Ok i have a 1984 chevy camaro. I have always believed it was an IrocZ/28 until the other day when someone told me Iroc didnt come out till 85. Its all badged up but what are differences to look for in an Iroc? Cause either this thing is not an 84 or its a clone. The engine was swapped for an 82 berlinetta so I couldnt compare its numbers. Any ideas? Thanks for reading ur feedback is much appreciated.

"In 1984, Chevrolet introduced the Camaro IROC-Z/28 for the 1985 model year."

http://www.iroczone.com/history.asp

Is it badged as an Iroc? Maybe someone just stuck "IROC" on a Z.

Welcome to TGO. A search will provide more info than the following: The first year for the IROC is 85. Look for RPO B4Z in the console. The door placard should have info for 16" wheels. Only the IROC is equipped with a Wonderbar (aka. steering box brace).

JamesC

didn't some come with 15"?

Yes, but not until 88 or 89. 85-87 cars were equipped with 16's.

JamesC

Your saying IROCs had 16s, 85-87, then went DOWN in size to 15s, in 88 or 89?

I think you have that backwards....

No, that is correct. All 85-87 IROCs came standard with 16 inch wheels. Starting in 1988 15's became the base wheel on IROCs but most of them still got 16 inch wheels.

15" on an IROC...That doesn't sound correct.

the 88 tech data vaguely mentions this...

Thanks. I checked the RPO B4Z number and it was not listed. I cant check door card cause the car was painted and it was removed. I still have to check for a wonder bar but I'm sure I wouldnt know it even if I was starring right at it lol

I agree as well with the 15 inch base wheels on irocs in 88-90. I have personally seen a 90 iroc with no power options and 15 inch iroc wheels...not to be confused with normal z28 wheels. These wheels were identical to the normal 88-90 wheels but were 15s instead.

If the car is truly an 84 and there's no B4Z RPO, I'd say you have a clone. Following is a pic of an after market Wonderbar, post #14, the black piece running above the red:

http://www.thirdgen.org/techboard/af...rin-brace.html (global west steerin brace)

The above could have easily been swapped in by a cloner; however, if it's not present....

JamesC

I'm not sure why your looking for the answers by looking at the stuff on your car. Anything can be swapped and/or modded.
Simply check your car VIN's tenth digit . . .
E = 1984 - Not an IrocZ
F = 1985 - Possibly an IrocZ. Verify with the RPO B4Z (which you say unfortunity isn't to be found.)

If your VIN turns up an F, then there's hope and we'll be gald to keep helping. If it's an E, then you've found the answer.

It is a z28 not a an IrocZ =(. I still loves her tho =)

My wife's 1998 IROC had 15" wheels. As stated, they are IDENTICAL to the 88-90 IROC 16" wheels, just in 15" size.

You must mean that your wife's 1989 IROC had 15" wheels since IROCs weren't made in 1998?

Here are some numbers on the 88-90 15" and 16" IROC wheels:

1988-RPO (N96) for the 16" wheels had 21,803 orders, on 27,811 IROCs built, 6,008 apparently must have had the RPO (N90) 15x7 wheel same as the 1982-87 Z28. Drew corrected me on the type of wheels with information in his brochures. Although, the white book doesn't list any N90 wheels for 1988 or any 15" wheels at all for 1989 or 1990. I wonder what the RPO is for the identical 15" IROC wheel in 1989 and 1990?

1989-RPO (N96) for the 16" wheels had 16,449 orders, on 24,007 IROCs built, so 7,558 IROCs came with the identical looking 15" wheels, or 31.4824842%.

1990-RPO (N96) for the 16" wheels had 4,004 orders, on 5,507 IROCs built, so 1,503 IROCs came with the identical looking 15" wheels, or 27.2925367%.


Total number of IROCs with 16" wheels from 88-90 were 42,256.
Total number of IROCs with identical 15" wheels from 88-90 were 9,061.

So 21.4431086% had the identical looking wheel in the 15" size. I didn't think that there were that many IROCs with these wheels till I added up the production numbers. It seems like you don't see them very often.

I hope I got the math right!

