How to alter wheel bolt circle?

Think Challenge car for this, so need a low cost solution. I can find  cheap 15x10 wheels in steel or aluminum fairly easily, but they are always truck wheels of some sort. I've considered welding new centers into the steel wheels. The aluminum ones present a tougher problem. How do you change a wheel with a 5x5.5 circle to a 4x100? The center bore is probably well over 3 inches to begin with. Adapters will cost more than the wheels and aren't particularly budget friendly. I've even contemplated machining the centers out of an aluminum set and making bolt in centers from a second set, but that's costly ,too. Any other ideas?

It would probably be easier to redrill the hubs rather than redrill the wheels.

stuart in mn said:

It would probably be easier to redrill the hubs rather than redrill the wheels.

5.5" is 140mm and there's a good chance the hubs aren't that big.  5x4.5 (5x114.3) may work if you can find them.

Fiero's Have This Problem With a 5 x100 pattern and the hub Diameter is small not allowing larger than a 5x114.

You not only want to get small but reduce the number of Holes...........

  In The Speedway RACE Catalog You can buy rims and centers to build your own wheels but did not notice a 4x100 center.  Maybe you can find a wheel maker that can sell you some or get them from another rim and build yours with their  ( Speedway ) rim, Heck They may know .I Bet Aero Makes them and not too Expensive

I would say to keep an eye on CL and FB classifieds for used adapters. I've seen them come up for sale now and then - including 4x to 5x versions.  Often for less than half what they cost new.

Replace the hub with another one.  Start by looking at hubs that share the same wheel bearings.  A buddy of mine recently found that S-10 hubs perfectly matched the spindles on his 55 Hilman Husky.  I'm playing around with a set of aluminum A body Willwood hubs that share the same bearings as the TR8.  From the Willwood catalog, there are 2 or 3 other hubs with the same bearings, but the overall dimensions are off.  Wish I could just buy a blank hub from Willwood and machine them myself.

In reply to tr8todd :

Interesting idea.  Have you tried asking them?  If you send them the bearings, maybe they would machine the hub to fit?

While the I can see front hubs being somewhat easier to adapt, what do you plan to do with the rear hubs?  Or are you just going to replace the entire rear axle with something that matches the front?

I like to use Ford 8.8 rear ends.  They already come with 5X114.3.  Getting the front to match is the issue.  Some guys have adapted trailer hubs with bearing spacers, but that puts the wheel too far under the car.  You end up running large wheel spacers as well.  I have one car where I used Rover SD1 struts and hubs.  Rover hubs were 5X5 so I welded up the holes and redrilled them at 5X114.3.  Hard to find SD1 struts over here, so thats not an option going forward.  I love Willwood products.  There is literally $10K worth of Willwood  stuff in my garage now.  Always made my decisions based on the measured drawing they have.  Never once thought to talk to someone.  Always just figured I was so deep down into a numbers rabbit hole that not even one of their engineers would understand what I was thinking or talking about.  Plus why would they care about something they couldn't mass produce and make money off of.  Racing TR8s gave me the mindset that if something needs to get done, I had better do it myself, because nobody is making the parts I want.

Bassett makes off the shelf 15x10 4x100 wheels for under $100--is that too expensive?

Diamond makes race wheels to spec--might be about $125 for 15x10.

In reply to tr8todd :

Looking at the website, I get the impression these hubs are made to order from blank castings/forgings. They list a hub for a Sunbeam Tiger - and I really doubt they get many orders for those. It was probably asked for, they made it, and then just added it to their catalog. I'd bet that as long as what you need is within what the casting can be machined to, they would be game.  Makes me wonder if they would do a 4x100 Spitfire hub... 

Since this is a Challenge car $100 rims are out of the question. Think more like $100 per set. The front hubs will be Miata parts so there's no extra meat to move the studs out further. The rear will be a 4 bolt ,Fox body 8.8 rear, so that might have a flange diameter large enough to work. I'll have to check. As a last resort I'll attempt to widen some steel 4x100 rims but I'd like to end up at 38mm offset so the Miata scrub radius is retained. To do that I would have to add material in both directions which would require removing the center, banding the rim and re-installing the center. I'm concerned about keeping them round and air tight.

