Wide Tires..

[sponaugle]

I have this in my build thread, but I thought I would put it over here in the wheels and tire section in case someone else was looking to do some wider wheels/tires.

I got my wheels and tires today. I was going to get the Mira 398s like Kurt did, but the 18x8.5s are on back order. I called Luke at TireRack and they had the Enkei RFP1s. Since I am planning on doing some reasonable power I wanted to be able to run a larger tire. I also have the STI hubs so my wheels need to be in 5x114.3.

For the front I got the RFP1s in 18x8.5 +30 Offset with 255/35R18 tires.
For the rear I got the RFP1s in 18x10.5 +15 Offset with 295/30R18 tires.

Both front and rear are the same rotational size at 25.1 inches. I got R888s, which are a bit wide for their size. The front 255s are 10.2" wide and the rear 295s are 11.8" wide.

First, a picture:



Now to fitment. The rear wheels have a low offset, and combined with the wide tire make a perfect fit. (at least as far as the frame and suspension is concerned).

Here is the clearance on the rear wheel:





I could fit 305s if I wanted. Enough room on the inside with both the upper links and the lower trailing arm. (with the help of the VCP arms).

My guess is you could get away with +20 offset as well, which is what Kurt is doing. I think +25 offset would be a bit too close. at least with a 10.5" wheel.

On the front, I knew the +30 offset was going to be a problem. I bolted the wheels on without any spacers, and at full lock the wheel was into the bottom chassis brace. I added a 20mm Perrin spacer and it is just enough. A +10mm offset version of that wheel would be just what you need.

Here is the front tire at full lock:



This should be the worst case as the suspension is fully unloaded and the wheel at the lowest point (which brings it closer to the lower frame member).

On the top side there is a lot of room:



I assume I will have body work to do. I did measure the front and rear track. (outside edge of wheel to wheel). In the rear it is 73" and the front 71". My 02 WRX is 69". Without the 20mm space the fronts were noticeable closer.

So if you are looking to run some wide tires and wheels, you have some more data to start with.

Jeff

[Boog]

Do you think there will be a change in the interference after the front inner fenders get put in?

[Bob_n_Cincy]

Hi Jeff,
Are you going to add fender flares, I figure your rear tires are going to stick out at least 2" in back.
Bob

[JeromeS13]

I would also be interested to see your front clearances at ride height and full compression.

[Hindsight]

VERY cool!

I'm really curious as to what your plans are for the rear fenders. I hear a lot of people talking about modifying the rear fenders, but haven't heard many specific plans, or seen what it might look like.

I'm not that great at body work.... certainly done some in my lifetime, but fabbing up widened fenders and making them look right from scratch seems to me to be a very difficult undertaking. If you could locate some fiberglass fender extensions that could be attached to the body in a specific spot, and you then just had to feather the area where they meet the body and cut out the existing fender in the areas the new extensions cover, that wouldn't be bad at all...... but fabbing from scratch?

[flynntuna]

+1 very cool I hope you share a lot of details on the creation of the flares. It's great to see the way the people who build F5 cars take a great platform to extraordinary levels.

Do you think you might go in this direction?

[sponaugle]

Do you think there will be a change in the interference after the front inner fenders get put in?

Yea..I think Kurk is a number of steps ahead of me, and he indicated there will be some work with the inner fender sheetmetal. So I expect some tweaking will be needed.

Hi Jeff,
Are you going to add fender flares, I figure your rear tires are going to stick out at least 2" in back.
Bob

I think I will have to. I have not figured this out yet, but I do know there will be some custom fiberglass work. I have non experience with fiberglass, so this will be entertaining.

I would also be interested to see your front clearances at ride height and full compression.

Yea.. good idea. I'll remove the spring and take some pictures of the articulation interference.

VERY cool!
I'm really curious as to what your plans are for the rear fenders. I hear a lot of people talking about modifying the rear fenders, but haven't heard many specific plans, or seen what it might look like.
I'm not that great at body work.... certainly done some in my lifetime, but fabbing up widened fenders and making them look right from scratch seems to me to be a very difficult undertaking. If you could locate some fiberglass fender extensions that could be attached to the body in a specific spot, and you then just had to feather the area where they meet the body and cut out the existing fender in the areas the new extensions cover, that wouldn't be bad at all...... but fabbing from scratch?

Thanks. I think fabbing the fenders from scratch would be very difficult. I might try the fender flare as a starting point, and do some fiberglass blending to make it look like one piece. I'll be sure to post up lots of pictures and data once I get to the body part.

+1 very cool I hope you share a lot of details on the creation of the flares. It's great to see the way the people who build F5 cars take a great platform to extraordinary levels.
Do you think you might go in this direction?

Hmm.. that is cool.. might be a bit more then I can do.. but why not try!

Jeff

[Kurk818]

Might as well post mine in here. Same rim and tire sizes with slightly different offsets as Jeff.

[flynntuna]

Before you hack up the fenders, you might want to make a mold of the body parts you have. This way you can make copies of the fenders so you can practice with.


How to Make a Carbon Fiber Car Bonnet/Hood - Part 1/3 - YouTube
www.youtube.com/watch?v=UgKvDw1E60E


► 19:32► 19:32
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Incredible series of advanced composites video tutorials showing exactly how to make a ...



► 10:10► 10:10
www.youtube.com/watch?v=P8ucNBRaBYs
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Incredible series of advanced composites video tutorials showing exactly how to make a ...


