wheels for wide body HELP Please
 

Hi,
I`m in the middle of making a custom wide body for miata 1993 and trying to come up with some good wheel options to fill the wheel wells up. I`m planning widening the rear 5.5” each side, and the front 4” each side.
My body kit will be exactly same as this one here, The guy who did this body kit, using following wheels: Tires : 275/35/18 front and 335/30/18 rear.
But I cannot install this kind of rims on my Miata 1.6 axle, I choose something a little smaller but want to get maximum wide rims (deep lip)
The sizes is still flexible, The sizes which I was looking at, is similar to this:
FRONT:
size:
R17" x 10" Wide offset +11" 4×100 bolt pattern

REAR:
size:
R17" x 11.5" Wide offset +11" 4×100 bolt pattern

So I think my setup for my wide body should be right maybe wrong, but i`m not sure about offset and not sure wich tires i can install on this wheels. the problem is that we do not have anything like that, and it very hard to choose something that you seen only on photo :)
My goal is:
A wide body to run maximum wide rims & tires (similar to this but different body kit)

tires and wheels will be driven on weekends and mostly drag racing.

275/35R15 on a 15x10 +25 is the widest I am readily familiar with.
949 Racing - 15x10 6UL

You are in uncharted waters.

Thanks a lot for your reply,

so that mean if i buy lets say this ones
they will work as bolt-in ?

but which rims will be better for front, how you think? 9" or 8" and what tires to take for front
my question is this size and offset gonna hit the frame when turning on full lock??

also what if i install stretched tires which size i will need then? maybe 195/50/15 ? ??

and by the way just make some research: offset +25 will move wheel inside

where a negative offset (same width wheel) can achieve the aggressive look as you move outside the "fender" where my wide body should be :)

so i think i`m clear in my question correct me if i wrong:

I need wheels with max. negative offset (if i will need cutting to fit them - no problem) as long as size and offset not gonna hit the frame when turning on full lock
also planning to have two sets of tires:
what size of max wight tires i can install as set 1 and for set 2 i want install stretched tires which size i will need then for set 2?

After a brief Google Images search for 15x10 6UL I found these.

Unknown tire size. This one might be using spacers:

https://www.miataforumz.com/attachme...ine=1374869733

275 size Hoosier A6 slicks on 15x10 6UL's

https://www.miataforumz.com/attachme...ine=1374869733

https://www.miataforumz.com/attachme...ine=1374869733


15x10 versus 15x8

Attachment 7246


225/45/15 stretched on 15x10

https://www.miataforumz.com/attachme...ine=1374869733
On 275/35/15 again:

http://www.miataturbo.net/attachment...ine=1331482196

245/580R15 Hoosiers:

http://i241.photobucket.com/albums/f...IMG_0134-1.jpg
Attachment 7036



I would buy the same size all the way around, that way you can rotate them to make the tires last. Just use a thicker spacer in the rear, like a 1 inch (25mm) to get them flush with the fenders or if you want to make the back look wider.

BEST GUYS, now i know what to gooogle :)

i done some research as per your advice and I think I want to use 15" size rim

For rear I choosing 15x 11" (with 0 offset - less stress on bearings)

&

15x10" 0 offset for front

what are the best tires size for those specially for front? and what you think about my choice? any suggestions?

I'm between two tire sizes



rear
15x11 0-offset 245/40 -15

front
15x10 0-offset 205/50 -15

or

Rear
15x11 0-offset 225/50 -15

front
15x10 0-offset 205/50 -15

Zero offset tires stick out an inch further than the +25 15x10 6ul wheels I linked above. Beware that the zero offset or spacers will be worse on the bearings and our fatigue-susceptible rear hubs and the car will be much more difficult to steer.

Your car won't corner worth a crap on stretched tires so I'm not worried too much about the handling losses.

But you should know about putting undue stress on the rear hubs and fatigue stress. See examples:


Watch in the rearview mirror after he stops.

It isn't exactly rare.

So basically if i need normal handling on drift, drag and just daily driving i need forget about 0 or negative offset & stretched tires, or i need to be prepare for HUB damage.

You suggest to look on wheels with +25 offset with out stretching tires correct me if i`m wrong
if that correct then what if i choose this sizes:

Rear:
15x11 +25offset - 275/35/15

Front:
???????? 15x8 or 15x9 or 15x10

The rear hubs fatigue and fail from being stressed over time. Race rubber is sticky and transfers a lot of force to the hub. Having a low offset tire also tries to bend the hubs by uneven force from the inside and outside of the centerline of the tire. I'm not saying don't do it at all, but be aware of the possible pitfalls and plan to inspect them for signs of fatigue.

