PotM GrandMarq.NET - Panther Headquarters Forum Index PotM
GMN Chat Room GMN's STORE!! GMN's Gallery Please!!
Page 1 of 2 12 LastLast
Results 1 to 20 of 24

Thread: Will 17x8 with +38 offset (6" backspacing) work on my 87? How much spacer? HELP!

  1. #1

    Question Will 17x8 with +38 offset (6" backspacing) work on my 87? How much spacer? HELP!

    Title kinda says it all, found these https://www.facebook.com/marketplace...8441479696544/ American Racing wheels local that I'd want to run until I get some Dayton (or other brand) wire spoke wheels. This will let me see how the 17x8 size affects the handling and ride with the rest of my current setup. I realize the less sidewall will make it somewhat stiffer and a wider tire will help out my cornering to some degree.

    These will go on a '77 Plymouth Volare wagon I have after that, because it should be together and running/driving this year. I am almost certain I'd need spacers, but not certain how much to be able to run what tires on them without clearance issues. I'm currently sitting on the Speedway lowering springs all the way around (1000 lb/in fronts, 350 lb/in rears if I remember correctly). I'd really like to run at least a 235 tread width, but the widest I'd want to go on a 8 inch width wheel is a 255 like I have on my 15x8 wheels on a '72 Chevy C10 I have.
    I'm not opposed to running a 255 in the back and a 235 in the front, though I would certainly prefer a square setup, this car isn't carving mountain roads like my Miata, I just like my daily driver to be a bit more cool and nice overall.

    tldr; Speedway springs, these wheels, what size tire can I run, and what kind of spacers will I need? Wheel and tire math is hard.

  2. #2
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    657

    Default

    From what I've read, 245s and up will rub a bit into the front fenders in bumps when turning. Maybe sway bar when full lock.

    17x8 wheels with zero offset (4,5" backspacing), clears the front control arms relatively comfortably, but 6" backspacing will require atleast an inch spacer, 1,5 inches to be safe. That much spacer to save money on wheels might not be the best option, quality spacers aren't cheap.

    I'd say 245 all around is completely feasible, you just might need to roll your front fenders a bit.
    1985 Mercury Grand Marquis LS
    1997 Volvo 850 GLE Estate

  3. #3

    Default

    Quote Originally Posted by Arquemann View Post
    From what I've read, 245s and up will rub a bit into the front fenders in bumps when turning. Maybe sway bar when full lock.

    17x8 wheels with zero offset (4,5" backspacing), clears the front control arms relatively comfortably, but 6" backspacing will require atleast an inch spacer, 1,5 inches to be safe. That much spacer to save money on wheels might not be the best option, quality spacers aren't cheap.

    I'd say 245 all around is completely feasible, you just might need to roll your front fenders a bit.
    I'm not against rolling my fenders, some, I just don't really want to have to lose my fender liners, And some rub at full lock is livable, if it has to be. I'd be justifying the spacers on the fact that I'd need them on the Plymouth as well. So it would be a solution for more than just a little while. I just would rather not spend $1,200-3,000 on a set of wheels right now without knowing if I really really want to run 17x8s on this car or not.
    Any advice on where to get a good set of spacers though? A 1.5" spacer would put me at 0 offset, I think?

  4. #4
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    657

    Default

    A 1,5" spacer on +38 makes it basically a 0 offset. 38 millimeters is pretty much dead on 1,5 inches.

    If you'd need the spacers on your Volare aswell, I'd justify getting fitting wheels all the more, in my opinion. I can't say where to buy spacers from, maybe Custom Offsets? But don't buy the cheapo stuff from ebay atleast.
    In Finland, I've gotta spend like 100-200 euros for quality spacers that pass inspection. And I doubt its wiser to go any cheaper over in the US.
    And that's where your $350 wheels become $550 wheels. That bump in budget can find you more fitting wheels on the market. Due to our boxes age, most modern wheels don't fit due to modern cars being built high offset & backspace wheels.

    If you really like those exact wheels, go for them, spacers aren't the end of the world.

    EDIT: Spacer should ideally be hub-centric, where the middle hole in the spacer matches the diameter of you wheel hub. Wheels can be centered to hubs and spacers with inexpensive hub-centric rings, but spacers and adapters should be a direct fit.

