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Discussion Starter #1
hey gang, check it out. i want to do a 5-lug conversion on my na. now, from the research i've done on the miata.net forum, i found out that the way monster used to do their cars with the 5-lug conversion was that they used the FC RX-7 front spindle on the miata. now the issue is the following the FC spindle will bolt right up to the upper arm on the miata, but not the lower. in order to make it work, the way monster did it was that they basically took a miata lower ball joint and a rx7 lower ball joint, cut them both open and basically made a hybrid ball joint. now my question is the following. i think that having to make a hybrid ball joint seems to be alot of work, especially for a part that can easily go bad or is something that i might have to replace in the somewhat near future. i know it would cost more, but wouldn't it make more sense to just make a new custom tubular control arm that would bolt up to the miata and properly use the standard rx7 ball joint. if done this way, in the future, replacing ball joints would be a snap and you wouldn't incur future costs of having to make a new hybrid ball joint. what do you all think? how hard do you all think it would be to make this type of control arm? i know that accuracy in the construction is key, but that shouldn't be a problem. if anyone can help in this matter, i'd really appreciate it.

also, how would i go about converting the rear to 5 lug? i got tired of searching on the miata.net forum for an answer as the question has been asked but no one seems to want to answer it.

thanks
alex
 

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bro:

You are searching for an easy answer. What you have to do is machine the 5 lug hubs to make it fit in the miata spindle. I did it on my other car. it's not difficult. give me a call, like I said I did it on my previous miata.
 
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Or...

See pics of my conversion of FC TII rear 5-lug hubs into Miata 4-lug hubs.

http://billwilner.myphotoalbum.com/view_album.php?set_albumName=album07

What you want to do is much easier:

Go shopping...
Buy a pair of new front Miata hubs/bearings (to have fresh bearings). (Mazda #NA01-33-04X)
Buy a pair of salvaged rear hubs from local junk yard.
Buy new rear bearings (Mazda #B455-33-047B)
Buy new rear bearing seals (Mazda #G3004-33-065)
Buy (20) ARP studs (2.5" long = ARP #100-7708).
Buy (4) 5-lug brake rotors (you're on your own here to find ones with correct I.D.s on hats, center hole, and compatible rotor surface thickness and alignment with Miata calipers. If you're lucky, off the shelf FC parts may fit. Mazdatrix.com may be able to advise you on this.)

Go to the garage...
Remove bearings from new front hubs and used rear hubs. (You aren't going to want to weld the hubs with grease inside them...)
Toss used bearings from rear hubs.
Weld up the 16 holes.
Grind down welds.
Use new 5-lug rotors as templates to drill 20 holes in hubs. (Confirm hole size with ARP before drilling.)
Powdercoat as needed.
Mount bearings in hubs.
Press in 20 studs.
And stir!

Bill
 

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Discussion Starter #7
actually, i was thinking of going ford rear, but i'm not sold on that one yet. i know that would probably know this project off a bit.

eli, how did you do the conversion on your old car? i need to know what i need to buy to do the conversion so i can start pricing out what i need. i'll call tommorrow to get some info, but post it up here also so that others can see how to do it.

let me know
alex
 

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Just out of curiousity...you have any extra power plans? Not really understanding the logic behind a 5-lug conversion without it...
 

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Discussion Starter #10
yes i do have some power plans for the future. i'll be going turbo with a semi-built motor setup and very possibly a standalone engine management system. as for the reason for the 5-lug, it is going to be easier to find wide wheels for my future body setup with 5 lugs than with 4. i don't want to give away all my plans yet, but i'm working on getting all my parts together.

thanks
alex
 

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Ok...won't make you spill the beans. It just seemed silly to go through all that trouble if you weren't up to something else--especially considering the afformentioned fact that the weakness in your drivetrain is not the 4-lug hub setup.
 

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You get More, & better rim options with a 5-lug.

I wonder if anyone has checked to see the compatiblity of the 5-lug from the new 2006 Miata? I imagine that we should start seeing used parts for sale on ebay soon, once people start crashing them or whatever.


