Pennock's Fiero Forum
  Technical Discussion & Questions
  5x130 bolt pattern upgrade.

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
5x130 bolt pattern upgrade. by darkhorizon
Started on: 03-10-2014 10:38 AM
Replies: 11 (583 views)
Last post by: fast40driver on 03-17-2014 12:35 AM
darkhorizon
Member
Posts: 12227
From: Flint Michigan
Registered: Jan 2006


Feedback score: (1)
Leave feedback





Total ratings: 450
Rate this member

Report this Post03-10-2014 10:38 AM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I was planning on using this page http://fiero.cc/fiero-tdc/m...s/Boxster/index.html

But sadly it is down. I believe that page talked about using a backing plate to hold studs then you bolted that to the hub. My idea would be to use cap headed screws that would fit in the 5x100 configuration and let me bolt through to the rear, then drill bigger 5x100 holes to clear the cap screws and then drill normal 5x130 holes offset slightly for my porche wheels.
IP: Logged
PFF
System Bot
sspeedstreet
Member
Posts: 2260
From: Santa Maria, CA
Registered: Dec 2002


Feedback score:    (18)
Leave feedback





Total ratings: 53
Rate this member

Report this Post03-10-2014 01:47 PM Click Here to See the Profile for sspeedstreetClick Here to Email sspeedstreetSend a Private Message to sspeedstreetEdit/Delete MessageReply w/QuoteDirect Link to This Post
I mulled this over for a long time before I decided to use adapters on mine. Yeah, yeah, I know - adapters are certain death and against all laws of nature. I've heard it all, thanks. These are made in Germany to put Porsche wheels on the Audi TT. 15mm thick is a perfect offset for the Boxster wheels on the Fiero. One of the negs of modifying the hubs themselves is all the work is lost if the bearing goes bad.

http://www.urotuning.com/Wh...thick-p/30295572.htm

Still needs a hub-centric ring for the adapter, but it fits the wheel snuggly.

Neil
IP: Logged
mitchjl22
Member
Posts: 1141
From: Boise, Idaho
Registered: Sep 2011


Feedback score: (5)
Leave feedback

Rate this member

Report this Post03-10-2014 03:18 PM Click Here to See the Profile for mitchjl22Click Here to Email mitchjl22Send a Private Message to mitchjl22Edit/Delete MessageReply w/QuoteDirect Link to This Post
My dad is working on something like this... its a secret project, but if all goes well, you'll be able to order a fiero 84-87 front hub, made to whatever bolt pattern you want. Is anyone interested in a product like that? Are you just trying to convert the rears in this post?

-Mitch

------------------
My Car - 87' GT 3800sc
http://www.fiero.nl/forum/F.../HTML/121571.html#p0

IP: Logged
fieroguru
Member
Posts: 11304
From: Champaign, IL
Registered: Aug 2003


Feedback score:    (45)
Leave feedback





Total ratings: 255
Rate this member

Report this Post03-10-2014 05:53 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
You can disassemble the bearing and press on a stepped flange on the rear. It needs to be stepped so the face of the larger flange will be the flush with the stock wheel bearing face. You could just countersink (from the wheel side) the 5 wheel stud holes on the fiero flange and have the bolts thread into your new rear mounted flange.

This one was done in a similar fashion, but they welded it together and then turned it true again:
IP: Logged
darkhorizon
Member
Posts: 12227
From: Flint Michigan
Registered: Jan 2006


Feedback score: (1)
Leave feedback





Total ratings: 450
Rate this member

Report this Post03-11-2014 08:14 AM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I am afraid of my 88 fiero front bearings at this point... seems if I touch them and break one im out many dollars....

spacer adapters might be the way to go after all.. but I am going to have 500whp running to drag radials in this thing... it will see 130mph more often than most.
IP: Logged
LFiero67
Member
Posts: 819
From: Lethbridge, Alberta, Canada
Registered: Jun 2002


Feedback score: (2)
Leave feedback

Rate this member

Report this Post03-11-2014 10:53 AM Click Here to See the Profile for LFiero67Click Here to Email LFiero67Send a Private Message to LFiero67Edit/Delete MessageReply w/QuoteDirect Link to This Post
Drag Radials????

Welcome to the dark side

------------------
10.263 @ 134.44MPH - 1.49 60'
Billet 6262 Precision turbo, PT1001 intercooler, ST1 cam, 130lb springs, comp pushrods, HV3, ARP Rod bolts, otherwise stock L36.


Old M90 XP Cam time -
11.425 @115.60
1.543 60'

IP: Logged
rogergarrison
Member
Posts: 49593
From: A Western Caribbean Island/ Columbus, Ohio
Registered: Apr 99


Feedback score: N/A
Leave feedback





Total ratings: 552
Rate this member

Report this Post03-12-2014 12:59 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by sspeedstreet:

I mulled this over for a long time before I decided to use adapters on mine. Yeah, yeah, I know - adapters are certain death and against all laws of nature. I've heard it all, thanks. These are made in Germany to put Porsche wheels on the Audi TT. 15mm thick is a perfect offset for the Boxster wheels on the Fiero. One of the negs of modifying the hubs themselves is all the work is lost if the bearing goes bad.

http://www.urotuning.com/Wh...thick-p/30295572.htm

Still needs a hub-centric ring for the adapter, but it fits the wheel snuggly.