Laser cut (or otherwise) a 3/16" - 1/4" plate with the 4x100 pattern in it, center it on the wheel and weld it in place?

That's funny, I made some 5 x 114.3 to 4 x 108 bolt adapters once.  I never used them, probably got recycled.  Made from 1" thick ally, after the hub centric part moved the wheel .750 out.

Altering the wheel sounds like a nightmare.  Focus on the hub.  Redrill the bolt pattern on the flange, not the wheel.

The only thing I could think of for 15x10 wheels with that existing pattern would be from the drift crowd, so probably not cheap.

In reply to ProDarwin :

Since I can  alter steel wheels, I'm more concerned about doing something to aluminum wheels, if possible. I had thought about doing what you suggest but have no way to weld aluminum at home. I have welded 4x100 centers into some GM 15x7 steel wheels in the distant past and successfully autocrossed on them.

I had thought about drilling the 4x100 pattern through the aluminum wheel, even though there isn't enough meat for the complete lug seat, and then bolting  a round ring flat against the outer surface. The ring could have a centering lip on its back surface. The lug nuts would then be sandwiching the wheel between the ring and the hub face. The studs would be behaving like drive pins on center mount racing wheels. That started feeling kinda sketchy though.

In reply to Curtis :

If I weren't constrained by a Challenge budget I'd simply buy some Bassett, Diamond, or Aero wheels. There's a slightly used set of 5 locally for $350 ,for example. I'd buy those in a heartbeat if I were building this for autocross instead of the Challenge. The Challenge is a challenge. 

In reply to DeadSkunk :

Crazy idea - buy cheap 13” steel 4x100 wheels(possibly spares?), buy wide 15” wheels, cut center section out of 15” wheels & replace with the entire 13” wheel. I’m sure it would take some fabricobbling to get it all aligned, but it may be easier than the other options presented. 

get a street car that uses same bolt circle as challenge car.

buy new race rims for street car.

install street tires and run them until they are "used".

buy used challenge-priced set of rims with wrong bolt circle.

trade to self.

The Condor Racing guys used 15x10 wide 5 wheels with custom adapters to get down to 4x100.  I think this might be the best way to go for a budget setup if you have access to a mill and lathe.

https://grassrootsmotorsports.com/forum/grm/condor-speed-shop-2010-challenge-car-build/27209/page1/

In reply to 2002maniac :

Wide 5 wheels on an adapter that's just a slab of aluminum. Hmmmmm?

Make a set of these

https://www.wheelspacers.nl/contents/nl/d335_van_4x100_naar_5x140.html

The bolt circles are different enough that you have a lot of metal to play with.

Edit: I guess not everybody is lucky enough to have a lathe and milling machine to play with.

Have you tried a shotgun? I'm pretty sure that a shotgun is the accepted way to alter a wheels lug pattern.

TheV8Kid said:

Make a set of these

https://www.wheelspacers.nl/contents/nl/d335_van_4x100_naar_5x140.html

The bolt circles are different enough that you have a lot of metal to play with.

Edit: I guess not everybody is lucky enough to have a lathe and milling machine to play with.

Yep A Picture is worth a Thousand words.  Now about that Offset.

I'd change the hubs.  Google search came up with several Miata hub changes to other 5 bolt hubs.

Hope this helps someway.  For me it helps to plan out the wheels and hubs together.  I have 2 Rotten Leonard drill guide tools.  I don't remember him making a tool to go from 5 bolt to 4 bolt.

If it will help I will loan out these tools to anyone here that needs them.  One is 4.5" to 4.75", or 4.75" to 4.5" and I think? the other is 5" to 4.75" or 4.5".  Might be 5.5"? to 4.75" or 4.5"...have to dig it out and look.  

Some hubs and rotors have odd holes that might discourage re-drilling.  I have run into this.  It can be difficult re-drilling hubs and rotors from a smaller size to a larger size.

Last night I re-drilled PullaPart 2003 Lexus LS430 hubs with 12.5 floating brakes from a 4.5" to 4.75".  This is to fit wide Corvette wheels found at the PullaPart too on a S10.  It is only 6.35mm wider, but the room was certainly limited.

TheV8Kid said

Edit: I guess not everybody is lucky enough to have a lathe and milling machine to play with.

Now , go thank your father for spoiling you.