Enkei RPF1 18x10.5" +15 test fit

[xevilpetex]

I have over the course of the last year been researching possible track wheels for my SRT8. I had originally considered following in MattR's footsteps and picking up a set of 18x8.5" Borbets. My only issue with these wheels was the major limit they put on tire size. With our heavy cars its critical to have as much rubber underneath as possible to provide the grip needed to keep it in line during hard cornering. I had been searching high and low for something with an 18" wheel that was at least 10" wide (for the rear), had enough clearance for the brakes, came in a 5x115 bolt pattern, and had the correct offset. Oh and I wasn't willing to pay nearly $3k for a set of custom CCW's or the like. I had nearly given up, the main sticking point seemed to be the bolt pattern. Its not the most common pattern and because most of the cars it comes on aren't very racey, good, wide 18" wheels are nearly non existent.

This hurdle was however lowered when i found out that RT Nomad was running a set of Enkei RP03's with a 5x114.3 lug pattern. I PM'd him asking what he had to do to make the wheels fit. I figured he had gotten the holes bored out to fit properly. It turns out he didn't have to do anything to get them to fit. All he needed was a set of hubcentric rings and they fit great.

Now I wasn't thrilled with the look of the RP03's, but the fact that he was running them without issue meant a whole slew of race wheels became an option. I found something not too far away from what he got, one of the most ubiquitous club racing wheels around. The Enkei RPF1. Now after a bit of research, I came to the conclusion that the +15 offset would be close enough to perfect that it would be worth a try. A week or so ago I ordered 1 wheel for a test fit, It came in today.


Since my primary roll for this wheel was as a rear wheel, I tried it on the back first.


It went right on with no issue (no rings yet) and it looks like all the clearances are good. Though it does stick out a tad (i might look into getting my fenders pulled a bit)


Lots of brake clearance



No issues on the inside either




Out of some hope that I might be able to run 305's all around I then tried to see if they would fit up front.

They stick out quite a bit further up front



Once again, Lots of brake clearance




Unfortunately the clearance isn't so great on the A arm. It doesnt look like these wheels will be an option on the front





Its not so much the width or offset as it is that the knuckle was designed with a widest wheel fitment of 20x9. The wheel would probably fit just fine if it was a 20" wheel.

New wheel

Stock wheel



This however isn't really a big problem. I should have no trouble fitting my original option for the front wheel, the 18x9.5" +15 RPF1. It will give me 13mm more clearance on the inside and will stick out 13mm less from the fender. It will also allow me to run a 285/35/18's in front while i run 305/35/18's in the rear.

Overall I'm quite happy with how this test fit went and I should collect the other three wheels and four tires over the course of winter and be ready to test them out at the LX track day at NJMP Lightning at the end of March.

Also, if I show up at the track day and half of you bastards have these wheels and Rcomps, I'm going to be mega pissed.

[MattRobertson]

OK so I went to the Enkei site and they say the 18" silver wheels are available in 7.5, 8, 8.5 and 9.5 sizes. But you are saying you are going to downsize to an 18x9.5 wheel for the fronts... what size are these wheels then?

"hub centric rings". Pics or links? I have little 3mm and some 5mm spacers but I'm sure thats not what you are talking about. Or is it? My daddy raised me such that I am supposed to turn my nose up on 5x114.3 because it causes the wheel to support itself on the lug nuts. How does a hub ring change this (you've gone further in this than I ever have)?

If I could do 9.5's all around I'd be delirious...



More delirious than usual.

[MattRobertson]

And where did you buy your wheel? Tire Rack insists on asking for a vehicle they fit and I haven't figured that out yet. Looks like about $325 each from what I've seen elsewhere so far.

[xevilpetex]

Hubcentric rings are small rings that fit between the hub and the centerbore of the wheel to provide the correct fit. Many aftermarket wheels are made with over sized centerbores to accommodate more vehicle fitments. You just add the correct rings to tailor it to your application.


I got my wheel from an ebay seller, Alamo performance wholesale
9.5
http://cgi.ebay.com/ebaymotors/Enkei...item56365dbc1a
10.5
http://cgi.ebay.com/ebaymotors/Enkei...item56365d89ce

Its $295 shipped for the 9.5's and $300 shipped for the 10.5's

For whatever reason the RPF1 spec page on enkei's site is down, but the wheel I've got is an 18x10.5 +15

[xevilpetex]

This is a 350z fitment by the way

[MattRobertson]

OOOH. OK I understand what the rings are now.

