For the last 3.5 years people have been curious if the 9.5″ RPF1s cleared the Subaru Impreza WRX STi brembos. Well, they don’t. They require a spacer, how large of a spacer?
Up until last week I couldn’t say with confidence what size they needed to clear. Luckily for me a fellow Subaru owner on the forums with a crazy Wide Body STi happens to have a few Enkei connections. Earl managed to test fit one of the 17×9.5 +38mm RPF1s for Brembo Clearance.
He had a couple spacers laying around so he decided to test it and snap a few pictures to finally put the question to rest, “How big of a spacer do I need to run 17×9.5 +38mm RPF1s?!”
Once Earl got the wheels back to his house he tracked down the spacers and jacked up the car.
Now through the grapevine I’ve heard that these wheels could require a spacer as big as 15mm, I found that hard to believe. Luckily all that is needed to clear the Brembos is a 5mm spacer.
As you can see here the clearance isn’t massive but it should be plenty.
To Recap, 17×9.5 +38mm RPF1 require a 5mm spacer to clear the Brembo Brake Calipers on a Subaru Impreza WRX STi.
The 18×9.5 +38mm has NOT been tested and may require a larger spacer due to the different diameter/spoke design, I’m going to see if we can get that size confirmed as well. 
A 5mm spacer on a Subaru will require longer wheel studs to allow full engagement of the lug nuts. There will be future articles on Longer Wheel Stud Options and the Negatives/Positives of running a spacer.
I want to thank Earl for testing these out and ending the rumors/misinformation floating around the Internets. We now have solid proof of what is required for 17×9.5 +38mm RPF1s to clear the Brembo Brakes on a Subaru Impreza WRX STi, Thanks Earl.
As always feel free to Comment, Email or PM with any questions.
-t3h_Clap
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so, Enkei could just build a proper +33 wheel in the first place!
Teh_clap, I’m pretty excited that I found this since these are the exact wheels I was looking at. My question now is the +38 offset RPf1s would be very hard to fit correct? Inother words you’d need a lot of rolling and pulling right? So then adding a 5mm spacer.. Wouldn’t that make it like a +33 offset? Wouldn’t that be harder to fit and even worse on the wheel bearings?
I’m qmania2 on nasioc in case you were wondering lol. Any insight would be much appreciated!
..hoping that you still watch this for comments lol!
Cory, it’s not super hard to fit. if you have an 05-07 STI you can use my fender mod article for the fender work. http://t3hclap.com/archives/49 and you’ll need coilovers stiff ones. You’ll need -3.0 camber front and -2.0 rear camber (or so + or -1 .1 or .2 degrees). The +38mm and +33mm will wear your bearings more then a stock offset but what modifications don’t reduce longevity of the stock parts? How much life is dependent on the current state of your wheel bearings and what type of driving/racing you do.
Hello, thanks for all your advice on wheels. I’m looking into this exact set up for an 06/07 STI. Is it necessary to have stiff coilovers if fenders are rolled/pulled enough? I’d run a 245/40 tire.
Thanks!
You can get away with a stiff spring that isn’t very low like the RCE Blacks but most springs you’ll rub due to them being too low and too soft. It’s possible, but the coilovers make much better use of the added grip and width. Plus they are stiffer so you’ll have less chance of rubbing.
Do you think a 3mm spacer would also work instead of 5mm? I am wondering if this fitment could work without having to use extended wheel studs.
Thanks!
Any info on Brembo clearance with the Enkei NT03+M Wheels (17×9.5″, 5×114.3)? I run in SM class and want to fit 265s on this wheel, question is should i get the 44 or 38mm offset?