fast lenny

Hello. I am looking to put 18x10.5 inch rims on my 85 Iroc. The offset is 56. I have front disc brakes that are stock and the stock drums on the rear. Car is lowered about an inch and half. I am wondering what size spacers I will need and also tire size? I appreciate the help.

fast lenny

I bought these wheels tonight and think they will suit my car well. I am curious as to what spacers I need either hub centric or not? I found these two choices and one is hub centric. Both say they are for my car. I appreciate any help.

Hub Centric
http://www.ebay.com/itm/4-Pcs-5x4-75...tY2gQL&vxp=mtr

Lug Centric
http://www.ebay.com/itm/4pcs-Chevy-5...tWOm6R&vxp=mtr

Black_TA

Car looks great, I still have the 14 inch bowling ball rims with 205/70/14 Need bigger tires
keep putting it off. What are the best stock rims and tires for 83 TA with stock suspension.
Not too many options in reproductions. Should I go with like 235/70/14.

Black_TA

How about these to they fit using spacers in the front?



17x9

Robbie_S

Can you fit 10.5's on our cars without flaring the fenders or putting in a mini tub?

rgauder

iTrader: (1)

Search for xxr wheels here on the board. Many members running 18x10 wheels.

fast lenny

I have been doing a ton of a research on the board here and you can. I guess you can go 275 and 285 with no real issue for tire size. I am going to probably do a 285-35-18 on all 4 corners. I am just trying to figure out if I should be going hub or lug centric with the spacer and what size I need. I am guessing 2 inch but not sure.

85Z28NOS

iTrader: (2)

Im running a 18X9.5 front with 275/35/18 & 18X10.5 rear with a 295/35/18 on my lowered camaro with no problems. I run a hub centric 2" spacer on all four corners. The from offset is 54mm and the rear is 56mm

fast lenny

Thanks for the info. I have heard of people having trouble with certain hub centric spacers do to the hub bore size. Which ones did you use or recommend?

//<86TA>\\

iTrader: (14)

I ran 18x10.5 with 295/35/18 on all 4 for a while. Fitment it tight but it works. 17mm offset fits the rear with only a little hammering and a centered rear. You can use a little more offset, but that's what I call perfect.

I had custom hubs made for the front so I could run 4 identical wheels with the same offset and no spacers. With stock brakes you probably need 9/16" + the width of a rotor about .22-.3 and about 30mm more.

This is off the top of my head, I'm pretty sue I'm right but a tape measure helps and you should verify. Keep in mind, you need some extra camber on the front, stock strut mounts may not get you enough, you also need to lengthen the steering stops a little bit.

//<86TA>\\

iTrader: (14)

If your only going to run a 275 tire, just use a 18x9.5 with zero offset or maybe up to 10mm+ offset

85Z28NOS

iTrader: (2)

I found some that had the correct bore and hub size that fit my corvette wheels. Can't remember excerpt size
This is what the new wheel spacers looked like compared to my old ones. Changed them when I bought the new wheels
http://m.ebay.com/itm/4X-2-5x4-75-Hubcentric-Wheel-Spacers-12x1-5-For-1991-2005-GMC-Jimmy-/282138415914?nav=WATCHING_ACTIVE

85Z28NOS

iTrader: (2)

I remembered that you were running all four and tried my rear on the front with the 2" spacers and the hit my struts. It would need a bigger spacer to clear or a different offset than mine have

fast lenny

What offset is on yours?

85Z28NOS

iTrader: (2)

if memory serves me I think 56 or 58mm

fast lenny

Yeah these wheels are 56mm. I assume I will need 2 inch on the back and 2 and 1/2 on the front perhaps. Still locating tires and waiting for the wheels to arrive so still searching the right adapters for them. I appreciate all the help from everyone. Just trying to figure this out.

Beater79TA

You can fit a 315/30/18 tire on all 4 corners without flaring or rolling the fenders if you get the offset and suspension set up correctly. We do it on our GTA. It did involve some clearancing inside the wheel wells to eliminate rubbing in hard corners.

I can't give any help on spacers though as we did custom wheels with the backspace we needed to make everything fit.

Robbie_S

I am running Koni Yellows all around. What was the backspacing you used? I wish I would've talked to you before I bought wheels. Everything I found would have involved rolling the fenders.

//<86TA>\\

iTrader: (14)

Oh I forgot to add the width of the rotor to my previous measurements, so I'm may case add anothe .3"

Beater79TA

Front backspacing with aftermarket brakes is 6 inches. Rears are 6.5 inches. With factory front brakes you'll likely need a 1/4 inch spacer to adjust for the 2 piece rotor we use. The only downside is you can't rotate easily with different offsets. I'd complain more about this but a set of track tires usually lasts about 3 days so rotating them isn't really an issue. If we didn't road race and autocross the car 20 weekends of the year, I would have stuck with a 17x9 wheel and run 275/40/17 tires because the tires are easier to find and less expensive. And a 17 inch wheel still fits plenty of brake behind it for street use.

