I sell colorado custom wheels so i get a nice discount and currently i have 17x7 lazears in front...

i will be upgrading to 19x8 with a 275 tire in front, so I need to know what backspacing i need to get them to fit. Is there any minor modification that would need to be done to the suspension that would help keep the tires from rubbing?

i have eibach sportlines to lower the car and koni yellows, but they are not installed, and i want to install them after i put on the new wheels (if i can without suffering wheel rub or something).

can anyone help me in getting the right specs so that the tires dont rub, or very little if it cant be avoided?

the car is driven on the street occasionally, and i am getting 20x12 wheels in back (mini tubbing and getting a custom rear end built, but that is going to be done at the end of december)

thanks to anyone that can help me!
jarrod fawcett

 

a 245/35/19 is the correct tire....a 275 is better suited for a 9.5" rim. or at least a 9" going that large on something that small will look funny and be very noticeable with such a large wheel.

12 is crazy in the rear as well but makes since if your tubbing it. those tires will be very pricey.

i have 245/40/18's and it's right on the border with the 8" rim and the same sort of drop your considering. if you plan to keep it true stock height you should have no problems. good luck.

 

I'd love to put a 335/35/17 tucked on the rear of my car! Looks like I'm barely gonna get by with 315/35/17's though.

 

i have 275/40/17 wide tires on a 17x8 in the rear now and it fits perfectly fine...

but i figured 19x8 is the pretty much the widest i could go, if i could go 9.5" then i will...

i would like to go 275 because i am getting 345 wide tires on the 12 inch wide rims...

the tires are perrelli's and i am getting them half off, that how i am affording getting such big wheels and tires, (and a 400 c.i. engine to spin them)

still would like to know what I have to do to get 19 inch tires to fit, anyone with backspacing nymbers?

thanks for all the help!

 

You can go 9.5, but you need to get some spacers.

 

Because you are going with oversized wheels,you will definately need really small sidewalls to get the closest overall dimensions to the OEM wheels. And getting the same overall dimensions as the OEM wheels (or as close as possible) is important because too big of a wheel can cause fitment issues and bad speedo readings (as well as an unaccurate odometer). Another thing that you have to keep in mind is the load rating. When you go with an extremely small sidewall, you have less options as far as stretching the sidewall and this affects your load rating. If you look at all the major tire manufacturers tire stats, you will see that the lower the sidewall goes, the more exact the fitment becomes. A good example is the difference between a 315/60/15 and 315/35/17 tire (Drag Radial in this example). You'll see that the 15" version with the bigger 60 sidewall will work on wheels between 8.5 and 11 inches wide. On the other hand the 17" version with the smaller 35 series sidewall will only work on wheels between 11 and 12 inches wide. You need a bigger wheel to support that sidewall.

Keeping that in mind, if you went with a 19" wheel in the front, a 35 series tire will give you the closest overall OEM size. If you wanted to run a 275 tire in the front with a 35 series sidewall, you will need between a 9 and 11 inch wheel. On the other hand, if you could settle for a 245 tire in the front with a 35 series sidewall, the 8 inch rim will work. So like Jeff said, for a 19x8 wheel, the 245/35/19 is the tire choice that will get you as close to the OEM overall dimensions as possible. In the rear, you will need a 30 series sidewall on those 20's to get the closest overall dimensions bla bla bla. And since you want 345's that means you need a 345/30/20 tire. I dont know anyone off the top of my head that makes a tire like that, but I'm sure its out there. I would recommend you check out the tire and wheel sizes of some of the higher end exotics out there. I remember when I was looking for tires that would fit a 19x13 wheel (rear wheel I plan to use for the Evo kit ... if I end up doing it) I found my tire by looking at some of the OEM equipment on some top model Lambo's and Ferrari's. Google is your friend.

Oh, by the way, for a 8 inch wide front wheel, the backspacing is 4.5 inches. You can experiment with more backspacing to move the wheel out more, but at that point you might as well get a wider wheel. 8 inches in the front is a nice safe width when going with oversized wheels and a low suspension as shown by Jeff and myself. No idea what the backspacing is for a 12 inch wide rear wheel. Good luck!