Phat
 

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Alex:

The cheap way to do the conversion about $100-200 or so if to go a local rim place by Opalocka or near by where they adapt 22 inch wheels into the old impalas and other cars and ask for a custom adapters that can convert 4 lug to 5 lug patern. It should be easy to do for what you want it in your car.
Check a few companies online I have seen this done before.
The place I am talking about is right in Opalocka. It's called Chico's Hydraulics.
 

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Discussion Starter #14
OK, i'm still trying to get info on this conversion, but i think i'm gonna do the spindle coversion on the front. now, i'm having problems because originally i said that you need FC spindles, then i went back and said FD spindles. i know for a fact you can't use the FC unit because it does not have an upper ball joint mount. now, i'm getting my info from many sources so its kind of hard to figure out what is right and what is wrong. basically here is the problem. i read through searching that Monster Motorsports used to do the 5-lug conversion on their Mega cars. now, the conversion was based on the rx7 spindle and thats all the info i can gather from monster stuff online. an actual ex-mega owner stated that the way they did it was that they used FC spindles with a custom hybrid lower ball joint and that the spindle just bolted right up to the upper miata ball joint, but seeing that the FC spindle doesn't have an upper ball joint mount, there has to be some incorrect info there. thats why i think that the conversion would take the FD spindle instead since that spindle does have an upper ball joint mount and the suspension setup on that rx is similar to the miata, but the FD came out in 1993, and Monster was building their Mega cars with the 5-lug deal back in 1990, so now i am all confused. i tried emailing Martin at v8miata.com, but so far no answer. someone told me that he knows how to do the complete conversion as he himself has done the conversion on some of his customer's cars. i'm just hoping he gets back to me with some useful info.

is there anyone on here that can offer help in reference to trying to do the conversion in the manner that i am trying?

maybe someone in japan has done a 5-lug conversion. if so, i know one of you gurus on this site can find them and see how they did it.

well, someone please help
alex
 

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Discussion Starter #15
ok, so i found somone on the .net forum that has actually done the conversion on their miata already and has been driving around with it done for a few years already. the guy is actually gonna help me do my conversion. basically what he did was that he machined a solid "adapter" then he machined down part of the FC spindle and welded the new adapter to the spindle. then the spindle was able to bolt right up to the miata. he didn't bother making the hybrid lower ball joing, so no problem there. he is going to do all the work for me and ship me back the newly modified spindles. now all i have to do is find me a good set of spindles to do the conversion with.

well i guess that this means my baer big brake kit for the front that is still new in the box is probably gonna be for sale real soon.

thanks gang
alex
 

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bump from the dead
you still have contact info for the guy that did the 5 lug swap ?
thanks

edit: if you are running around with 5 lugs right now can you post some pics ?
 

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Why not
1. Buy new hubs
2. Press out old studs
3. Get a machinist to redrill a 5-bolt pattern
4. Install new studs
5. ???
6. Profit.

If you're worried about the integrity of the hub after drilling 5 more holes into, it would be easy enough to weld the holes closed.
 

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You aren't going to get the common 5 x 114 pattern in a stock hub by redrilling because the diameter is too small. 5x100 will fit with some overlapping holes, but it is not the common american size that you would be doing this conversion for in the first place. In the front you don't need to swap spindles, just have a sleeve machined to reduce the diameter of the RX-7 wheelbearing to the Miata spindle size. Use the Miata spindles. All 5x114 conversions require completely new brakes, as redrilling the rotors is not enough because they do not have a large enough inside diameter to fit over the larger hubs.

Andris
 

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Discussion Starter #20
ok, bringing this one back from the dead. as per the post from fwdtamiya, the front conversion doesn't look so hard to do. just modify the miata front spindle to accept the FD RX7 hub and bearing setup. now, what rotors to run with that setup? i'm looking to find something basically off the shelf from another car that can be used with that hub setup on the front. not sure what calipers to use just yet, but possibly FD calipers in the front.

now the problem comes in as to the rear. how can the rear be converted to the 5-lug pattern without too much work? can anyone give me some insight?

thanks
alex
 
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