Neil


I looked at your link. Tell me how those work out for you when you try to take a wheel off and the studs just spin. I had those on my Ferrari kit and had to cut the wheels off with a torch, trashing them.

I dont know if they defy any of natures laws. They are not certain death, since Ive survived more than a few failures of them. The risks...for me...arent worth the benefits. I rather get wheels that fit, even if I have to have them custom made from scratch...as I ended up doing on that Ferrari kit. 4 wheels that bolted right on cost me $1700. Feeling safe was worth the extra dollars.

IP: Logged
darkhorizon
Member
Posts: 12227
From: Flint Michigan
Registered: Jan 2006


Feedback score: (1)
Leave feedback





Total ratings: 450
Rate this member

Report this Post03-12-2014 07:46 PM Click Here to See the Profile for darkhorizonSend a Private Message to darkhorizonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by LFiero67:

Drag Radials????

Welcome to the dark side



Drag radials... roll racing.. sigh. Its a spare fiero I have laying around, the idea is to finish it up and sell it I guess unless I like driving it. Ill never take it drag racing most likely but it will still be a solid 10 second setup.

I will do some investigating on where wheel spacers will end up putting my offsets at, I know I have some room to work with but one main advantage to these Porsche wheels is the dead nuts offset.
IP: Logged
fast40driver
Member
Posts: 258
From: Portland, Oregon USA
Registered: Jan 2008


Feedback score: N/A
Leave feedback

Rate this member

Report this Post03-15-2014 12:06 AM Click Here to See the Profile for fast40driverClick Here to Email fast40driverSend a Private Message to fast40driverEdit/Delete MessageReply w/QuoteDirect Link to This Post
I did this, and possibly might have printed the article. Will look tomorrow, and post if I have it. Having said that, it is not that hard, if you have access to the equipment. Fronts are easy, just set up, re-drill, there is JUST room for the pattern. I used a horizontal rotary table in the mill, with a mounted 8" chuck in the mill - you could also use the DRO bolt circle program. Not sure I would want to do it on a drill press. Then make a centering ring, press it on, bore the rotor, and drill for the new pattern, press in studs. I used 12mm studs, with Honda ball seat lug nuts, have worked OK on the Porsche wheels - yes, I know they use 14mm studs.

Backs are a little harder. Press bearings apart I took a light cut on the flange back side and OD, just to true. Then, as suggested above, I made a shallow "cup" that I pressed onto the back of the bearing flange. Took a light cut over the face to true it. I did as you thought, and drilled/tapped the old stud holes, think I used 1/2 13 x 3/4 button head capscrews, but they might have been shallow socket head. Drilled the new pattern, again, just fits. Made, pressed on rings, bored rotors, drilled new pattern in rotors, bored the old holes for clearance on heads of the bolts above. Been on there for 5 years, no worries. Seems like I had 8-10 hours in the whole project, maybe 12.

Seems like the original article showed a pretty crude plate and separate spacer arrangement, that I personally would not be happy with. Not really a backyard job, IMHO.

I have no problem with spacers, properly executed - solid stock, no cast 356, good tight pilot, adequate thickness to prevent flexing, supplemental fasteners as required, etc Remember, the wings are bolted on the next plane you fly on. But, as you say, there is the offset thing.

Best of luck, Mike

IP: Logged
qwikgta
Member
Posts: 4520
From: Virginia Beach, VA
Registered: Jan 2001


Feedback score:    (21)
Leave feedback





Total ratings: 83
Rate this member

Report this Post03-15-2014 08:24 AM Click Here to See the Profile for qwikgtaClick Here to Email qwikgtaSend a Private Message to qwikgtaEdit/Delete MessageReply w/QuoteDirect Link to This Post
what is being done about brakes (rotors/calipers) after you modify the bolt pattern?

Rob
IP: Logged
fieroguru
Member
Posts: 11304
From: Champaign, IL
Registered: Aug 2003


Feedback score:    (45)
Leave feedback





Total ratings: 255
Rate this member

Report this Post03-16-2014 08:40 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by darkhorizon:

I was planning on using this page http://fiero.cc/fiero-tdc/m...s/Boxster/index.html

But sadly it is down.


The wayback machine still has it:
http://web.archive.org/web/...s/Boxster/index.html
IP: Logged
PFF
System Bot
fast40driver
Member
Posts: 258
From: Portland, Oregon USA
Registered: Jan 2008


Feedback score: N/A
Leave feedback

Rate this member

Report this Post03-17-2014 12:35 AM Click Here to See the Profile for fast40driverClick Here to Email fast40driverSend a Private Message to fast40driverEdit/Delete MessageReply w/QuoteDirect Link to This Post
I used stock brakes, just bored the pilot hole for the new wheel pilot, and drilled for the new bolt pattern. You could leave the center hole alone, and use a short centering ring on the outside of the rotor, but the Porsche wheels have a deep pilot hole, and if a ring comes loose, it can migrate down inside the wheel. I used bronze rings, pressed onto the hubs, full depth, and bored the rotors to fit over them. Easy, compared to the rest.

Mike
IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock