replacing camshaft and gears

22Silver · Postby **22Silver** » Fri Nov 15, 2013 12:46 pm

I'm looking at mild cams for my NB8A. However I don't think I can get an ECU approved in VIC, so I'm trying to figure out if I can either find an ECU which is approvable, or a set of cams that work (streetable) without a tune.
The other thing of interest seems to be electronic fuel control, to get a more suitable fuel map.

So far looking at..
http://949racing.com/mazdaspeed-miata-intake-cam.aspx

Apparantly a cam gear helps, but I can't figure out why?
http://949racing.com/Toda-cam-gear-miata.aspx

Only other mods are exhaust from headers back. Will at some point be putting 4-1 racing beat headers on.
So the long term goal is cams (and whatever is needed to make it work) headers, exhaust (done). Possibly intake if it seems worthwhile.
It already has an adjustable timing wheel, not sure if that wheel help me get the most out of my mods?

aany pointers in the right direction very much appreciated.
Oh and yeah, one last thing.. would you go cams then headers, or headers then cams?

emily_mx5 · Postby **emily_mx5** » Fri Nov 15, 2013 12:55 pm

headers, 4-2-1 for the street
a proper cai like through the firewall or a ddm unit that has an enclosed box
and actual exhaust, not some mangled SE rubbish
mild cams, wozzah does regrinds which will suit perfectly on oem ecu.

Common upgrade path, but by the time you've done all of that, you won't see that large of a gain and it's probably cost you over 2k.
Why are you worried about an ecu not being legal? all the other mods have made the car illegal anyway.

hks_kansei · Postby **hks_kansei** » Fri Nov 15, 2013 12:58 pm

Have a close look at the cam specs and see if it's worth it.
I seem to recall the cam change wasn't much difference on a Aussie car (I might be thinking of the exh-intake swap though)
Also look hard and make sure the cams will work on the OEM ecu and won't run it lean.

I think Maruha/Toda/Tomei do mild cams that supposedly work with the factory ECU and gain about 8kw or so, I'm sure local cam grinders can do the same specs for a lot cheaper.

Also factor in that since you've got an NB you will need to check the valve clearances etc, unlike the NAs with the Hydro lifters the NB uses solids which are manually adjusted via shims. (there's also somethign about changing the type of lifter on the NB to better suit bigger non-genuine cams)

Maybe PM Nitrodann to have a look at this thread, he has had some experience with cam changes in MX5s.
Also pm Wozzah1975, he makes cams for them.

rossint · Postby **rossint** » Sat Nov 16, 2013 12:03 am

I did mild cams and gears on my NA6, gained about 10% power. The Dyno curve was almost identical down low with all the gains in the top end. Hopefully I will do a computer and get rid of the AFM soon.