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How wide a tire/ wheel combo by Lou6t4gto
Started on: 09-22-2013 02:42 AM
Replies: 23 (604 views)
Last post by: jb1 on 09-30-2013 04:38 PM
Lou6t4gto
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Report this Post09-22-2013 02:42 AM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
How WIDE a Wheel/ Tire combo can be installed on the rear of an 85 Fiero with Coil Overs, using 16 or 17" wheels ? (While staying inside the wheel lip on top)
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jb1
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Report this Post09-22-2013 03:15 AM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I just ordered 18x8.75 rear , several have 9" rear.
edit: I should have read the whole post before answering.... I will find out soon how the 8.75 fit vs 9" hoping they do not stick out but a little will not bother me.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

[This message has been edited by jb1 (edited 09-22-2013).]

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Lou6t4gto
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Report this Post09-24-2013 04:12 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
another Question: will going from 215/60-15 to 255/55-17 (maybe wider)make the rear camber change any ? I'm asking this, wondering , (I May Widen the rear of the car). will moving the rear wheels outward (wider wheels , same back space) have a good/bad effect on alignment/Handling ?
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Will
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Report this Post09-24-2013 04:34 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
16x8 with 25mm offset works with 245/50 and 255/50 tires

17x9.5 with 45mm offset can work, but will be VERY close to the knuckle where the strut mounts

18x9.5 with 45 offset works, but has better clearance I think 275/40-18's work, but would probably go with 265/35's or 275/35's

[This message has been edited by Will (edited 09-24-2013).]

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Steven Snyder
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Report this Post09-25-2013 04:02 PM Click Here to See the Profile for Steven SnyderClick Here to visit Steven Snyder's HomePageClick Here to Email Steven SnyderSend a Private Message to Steven SnyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:
will moving the rear wheels outward (wider wheels , same back space) have a good/bad effect on alignment/Handling ?


Backspacing and width do not affect alignment.

Good for handling. Wider track width => less lateral weight transfer
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jb1
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Report this Post09-25-2013 08:36 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Will:

16x8 with 25mm offset works with 245/50 and 255/50 tires

17x9.5 with 45mm offset can work, but will be VERY close to the knuckle where the strut mounts

18x9.5 with 45 offset works, but has better clearance I think 275/40-18's work, but would probably go with 265/35's or 275/35's




You must be talking about on an 88 ,

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Lou6t4gto
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Report this Post09-25-2013 11:39 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sorry, I was talking 1984-87 with coil overs.
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jb1
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Report this Post09-26-2013 12:14 AM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
18 x8.75 fits but gonna have to use short springs on coil overs
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Will
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Report this Post09-26-2013 09:46 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jb1:

You must be talking about on an 88 ,



Personal experience with the 16's on my '87 GT.

http://www.westcoastfiero.com/faq/faq.html

For the 17's and 18's.

Based on measurements I've taken with my 16's, I don't see a reason why the 17x9.5-45 wouldn't work.

Yes, it will require coil overs.
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jb1
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Report this Post09-26-2013 11:43 AM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
The 16 I see no problem with fitting, but the 18x8.75 35 mm offset I can get one finger between the wheel and strut.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Lou6t4gto
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Report this Post09-26-2013 01:05 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
I will be going either 16 or 17, probably 17. Thanks
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Report this Post09-26-2013 04:01 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post



18x8.75 35mm offset. to close to spring seat but shorter spring will fix it, I would say 17x8.75 would be fine
with app 1.5 degree of camber wheel set about 1/4 in wheel well at top

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Lou6t4gto
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Report this Post09-26-2013 04:36 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
ah, pictures are always good ! so, it will/might be the sidewall of the tire that could create a problem.
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jb1
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Report this Post09-26-2013 05:28 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I. think 235/40 will be fine on the 8.75. just can't be much bulge in the sidewall... plus not to mention I have to order new springs and sleeves.

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Will
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Report this Post09-26-2013 06:41 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
The rate and length of spring matters, of course.

235 is quite narrow for an 8.75" wheel. 245's and 255's fit on an 8" wheel (255 is pushing it a little bit for the width) with 20mm of offset. With my setup there's over an inch between the tire and the threaded sleeve. I run ~ -1.5 camber and the tire tucks inside the fender on bump.
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Will
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Report this Post09-26-2013 06:59 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jb1:




This doesn't really show anything, as the angle and lateral position of the wheel will change significantly when the suspension is at ride height.
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jb1
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Report this Post09-26-2013 07:48 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
it was same when I used floor jack under the control arm the difference was minimual.. with seeing how close the wheel is to the strut what tire would you suggest? the width of a 235 was around 9" was why I figured it would be best option... but would prefer a 255 or 265 aslong as they would not rub the strut.

one thing the pic doesn't show is there are suspension limiting straps installed so it is not fully extended...but it will probably lay out more when weight is on tire... so yeah I see where that pic is pointless now
------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

[This message has been edited by jb1 (edited 09-26-2013).]

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Will
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Report this Post09-27-2013 11:38 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
For shorter sidewall tires (on the Fiero, 17"+ wheels), you want the tire to be 1 to 1.5" wider than the wheel. That can be 2" or more for taller sidewall tires (16" or smaller wheels).

Get the suspension at ride height, make sure your alignment is correct and look at tire clearance 1-2" out from the outer edge of the wheel.
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jb1
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Report this Post09-27-2013 02:17 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
so you are saying once I get alignment correct and and at ride height that there should be more clearance?
I was looking at my other car and realized you were very correct on the 235 being way to small, my 245/45 on 8" rim fit exactly like I need on the 8.75, so 255 or 265 should be just right..

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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aaronkoch
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Report this Post09-27-2013 02:39 PM Click Here to See the Profile for aaronkochClick Here to Email aaronkochSend a Private Message to aaronkochEdit/Delete MessageReply w/QuoteDirect Link to This Post
The wider the rear wheel, the more you will hate driving on any road that has weird crown or ruts.

I know everybody will say "you're over-reacting, it's not that bad" but it IS that bad.

------------------


Build thread for my 88 + 3800NA swap

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Will
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Report this Post09-30-2013 02:43 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Only if you have worn out bushings, ball joints, inner/outer tie rod ends, wheel bearings, struts, etc.

Get your suspension in good shape and it's not a problem

So, no, it's really not that bad.

[This message has been edited by Will (edited 09-30-2013).]

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jb1
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Report this Post09-30-2013 03:01 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
everything is brand new , ball joints tie rod ends bearings struts , app 10, 000 miles on control arm bushings.. I ordered shorter springs and they gave a lot more clearance for the tire

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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Joseph Upson
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Report this Post09-30-2013 04:16 PM Click Here to See the Profile for Joseph UpsonClick Here to Email Joseph UpsonSend a Private Message to Joseph UpsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
245/40R18 on 18x9s, 35mm offset fit on my 86 SE with the stock struts in place. It was close but clear. If the alignment is out regarding camber adjustment it can change the clearance between the spring perch and the tire. With the coil overs using 12" springs I ran into clearance trouble with the adjustable coilover spring perch before the car was lowered to the height I wanted, so you may need a shorter coil spring, 10" for example if it's available if you intend to lower the car a good bit. I posted a picture in a thread involving the engine I believe, but can't find it.

[This message has been edited by Joseph Upson (edited 09-30-2013).]

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jb1
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Report this Post09-30-2013 04:38 PM Click Here to See the Profile for jb1Click Here to Email jb1Send a Private Message to jb1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I had 12" springs, just put 10" on today

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar/ 4t80e
86GT 3800 n/a
My Build

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