Light Weight Wheels and why, add yours to the list, read the requirements first

[RAAMaudio]

Rotors come in many different offsets, bolt patterns, hub bore diameter, rotor diameter and thickness....perhaps somebody found a bolt on 4x100 rotor, you may want to search for that or check with Gunrunner.

Depending on how hard you are on brakes a BBK could end up being not only a better but lower cost solution.

Lots of stuff posted about brakes, searching before asking is the best approach to finding the answers to your questions

 

[blancheezy]

I'm new to this forum, but I need to ask, how much did those motegi cost, and how is fitment??? I'm having a pain finding anything worthwhile that is 17x7 so I figured jumping up in width might help. So far your motegi are the best looking I've seen aside from rotas, which are mostly cast fake wheels.

 

[mco30mco]

would oz ultralegga 15x7 at 12 pounds and michelin primacy a/s 195/55/15 at 18 pounds be a good combination?

 

[RAAMaudio]

I like the low weight of the wheels

Tire weight is great, wear rating is very high at 640 as a grand touring car so dry grip is probably decent but not great, supposed to be very good in the snow....a bit costly.

I have been looking at every all season in 15" made and so far and with a strong recommendation from someone I trust it seems the Nitto Neo Gen in 205/50/15 is the best in 15's for summer grip, good in rain, can get by in the snow, around $200 less per set. Wear rating is 280 so they are softer and will not last as long but should be a better match to our cars performance capabilities.

If Mich made the PS-3 A/S in 15" I would likely run them as have 17's now but want to go smaller for a better ride and save weight.

 

[twolf]

RAAM, what are your thoughts on 6uls?

http://949racing.com/15x7-6UL.aspx

10 pounds for a 15x7. 4x100. The only concerning thing to me is the offset... +36...

 

[RAAMaudio]

6UL wheels are great, I am going to test fit the 15x8 over my 11.75" BBK next week when I drive the car down to San Diego to Goodwin Racing. I will test a couple of other wheels as well.

+36 is not optimal but not horrible, I am running Konig Helix in 15x9 +35 with 5mm front spacers so really +30, and barely clear the coilovers but getting 13.4 lb roll formed wheels that look great, give a ton of support for my race and summer only 225 tires was worth it but I did alot of drawing things out to be sure it was not adding to much scrub radius, it is close but the car is amazing on track and the street. I would love to run the Helix in 15x8 but only comes in +25mm so going to test the +35mm 15x7 and 15x8 6ULs.

If somebody comes out with a flare kit that covers the front of the tires I might end up with some 15x10 or 15x11 6ULs!

 

[twolf]

Please get me a picture!

Do you think I'll have any difficulty fitting 16x8 +38s with 225s?

 

[RAAMaudio]

As I have mentioned many times on various threads and in PM's tire size is not accurate with what is stamped on them, I have seen 225 narrower than 205s in extreme cases and 225 race tires that were closer to 245. You will want to look at the diameter, section width and tread width of the tires you are considering as some 225 are a bit to wide for an 8" wheel and some 205s are perfect for it. I chose 9" wide wheels knowing it was going to be a very serious fitment issue including changing the rear camber and then rolling and pulling the fenders and barely get them to fit in the back.

A 16x8 +38 which sounds like the RPF1, with the right 225 should work out well though you will have to trim a bit of the front fender to bumper cover mounting area which is not hard to do and many have done so.

What specific tires are you looking at or if in general what do you need from them, ultimate summer grip, great summer but last a bit longer, autocross, HPDE, high performance all seasons?

I do not have a really good rear picture and do have the rear higher than the front for aero reasons and when we have the dogs and us in the car it is around 600lbs plus cargo, that and I only lower a car to where the geometry still works very well, too low gives up to much grip and too many headaches driving on public roads.

