NC now a better option than NA/NB?
#26
I want the NC to be a good platform, otherwise there is a 9 year gap in cheap/fully depreciated Miatas/MX5s headed our way. And my recent experience in sourcing a used VVT motor seem to indicate that some NA/NB parts are becoming more scarce. The last time I needed to buy a 1.8 was 6 years ago; for $700 I had plenty of local options. Last month I couldn't find any decent local motors for less than $1000, and there were far fewer options than a few years earlier. I ended up importing a motor from the UK. That may get us through the next few years, but what happens after that?
#27
For years we could find <3% leakdown used BP6D's locally for ~$900. Perfect race, Enduro or HPDE motor. Those days are gone. Now it's full $1500-$2500 rebuild on that same core that is avg 10% leakdown when you buy it for $1200.
The virtually endless supply of $600 2.5L 200hp motors and free step by step swap info is a major tipping point.
The virtually endless supply of $600 2.5L 200hp motors and free step by step swap info is a major tipping point.
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#29
Um, everything? I'm not referring to a full track prepped car. I'm referring to an 80k mile $14k craigslist car you slap some 285 Rival-S on a try to do a 8x 20 minute HPDE sessions over a weekend in 90° heat. $12-15k later that car will survive that weekend, but not straight off CL it wont.
Lest we forget, a stone stock but otherwise healthy $3500 CL NB1 can survive that same weekend with just a set of brake pads and a roll bar. Faster with a bunch of money dumped into it, but not needed.
Lest we forget, a stone stock but otherwise healthy $3500 CL NB1 can survive that same weekend with just a set of brake pads and a roll bar. Faster with a bunch of money dumped into it, but not needed.
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#30
I've owned my 2006 NC1 since new as a dual-purpose DD and autocross car in SCCA CSP class, stock motor with intake and exhaust and all the other *SP-allowed suspension/brake/wheel/tire upgrades. Car won at SoloNats in CSPL with Juliann Pokorny in 2009, and I trophied 4th in 2011 in CSP after leading Day 1. I even drove it from Dallas to Lincoln pulling my tire trailer! Now a trailer queen track-only car, in SCCA Time Trials Nationals I podiumed in 2018 (M3 class) and 2019 (new P3 class). My motor is now a 2013 2.0L MZR rebuilt by Jesse Prather and with Xero Limit (formerly Moto East) cams and intake and a PPE LTH with a ECUTEK RaceROM tune on E85. Still normally aspirated, I pulled 190whp and 147wtq (stock 132/125) on Jesse's dyno. Car handles like a dream and has been bulletproof. Happy to see they're finally getting the props they deserve!
#32
This is well timed to my interests, lol. I just bought a 2019 RF GT-S as a DD, so now I need a track car. I have previously driven an NC Cup Car (not the new Spec MX5) at COTA and I thought it was great fun. Having already had 2 NC's, I think they are vastly better than the 3 NB's I also had.
The NC2 Sport's are now at the 10kish mark, so I would rather go with one of those. The NC2's have lots of little reliability refinements over the NC1's that I think are beneficial, along with a much better engine. My plan is to do full bolt-on's, suspension, rollbar, seats, harnesses, and all that good stuff with the NC2's better set-up. Then build a 2.5 engine on the side when I am ready for a good chunk of more power. Dynotronics recently posted that ECUTek is working on implementing flex-fuel on the NC now, so that will be perfect for a high-compression 2.5 build.
I didn't like the street ride of my ND XIDA ACE's and I have never driven XIDA's for the NA/NB's. I have never experienced their supposed great street ride, but I have high hopes that the NC XIDA's will make my driven-to-the-track car tolerable to and from the track.
The NC2 Sport's are now at the 10kish mark, so I would rather go with one of those. The NC2's have lots of little reliability refinements over the NC1's that I think are beneficial, along with a much better engine. My plan is to do full bolt-on's, suspension, rollbar, seats, harnesses, and all that good stuff with the NC2's better set-up. Then build a 2.5 engine on the side when I am ready for a good chunk of more power. Dynotronics recently posted that ECUTek is working on implementing flex-fuel on the NC now, so that will be perfect for a high-compression 2.5 build.