I should add that we also run a very stiff suspension to limit upward wheel travel and an aggressive track alignment. The front springs are 1100 in/lb coils on weight jacks and the rears are coilovers with 400 in/lb springs. The car also has the bumpstops in place to limit axle travel upward. With a looser suspension and a less aggressive alignment, there is a good chance you will contact the front fender. Same goes for the rear if you have removed the bump stops.

Robbie_S

I am running Wilwoods 14" big brake kit. Sounds like the suspension set up would be too aggressive for what the car will be primarily used for, cruising. Thank you for the additional info.

Beater79TA

For a car that is primarily a cruiser there really isn't justification for the costs involved in tires wider than a 275. There is a significant price increase to go to a 315.

Robbie_S

Well, the car will end up with a Gen V LT4 and 8L90 trans here in a few months. So getting power down with narrow tires will likely be a issue. So the car might end up getting an IRS and wider tires in the future.

Beater79TA

Just my opinion here but it seems like you're going to be spending a lot of money for just a cruiser. The 8L90 will require tunnel modification. The IRS requires frame modification. Plus the cost of parts. My cruiser is still bone stock except for the muffler and stereo. But it's your car not mine so I look forward to seeing the build thread.

Going wider than a 275 will still force some compromise to the front suspension to guarantee clearance to the fender. This means either flaring to allow the wheel well to move outward or stiffer suspension to limit upward travel of the wheel.

paul_huryk

I'm going to agree with Beater - you are going to spend as much money as someone building a pro touring 1st gen if you go this route.

Now there is nothing wrong with keeping the stock style stuff - just going to aftermarket replacements and getting 98% of the performance for 20% of the cost. No one so far has proven statistically that any IRS system for a 3rd gen will outperform an aftermarket optimized solid axle setup - not even counting the cost differential.

Now it is obviously your car and budget - but we all come across too many semi completed projects for sale that the builder either ran out of money to complete and/or lost interest. For $20k, you could build a 3rd gen to be faster than all but a handful of new hypercars, which is why many gravitate toward these cars.

Robbie_S

It is an expensive build. The IRS is a worst case modification. The tunnel issue is something I knew was going to have to happen. But for cruising long distance I think having that 8 speed will make me, and the wallet at the gas station, happy for everything I am looking to get from it. The car will see some autocross on occasion, just not regularly. As for overall cost, it was buy a newer car to cruise or overhaul the one in the garage. The latter sounded like more fun. I have a build thread going here; https://www.thirdgen.org/forums/memb...rades-gen.html

Robbie_S

The car has a Currie 9" rear with Koni yellow and Eibach pro springs, sway bar, LCA, etc.... I haven't driven it yet with the current upgrades, still waiting to finish welding in the subframe connectors and LCA relocation brackets. But it should be good enough. IRS would only be a last option.

Beater79TA

I just posted in your build thread. Do not use the TDS SFCs with a swap car if you haven't put them in already.

Robbie_S

Of course its going to cost as much as a 1st gen pro tourer build, its a 3rd gen pro tourer build. Just happened to have a 3rd gen in the garage. If it was a 1st gen, then it would be the same build with that. The idea was this from the start. And as far as the project is concerned, if the build stopped right now that would be fine. The only thing left to do is to replace the drive train. Sorry if this reply is coming off argumentative, not the intent.

fast lenny

Came out good. Very happy.

yankeecarman

iTrader: (9)

I love those wheels. Can I ask you the name and size that you got? I have a 91 TA convertible that is red and those should look great on it. Thanks for the info.

jayg

https://www.oewheelsllc.com/CV18A-D1...rolet-Corvette

fast lenny

I got them off of Ebay. here is the link for them. I paid more but they are on sale now. Makes me wish I waited a couple months. haha https://www.ebay.com/itm/18x10-5-Bla....c100642.m3226

yankeecarman

iTrader: (9)

Thanks for the info. I am looking for standard offsets for a 1991 Trans Am. I am limited because in Australia we are not allowed to use spacers on the wheels so I need the standard offsets.

Beater79TA

18x10.5 inch wheeels will work with a 6 inch backspace on the front and 6.5 on the rear with no spacers. You may have to go with a true custom wheel to get something this wide to fit without spacers though.

yankeecarman

iTrader: (9)

Thanks a bunch. I will start looking.