 

oh, i have put LOTS of time and thought into this...

pirrelli P Zero Rosso
345/25 ZR20 in back

275/30 ZR19 in front, tire is 25.7" OR
275/35 ZR19, tire is 26.6"

should i go with the 30 series tire or will i be able to fit the 35?

colo. custom only make 19x8 and 19x10 rims so do yoy think i can fit a ten inch rim up front easy?

i dont care about speedo, tach either...
i also know that thin sidewalls leads to excessive loss of traction... but the car is being built for speed and show so i know what i am getting into

and i will get drag slicks for when i get to the track so i can at least hook up there...

i thought more backspacing would move the wheel more into the car? Or is that what you mean...

thank you very much for the thoughtful insight!!!

jarrod fawcett

 

if you want the wheels to be in as much as possible you'll want more backspacing...less backspacing moves them out or in visual sense gives you a larger lip or dish to the wheel.

a 9.5" wheel fits up front but it isn't easy and you can't lower your car much beyond the true stock height which is quite lifted. having the size closest to stock isn't only about keeping your guages acurate but the many other things it throws off. the larger tires slow your car down greatly, the handling characteristics will change and not always for the better, your gas mileage will drop significantly, and many other things. you have to ask your self what is the real reason you want to go so wide and hope it's worth the cost. a 9.5" setup all around is plenty wide enough for the true racer, you can certainly do as you wish but there is some definate added work in measurments which shouldn't stop you if needed.

 

Be sure to check the load ratings of those tires. You can make a bad mistake by running tires that wont be able to support the weight of the car. You will be able to fit a 35 series tire in the front on a 19" wheel, but a 275/35/19 wont fit on a 8" wide wheel (same thing with the 30 series). It would fit on a 10" wide wheel, but you might run into fitment issues with the front backspacing/offset. It all depends on if the wheel specs are right. I know its possible to run 275's in the front with a 10" wide wheel because alot of guys run 17x9.5's in the front with 275 tires. You just need the right wheel specs. I recommend you contact Andris Skulte (http://www.skulte.com/) because he is the only person I know that has big wheels like that on the front with a roadracing oriented suspension setup (he runs 10.5" wide wheels in the front!). When I was researching my wheels, I opted to stay with a 245 in the front (and 8" wide wheel) because I plan to almost completely lower the suspension (almost bottom it out) at shows via adjustable spring pertches. The smaller wheel and tire would give me more room to drop the front considering how the front wheelwells are. And tubbing them was not an option since my car is a daily driver. If I went with the wider setup I would not be able to drop the car as low. I meant to say more backspacing to move the wheel in more, not sure what happened?? LOL

 

well, as i said, i dont care about the gauges being thrown off, and i know all the disadvantages with having such big wheels...

but to me, the benifits out weigh the disadvantages...
(maybe it would help if i say that i am building a blown 400 c.i. engine, but it wont be ready to go for about a year)
I want the wheels now so i can cruise around with them while my engine is built, then when that goes in, i will redo the entire suspension to hold and get the power to the ground

i really would like to lower the car, if just an inch, i would be happy.... if i cant, oh well... i want to do as much as i can get away with.

this car is completly custom built, and i want to impress people, so i want the sweetest paint job, the largest wheels and the fastest engine i can build

anyways, so i am going to seriously look into a 19x10 rim and for $200 i will get a mock up wheel from colo. custom (and mount the tire), it ill help me see what will rub and where and it will help me see if i can change the backspacing, etc... to get the wheel to fit.

i was hoping their was someone on this board that could supply me with exact measurements that they used that worked for them, so i could see what they did and stuff, but i appreciate all the help none the less!!!

i will check up on the load ratings tomorrow...
thanks for the advice! i will let you know how it goes...

 

Good way to put it! I say go for it. I live by the same philosophy. Here's a pic of mine, SOM 91Z with a blown 350 on 18's. I'm about 40% done, still alot of plans I have to finish.



Good luck on yours! 275's on the front and 345's on the back are some huge meats! What kind of tranny you planning to use with that blown 400 motor? Sounds like a fun project!

 

you sure are doing a good job on your car there, i have seen it on the boards and have read many of your posts. with that said, i appreciate the interest you have in my car!

i like to shy away from telling people the plans i have for my car because people always roll their eyes or they claim B.S.

but i plan on using a jerico or G-force five speed tranny, they cost like 5 grand but i will need one when the engine is put into the car.

the engine is a dart little M block, with an 8 or 10-71 roots blower out the hood. I chose a roots because the car is an 87' and carbed and i always felt that a roots blower would bring back the old school from the old days when muscle cars had 'em.

so by combining old school and new school (large wheels) hopefully people will take notice and appreciate the amount of time, work, and thought i have put into this car.

i recently installed new black leather seats from a 98 camaro and redid the interior all black and i put in blue/black carbon fiber inserts, billet aluminum steering wheel... way to much to list

i will get a custom made bullet proof rear end made, 12 bolt

right now i am building a fiberglass body kit that i am making myself to put on my car... i am trying very hard to make it look as tasteful and anti-r!ce and possible... looks kinda like the sledgehammer corvette body kit

didnt you use a vortech supercharger? what size you get or or how much boost you runnin?