I didn't like the street ride of my ND XIDA ACE's and I have never driven XIDA's for the NA/NB's. I have never experienced their supposed great street ride, but I have high hopes that the NC XIDA's will make my driven-to-the-track car tolerable to and from the track.
#33
The big difference for me was always that a bone stock 90 A package NA6 was a fantastic car right off the showroom floor. Faster and better if you spent time and money but damn good right off the bat. The NC1 OTOH, was pretty miserable until you fixed a bunch of things. Those "things that need to be fixed" are now dialed, the knowledge base solid. The key being the low cost of a NC1 donor cars ($4000~8000) and the relative ease of dropping a $900 2.5 MZR into it. Add in Goodwins new 17x10 wheels and upcoming Xidas and you have the foundation for a really fast and reliable $12k build. We're talking a 12:1 lbs /hp build with roll bar and race hard top skin with 255/40/17's. Such a car will vaporize a $12k NB build on track or autocross.
#36
Fair question. I thought it appropriate. Where would you suggest the mods move it?
Sorry you were never able to get your Xida ACE dialed. I don't recall us having many offline conversations or consultations to address any issues you may have had. The ACE setup on my 30AE are amazing.
255 on 17x10's with stock-ish power would be a good autocross setup. Possibly too much tire for track though. 2.5 bro.
255 on 17x10's with stock-ish power would be a good autocross setup. Possibly too much tire for track though. 2.5 bro.
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Last edited by emilio700; 11-15-2019 at 11:21 AM.
#39
Good thread on m.net from 2013. Guessing the most current swap info has some improvements. https://forum.miata.net/vb/showthread.php?t=522719
NC 2.5 FB group: https://www.facebook.com/groups/2006740659573188
Sounds like 170whp with bolt ons for a 2.5. Our bone stock 88k mile NC2 made 147whp Dynojet on CA91. Mike states 140whp from the NC1 so gains depend on which gen you start with.
The MZR isn't as good as a K24 but easier and cheaper to swap in.
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#40
2.5 swap info from Armand Hindrichs
Courtesy of Armand Hindrichs 2.5 swap facebook group:
REQUIRED PARTS:
-Duratec (Mazda L) 2.5L motor (preferably Ford origin for better internals)
-Wiring pigtail to VVT solenoid on the 2.5L motor (Ford WPT1251)*
-VVT solenoid gasket from 2.5L valve cover (Ford BR3Z-6C535-B)*
-Larger injectors (2.5L injectors will work)
-Balance shaft delete set (=AT1x5sdFMVPOshm5nlbGPjkKi9r7TMLY2Tn1pcyhTgR7rnTgJ H237wSuKzNCx1ybJucAfp1lWL6ijvRzg5lfU2KH0m9I0IpTJWg WsKTNCujKxkyUEwwJpNzaCNW-UT0Hng]massivespeedsystem MAEN'8647)
-Timing kit for Duratec motors (for installing crank pulley) (=AT1x5sdFMVPOshm5nlbGPjkKi9r7TMLY2Tn1pcyhTgR7rnTgJ H237wSuKzNCx1ybJucAfp1lWL6ijvRzg5lfU2KH0m9I0IpTJWg WsKTNCujKxkyUEwwJpNzaCNW-UT0Hng]massivespeedsystem MATO'8754)
-Laser iridium spark plugs (NGK LTR5BI-13 if NA)
-Serpentine belt (6PK2310)
-Dipstick (Mazda PE07-10-450)
-2x diamond washers for crank assembly (Ford 1S7Z-6378-AA OR Mazda L3H5-11-407)**