Basically the same car, different name. The name Z28 was replaced when Chevrolet got the rights to use the name IROC. Once the 3rd gens were not used in the International Race Of Champions, the name Z28 came back.

The 1988 Irocz (base model Z28) used the same N90 15x7 aluminum wheel as the 82-87 Z28. The Iroc styled 15" wheel was new for 1989.



and notice it says the 16" wheels are OPTIONAL on the Iroc...



and notice what it says on the door?



These are all scans of the 88 sales brochure on this website.

And then here's some scans from 89... Notice they say the Iroc comes with 15's, and mention the new Iroc styled 15" wheels.

Drew, thanks for the information on the base model 1988 IROC's wheels. I didn't know that they used the Z28 15" wheels. I'll go back and edit my previous numbers on the 15" and 16" IROC wheels.

No problem... I don't think most people notice the 15" Iroc wheels much since they were only 1989 and the shortened 1990 production run, and they look so much like the 16" wheels they don't stick out unless you look really close.

Drew, I edited the numbers above. Have a look. I'm curious as to what the RPO was for the identical 15" wheel in 1989 and 1990. The white book doesn't list any at all.

RPO PF2 is the 15x7 Iroc styled wheel. Incidently I didn't scan the brochures, I just hot linked them from the media section here.

Do you notice that the diagram of the N96 looks like the 1985-87 wheel around the lug nut holes and the PF2 looks more like the 1988-90 N96 wheels around the lug not holes?

I had, but attribute the appearance to a sloppy artist. Several of the 82-92 wheels in the artists line drawings don't look anything like the real wheel.

I saw a set of the 15 inch 88-90 style iroc rims on a junkyard camaro a few years back.The car was not an iroc.Would have got them but the 15 inch rims are not very desireable.I did however grab the center caps and best part is the guy didnt charge me for them

Yeah, don't know how I made that mistake - Her's was a 1990. It had these wheels:



But they were 15", not 16".... I forget the exact RPO code, but it was there, showing 15" wheels.

Here are some others I found:

Looks like 16s to me. I've never seen a 15" in that style.

I suspect the car was built with 15" wheels, hence the 15" RPO code, but wither the dealer swapped them out early on to sale the car (if you are the original owner) or a previous owner swapped the wheels out.

I can't make out the tires size on the sidewall, but if it says 245/50R16? That is a 16" wheel.

It looks like it says 16" on the sidewall.

It sure seems like he's explaining that the car had that style wheel, which was available in a 15" size. The one in the pic is most likely a 16" wheel, if nothing else based on the fact that it's marked rear while the 15" wheels which were the same on all four corners.

If you want proof that a 15" IROC style wheel existed, it's already been posted. You've got dealer brochures showing the wheels, talking about the wheels, and you've got a screenshot from the GM parts database showing the wheels with the RPO code PF2. You can also look up 1989-1990 Iroc wheels at www.car-part.com or www.tacreationsusa.com and see that 15" Iroc style wheels are listed.

To recap...

85-87 Iroc 16x8" Iroc style wheels
88 Iroc base model 15x7" Z28 style wheels
89-90 Iroc base model 15x7" Iroc style wheels
88-90 Iroc 16x8" Iroc style wheels

The reason for the weenie 15's on the Iroc was because all Z28's from 88-90 had the Iroc package. To keep the Z28/Iroc affordable, they offered it without all the bells and whistles of the Iroc package.

BINGO!!! The black car's wheel IS a 16", I just found a random pic of the style. The red car's wheels are 15", just like my wife had on her 1990 IROC-Z.



....never thought this would have been so......... scrutinized. I thought EVERYONE knew about the 15" IROC wheel options...

Thanks for the post Drew! I've always wondered what wheels were correct for which years, and always assumed that the standard 15 inch 88 IROC wheel was wrong every time I had seen them on a base model 88 simply because I thought IROCs always had IROC style wheels.

That being said, my favorite are the 85-87 wheels.

The first time I looked at a 88 Iroc with the 15" wheels up close, I was pretty sure it was a badged up RS. It was a TBI car, with high back buckets, vinyl door panels, and had the silver painted 15's. It wasn't until later that I verified it was an option.

