Woke up today real early,to get my FM5's mounted on the new Sumitomos,they balanced all the wheels and every thing went really smooth ! Well,till they were to install the wheels on the car.-


My car is a 1987 Z52 Originally with 16" 9.5 wheels, and i purchased the MidAmerica wheel adapters to use 1989 wheels,this adapters goes to the original car bolts and you put a big head nut there and the wheel goes bolted into the adapters bolt.-
So the original bolts are just to attach the adapter to the wheel only.-

The problem is that the big head nuts match perfect the Corvette wheels because the Corvette wheels have slots that clears this big head nuts inside the wheels perfectly.-

Fikses doesn't have this slots,so the big head nut hits the back of the wheel and i can't install them !

Well,here im posting some examples of what i need.-

This Fikses has the stock C5 offset and my offset is 84-87

i tested the installing the wheel to the adapters without the big nut
just to see the match but there was another problem,the original bolts,where longer than the thickness of the adapter so the Fikses hit Yes or Yes,with the original bolt or with the big head nuts.-

I need something like this (i found this picture on the net)
the nuts are "inside" the thickness of the adapter and they don't hit the wheel, and the original bolt is practically hidden inside the adapter.
I dont know if the adapter will be too thick if i pretend to hide the bolt,if that were the case,can a cut the original bolts a little ?
just to clear the adapter's required thickness without hitting the wheel ????

You can see in this example picture this is not my car..,that the nuts and original bolts
don't interfere with the adapter.-



Is there some of you running this kind of adapters ?

My Fikses :
Front 17 x 8.5 (58mm Offset)
Rear 18 x 9.5 (+65mm offset)

I need an adaptor of the correct offset with "hidden nuts"
and im not sure what im gonna do if the bolts still interfere,
a) 1 Cut them a bit ?
b) Find a thicker adapter but i don't want the wheels out of the wheel well !!!

HELP !!!!!!!!!!
Thanks !!!!!!!

 

any of you running adapters here ???
do you have pics of them ?

 

I answered your PM and sent an e-mail through the forum.

-Dave

 

Thanks,just emailed you back !
i guess i need 2 kind of adapters :

1" for the rear
1.25" for the fronts

Correct me if im wrong THANKS A LOT !

 

Sorry to hear, Sammy, that totally sucks !!
The way I see it, 3/4" front and 1" rear adapters would work.
My 86 came with 90 wheels and no adapters. They sat inboard, 3/4". There were no driving issues with that offset.
With that in mind, I think you could mount them until you get new adapters, but you might need to put a 1/4" spacer on the rear, to clear the suspension.
Good Luck

 

Sammy,

You're pretty much on the right track if you're attempting to place the tire/wheel in the same location as the tire/wheel with the original 9.5 wheel application. I need the information I asked in the emails!

If you've already bought tires and they're mounted we can do the tire/wheel "placement" as an "assembly"! We'll do it a little differently but it will accomplish exact placement! If you've got the tires mounted you need to mention that in the email you send me and the sizes!

 

Yes i got the tire mounted,i sent u an email,did u get it ?
let me know

i got an email from the ebay vendor and he told me :

1" for the rear and 10mm spacers for the front
but im not sure abut this,since i want the exact location
to fill the wheel well ....how do i know ? because i was playing with
an online calculator and this is what i was told by the results :

Fronts : 17 x 8.5 (58mm Offset) The outside edge of the wheel will RETRACT in towards the body by 33mm (1.29")


Rear 18 x 9.5 (+65mm offset).- The outside edge of the wheel will RETRACT in towards the body by 27mm (1.06")

So my guessing is 1" for the rears and 1" 1/2 for the fronts
why the vendor is offering me a 10 mm spacer for the front ????

thanks

 

Why 3/4 for the front ? remember i have 8.5 " on the front and its 17" inch wheel.-

Fronts : 17 x 8.5 (58mm Offset) The outside edge of the wheel will RETRACT in towards the body by 33mm (1.29") damn , im confused...what do i need for the fronts ????
1.29 " inside the wheel well i need to put them out 1.29" more ...
what adapter do i need ???

1.25 " is 31.75 mm ...i guess i need do you think the 1.25 mm difference will be noticeable ???? 33 mm vs 31.75

1.25" for the fronts and 1" for the rears !!

 

I've sent you email and instructions! Don't order anything!! I asked for snapshots also!

 

No order yet
i will take lots of pictures now i will get the wheels/tires back to my house
i will be back in an hour or so...
thanks !

 

you can get shorter nuts at the auto parts store. I believe the size is M12 x 1.5

Robert

 

Did a google search. The correct size for a corvette is M12 x 1.50
You'll need to buy Acorn Lug Nuts. See below.

I know they sell them at the auto parts store. Advance Autoparts, Napa, etc...

http://www.lakeshorewheelandtire.com...2&prevstart=32

 

They wouldn't be made specifically for 84-87 If it was that simple.

 

Sammy,
I put C5 thin spoke wheels on my 86. 17x8.5 in the front and 18x9.5 in the rear.
I bought 1" spacers, and test fit them with one of the fronts.. The rear looked really bad in that it was too far in the fenderwell.
I went and dug one of the rears out of the box, and it fit perfectly.
I went with 1 inch spacers all the way around.
BUT:
The wheels didn't like the length of my lug studs, and I die ground off about 1/16" off the ends, and then the wheels fit flat against the spacer. The part I removed was the tapered section that really had a half thread, and was the little dish out on the end of the lugs. The spacers came with lug nuts that fit within the lug bores, and they didn't poke out past the spacers.
I got all 4 on Ebay for $100
Chris

BTW, I used 265/40/17 on the front, and 285/35/18 on the rear, and they are 26 1/4 " tall.............all 4. But, the rears aren't as wide as I would like, I think the 275/40/18 would have been a better choice, or maybe 315/35/18.

 

I run 1" all around too, I'm trying to find some pics.

I think it looks good, I'll look for some pics.

 

Even though the open end lug nuts will solve part of the problem, Sammy mentioned that the studs still stick out beyond the face of the adapter. Cutting the end of the stud off can work, but it has to be done carefully. Thread a lug nut on the stud to where the top of the nut is where the stud should be cut off. Cut the stud and remove the lug nut. That will clean out the threads and re-shape the thread at the point where the cut was made.

And his location (Valparaiso, Chile) may make it difficult to run down to the local auto parts store. But if there is any GM dealer around, they will have the M12x 1.5 open lug nut as that is a very common size now.

The existing adapter he has for the front wheel will work just fine. The 84-87 whel has a 38mm offset and he has a front wheel with a 38mm offset. That 20mm difference is just over 3/4" and that's all that is needed. The difference in the rear is 27mm (just over an inch). If the adapters for the rear is also 3/4" that should be OK depending on the backspacing of the Fikse wheel.

The important part will be to see if there is any interference between the inside rim of the new wheel and the suspension components. A quick way to test the fit for interference is to stack up some washers to one inch high and put three of these stacks on the rear studs (adapters not installed). Use 3 lug nuts to snug the wheel in place and rotate the wheel while checking for any interference. IF there is any rubbing, then add more washers until everything clears. Measure that new stack height and that's the size of adapter that will be needed.

BTW, read your PM and hope this helps some!!