-Crank bolt - (Ford 1S7Z-6A340-AA OR Mazda LF01-11-406)**
-2x Cam bolt - (Ford CV6Z-6279-A OR Mazda L568-12-428)**
-2x Diamond washers for cam (FORD 6M8Z-6278-A OR MAZDA L3K9-12-429)**
-Tube of RTV/liquid gasket
*Not necessary to order if it comes with the 2.5L
**One-time use part. Do not reuse.
Other part numbers:
-Exhaust studs on head (Mazda LFE2-10-104)
-Header-to-midpipe studs (Mazda L3M7-40-584)
-Alternate front engine cover which does not require modification for belt clearance (Mazda L3AW-10-500)
-Alternate block breather which does not require modification for intake manifold clearance (Ford 4L5Z-6A785-AA)
-Parts from stock 2.0L:
->oil pan
->oil pressure switch on oil filter perch (green)
->valve cover
->crank pulley
->fuel rail
->intake manifold
->pulleys & tensioner
->accessories
->intake manifold runner (should be ported to match 2.5L head)
Maintenance/upgrade opportunities:
-Rear main seal
-Front main seal
-Valve cover gasket
-Replace starter
-Clean intake manifold
-Clutch/flywheel
-Aluminum PCV breather
-Motor mounts
-EGR delete
-Cams
-Radiator
-Header/full exhaust
-Oil cooler
-Turbo/supercharger system
-Catch can
-Upgraded intake manifold
HOW TO CONVERT 2.0L to 2.5L:
-Remove oil pan, valve cover, intake manifold, and any other external accessories or attachments from 2.5L motor
-Remove sensor between cyl 2 and 3 on 2.5L motor
-Transfer VVT solenoid gasket from 2.5L valve cover to 2.0L valve cover
-Install balance shaft delete
-Port match 2.0L intake manifold runners to 2.5L, use RTV to seal to head
-Transfer crank pulley, replacing the diamond washers, replace the crank bolt with new, and torque to 71-76ft-lbs+ 90 deg
-The cam bolts must be replaced if cams are changed out, torque them to 51-55 ft-lbs
-Cut notch on timing cover to clear belt routing to power steering pump
-Transfer 2.0L components to 2.5L motor (motor mounts, pulleys, sensors, wiring harness, etc)-Swap the appropriate VVT solenoid connector on harness
-Install clutch/flywheel
HOW TO REMOVE IT FROM THE TOP:
-Recover AC system (optional but can make life easier)
-Drain engine oil and coolant
-Remove hood, battery & box, air box, and ECU & mount
-Remove plastic cowl covers and metal cowl cover brace
-Disconnect PS pump and move aside
-Disconnect AC compressor from motor (if system wasn't drained)
-Remove header & midpipe
-Remove transmission
-Remove motor
-Prepare 2.5L motor for installation (see above)
-Reassemble everything
-Refill coolant
-Refill AC system (replace the drier)
-Tune ECU
HOW TO REMOVE FROM BOTTOM:
-Recover AC system
-Drain engine oil and coolant
-Remove midpipe & disconnect driveshaft from diff
-Support transmission
-Remove PPF
-Remove shock tower nuts
-Disconnect PS pump
-Disconnect flexible clutch line
-Remove lower radiator supports
-Disconnect steering column
-Drain power steering fluid
-Disconnect upper and lower radiator hoses
-Support subframe
-Carefully remove the nuts and bolts that hold the subframe and underside brace
-Carefully lower assembly away from body (or raise body if on lift)
-Prepare 2.5L motor for installation (see above)
-Reassemble everything
-Refill coolant and power steering fluid
-Refill AC system (replace the drier)
-Bleed clutch line
-Tune ECU
Other torque values:
-Head stud/bolt torque sequence - 62inlb, 133inlb, 33ftlb, +90deg, +90deg (yes, that's twice)
-Cam cap torque sequence - 45-79inlb, 11-12 lbft
REQUIRED PARTS:
-Duratec (Mazda L) 2.5L motor (preferably Ford origin for better internals)
-Wiring pigtail to VVT solenoid on the 2.5L motor (Ford WPT1251)*
-VVT solenoid gasket from 2.5L valve cover (Ford BR3Z-6C535-B)*
-Larger injectors (2.5L injectors will work)
-Balance shaft delete set (=AT1x5sdFMVPOshm5nlbGPjkKi9r7TMLY2Tn1pcyhTgR7rnTgJ H237wSuKzNCx1ybJucAfp1lWL6ijvRzg5lfU2KH0m9I0IpTJWg WsKTNCujKxkyUEwwJpNzaCNW-UT0Hng]massivespeedsystem MAEN'8647)
-Timing kit for Duratec motors (for installing crank pulley) (=AT1x5sdFMVPOshm5nlbGPjkKi9r7TMLY2Tn1pcyhTgR7rnTgJ H237wSuKzNCx1ybJucAfp1lWL6ijvRzg5lfU2KH0m9I0IpTJWg WsKTNCujKxkyUEwwJpNzaCNW-UT0Hng]massivespeedsystem MATO'8754)
-Laser iridium spark plugs (NGK LTR5BI-13 if NA)
-Serpentine belt (6PK2310)
-Dipstick (Mazda PE07-10-450)
-2x diamond washers for crank assembly (Ford 1S7Z-6378-AA OR Mazda L3H5-11-407)**
