Enkei RPF1 17" vs 18" for speed3

[mrmonk7663]

I have a 2011 speed3. I am debating wheel choices. I have always like the rpf1 for the weight and I like the style. Currently my car sits on the stock 18" mazda rims. If I decide to go with the rpf1 is there any benefit to switching to a 17x8" rim (15.5lbs) or should I stick with a 18x8" rim (17.8lbs)? The main difference is weight between the two...but I am unsure if it will negatively effect my handling downsizing to 17". Also would a 35mm offset or 45mm be ideal? I plan on running no larger than a 225 or 235 tire. Any input and advice is appreciated.

Regards,
Michael

[2011speed]

stick with 18's. 17 inch rpf1 belong on an 8th gen civic.

[mrmonk7663]

10-4. The stock rims weigh in at 21lbs or 23lbs? Also any reccomendations on a tire for an 18x8....225 x ? or 235 x ? Finally offset...35mm or 45mm

[2011speed]

since ur stock ride height, id do 235. however im not sure about the offset since i do not know what kind of look ur going for.

[mrmonk7663]

Currently I am stock height. In the future the H&R springs are a possibility, but that would be the only spring I would consider. I think it drops it 1.2 and 1.3 or vis versa. As far as the look goes....I am trying to stay away from having to roll fenders...so whatever achieves that is what i'm looking for.

Thanks.

[2011speed]

personally i would rock 18x8 with 45 offset. i've seen it on a gen 2 before and looks damn good.

(i belive couple members on here have that setup as well so search)

[BLK_MS3]

For a street car, yes stick with 18's. But if you wanna track it the weight savings and larger selection of race tires makes the 17's a good idea.

[dizzydtrain]

only benefit 18's yield are looks (subjective). Go with 17's if you want improved performance, cheaper tires, and generally better grip due to wider tires w/ smaller wheel size.

[Dre]

stock wheels weigh 25.x lbs.. if you go 17's go 17x9 and throw some meaty tires on there.. use this to figure out what offset and size wheel you need to run if you do go 17s..

Tire and Wheel Calculator

i personally think 17 rpf1's with some meaty tires would look mean as fuck on a black, lowered gen2

[dizzydtrain]

Here you go:

http://www.mazdaspeedforum.org/forum/foru...-speed3-82062/

Matte Black Enkei rpf1 17x9 +45

[mrmonk7663]

Damn, thanks for all the responses guys. The gears are turning now going 17s is looking more appeasing. The weight savings would be amazing...damn near 40lbs.

[myt_tuf1]

This sums up the 17" rpf1's and tires I have (full specs in sig):

-I've got a lot more traction.
-These tires are rated to last longer than the stockers.
-I'm saving ~$200 buying 17" tires over 18" tires.
-I'm not carrying a dead ~40lb baby around with me everywhere I go anymore.
-I think it performs and looks a lot better than it used to.
-The ride is also a lot more comfortable due to the taller tire.

That's justified in my eyes.

[mrmonk7663]

Ok, looking at the offset calculator...

A stock wheel is 18x7 with a 52.5mm offset

A 17x9 with a 45mm offset moves the wheel 18mm closer to the strut and extends it 32mm out farther than stock. OP wanted to use spacers for extra clearance.

A 17x8 on the other hand with a 45mm offset only moves the wheel 6mm closer to the strut, yet still extends it 20mm (3/4")

Based on this, the 17x8 should fill up most of the fender gap AND NOT require any spacers. If my calculations are incorrect please let me know, but for now 17x8 seems like a solid choice at 15.6lbs per wheel and NO spacers necessary.

[super_pablo_]

go with 17x8.5. I run 18x8.5 on a genwon with 235s... you can easily fit an 8.5 on a genpoo.

[myt_tuf1]

You can easily fit a 17x9... That's what I have, flush as can be, no spacers required, no rub, and no roll on H&R's (but my Koni's are set at their stiffest, I'm not sure if it would rub if they weren't).

[Dre]

Originally Posted by myt_tuf1 -I'm not carrying a dead ~40lb baby around with me everywhere I go anymore.

40lbs of unsprung weight is the equivalent of roughly (**BE ADVISED! RICER MATH ONGOING IN THIS POST**) 320lbs of sprung weight for our cars i believe.. I cant find it now, but i've asked before and the number (for our cars) was around 1lb of unsprung = 8lbs of sprung..

[mrmonk7663]

The only reason I am not wanting 17x9 is because I don't want to take the chance of rubbing (stock struts/springs) and also because I never see myself needing more than a 245 tire on this car. It will be my daily driver. I will mod it with bolt ons, but nothing extreme. A 245 on a 17x8 should suffice....and for the first set of tires I anticipate a good 225 or 235 tire anyway. myt tuf1...your wheels look great though, I love them!!!

Changing the rims to the proposed rpf1s and removing the spare tire/jack assembly and installing a new intake, exhaust, and tuner should yield a whole new car that has a respectable acceleration compared to stock :-) Now I just need to find some decently priced 2 piece rotors to finish the unsprung weight removal!!!

[tragik]

dieciocho.

[JS + MS3]

OMG this is making me want to order a set of rpf1 17x9 right now. gotta resist......

anyway, OP go with 17x9 along with some meaty tires!

[Crarrs]

Originally Posted by mrmonk7663 A stock wheel is 18x7 with a 52.5mm offset.

Stock Gen2 wheel is 18x7.5. Offset is correct. Redo your calculations with that number.

[mrmonk7663]

Thanks for correcting me on the stock size. I'll recalculate a bit later and post here.

Michael

[mrmonk7663]

Ok I recalculated.