Even though these are for CF, the mold making process is similar for fiberglass. .Lots on youtube some good some not so. Tap plastics have some which are useful too. Learning half he fun though... Right?


http://www.youtube.com/watch?v=GXzR17LktSg


http://www.youtube.com/watch?v=p3idUl123kg

[DMC7492]

Here is my addition to the post.
Miro wheels front 18x8.5" 35mm offset with Yokohama Advon 225/35/18 25" OD
Rear 18x9.5" 35mm offset With Yokohama Advan 265/35/18. 25.4" OD
Clearance on front at roller height 4.75" minimum 1 inch to any part of the frame. With a 1/2" spacer between the inner tie rod and the rack the tie will not touch the aluminum shield.
Clearance on rear at roller height 5.25" trailing arm 5/16" and upper arm 3/8"
69.75" front track width and 70" on rear.
Caster 4.0 front camber-.5 rear -.3 toe in front 1/16" rear 3/16" rough alignment but very close.
No wheel spacers and stock stud length.
image.jpgimage.jpgimage.jpgimage.jpg

[wleehendrick]

9.5" rims with 265's out back on stock trailing arms? Nice! My 8.75" 35mm with 255's should have plenty of clearance (I'l find out soon).

[Harley818]

at full wheel lock on the front your tires will hit the corner of the firewall. Are you planning to trim it back a bit? or....?

[Bob_n_Cincy]

DMC
I also notice that you have a spacer the moves the tire forward.
Was that on the donor or did you add that?
Bobspacer.jpg

[DMC7492]

DMC
I also notice that you have a spacer the moves the tire forward.
Was that on the donor or did you add that?
Bobspacer.jpg

Bob I added the "free caster spacer". It is 3/8" thick.
Harley are you talking about this areaimage.jpg
A 1/2" spacer in the steering rack on each side behind the inner tie rod with prevent the interference.

[Scargo]

Some "track measurements" given here give me pause... Track is the distance from wheel center to wheel center. That means track will vary from car to car depending on the wheel width and offset. Some numbers don't come close to agreeing with mine. Though I have the six-speed adaptation and rear STi axles I am not gaining that much over the STi front axles. My lateral arms are at 16.6 inches and hub to hub is 62.4 inches which puts me at 61.2 for my track with 9.5 inch wheels and 15 ET.
See my build thread for more and pictures.

[Santiago]

I think some folks are using "track" loosely. You're right Glyn, the term is not meant to mean "outside-to-outside" measurement; it's center-to-center. But that also means wheel width doesn't matter, only wheel offset. Of course, those STi axles are chipping in their fair share too.

According the early R&T article, FFR's blue 818R mule had a front track of 59.5" and 59.0" rear track. So you've made nice gains out back. The fact that a certain someone I know is looking to duplicate it doesn't influence my appreciation at all...

Best,
-j

[Harley818]

DCM,
on the front, when you install the front firewall, you will have an interference at the corner on full steering lock if your diameter is more than 25 inches.
I don't have a picture, but Mechie3 has one showing his interference with a diameter greater than 25 inches.
Here is a pic of my car showing the front firewall corner ...... its only an issue when you turn to full lock

DSCF4695.jpg
I guess you can modify the front firewall to eliminate this issue.... but head up.

Harley

[DMC7492]

Harley , A 1/2" spacer in the steering rack on each side behind the inner tie rod with prevent the interference. Or a slight modification to the aluminum panel. Im on it!! Thanks For the Heads up!

[Canadian818]

Does anyone know the difference using STI hubs makes? After seeing kurt818's lastest picture (aka "meaty") I'm seriously considering ordering some wide wheels. However I don't know how comparable the offsets would be on 5x100 hubs. What I'm considering are;

XXR 530's 17x8.5 +35 fronts, 18.10.25 +20

I already have 3" studs, so spacers shouldn't be a problem, but I do want to hug the trailing arm as close as possible. I'll modify a ebay arm like Wayne's.

[sponaugle]

Does anyone know the difference using STI hubs makes? After seeing kurt818's lastest picture (aka "meaty") I'm seriously considering ordering some wide wheels. However I don't know how comparable the offsets would be on 5x100 hubs. What I'm considering are;

XXR 530's 17x8.5 +35 fronts, 18.10.25 +20

I already have 3" studs, so spacers shouldn't be a problem, but I do want to hug the trailing arm as close as possible. I'll modify a ebay arm like Wayne's.

Hmm.. I would not think any difference, as the hub spacings look the same between the two hubs. I could be wrong, but I thought the geometry was the same.

As you can see from my first post, with the modified arms at a 20mm space in the front, my wheels are ok. Since I was using a 30 offset for the front, and you are looking at a 35 offset, you would need a 25mm spacer.
The rear with the 20 should work... but will be a bit closer then what I have, but there looks to be room.

Jeff

[Scargo]

Another, I could be wrong caveat. It is hard for me to believe that an STi would have 5 x 114 studs and nothing else. Surely it's beefier elsewhere or has more built-in geometry (like more caster) than a plain WRX.
I know with GRs (2008+) there are some differences.

[Canadian818]

Hmm.. I would not think any difference, as the hub spacings look the same between the two hubs. I could be wrong, but I thought the geometry was the same.

As you can see from my first post, with the modified arms at a 20mm space in the front, my wheels are ok. Since I was using a 30 offset for the front, and you are looking at a 35 offset, you would need a 25mm spacer.
The rear with the 20 should work... but will be a bit closer then what I have, but there looks to be room.

Jeff

Thanks Jeff. If I go with 18's up front there's a 18x8.75 +20 I can use, which would be more ideal. The arp studs are long enough for a 25mm spacer, but the difference in stud stick out front and rear would bother me too much. How are your fronts for clearance on the frame? You're an inch taller than considered acceptable. I'm assuming that by spacing the front out to match the rear you solved that issue?

[Hindsight]

You can cut excess stud length. Just mark it, run a die down the stud to just past the cut mark, then cut the stud at the mark. Now back the die off the stud and it will clean up the threads.