Are you up for working something out where I buy an 18x9.5 wheel, followed by a tire ( a Hoosier 280/680R18 R100 if the wheel fits over the brakes), and test fit them, and if I can't make it work I sell to you? Or are your purchase plans already in motion? Maybe I buy a pair so there's no way you could get stuck with one wheel, and I obviously resell at a discount.

edit: yeah I found the 350Z on Tire Rack. Used a 2008 350Z Track as my model and got a Tire Rack price of $320, which includes lug nuts and rings.

[MattRobertson]

What worries me is you have an SRT front knuckle and I have an RT... and they are different.

[xevilpetex]

The wheel will fit over the brakes, i can damn near guarantee it. There is even less of a lip on the 9.5's and you can see how much space there is between the caliper and spokes in the picture where I easily fit my hand in between the two.

I'm pretty certain that I'm going to just buy all 3 wheels from the guy i got the first one from. Worst case scenario for you is if it doesn't fit on your R/T hub then you should be able to sell it pretty easily to someone with a 350z. This is a pretty popular wheel for them.

Heres a good resource for you to compare the fitment of your borbets to the RPF1's assuming you know the borbets offset
http://www.1010tires.com/WheelOffsetCalculator.asp

Im also not sure the rings that tirerack spec for a 350z would work for us. I think our hub size is different. I also doubt the lugnuts they would send would work either. They would probably be for a 12mm stud not a 14mm one like we have.

That is one other thing, you will absolutly need different lugnuts for these wheels. The space for the wrench is too small for our bigger nuts.

[MattRobertson]

The Borbet's are 15mm offset as well. Thanks for the link to that calculator, which tells me I'd lose 13mm of clearance. Thats enough for me to work with. The RT knuckle may turn out to be the limiting factor with this offset. We'll see.

So where are you getting your rings and lug nuts, then? I know my Borbets needed 21mm nuts that would fit in the deep holes those wheels have, and only one of the three or four sets of lugs I have will fit down in there.

[xevilpetex]

The hub centric rings we would need are 71.5mm ID/73mm OD.
http://cgi.ebay.com/ebaymotors/HUB-C...d=180423189677

[xevilpetex]

The Borbet's are 15mm offset as well. Thanks for the link to that calculator, which tells me I'd lose 13mm of clearance. Thats enough for me to work with. The RT knuckle may turn out to be the limiting factor with this offset. We'll see.

So where are you getting your rings and lug nuts, then? I know my Borbets needed 21mm nuts that would fit in the deep holes those wheels have, and only one of the three or four sets of lugs I have will fit down in there.

Also for reference an SRT wheel is 20x9 with a +25.5 offset. I've heard people need at least a 3 mm spacer to run them on the RT knuckle. With the +15 offset with these wheels you will gain 4mm of clearance over an SRT wheel. That should put you out far enough to be able to work with these wheels.

The long nuts you have would do the trick. I haven't quite gotten to that step yet, but I'm sure i should be able to find something long enough to work.

[MattRobertson]

As soon as I can break out of work today - telecommuting so the car is 20 feet away instead of 160 miles - I am running out and getting to work to test this out.

Thanks!

[CT-MSRT]

gonna be a sick combo. can't wait to see them with some R compound rubber on em.

[MattRobertson]

well it'll be awhile for me. If these fit in front, and it sounds as if they will, I will still need to use up the R compouind rubber I have already bought and paid for... and thats *still* six mounted tires... I just remounted my good-condition extra (8th) pair after taking a pair down to cords, and last Friday's day at Infineon resulted in zero tire wear due to *rain*. I rolled on the Bridgestones before throwing in the towel and grabbing an oar.

So I will take this a wheel or two at a time and slowly rotate in the 280's in 2010. IF I can make this work. I'm much more concerned about the knuckle than the brakes.

[xevilpetex]

gonna be a sick combo. can't wait to see them with some R compound rubber on em.

I'm not going to go too crazy at first with them. I'm not sure its a wise idea to just jump right on to full slicks, so I'm planning on running a set of Nitto 555R2's in 285/35/18 front and 305/35/18 rear to start. Then after ive burned through those ill try out the R100's in 280/680R18 front and 305/680R18 rear.

It's still about baby steps right now.