What wheels did you find that you like? If you want it to look a certain way, that is up to you. My only concerns are that you wouldn't be as pleased with the performance if you do it wrong. Which do you want more, performance or looks? It really is your personal priorities that matter. It is your car.

The reason everyone uses 15 inch wheels is because of the weight (which affects acceleration, braking, transfer of forces from the road into the chassis, and roadholding) , available good high performance tire sizes, and the size of the wheelwell opening.

I can actually feel a 3 lb per corner difference when I switch wheels at the track.

thank a lot for good answer,

performance or look is a good question

Let me explain i do not need super performance because is more like summer daily driving car with a little drift and drags on weekends i would say.

I like how negative offset look like, but i can see that it is a lot of stress going to hub, what i do not like.
so that why i`m looking something i a middle i do not want to stress hubs and do not want factory offset wheels.

I like when rear wheels are wide, so that why i was thinking that for rear 15x11 +25offset - 275/35/15 i think we have the same photo on your post with this tires size.
but can not choose for front.

You can see as per you suggestion i forget about stretched tires because of poor handling in all ways. so i do not need just look if car handling goes bad than factory.

15x10 +25 ofset from 949, is like something ideal for racing and driving daily, and i can still put 275 tire on rear.. from technical side of view i found them perfect for my project, but they do not look like rims with negative offset or even 0 offset, (because they +25) that the only problem with them.. but i think i will not find something better for my setup :(. On this tires i probably can drift, drag and just drive car with out lose of handling like on stretched 0 offset wheels? am i correct on understanding ?

I had a very long post for you and my computer ate it.


Here is what you need to know.
-The wheels from 949 are strong and very light because they are made for racing. Lightweight means better acceleration and braking, as well as better ride quality and cornering. Lightweight wheels move faster over bumps and road irregularities and that means the tire stays on the road better and gives you more grip all of the time. Heavier wheels react more slowly and cannot follow the up and down motions as quickly.

-The 275/35/R15 is only available in a racing tire. It is made by Hoosier and is called the R6. It can be used on the street but will not do well going fast in rain puddles because it only has two grooves in the tread to stop the car from hydroplaning. I have driven with this tire in 205/50/R15 size on the racetrack in my 225whp turbo Miata and the grip is amazing. It will surprise you how well the car will stick to the road. You will have fantastic grip for stopping, cornering, and acceleration. It will make you smile.

You can use the 15x10 and the 275 on all four wheels for best performance.

http://www.tirerack.com/tires/tires....omCompare1=yes

https://www.miataforumz.com/attachme...ine=1375276965


-If you want a street tire that is good in the rain, has good grip, has longer tread life, and will fit the 10 inch wide wheels, the Avon CR500 tire in 245/40/R15 is the only one available right now. It won't be as grippy as the Hoosier R6, will be 1/2 inch narrower at the tread, but will last longer. These tires are a new size and I have not ever tried them.

CR500 | Avon Motorsport
https://www.miataforumz.com/attachme...ine=1375276965


What springs and shocks do you have for suspension?

man, you reading my mind.

I`m fully agreed with 275 on the back but are those not big for front?

I think i need CR500 because i will drive more often on city-town streets, and will do only drift and drag a little just for fun, not for race.

i can see that CR 245/40R15 are maybe good choice for all four tires.
but if i get 10" wheels all around then tire will be a little bit stretched, which mean wheel dia. will go down, our roads not so good here :( but if there are no any more ways to go i will go with this setup.

but from my point of view i would love to have 275 on the back on 15x10" +25 rims, and something about 15x9 +25 in front with 245 or 225 in front
but i can see that there are only one size tire available at CR500 :(( i really do not think that i will swap tires because it is not race car for me, just fun car, the reason i want 275 on the back because mymiata is about 300hp, and i was thinking to get big tire so that will help me on drag and just street drag..

i have factory suspension, i was thinking to get one kit guys from flymiata recommended them 6 month ago what you think i`m planing to take wheels and new suspension kit, but this suspension kit a little bit expensive :( how do you think is it ok to go with this kit, or you have something in mind, as you know i`m driving car more for fun, not for super results on track.. but always like idea to go for race, same as drive daily on same setup.

i`m glad that you answering and helping me. thanks man.

