Front and Rear Subframes
#1
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Front and Rear Subframes
Is there an advantage to running either the NA or the NB front/rear subframe in a Miata? I've read that there were changes, but nothing that specifically says one is better than the other or the factual reasons. Most posts were just about making sure you have the proper steering rack if you do the swap. Besides that, what are the actual differences and which combination is preferred and why? I have access to two complete setups and need to decide which way to go.
#10
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Right now I have an NB and an NA, but I plan on putting the NB up for sale in a few months. Just trying to build the 93 using the smartest combination of parts. I also think it might be easier to swap the subframes/steering rack than to move the suspension, brakes, axles and diff over piece by piece.
#14
Is there an advantage to running either the NA or the NB front/rear subframe in a Miata? I've read that there were changes, but nothing that specifically says one is better than the other or the factual reasons. Most posts were just about making sure you have the proper steering rack if you do the swap. Besides that, what are the actual differences and which combination is preferred and why? I have access to two complete setups and need to decide which way to go.
Up front the NB front lower arm is mounted slightly higher on the subframe. The NB upper front arm is mounted slightly further back. The NB spindle steering arm is repositioned for less bump steer. The NB steering rack is mounted more securely to the subframe.
#19
I just put NB front upper/lower control arms on my NA to accommodate the NB spindles/brakes 30min ago, no issue whatsoever. I did go to a spherical rod end link setup I had laying around from an b13 Se-r project due to the differences in sway bar mounting tabs. I dont really agree that the NA end link tabs are superior due to the thickness of the NB tab but thats me. I know that the NB engine subframe has better steering geometry; I would ask would I need to update to the NB steering rack if I installed the front NB subframe...
quote from keith at flyin miata: "The NA and NB control arms are the same, geometrically speaking. The only difference is the sway bar mounting point. In fact, if you buy an NA replacement control arm you'll get an NB part. The changes in caster came from the control arm mounting point on the subframe, so you'll get them if you install an NB subframe.
The steering arm on the uprights was moved up by 7mm on the NB, IIRC. The rear uprights have 5mm more track per side. The rear subframe is the same other than exhaust and brace mounting points."
quote from keith at flyin miata: "The NA and NB control arms are the same, geometrically speaking. The only difference is the sway bar mounting point. In fact, if you buy an NA replacement control arm you'll get an NB part. The changes in caster came from the control arm mounting point on the subframe, so you'll get them if you install an NB subframe.
The steering arm on the uprights was moved up by 7mm on the NB, IIRC. The rear uprights have 5mm more track per side. The rear subframe is the same other than exhaust and brace mounting points."
Last edited by JEMERY; 11-13-2010 at 10:40 PM.