 

jfawcett10, Wanna show us some pics of your interior?

 

look at the this...

https://www.thirdgen.org/techbb2/sho...ne+happy+owner

but here is one pic, its a little old, doesnt show steering wheel, dash pad, and the things that arent all installed, but it gives you the idea...

 

Hey where did you get your carbon fiber inserts from, or did you make them yourself. I was looking at a guy on ebay that was selling them in diff CF color combo's but shyed away cause he didnt have any pics of the finished product installed or not installed.

 

i think it was off an internet site somewhere... something like www.interiorwoodfinishing.com or something. If you really want the site i can dig it up no problem

the carbon fiber all fits really nicely and sticks very well! Its real genuine carbon fiber and looks very sharp in the car. The pictures i have DO NOT do justice to the carbon fiber, in real life it looks amazing, but its costly...

this is the steering wheel i got to match my wheels, but i choose to get it slotted and i got black leather wrapping.

 

hi jfawcett10

I am thinking to put oversize tire too, I like 18s but if I go stock size, the tire will be very very thin (check the CrazyHawaiian's), it is like drive the rim only, maybe I should not use the rim which wider than 8J in the front but I got 18*8.5, I am running 235/40/18 front and 255/45/18 rear, the front is too small and the rear is oversize...I will only consider to put oversize tire in the front too, but you know that, it rubs, I thought the modification is needed, there is a red 91~92 bird go 275/40/17 all around, he did the modification to get the front wheel fit but my English is poor so can't understand some part name ......when I put 255/25/18 in the front, it rubs the sidewall of the car, I am thinking to grind the body to make it fit, show you the pic where it rubs...I just want to say go for bigger tire, they looks really good, I always want bigger rim and tire without thin sidewall...

Check the Skulte site to know the spacer and backspare stuff
http://www.skulte.com/adapterfaq.html

 

check the my rider, 235/40/18 in the front, 255/45/18 in the rear(oversize), sidewall of the front wheel is too thin, people said I can go 255/40/18 on my 8.5J rim but I like my rear wheel style .....

 

joekickass, good lookin car man!

i have 235/40/17 up front and they are way to small for me...
I have 275/40/17 in back on an 8 inch wide rim and it fits perfectly.

yea, havin big wheels usually means thin sidewalls, and i know first hand about stopping at every single freakin railroad track for fear of bending a rim.

look at www.tirerack.com and look at tire sizes, go to the specs of the tire, and you can see how big a tire is. This would be good for you because you say you want 18 inch rims, but you dont want thin sidewalls, so look at different tires, and see how tall they are.

255/25/18 is VERY thin too, so you must feel every crack in the road!

oh and by the way, it is www.exoticwooddash.com for the place where i got my carbon fiber interior pieces.

 

sorry, typing mistake, it should be 255/45/18 not 255/25/18.

when I putted 255/45/18 in the front, it rubs, I wanna grind the body part to fix it....

 

i could see how your set up would rub then...

do you have a two piece wheel? If so, what backspacing did you go with on your wheels?

 

they are BMW Rim, copy vision, not 2 piece, they are 18*8.5J 15MM offset, I use the information of SKULTE site to know the back spacing I am running, the backspacing is about 5.091, I should put a 3mm spacer in the front but I didn't, spacer will caused me more truble to put on the BMW rim on 3 gen.

 

joekickass--do you have more pics of those wheels on your car? I have always loved certain Beemer rims and often wondered how some of them would look on a 3rd gen.

 

just outta curiostiy....did you have to machine the fornt wheels at all to get them to fit

 

hi Winderlicker, I got pics but they are big, so I need some time to reduce the size, I will post it after I finish.

For BeNnYbooPy, no need to machine the front wheel to get them fit.

The BMW rim request a custom center ring to fit on thirdgen, I got pic but the same problem above, some member had ask me before to post the pic and procedure but I am too lazy.....I should do it soon.

 

here is the pic you can see the BMW rim

 

Those wheels look great on your car! If I hadn't just gotten other 18s I would probably consider those.