I have 6 more of the same wheels with race tires on them

 

[twolf]

The only real option I see for 225/45/16s is Star Specs, Proxes R1R. I need something I can drive every day. I could go with a different size, if you have a suggestion for a size with more options that would fit well. Indeed, I do want RPF1s. I'm also likely going to do the Eibach springs, for a ~1" drop, if that changes anything in regards to fitment.

 

[RAAMaudio]

The SS II is a very wide 225 with 8.9" section and 8.5" tread width, 23.9" diameter is not bad, weight is 23lbs which is pretty heavy, I would pick the 205/50/16 instead, just a little taller, 8.5 section and 7.5 tread width, 21lbs, I would prefer that size in this particular tire on an 8" wide wheel.

If you are considering a BBK there is a significant chance the RPF1 would not fit over them, I have owned quite a few of those wheels and they can be a trick brake fit.

The R1R is a wide tire as well, 205/45/16 is 19lbs, 8.1 section, 7.7 tread, 23.1 diameter so closer to stock, plenty wide for an 8" wheel, 140 tread wear, the 225 is 9 Section, 8 tread, 23lbs, 23.9" tall, I would give up .3" and save 4lbs absolutely!

Of those the SS II would be my pick in 205/50/16 more likely as will be a better street tire and likely better overall performance.

If you autocross look at the 215 Rival S, if into track days pick a different tire as the get hot to fast for a road course.

The Hankook R-S3 works very well as a track and street tire as does the SSII. 205 is the size I would go with.

Saving weight and having really good sidewall support will go a very long way to improve every aspect in performance including feedback and ride quality and less wear on the chassis.

The only way I would run overly wide tires on a given rim size is if dictated by rules in autocross racing or in drag racing, never for street or track nor for looks. I may not be an absolute expert but 47+ years of modding cars to make them handle better, hundreds of sets of wheels and tires chosen for the task and with readily available real specs and reviews I get it right at least most of the time

OK, got to get busy, moving the RV to SoCal today, lots to do!

 

[RAAMaudio]

The 225/45/15 Rival S I showed the pics on my 9" wheels work very well on an 8" wheel as the actual size is 8.4 section and 7.8 tread width, 23" diameter, 20lbs on 13.4lb weels. This particular tire was shown to be over 1 second faster on a short road course(not lapping for long periods) on the wider wheel than the standard but I wanted to run 9's as a challenge to make it fit which was a tough job but also because only 1 set of wheels in 15" available at the time would fit over my DIY BBK. I accomplished three things, fit over the brakes, maximized the performance of the tire and did something more challenging thus for me more rewarding and I happen to like how it looks

 

[RAAMaudio]

Just returned from a wheel fitment session at Goodwin Racing, great group of true enthusiasts there

Posted on another thread to help answer some questions but this thread is more directly related.

1 No 15x8 or 15x7 will fit over an 11.75" rotor BBK I know of, just got back from test fitting wheels at Goodwin Racing, they know what they are doing, see note below. I asked about the TD 15x8 and I was told no go.

2) 16x8 Enkei RPF1, 4x100, +36mm 14.8lbs, roll formed, fit the car great and easily cleared the BBK as well as did the 16x7, I have a set of new 16x8's om the back of the car now

3) A 4x100 conversion can be done for a very reasonable cost for the DIY group, for bolt on and go, still some work, then get a more complete kit but still reasonable at around $1200 for wheels and the parts to convert.

4) If you want to run 15's it looks like just the 15x9 Konig Dial In, Konig Helix and probably 6UL will fit over an 11.75" BBK but it is a very serious amount of work to fit the wheels, rear camber change a must. Of course you might be able to fit custom wheels but the front and rear offsets would be different so cannot rotate them.

NOTE: There have been some one off, very custom, very deep mounted rotors on special hats and brake caliper mounts fitted under 15x8 wheels caused by building to class rules, costly and a waiting period.

I went there to see what would fit as want to get all the info out there for my fellow enthusiasts, I drove in pooring rain there and back, 75 miles each way and got wet fitting wheels but worth it. I sorely wanted to run 15x8 or even 15x7 over my BBK which at 11.75" is the smallest rotor I would run on the track with race tires and lots of power and will have good cooling ducts soon as well.