If you are making 300hp, you will appreciate the grip of the Hoosier 275 tires. If you are street racing, you will appreciate the ability to stop very quickly in an emergency also. I would use the 275 all the way around if I wasn't worried about driving in the rain or in freezing conditions. If you only drive it when the weather is nice, then they are perfect.
These tires are not too big for the front:
https://www.miataforumz.com/attachme...ine=1374869733


If I was going to drive in the rain often then I would consider the Avons, even though they are 21mm narrower. Or maybe just the Avons for the front. On 10 inch wheels the Avons would not be stretched much at all. They are 10.6mm on the outside and 10.6mm on the inside less tread width than the 275 tires pictured above (21.2mm less overall actual tread width). The Hoosiers are 6.3mm taller in the sidewall than the Avons.

As for suspension, the best adjustable shocks for the best price are the Xida CS.

Xida Club Sport race coilovers Miata

https://www.miataforumz.com/attachme...ine=1375311023


But the cheap way is to make your own performance coilovers using these Bilstein shocks:
Spec Miata Bilstein Front Shock [F4-B46-1488-H1] - $119.55 : Weekend-Racer - Auto Racing Safety Equipment, Auto Racing Gear, Auto Racing Helmets, Auto Racing Suits, We're amateur racers just like you.

Spec Miata Bilstein Rear Shock [F4-B46-1489-H0] - $119.55 : Weekend-Racer - Auto Racing Safety Equipment, Auto Racing Gear, Auto Racing Helmets, Auto Racing Suits, We're amateur racers just like you.

and these springs:
Front http://www.summitracing.com/parts/sum-72-5450/overview/
Rear http://www.summitracing.com/parts/sum-72-5300/overview/

and any adjuster sleeves like this (and give away the springs and the top perch):
Civic EF Da DC2 EF EG EK HB Red Scale Sleeve lowering Adjustable coilover Spring | eBay


Then you can do something like this:
https://www.miataforumz.com/build-th...ge2/#post14271

And it is much better than stock on rough roads and on the race track. It will not ride rough but will ride controlled. The Xidas are better in every way on the street and on the track, but there is a price difference.

http://www.miataturbo.net/attachment...ine=1375225095

Hoosier 275 on 15x10 6ul wheels.

thanks for your reply,

I think i will go with 275 as per your suggests, but i checked Hoosier catalog, and i think they have tires smaller, why not use smaller tire and smaller rims in front ? like 10x9 and 255 or 245 or 225 in front?, by the way i think so, on your photos, cars have narrow wheels in front and wide in rear.

Everybody who races Miatas uses the same size tires and wheels front and rear. None of the cars pictured have smaller in the front. The shape of the car's body is designed to make it look that way to make it look tougher.

80% of braking force occurs at the front wheels and about 60% of the cornering forces. If you have smaller wheels and tires on the front on a Miata the car will understeer and not turn well. It will want to always go straight.

The 245/40R15 Hoosiers are listed on their website but have not reached production yet. They will fit on the 10 inch wheels according to Hoosier.

Now it is more clear for me, so i think i will go for Hoosier 275 on 15x10 6ul wheels.

and last: aren the front wheels and tires not gonna hit the frame when turning on full lock?

Any wheels that is even close to filling those fenders is going to hit the control arms at full lock. You just have to deal with that or remove the widebody. If you want a staggered look and don't care how it handles, maybe the new 245/40/15 Hoosier in fornt and 275/35/15 in back. This tire is basically a slick and will not last long on the street. The 245 Avon CR500 will be a better choice for street use. Maybe two sets of wheels with street and race tires.

Thanks for reply,

What if i will use 245 avon in front,and 275 Hoosier on back for daily drive, and then order another set of two Hoosier for front as spare, and when need just change front tires?

That sounds like a good plan. It is always good to have spare tires and wheels to make changing easy. I have three full sets of wheels. Some are wide slicks and some are narrower wheels with different tires for rain.

thanks lot guys for your help, as i said i will purchase 4 ea 15x10" +25 rims, and 245/40R15 Avon in front and Hoosier 275/35R15 in rear for daily drive, and 2ea of Hoosier 275 spare for front when i will be on drag or track.

I think you will be amazed at the grip.

Please tell us how you like them.

You will need adjustable coilover shocks and 2.5 inch diameter or smaller springs. The factory springs are too wide at about 3.5 inch and make contact with most wide tires and wheels. And the factory shocks don't let you adjust the ride height and are made to control very small wheels and tires. You will want better springs and better shocks with 300hp.