    That leads to another thing: Box front hubs are pretty massive, big center bore and quite long (from wheel mounting surface to dust cap). While the center bore of a wheel might fit, the hub might be too long for the wheel and it would poke out the center cap hole in the best case, and in the worst case the wheel wouldn't just go all the way on.
    I don't think that will be an issue with the wheels you've linked, since they have a pretty big center cap.
    Last edited by Arquemann; 02-15-2021 at 04:14 PM.
    1985 Mercury Grand Marquis LS
    1997 Volvo 850 GLE Estate

  5. #5
    Member of the Orb Alliance packman's Avatar
    Join Date
    Nov 2006
    Location
    Dirty Jersey Yo!
    Posts
    8,238

    Default

    Although I couldn't log onto Facebook; I had/will have again American Racing Ansen A69 Sprint Wheels 17x7 (front) and 17x8 (rear). With the 4.5" backspacing; I could run 235/R17 tires up front without rubbing issues. It looked good with the stock rear axle; but almost killer when I switched the rear out for a built '90 rear (IIRC, 1" wider on each side). The 255/R17s looked much wider than they were.

    Now when I switched over to the 10-hole P71 wheels; I made the mistake of using 1.25" spacers all around. The tires ate into the front sway bar. Next time I will do 1.5" to avoid that.

  6. #6

    Default

    Quote Originally Posted by Arquemann View Post
    A 1,5" spacer on +38 makes it basically a 0 offset. 38 millimeters is pretty much dead on 1,5 inches.

    If you'd need the spacers on your Volare aswell, I'd justify getting fitting wheels all the more, in my opinion. I can't say where to buy spacers from, maybe Custom Offsets? But don't buy the cheapo stuff from ebay atleast.
    In Finland, I've gotta spend like 100-200 euros for quality spacers that pass inspection. And I doubt its wiser to go any cheaper over in the US.
    And that's where your $350 wheels become $550 wheels. That bump in budget can find you more fitting wheels on the market. Due to our boxes age, most modern wheels don't fit due to modern cars being built high offset & backspace wheels.

    If you really like those exact wheels, go for them, spacers aren't the end of the world.

    EDIT: Spacer should ideally be hub-centric, where the middle hole in the spacer matches the diameter of you wheel hub. Wheels can be centered to hubs and spacers with inexpensive hub-centric rings, but spacers and adapters should be a direct fit.

    That leads to another thing: Box front hubs are pretty massive, big center bore and quite long (from wheel mounting surface to dust cap). While the center bore of a wheel might fit, the hub might be too long for the wheel and it would poke out the center cap hole in the best case, and in the worst case the wheel wouldn't just go all the way on.
    I don't think that will be an issue with the wheels you've linked, since they have a pretty big center cap.
    I found some 1.5 inch spacers that are hub-centric to both the wheels and the car, and seem solid. So that's a good thing. at just under $100 shipped, I'll take it.
    Justifying the need for the spacers, I have some stock 03 Towncar Cartier wheels that currently have good tires on them. So I'll have three wheels options at my disposal. Since they require the same spacers to work on the box.

    Quote Originally Posted by packman View Post
    Although I couldn't log onto Facebook; I had/will have again American Racing Ansen A69 Sprint Wheels 17x7 (front) and 17x8 (rear). With the 4.5" backspacing; I could run 235/R17 tires up front without rubbing issues. It looked good with the stock rear axle; but almost killer when I switched the rear out for a built '90 rear (IIRC, 1" wider on each side). The 255/R17s looked much wider than they were.

    Now when I switched over to the 10-hole P71 wheels; I made the mistake of using 1.25" spacers all around. The tires ate into the front sway bar. Next time I will do 1.5" to avoid that.
    I did like the Crown Vic with the Ansen Sprints on it! Very classic look!

    I'm ordered some Federal 595SS tires in 255/50 for all four corners. I know I'll likely (definitely) have to roll my front fenders and possibly be pushing the boundaries of what actually fits, but I read a thread on here where another user was running the Nitto NT-555 in that size on some 17x9 wheels with the same backspacing and seemed to only have rubbing issues turning in to driveways. Which is an acceptable tradeoff for "at speed" handling and general aesthetics to me. I have the same tire on my Miata, although in a much smaller size, and for a daily driving application in East Tennessee, I feel it's a better option for me. Also, after mounting and balancing it saves me a little over $200 on rubber alone. All season performance tire vs a Summer performance tire, it makes sense for me.

    I'll update this thread when I get the wheels either tonight or Wednesday, and they Saturday when they're on the car!
    If I get smart, I'll remember to email myself some pictures of before/after to post with it.
    May even try to submit to the fitment gallery on Fitment Industries, since nobody does the older cars even with being slightly lowered.

    Thank you all for the advice thus far! I'm sure I'll have more questions!

  7. #7
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Hubcentrics don't work on the front unless you trim the rotor stub.

    http://www.grandmarq.net/vb/showthre...s-on-the-front

  8. #8

    Default

    Quote Originally Posted by JeffBoudah View Post
    Hubcentrics don't work on the front unless you trim the rotor stub.

    http://www.grandmarq.net/vb/showthre...s-on-the-front
    This will become much more fun then. Always a little excitement in making things work "right". Any spacers that work for the front as is, while I can still cancel my Amazon order?