If you want to run bigger brakes the 12.19 rotor standard kit but with GT rotor upgrades will fit 17's and a very close call if fit the 16x8 RPF1, I cannot promise it will. If running 17's it would not be a bad idea to upgrade to 12.8" GT rotors but anything besides the 12.19 requires custom caliper mounts.

 

[RAAMaudio]

More good news for the future!

Goodwin is working with Konig on coming out with Avanti Storm roll formed, low weight, strong, good looking and low cost in 16x7, 8, and 9" wide.
Offsets would work on this car, 16x7 being decided, 16x8 likely 35mm, 16x9 45mm, 4x100 only unless Konig decides to drill some in 4x108 which could happen, PCA??????

If they get made I will get a set in 16x8 for my street wheels and sell the RPF1 wheels I just bought today but it will be done the road sometime, it takes awhile to get new wheel sizes made.

 

[twolf]

Pics of the RPF1s? I'm still trying to decide on tire size.

 

[RAAMaudio]

Sorry, still in boxes in the garage, not sure when I will get the tires on them and on the car but they do fit really well, I will paint them satin black most likely.

 

[Dsquared46]

Just want to know what people think.......TD Pro Race 1.2 17x7s About 5 lbs per wheel lighter than stock with stock tires. With vehicle being 20 lbs lighter overall and 5 lbs per wheel rotational weight being removed from the vehicle it should be slightly quicker off the line. Shouldn't that be almost the equivalent of picking up somewhere between 5-10hp? Just a guestimation.......... I mean obviously there's a formula for lbs per hp + or - rotational weight. Any physics majors out there want to tackle this? Hp/lbs is easy to figure, but the rotational weight is a different animal.

 

[RAAMaudio]

I am not qualified to answer the question though I have studied many things the last few years like Quantum Physics, now into Astrophysics and many other areas.

I know it will make a very nice improvement but I also most highly recommend 15 or 16" wheels instead as 17's are not a good match for this car. I used Mich PS A/S3 205/45/17 on 17x7 16.8 lb wheels and compared to my 15's the ride like a cement truck and far more noise. I gave the tires to my daughter where they ride far better on her 3200lb car with softer suspension but still are pretty stiff over expansion joints.

-----------------

I bought the 16x8 Enkei RPF1, 14.8 lbs, roll formed, because could not find any 15's in 7 or 8 wide to fit over my BBK but really wanted 15's and now have it figured out, a close call, have to get the wheels here to be sure and might have to run a small spacer up front or trim the calipers just slightly but I can also move them in a bit closer to center with the way I designed the caliper mounts then get new mounts made in a fixed position.

----------

You can save even more weight going to smaller wheels like 15x8 TD's and put some really fun tires on, the car will be better in all ways but even 16's will be much nicer than 17's.

 

[Dsquared46]

Thanks for the info. 16's sounds like the best compromise and way to go. Especially for everyday use and canyon carving. Less expensive too.

 

[RAAMaudio]

Thanks, just want to help my fellow enthusiasts make their car more fun to use and enjoy


I like the look of bigger wheels to a degree but only if it really works well in the real world or on track. I have built pure race cars that weighed less than this car and ran 18" wheels because that is what I had to run to get the wheels and tires I needed to use, not for style and I did not have to worry about potholes and ride comfort is not something to concerning as you need to feel exactly what the car is doing at all times, many racers do not use any padding in the seats at all.

 

[1Quik89GT]

I ended up finding a set of the TR motorsports wheels second hand for dirt cheap, swapped on the stock Bridgestones to finish them off this summer. Plan to move to a 205/45 for ride comfort reasons when the time comes. I was surprised how light they were for a cast wheel.

Specs: 17x7 +42, low pressure cast/flow formed. 14.7lbs each.