years that comes as no surprise to me. I remember when drifting first got popular in USA back in 2004, most people here trashed it... they trashed touge too, thinking only their form of racing is legit.

Chuck629

Then do a 15x10 cast (flow formed) wheel at that price point then. No matter how much stronger that forged wheel is, people generally don't want to spend 2 1/2 times as much money on a wear item like that when there's something readily available for less money. People that are, are having custom wheels made (bogarts/keisers/etc).

And are gen 4 6ul's really cracking that much? I've seen the problem on older ones.

exgr

A properly engineered forged wheel will NOT be a wear item. Unless hit with direct impact it should not have an type of wear and tear issues. I don't know if 6UL gen 4 still have crack issues or not...

.one lane

If you download the excel file, it will list the 245/40
https://shop.bfgoodrichtires.com/tir...-force-rival-s
PN: 84280

And RS4 (see attachment)

The older gen 6ULs had issues cracking with heavy track usage. Gen3s and 4s don't have the same issues (at least I haven't heard of any). I don't have any issues with 6uls; I think they're a fantastic wheel at a great price point, but I wish there were more options.

You should keep it Miata friendly offsets because I have a Miata

exgr

keeping the offset Miata and Honda friendly will be easy since it is not that different.

exgr

First drawing the CAD guys made. First look I dont' like it, I told them to copy the MF8 center. This is epic fail lol. Also, this looks like a very heavy design. But not to worry, revisions coming soon.



There is some lip here. I'm leaning towards more concave face for maximum caliper clearance. It might be slightly heavier though. Hmm... or maybe a compromise. We shall see...



Original concept vs. 1st drawing. Grade given B-.

.one lane

I know function > form

but geez that's not appealing at all lol.

exgr

I almost thought maybe I should use the KISS philosophy. 6 spokes anyone?






Hopefully the next revision will look a lot more like what I want, MF8 center with additional spokes... the center better look like:

Caoboy

i think I saw a set like that on tirerack.com amirite

Also, exgr if you were to make it a universal lug pattern you'd be able to keep costs low and sell to a higher market.

Then again idk who runs 4x114.3 that would want a 14" wheel.

exgr

yeah i'm almost certain first batch will be exclusively 14x7, et35, 4x100. that should do it. but i've made provisions in the tooling to allow offset range of 28 mm to 45 mm and also allow 4x114.3 bolt pattern as well. so if there is demand for variations i can produce a batch. center core will be large size, probably 67 mm, and hub centric adapter rings made. it's not really necessary though.

since old school cars are being appreciated more, there is a chance some might ask for 4x114.3. but first i have to make the wheel cooler looking lol.