You might also look at better brakes. Are you still using the stock 1.6 brakes? 1.8 brakes are larger. Upgrading is easy. And there are upgrade kits for even better brakes than that.

Hope you right :)

regarding shocks i will not able to buy Xida shocks (my wife will kill me:) i already invest about 10k to engine and gear box :)

anyway i want to guy with something that will make Miata a little bit comfortable for daily drive, as i said mostly car will be driven on street.

I think i have something about 600-700$ for shock setup, what is a better way to go.

I`m still on factory brakes, and for a moment i found them ok for my daily drive, do not want invest a lot in brakes.

another problem that i`m only one in my city who owns miata, there no such model here..:( so it very difficult to find here any part from miatas

The better way to go on your budget is the option below:
You can do this option with new shocks for:
special Bilstein shocks = $120 x 4 = $480
springs = $35 x 4 = $140
Coilover sleeve adjusters = $65

If you get used shocks it will be less. If you use the springs that come free with the coilover sleeve adjusters it will be $140 less but you don't always get the right springs for a good balance. Good shocks are most important thing. If you get the wrong shock valving, the car will ride very badly and you will not like it.

I will help you find the good used shocks if you want me to.

think i will go with new ones, the springs from summitracing are ok? i mean they not very strong? because i need something a little bit soft for daily driving, our city have very bad roads :( if i get that setup you recommend it will be good enough.. so i think i can go with that setup.

I hated driving my Miata with the stock springs because they were so weak. Every time I hit a bump or dip in the road the suspension would "bottom out", which means the shock would contact the hard rubber bump stops. This is uncomfortable and sometimes painful. The stock ride was very rough because of that.

Race Miatas use 700-900 lbs spring in the front. My car uses 550lbs in the front with a very large 25mm front sway bar and I drive on the street and the track. At 400-450lbs in the front your car will be very good riding.

These special Bilstein shocks are very good for controlling the movement of the wheels to keep the ride comfortable and smooth and still keep control of the car for good handling when you want to drive fast on rough roads.

You will want to cut the stock rubber bumpstop to make it 13mm shorter for better ride as well. This will let the shock and spring move without making hard contact so easily. This will give you about an inch (25mm) more suspension travel at the wheel without hitting the hard rubber.

This is what the stock bumpstop looks like:
https://www.miataforumz.com/attachme...ine=1375886276
https://encrypted-tbn0.gstatic.com/i...cdJ7pSAiBez0Qg



This is what it looks like when you cut the bottom piece off:
http://img251.imageshack.us/img251/2751/bumpstop2.jpg

The rubber bellows doesn't help anything, so don't worry about losing it.

so all spring should be same 400-450lbs i mean in front and rear?

do you have weblink for sway bar, there are a lot of them on the market and which links you use, factory ones?

BTW what you think of this shocks setup


for example this kit using following:

Fornt - 8 kg/mm; 450 lb/in
Rear - 6 kg/mm; 337 lb/in

The shocks will ride rough because of too much low speed damping. They will not be comfortable and controlled. There have been hundreds of comparisons done on shock dyno machines and years of street and track use to develop the Bilsteins and the Xidas. Have you ever seen a shock dyno graph?
http://www.miataturbo.net/attachment...ips-5-3-12-pdf
http://www.flyinmiata.com/pdf/V-Maxx...eak%20Test.pdf
http://www.miataturbo.net/attachment...ine=1318384525
http://www.miataturbo.net/attachment...ine=1318384525


Monotube shocks are better at controlling the wheel movements without hysteresis and cavitation of the shock oil than twin tube designs.

Most "sport" shocks are designed to ride rough to make them feel sporty to the driver, but that is uncomfortable and actually causes the tire not to stay in contact with the road very well. Instead, a good performance shock dampening curve will be digressive. That means as the shock travel speed increases, the shock resists less so that the car is not upset and the ride is not harsh. This allows the tire to follow the variations in the road surface and maintain grip without causing the ride to be rough inside the car. The slower speed shock movements will remain very firm to keep the car from "floating" and keep the car even with the surface of the road so that the full range of suspension movements on each corner will be available to follow the surface, both in compression and in droop travel.

Most cheap sporty suspensions are designed incorrectly for real performance. Most will vibrate too much over rough roads and will bounce like a basketball on a bumpy road. A good performance suspension will let you drive faster over a rough road or track without losing control.

The 450lb springs are a good rate for the front, but the 337lb are too much for the rear with those front rates and would make the car oversteer (want to spin). You would do best with 450 front/ 300 rear or 400 front 275 rear.

