***i can't seem to find this topic anywhere else

i'm thinkin about putting BBS rg-r on my fd and i cant seem to find rg-r in 17x10 and i dont think they exist so i may just put 18x10 in the back n stick with 17 in the front for weight savings.

assuming i use coil overs, keep the final drive stock, lower all 4 corners the same amount, keep the rear end softer, and i dont want to roll any fenders:

**will the car be stable at higher speeds? will the car look funny? have people gone with larger rear wheel setup before on an fd? ne thing i should know about this setup?**

i know it works fine on vettes and prancing ponies but never seen it on an fd

 

It will work, but I would rather have the extra sidewall out back, ecspecially if your car is making good power.

 

hmm good point about side wall.

do you think i'd get better traction and power down on 9" wide wheels and extra side wall or 10" wide wheels with less side wall? what would you go with?
(assuming same compound, temperature, and ignoring tire compound tread life)

 

Not to harp but I'd find a wheel that was available in a 17x10. Track duty is usually all about function so having your heart set on one stylistic design (RG-R in this case) doesn't make much sense.

 

I used my new RGR's on track once or twice, saw all that crappy dust on my beautiful wheels, and went out and bought track wheels... mesh is too tough to clean!

however, you're only going to save about a pound from a 17 to 18" front wheel. I'd just go 18" all around.

 

RPF1's make for a pretty good track wheel in terms of price/size/weight/strength. However the jump from 17x9.5 to 18x9.5 is a two lb increase, not one.

http://www.enkei.com/RacingSeriesSpecs/RPF1.html

I disagree with ptr above. Don't forget that in wheels it's not just the weight it's where you add the weight. 2 lbs of rotational inertia at the perimeter of a wheel is HUGE. The only reason to go up wheel diameter in track usage is to clear big brakes (assuming you're already ducted and you still need them.)

 

Unless he's competing with the car and has a ton of track experience, he'll never notice that 2 lbs difference. Only a very small percentage of this forum has enough experience and talent to notice that kind of difference (and I'm smart enough to know that I'm not in that small percentage).

 

Not quite the only reason.

1. There's also the matter of tire weight though. It's not uncommon for 18" tires to be lighter than 17". Figure same width, same diameter, less sidewall, less rubber.... and that's even FURTHER out on the perimeter.

2. There's also a matter of (as time goes on) more choices in terms of brands/sizes in 18" sizes, even in track tires because Porsches drive the decisions in that regard.

3. The third aspect is diameter, particularly up front. A 285/30/18 is going to be a much shorter tire than say a 275/40/17 or even a 255/40/17, so there'll be fewer clearance issues.

 

im not the type to give a **** about weight, but my 18 rpf1s do weigh noticably less (by picking them up, driving i sure couldnt tell the difference)than my 17x10 fno1r's. and tires on the 18s are wider

 

see above

 

I think the effect of weight on wheels is a little over-hyped.

Anyway, a larger diameter wheel is heavier, but also removes some weight from the tire assuming you keep the same overall tire diameter and run thinner tires. So a 2lb heavier wheel may only end up being a 1lb heavier wheel/tire combo.

Also, as previously mentioned, the selection of wider tires will favor 18inch rim geometry.

I'll be running 18inch fronts on my track set just for the BBK fitment, and yes CF ducts are already there, but I brake a lot

 

my heart is set on a strong and light wheel without going Mg. not a strong or light wheel. i didn't pick rg-r for the looks.

ppl on here are saying that the rpf1 is a 'trackable' wheel. i ignored the rpf1 at first because it's cast and i've never seen rpf1 on a track car in my own experience (even tho i've seen them in pictures on track cars)

in my experience everyone either has cash or they don't. i see cars on the track either running stock wheels with large side wall or very expensive track wheels. guys with stock wheels that break or bend when they go off the track (not crash) just get more stock wheels, guys with very expensive track wheels get to drive the car back to the pit lane.

and don't tell me that the porker 3pc 10" track wheels have imperceptible drop in performance compared with the lighter 1pc when used on a small turbo charged engine running under 320rwhp in places other than flat out straights.
i want lest rotational inertia ESPECIALLY during turbo lag conditions (that's when the NAs start showing up in your rear view nice n big: the 1.3 trying to respool and u got porker 3pcs in the back like ball and chains).

i'm hearing some chatter about buddy club wheels.. i've seen those on the track before. what do u guys think about those?

anyways, i was considering the advantages of have the 17s up front and 18s in the back also b/c i can go a tiny bit lower with suspension travel up front- 18s in back to give longer tyre patch (which means the tyres have longer life times than 17s) and a neutrally balanced fd will eat up back tyre unless you're conservative at the exits

thanks for the input too!

 

that sounds true, but i'm not sure i want to compromise with smaller sidewalls. so in reality i'd probably have to go with a heavier 18" tyre altogether.
but it is food for thought tho thanks.

 

This is not true.

A 17" front will most likely be TALLER than an 18". Examples:

255/40/17: 25.03" diameter (some are slightly more)
275/40/17: 25.66" (most actually listed at 25.7")

255/35/18: 25.02"
285/30/18: 24.73" (most list at 24.8")

To your other point: Actually, it is not typically the rears that take the beating on track, it's the fronts, and this will particularly be the case if you run a smaller front to rear. Lots of folks run the same size all around not only for handling considerations, but also to be able to give the fronts a break by rotating them to another corner.

Finally, if you're really looking for a low-weight track wheel, much as I love my RG-Rs, and they are pretty light weight, trhere are lighter less expensive wheels out there. SSR competition for instance.

 

Smaller sidewalls aren't necessarily a compromise on track, they typically compromise ride quality on the street.

 

BEX,

If that's your goal, why not get Volks CE28N's? You can get 17x9 (or 17.x9.5) and 17x10 in offsets which work well on the FD. They are a very strong, lightweight proven wheel.

http://www.autornd.com/catalog/image...olkCE28N10.JPG

 

Yes I agree. I eat up my front tyres very quickly on my Z out there.. (that car wants to understeer no matter what u do to it lol)

but i disagree about the tyre side wall issue. i find that i can tweak the balance of the car more easily with tyres that have larger side walls by simply adjusting air pressure.
my experience with small tyre wall is that u have to be more careful when adjusting air pressure. they heat up faster (which is good) but at the same time are fussier and less forgiving if u don't get the tyre pressure right.

you're right also about the height of a 17 wheel with larger sidewall versus an 18 with small sidewall but i'll be damned if i ever take an 18" 275 tyre with tiny 30 side wall out to any track lol!

 

hmm... i think i may have found a winner! lol those are what i'm looking for. i have seen those on the track before but didnt know how much they weighed.

all this time i've been around competitive cars and you'd think i had a better handle on the wheel market .. i guess i've just been one of those guys who always used stock wheels with balloons on them!