The bulk of the 15x7 N90 wheels are either painted body color as they came on some RS, or they have the area around the center cap painted black (Z28 style). The 88 Iroc 15's have the center left argent, with a gray cap and I believe the emblem says Irocz. The 88 Sport Coupe used the same argent wheel, with argent center and cap with the Camaro logo.

Call me crazy, but I actually like the look of the 82-88 Z28/Iroc 15x7 wheel the best of the factory Camaro wheels. They're more bold then the others. That said I wouldn't buy an Iroc with 15" wheels, it defies the whole point of owning an Iroc.

This is interesting , my 90 iroc has 15 inch rims, like the ones posted. Since this is my 1st camaro I thought maybe someone swapped them out. But I will get the rpo code to find out for sure if it came original with 15s.

the 15 inch and the 16 inch wheels at a glance "almost" look the same but they are not...at all, and no am not talking about the z28 style wheel,but the IROC wheels, the pattern is completely different am i the only one see this?

yep the wheels styles are correct for the years! i had a 87 iroc and i did all kinds of research i have all sorts of info i collected to refer to,down to what every number and letter means in the vin.run your vin number and find out everything about your camaro.

rpo code for 15" tires, p215-65-r15 and wheels for 1990 camaro is QYZ

I've got a friend with a 20,000 mile 89 IROC. It's a well optioned car... but has the 15" wheels. Most of the IROCs that I've seen with the smaller wheels were TBI cars with little to no options. His is an LB9, but it's got the nice interior, power everything, etc.

My wife's 1990 IROC with the 15" wheels had the 305TPI, power everything, upgraded cloth (not the highbacks). It was missing any real performance options (G80/G92/J65?) but it was "loaded" otherwise.

Must be. Got some A/B pics to back this up?

If I remember right, the 88 wheels were rough cast as opposed to the smooth finish of the earlier Z28's.

The IROC 15" wheels pretty much looked like the IROC 16" wheels though.

so you think this look identical? other than size ?

W1454.gif

16 inch

W1610.gif

15 inch

Different year wheels. First pic is 85-87 IROC wheels. Totally different than later IROC wheels.

Ya they also started putting crappy gear ratios in them during those years too.. The only good thing about my '89 is the bigger rear brakes and no cold start injector. Oh ya, gotta love the VATS too!! I wish I had an older model.......

They do look the same if your wearing 3D glasses while looking at the computer screen. No, just kidding.

Look at Drew's recap on #32 above. Both styles of 16" Iroc wheels have the same RPO code N96, but are for different year Irocs. The 16" single slotted spoke wheels are 1985-87 and they didn't make any of these in an identical 15" version. The 16" double slotted spoke wheels are 1988-90. These they made in an identical 15" double slotted spoke version, RPO PF2 and were used on the base model Irocs in only 1989-90 and you had to up-grade to the 16" wheels at a cost of $468.00 in 1989 and $520.00 in 1990. If you didn't buy this option you got the 15" identical looking RPO PF2 wheel for no additional cost on the base Iroc. Did that clear anything up or confuse you more?

Drew posted all the details in the brochure pictures above. People have owned '88-'90 IROCS with 15 inch factory wheels (myself included). People have seen other peoples '88-'90 IROCS with factory 15 inch wheels. Yes, the '89-'90 15's look like the 16's.

Why is it still so hard for some people to understand that some '88-'90 IROCS left the factory with 15 inch wheels installed?! Please for the love of everything that is holy, nobody else say that there were no '88-'90 IROCS with 15 inch wheels!!

I personally have a theory that it has something to do with UV radiation, magnified and concentrated onto the heads of thirdgen owners through the t-tops. The resulting brain damage is the #1 cause of most Thirdgen mysteries, such as 99% of the posts on the Auto Detailing and Appearance, Body, and Interior, forums. "Low-baller-itis" is another affliction that might be related to 'hatch roof cranial radiation sickness'. Early thirdgen'ers knew the risks and practiced prevention through the use of the 'Mull-et' but due to the social stigma, many thirdgen'ers are now sick in the head.

Well, that's my theory anyway.

Reread the above posts.