  9. #9
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Nope, that wall thickness would be less than .010"

  10. #10
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Any non hubcentric spacer will work.

  11. #11

    Default

    JeffBoudah, do you happen to know the size of the "hub" in this case off the top of your head?

    If not, I'll measure it tonight and see what I can work with. Hub-centric does work with the back though, right?

  12. #12
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Hubs front and rear are standard Ford 70.5mm

  13. #13

    Default

    Quote Originally Posted by JeffBoudah View Post
    Hubs front and rear are standard Ford 70.5mm
    Ah, I guess I'm just confused on the rotor stub part then. As I've only had my wheels off the one time before I didn't pay too much attention to it.

    Any photo reference for that pre-trimming?

  14. #14
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Check that post I linked. You can see the hub diameter is only about .50" of land. The rest of that stub is .02" smaller or whatever dia. I posted. I turned it back about an inch maybe a bit more, as you can see in the pic. That'll depend on your spacer. Mine were 1.25", if you had 1.5" that shoulder could be further out. I didn't measure, just turned back as far as the studs protruding allowed, and not hit them with the tooling.
    Last edited by JeffBoudah; 02-16-2021 at 06:28 PM.

  15. #15

    Default

    Quote Originally Posted by JeffBoudah View Post
    Check that post I linked. You can see the hub diameter is only about .25" of land. The rest of that stub is .02" smaller or whatever dia. I posted. I turned it back about an inch as you can see in the pic. That I'll depend on your spacer. Mine were 1.25", if you had 1.5" that shoulder may be further out. I didn't measure, just turned back as far as the studs were protruding so I didn't hit them with the tooling.
    I guess we'll find out Friday night some time then what my predicament will be. Thanks for the info! I guess I just didn't fully grasp what was going on there to begin with.

  16. #16
    Member
    Join Date
    Jun 2006
    Location
    Holland,MI
    Posts
    518

    Default

    Another option is doing the big brake swap, which uses a unit bearing and does not protrude as far past the mounting flange.

  17. #17

    Default

    Update:
    Did a test fitting of the wheels without tires since the tires and spacers both finally arrived. Seems like clearances should be alright, if I get really lucky I won't have to roll my fenders, but we'll find out tomorrow morning when they get mounted and balanced.

    I went ahead and installed the 1.5 inch (38mm) spacers on all four corners. This did require drilling out the front two, as JeffBoudah had mentioned, the front hub on an '87 is kinda funky. I used a hole save that was the same size as the hub. So the spacers have remained hub-centric, and the hub seems to protrude far enough that the wheel remains properly fitting. Currently the stock (for the later 90s body style as I found out) 15x6.5 wheels that are on the car clear everything with the spacers in place and even at 80mph I don't have any odd vibrations or anything after bolting it together.
    I do believe the American Racing wheels I picked up might be lighter than the stock wheels. The car already feels more confident in turns with the slightly wider track width, and it looks better as well.

    If my estimations and back of the napkin math it correct, then the new setup will sit in as deep as the current wheels without spacers, and sit out as far as the current wheels with the spacers. So it will all fit.

    I think my wheel gap may be partially due to the 1000lb front springs I went with. Even using the speedway springs, I know the spring rate affects the final ride height.

  18. #18
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    657

    Default

    That's great to hear. Please do post pics when you get them mounted. And maybe one or two with the spaced out stock wheels?
    1985 Mercury Grand Marquis LS
    1997 Volvo 850 GLE Estate

  19. #19

    Default

    Quote Originally Posted by Arquemann View Post
    That's great to hear. Please do post pics when you get them mounted. And maybe one or two with the spaced out stock wheels?
    I'll try to post some up later today.

    Had a super busy weekend. But got the wheels and tires on, no rub, and didn't have to roll my fenders for any clearance issues. I likely will still do this for good measure though.

    I only have two short videos with the stock wheels spaced out, I forget if I had mentioned that they were the stocks for the new body style. But it looked and felt better even just with those spaced out.
    I'll find a reason at some point to throw the stock wheels back on again as well. And get pictures on that day, eventually.

    I'll get some more pictures with the current setup, as I have to take some to post on Instagram anyhow. Gotta get those likes or whatever.

  20. #20

    Default

    Currently this is the only "after" shot I have. As somehow I've discovered another yet to be diagnosed electrical issue when I went to do a 3g alternator swap last night.
    Click image for larger version. 

Name:	20210228_160151.jpg 
Views:	19 
Size:	100.8 KB 
ID:	55878

    However I have no pictures of the couple day with spacers on stock wheels. I have two video clips though, will get on uploading those somewhere soon. Likely instagram.

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
GMN Approved Links!


www.rockauto.com www.adtr.net