If you don't want to spend as much as the Xidas, and don't want to make your own coilovers from separate parts using Bilsteins and Summit springs, you can buy the FM V-Maxx Classic Stage 2 Suspension Kit. The V-Maxx is a good shock and the springs are 390lb front / 260lb rear, which is stronger than stock and should be a good ride. The suspension kit also comes with upgraded adjustable sway bars, which is good. The kit is $869 for everything. That kit has a very good reputation.

The V-Maxx:
http://www.flyinmiata.com/Store/images/13-16210.jpg
The FM sway bar kit:
http://www.flyinmiata.com/Store/images/13-30000.jpg

thanks a lot for your answer, with your post i really can make my miata drive as i want, this is very good post, because now i got 3 options, first is very expensive and most effective way to go, second V maxx, and third is Bilsteins.

that very good information thanks a lot!!

also i was think to install differential lock which one u suggest?
also want to maybe change or maybe not :confused: my gear ration, so then i can make 0 to 100km/h very quick rather than have 180km/h max speed

What differential are you using? The standard differential in 1.6 liter 1993 cars is very weak and fails often at 100hp. The '94-05 cars with 1.8 engines had very strong differentials and would take 300hp no problem. The 1.8 differentials also use larger CV shafts between the differential and the wheels.

I use 1.6 (very well for 2 years with 250HP) as I mention previously we do not have Miata in our country, I’m only one owner, so maybe is good way to find used 1.8 from USA?

2 years at 250hp on a 1.6 differential is very unusual. Maybe it has been changed already? Or you are just very lucky?

Good used 1.8 differentials and CV axles are common here. The rear wheel hubs must also be changed because the spline shaft on the CV axle is larger to handle more torque. Limited slip differentials are a little more expensive but there are many around. I will look for one for you.

Please post pictures of your engine, turbo and car. Tell me details about your car and engine.

The rear differential gear ratios in the Miatas were 4.30, 4.10, and 3.90. Other gears available to buy are 4.44 and 3.63 but you can only get them new from Mazda. What ratio do you have and what ratio do you want?

so sorry for late reply, just did not have time to post anything :(

regarding photos, sorry got only one picture :(

those what i installed:

FM II Hydra turbo system
Flyin` Miata turbo single exhaust race pipe (cat replacement)
Flyin` Miata supersize clutch Happy Meal
OEM Shifter Boot
AEM gauge/wideband kit
Magnecor 8.5mm spark plug wires
NGK extended reach spark plugs V-power Price:

looking for good Water/Methanol Injection System

my ratio is factory now, how can i check ?

All 1993 cars had a 4.30 axle ratio. The 1.8 cars were available with 4.30, 4.10, and 3.90.

Are you running 300hp on a stock engine? Usually forged steel connecting rods and forged pistons are required to reach those power levels. The stock connecting rods are soft and usually bend under loads above about 250hp. Chinese forged rods with good ARP bolts are available online for about $300 and nobody I know about has ever broken them at any power level.

That's a nice car except for the wheels!

I)) that`s why i want to change them, i just found ferrari gt250 replica kit i think i will go with that kit.

for the engine i would say that i have 250 hp, but in some time i need to definitely look to update engine, i still need to calculate how much it will cost to update 1.6 or maybe go for used 1.8 or maybe it will be better to go for 2.0 flymiata engine, but that mean that i will need to change turbo kit what i do not want to do. because i will not be able to sell my one.

what you think is there a point to update 1.6 engine, maybe try to find used 1.8 and update it? or there are not big difference? to upgrade my factory 1.6 is most cheap way to go :) and i can still use my 5k turbo kit :) my turbo kit.


Regarding axle if my have 4.30 then there are no way to go, i do not need top speed, i need acceleration. so i just need to find 1.8 axle with 4.30, and i think i will definitely need better transmission my one on 140km/h going till 5000rpm

Since you have the 1.6 engine already it will work fine. The kit you have is good for 230whp at 12psi, and that is probably all you should do on the stock connecting rods and pistons for safety. The stock connecting rods are soft and will bend if you make too much cylinder pressure. The stock pistons are cast aluminum and not forged aluminum and are not as strong.

You can change the connecting rods to these and get these 8.8 to 1 compression ratio forged pistons and you should be able to go to 300whp without any trouble.


I'm not sure I understand. Do you want more rpm at 140km/h or less rpm at 140km/h?