Stock-18x7.5 52.5mm offset
Enkei RPF1 17x8.5 40mm offset-1mm closer to strut, 25mm farther out toward wheel well. This will fill up the wheel well almost as much as the 9" wheel but it will only reduce clearance by 1mm. Seems like the best comprimise. 8.5 it will be for me

[Fermion]

I have 17x9s on my gen 1. Love the cheaper price of tires, the weight, the way they make my suspension respond, and the look. IMO I like the way the 17x9s look better than any of the 18s. yeah my revs are higher and my speedo is off, but who cares.

[mrmonk7663]

From Enkei...

Enkei RPF1 Wheel Features:
•MAT PROCESS: Shaping by the MAT process reduces wheel weight by 10%-15%. Every pound of unsprung weight savings has the effect of reducing overall vehicle weight by 20lbs.


This seems optimistic but still bad ass!!!

[JS + MS3]

Man! Just ball up and get the 17x9! You won't need to modify your fenders according to others who have them on!

[Fermion]

On my gen 1 I had to roll the rear bc im on eibach pros. I'm not sure about gen 2s.

I have a wheel thread of them installed

[Dre]

Originally Posted by Fermion I have 17x9s on my gen 1. Love the cheaper price of tires, the weight, the way they make my suspension respond, and the look. IMO I like the way the 17x9s look better than any of the 18s. yeah my revs are higher and my speedo is off, but who cares.

i dont think your speedo is gonna be off by much depending on what size your tire wall is.. if you use the tire calculator i linked earlier you can get it to like 1-2 mph of stock.. on a genpu at least..

[RJD23]

Enkei RPF1 17x8.5

i use to drive a sentra spec v and once i dropped it i hated the car i dont want to mess with my mazda and keep suspension stock

if i get the wheels named above and not get suspension what tire size should i get? will it rub?

as you can see by my questions this is my first time buying wheels

[cjanota]

Originally Posted by mrmonk7663 From Enkei... Enkei RPF1 Wheel Features: •MAT PROCESS: Shaping by the MAT process reduces wheel weight by 10%-15%. Every pound of unsprung weight savings has the effect of reducing overall vehicle weight by 20lbs. This seems optimistic but still bad ass!!!

That is incredibly optimistic. For straight line acceleration, the added effects of rotational inertial mean that reducing 1Lb of mass in the wheels is equivalent to a 1.5-2Lb reduction on the sprung weight depending on mass distribution of the wheel. The biggest benefit you see is in the ability of the wheel/tire to follow bumps on the road. This is much more important for cornering and high speed. Spring rates and damping rates need to be adjusted to take full advantage of significant changes in unsprung mass.

[Juliandlr1004]

I AGREE! I CURRENTLY OWN AN 8TH GEN CIVIC THAT I HAVE UP FOR SALE TO GET A MAZDASPEED3 AND 17" RPF1 BELONG ON THAT CAR NOT THE SPEED, WHICH IS WHY THE SPEED COMES ORIGINALLY WITH 18S AND THE CIVIC WITH 17S
I WAS RUNNING MY CIVIC WITH 18" EVO X MR BBS WHEELS AND THEY WERE SICK!
THINKING ABOUT SAVING THOSE AND SLAMMING THEM ON THE SPEED ONCE I GET IT!

Originally Posted by 2011speed stick with 18's. 17 inch rpf1 belong on an 8th gen civic.

[327whp]

I would run the 18's with a 235 and a 45mm offset. I had a 48mm offset on mine and loved it. My wheels were 8.5 though.

[Midnitehours]

17's all the way! as long as you get the ride height right.



the 17x9 +45mm fit the gen2's perfectly thanks to the little indent on the stock strut.
If you decide to get struts/coilovers from a gen 1 you'll need spacers up front.

[ahfunaki]

Does anyone have pics of a Genpu running 18" RPF1's? Every pic I have seen has been 17"...

[Scoobs]

Originally Posted by Midnitehours 17's all the way! as long as you get the ride height right. the 17x9 +45mm fit the gen2's perfectly thanks to the little indent on the stock strut. If you decide to get struts/coilovers from a gen 1 you'll need spacers up front.

What size tire are you using, 245? Looks great by the way.

[Midnitehours]

Originally Posted by Scoobs What size tire are you using, 245? Looks great by the way.

235/40/17. they're shorter than the stock tire size so wheel gap was bigger than norm.

the r888's run rather meaty compared to dunflops. I have to roll the rear at my ride height.

[token_asian_guy]

Originally Posted by mrmonk7663 Ok I recalculated. Stock-18x7.5 52.5mm offset Enkei RPF1 17x8.5 40mm offset-1mm closer to strut, 25mm farther out toward wheel well. This will fill up the wheel well almost as much as the 9" wheel but it will only reduce clearance by 1mm. Seems like the best comprimise. 8.5 it will be for me

So basically 17's run to these specs would be fine with the stock suspension setup?

[kunfu]

Originally Posted by Fermion I have 17x9s on my gen 1. Love the cheaper price of tires, the weight, the way they make my suspension respond, and the look. IMO I like the way the 17x9s look better than any of the 18s. yeah my revs are higher and my speedo is off, but who cares.

Do you have a thread with pics of your set up. Would love to see it on the red.

[mrmonk7663]

Yes it was fine on my stock suspension. With my swift springs it would rub going over big dips fast. I rolled the fenders and problem solved.

Originally Posted by token_asian_guy So basically 17's run to these specs would be fine with the stock suspension setup?

[cabrone]

I'd go 17x9

Tapped

[Matt]

The latest issue of GrassRoots Motorsports covered 18s vs 17s. Their track times showed that 18s were actually faster (average and overall). They came to the conclusion that because the 18s have a shorter tire sidewall that the contact patch is larger, which equaled more even heat distribution in the tire and much better grip at the limits of the tires heat threshold.

They used an MS3 for the tests too.