Freshdot

Good day all,

I'm looking into a set of 15x7 or 16x7 RPF1's wrapped in 225/45/16 or 15" RA-1's or R888's.

The 15 is offered in +35 and +41, the 16 in +35 and +43.

My concern is having the tire stick too far out of the fender, offset to me is a black art. I've been at it for 2 days now and can't seem to figure out which wheel would be best for me. It should also be noted that I don't like to ride slammed or anything, but I'm not a fan of wheel gap at all.

Freshdot

anyone

Black R

Willtheyfit.com


225's fit best on an 8" wide wheel.

Oem backspacing would work out to 5.5" or +24 offset in that width.

Are you allowed to roll / pull fenders?

What chassis?

Staggered setup?

Freshdot

sorry, dunno how i managed to leave all of that out.

EJ1 chassis, I'll roll fenders if need be, staggered would be cool but not mandatory.

Lo-Buck EF

how much camber?

mike-y

The difference between the two wheels is the 35 will stick out 6mm more than the 41.
And if you plan on running some negative camber, you should be fine with either, but the 41 will leave a bit more room for the fender.

If you have an older civic (88-91), you might want to go with the 41 offset, but newer cars have a bit more fender clearance, and if you run some negative camber, you shouldn't have any issues.

Here is a handy link that can help you compare wheel offsets
http://www.1010tires.com/WheelOffsetCalculator.asp

Freshdot

I've decided that I ultimately want to run the 15x7 RPF1's with 225-45-15 RA-1's. Which offset would give me the least amount of headache +35 or +41??

Black R

225's really aren't ideal on a 7" wheel.

That said, you can actually get away with +35 offset on this chassis without rubbing with a 225.

Freshdot

I have 2 issues..I'm dead set on running the RPF1's on the my car, and they don't have a 15x8 option. The reason I want to run a 225 is because this car is expected to make about 375whp.

I really feel like the 16x8 +38 RPF1 option will give me a big headache trying to fit with a 225/45. I just can't see it working without a good deal of fender rolling/pulling and possible issues on the inside of the wells as well.

CivicSiRacer

You realize also the gearing would be totally different too with 225/45x15" vs 225/45x16"?

Also if you are going to make that much power; style shouldn't take precedence function. Personally I would want the correct wheel/tire combo so I can get the power down to the ground correctly with an 8" wheel over a 7" wheel.

solorex

If you are set on getting the RPF1's, why don't you just go with the +41? If you rub on the inside just move the wheel out the amount you need by using a spacer. And others are correct, you are better off running a 195/50 or a 205/50 on a 7" wheel regardless of the power you are making.

Freshdot

I won't be making my purchase until about march or april, if I find a nice 15x8 wheel that tickles my fancy I will surely go that route. Right now I'm preparing myself for the RPF1 purchase.

Black R

I'd stay away from 16" wheels also.
Tire selections are rather limited.

Go with a 15" or 17"

Calif_Kid

The RPF1 wheels have a small step down in the rim diameter out where the spokes are, so the front wheels might rub the brake caliper and bracket, so if you want to use the wheels, you'll need to grind away some of the caliper and bracket. I'm running 15x7 ET35 RPF1's (initially with 8mm spacers and now with 10mm spacers) on my EK, and I had to do the grinding. Other 15" wheels might have more clearance than the RPF1s. Anyway, just wanted to mention it. - Jim

JHall250

+41 would cause issues with the trailing arms. 15x7 +35 205/50R15 my tires lightly rub the trailing arm on a car I use for DD and the occasional competition use. I was planning on running a similar setup (15x7 +35 225/45R15) and the research I did both on forums, and with my car, show that +35 is the highest offset you can run and not have problems.

Natural Aspirations

The +35 is the perfect size for a 225/45/15 on an 7.5-8" wheel. No camber kits needed to clear on 3 different combinations fenders did need rolled. R1R/NT01/Z214

If your dead set on Enkei's they do have a PF01 available in 15x8 with the 35 offset similar weights.
Remember offset dictates where the tire sits in the well not the wheel width.

Targa250R

If you're planning to use any sort of hybrid brake setup, keep in mind that 15" RPF1s won't fit over anything larger than the stock EX (or comparable) front brakes.

mike-y

That doesn't sound right. I run 15x7 +40 with khumo xs 205/50/15s on an EF and there is plenty of trailing arm clearance.

I've even test fitted a 15x8 +36, which is 8mm closer to the trailing arm than the above wheel, and still had clearance with a 225mm tire (just barely though). I am running DC rear trailing arms though, so that may be the difference.

+35 offset should have plenty of inner clearance on a 7" wide wheel.

JHall250

11.1 Honda OE brake setups fit under 15" wheels no problem. I have ITR brakes on my Si and they even fit under the stock wheels.

At static position they clear but when you are cornering the tire will flex and move around a fair amount, the taller the tire the more this will be true. I'm not saying it will be catastrophic but it's not ideal and it could cause a structural weak point in the RTA. Another thing to consider is ITR hubs put the wheel position about 4mm further out than a standard DC2 or EK RTA.

Freshdot

for arguements sake I currently run a 205/45/16 on a 16x7.5 +35 with little to no rubbing issues. only at close to full lock, it should be noted that my car is lowered a fairly large amount.

I don't think I'll have any troubles at all on a 15x7 +35 with 205/50 at all. Hell I even plan on spacing the front 5mm and rear 3mm.

let's talk about rubber...just how comparable is a R1R to a RA-1 or R888?

Natural Aspirations

R1R is a a street tire, the rest are competition tires.

I've had the R1R and NT01 (supposed to be same compound as R888/RA1) the R1R will squirm/chunk under heavy cornering due to the smaller tread blocks if not shaven. Both tires seemed to last about the same NT01's seemed to handle more heat.

Targa250R

17CL15VN calipers on an 11.1" rotor won't fit under 15" RPF1s - period. It doesn't matter which other wheels they do fit under.

Calif_Kid

There was thread https://honda-tech.com/forums/road-racing-autocross-time-attack-19/15-rpf1-what-brakes-will-clear-itr-2836345/ a few years back on the clearance on 15" RPF1's. I posted reply #20 that has pictures of the grinding I did (angle grinder with flapper disk) of the calipers and brackets. There isn't much metal left at all over the slider pins when you get done grinding - one of mine broke thru a little, so I'll redo it when I get a chance. When I needed to get the brackets and calipers, I just looked for an Accord V6 that has the caliper and 25T brackets (I needed the 25T brackets for side clearance for my Fastbrake rotors). The spring metal pieces that the brake pads slide on also need a little trimming (shown in my reply #20). Anyway, the brackets and calipers will fit under Enkei RPF1s, but only if you're willing to do some grinding. - Jim

JHall250

Interesting, I did not know that. I would have figured that stock wheels would have less clearance than RPF1's but I can definitely see the part you are talking about. And, interestingly enough, Tirerack's wheel fitment guide does not have RPF1's in 15" for the ITR. Glad I read this thread before buying a set and bolting them on to figure out they don't fit.

Freshdot

because i'm slightly nuts i'm actually buying 2 tires in 2 different sizes when my wheels come in.

i'll be getting 2 RA-1's in 225/45/15 and in 2 in 205/50/15

the 2 that look the best while also giving me little to no fitment issues are the ones that I am going with.