-Crank bolt - (Ford 1S7Z-6A340-AA OR Mazda LF01-11-406)**
-2x Cam bolt - (Ford CV6Z-6279-A OR Mazda L568-12-428)**
-2x Diamond washers for cam (FORD 6M8Z-6278-A OR MAZDA L3K9-12-429)**
-Tube of RTV/liquid gasket
*Not necessary to order if it comes with the 2.5L
**One-time use part. Do not reuse.
Other part numbers:
-Exhaust studs on head (Mazda LFE2-10-104)
-Header-to-midpipe studs (Mazda L3M7-40-584)
-Alternate front engine cover which does not require modification for belt clearance (Mazda L3AW-10-500)
-Alternate block breather which does not require modification for intake manifold clearance (Ford 4L5Z-6A785-AA)
-Parts from stock 2.0L:
->oil pan
->oil pressure switch on oil filter perch (green)
->valve cover
->crank pulley
->fuel rail
->intake manifold
->pulleys & tensioner
->accessories
->intake manifold runner (should be ported to match 2.5L head)
Maintenance/upgrade opportunities:
-Rear main seal
-Front main seal
-Valve cover gasket
-Replace starter
-Clean intake manifold
-Clutch/flywheel
-Aluminum PCV breather
-Motor mounts
-EGR delete
-Cams
-Radiator
-Header/full exhaust
-Oil cooler
-Turbo/supercharger system
-Catch can
-Upgraded intake manifold
HOW TO CONVERT 2.0L to 2.5L:
-Remove oil pan, valve cover, intake manifold, and any other external accessories or attachments from 2.5L motor
-Remove sensor between cyl 2 and 3 on 2.5L motor
-Transfer VVT solenoid gasket from 2.5L valve cover to 2.0L valve cover
-Install balance shaft delete
-Port match 2.0L intake manifold runners to 2.5L, use RTV to seal to head
-Transfer crank pulley, replacing the diamond washers, replace the crank bolt with new, and torque to 71-76ft-lbs+ 90 deg
-The cam bolts must be replaced if cams are changed out, torque them to 51-55 ft-lbs
-Cut notch on timing cover to clear belt routing to power steering pump
-Transfer 2.0L components to 2.5L motor (motor mounts, pulleys, sensors, wiring harness, etc)-Swap the appropriate VVT solenoid connector on harness
-Install clutch/flywheel
HOW TO REMOVE IT FROM THE TOP:
-Recover AC system (optional but can make life easier)
-Drain engine oil and coolant
-Remove hood, battery & box, air box, and ECU & mount
-Remove plastic cowl covers and metal cowl cover brace
-Disconnect PS pump and move aside
-Disconnect AC compressor from motor (if system wasn't drained)
-Remove header & midpipe
-Remove transmission
-Remove motor
-Prepare 2.5L motor for installation (see above)
-Reassemble everything
-Refill coolant
-Refill AC system (replace the drier)
-Tune ECU
HOW TO REMOVE FROM BOTTOM:
-Recover AC system
-Drain engine oil and coolant
-Remove midpipe & disconnect driveshaft from diff
-Support transmission
-Remove PPF
-Remove shock tower nuts
-Disconnect PS pump
-Disconnect flexible clutch line
-Remove lower radiator supports
-Disconnect steering column
-Drain power steering fluid
-Disconnect upper and lower radiator hoses
-Support subframe
-Carefully remove the nuts and bolts that hold the subframe and underside brace
-Carefully lower assembly away from body (or raise body if on lift)
-Prepare 2.5L motor for installation (see above)
-Reassemble everything
-Refill coolant and power steering fluid
-Refill AC system (replace the drier)
-Bleed clutch line
-Tune ECU
Other torque values:
-Head stud/bolt torque sequence - 62inlb, 133inlb, 33ftlb, +90deg, +90deg (yes, that's twice)
-Cam cap torque sequence - 45-79inlb, 11-12 lbft
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