benbr84

Well I've had my NC for close to a year now and I just seriously took a look at your website. I must say... More informative on the turbo stuff than m.net. Big surprise. I have a 2.5l sitting in the garage waiting to be mated with Fab9's new turbo setup. Patiently waiting. I am debating over building the 2.5 before the turbo arrives but I am a little hesitant being that I've never gone that in depth on a motor. Looking forward to sharing my build and getting great advise. Cheers!

-Ben

albuquerquefx

Welcome to the dark side, Ben! Glad you came over, all the super-duty boost heads are over here. I'm keeping a copy of my build thread on this site too, as I'll probably end up with more boost-related help from this gang vs M.net.

benbr84

Hey alright! I learned more about the setup after I ordered it from reading on here. I find the best way to accomplish things is to throw money at it until you're happy... Probably not the best plan but oh well. Now I'm not sure what to do with this header I bought before this whole thing came up. Guess I'll give it to my dad.

Braineack

iTrader: (62)

Thanks for joining, benbr84!

Chilicharger665

iTrader: (2)

How much power are you two aiming to make? The engines can easily be built to take the power, but I am worried about the transmissions and rear ends. Who has pushed those limits in NC's and how high have they gone?

sixshooter

iTrader: (12)

Welcome to the forum.

I heard the NC 5speeds are stronger than the 6speeds. Any truth to that?

benbr84

I guess we'll find out. I have the six speed. Currently trying to decide what direction to go with the clutch. Wanting to do at least 325 to the wheels initially. Ultimate goal of 400 at the wheels with wheel and tire upgrade.

albuquerquefx

I'm aiming for 350whp+ on the stock 2.0L, 6spd and factory LSD.

There are a significant number of boosted NC's over on M.Net. Essentially all of them (outside of some REALLY high end fab work) are kits, rather than the DIY'ers we find here on MT.

The NC1 (2006-2008) engines use powder cast / sintered rods which are, at least technically, inferior to the "powder forged" parts in the NC2 and later (2009++). While there's no specific proof of this, the NC1's did have a reasonably well documented problem with rod knock issues, even when left completely stock. I'm not sure if Mazda ever fully fessed up to that challenge, but the internals changed in 2009 and those problems seemed to go away. Part of the parts change was in relation to the raised redline in the NC2 and later models; Mazda's own marketing crapola in 2009 specifically talked about "the engine was fortified with a new forged steel crankshaft, forged steel connecting rods with floating wrist pins, revised pistons with stronger wrist pin bosses, stiffer valve springs, and an oil cooler"

Take that for whatever you think it's worth

Both motors are easily good to 300whp; there are a number of NC2 turbo folks running beyond 350whp for multiple tens of thousands of miles, including cars that are raced regularly at both HPDE and various autox events. The general consensus seems to be 350tq is about where you want to stop, the highest HP number I've seen reported over a LONG duration (thirty thousand miles) on stock internals is ~380whp as reported from a dynojet.

Also keep in mind the OEM computer on the NC's is soft, fine putty in the hands of a proper tuner. I'm not aware of ANYONE who is running aftermarket ECU, including a 211whp N/A 2.0L custom uber-compression, uber-cam, ITB and E85 build, nor the "big HP" fully built lower compression boosted 2.0L and 2.5L swaps. Strap on a 3bar MAP sensor and a set of 1000cc injectors and you can do insane things on the stock computer equipment. Hell, there's a guy over there running a >300WHP roots blower on E85 on the stock ECU

Nope. The 5spd are the weaker transmissions of the two. Further, the NC1 version of the 6spd had problems with bending the 3/4 shift fork (rectified in the NC2) and also a challenge with >300TQ applied in 6th resulting in shearing the teeth from the gear.

The NC2 Asin transmission is absolutely stronger in the shift fork area, and is purportedly (not necessarily proven) stronger across the various gears to include 6th. A (small) number of owners with failed NC1 6spd transmissions swap up to the NC2 and, again purportedly, have good luck there.

Finally, I'm not aware of anyone shredding the stock rear end, even when swapping for a taller ratio (3.7:1 is the tallest ring and pinion set I've seen.) The factory LSD in the NC is a clutched type, so eventually I assume they will burn up. Still haven't actually seen it yet. If/when it happens, there's plenty of aftermarket options, with Quaife being one of the more popular.

Chilicharger665

iTrader: (2)

Thanks for the info!

My idea is to get a 09+ PRHT and put a 6258 on it, specifically because of the engine and transmission being stronger. 300 whp would be plenty for me, so it is good to know they can handle that with no problems. I just want a fun DD to replace my dieselgate Jetta.

When it comes to the rear end, Puddymod has built custom pieces to put the previous generation 3.63's in NC housings.

albuquerquefx

I ducked the PRHT because of the weight gain (70+ lbs) and the distribution of that weight gain (nearly the top of the car.) I'm not sure that you'd want the 6258 only because, if you're going to break the motor, you're mostly likely to do it by spooling FAR too early.

If Fab9 is to be trusted (and I have no reason to believe otherwise) the 6758 will spool faster than the stock internals would be realistically happy with. I suppose you might argue a difference in response, but again I'm told that this should NOT be a worry.

I've been thinking about a taller final drive, mostly because the 6spd is REALLY short. I'd love to hit 60mph in 2nd gear...