Howdy from Dallas!

Good to be here. I picked up my 2007 MS3 GT "Shadowfax" on 3/19/20. I got her with only about 110k on the clock. I'm now a little past 113k and climbing. I gotta say that I really like this car. I take a lot of road trips and drive for work and love how this car just tucks in at 80+ and eats miles and, of course, turbo noises turn everyone into a 12 year old.

The only mod is a Cobb SRI that came with the car. I've so far replaced the pivot shaft seal, driver's CV axle, shocks and struts, upgraded the front and rear sway bar bushings and brackets to JBR stainless ones, sway bar end links, new spark plugs, and new tires (225/45/18 Sumitomo HTR, I think). I still have to replace my turbo (eating a quart every 3-400 miles or so!) and my HPFP internals and then I'll do some light mods. This is also a DD so I'm not getting too mod heavy, more like OEM+.

For the interior, I plan on redoing the Bose system, putting in an Android HU, Weathertech mats (does anyone know where to get an all weather hatch liner?), a better shift knob than the Cobb that came on it (decent, but not my preferred texture), a bunch of Dynamat and jute mat to quiet her down, and a dash mat to cover the couple of inconsequential cracks and reduce glare.

 

Welcome! I've been hunting for a good all weather hatch liner years and haven't found that I've bought yet... could have been due to cost can't remember I just use a tarp when the scuba gear is in the car XD.

What's your plan for turbo? A fresh k04 (stock) one can run you around the same price (little cheaper) than a BNRS3 and that thing will make the stock block sing!

As for shift knobs @Maisonvi makes some amazing ones not sure if he has any ready to go but talk to him

 

My plan for the turbo is an S2 or S3. I'm not looking for more than 320 WHP max (since I think it would be fun to break the 10 lbs/HP mark) but I'll be happy with 275-300 WHP if it is going to be a more reliable and tractable amount of power since some of the roads I drive on aren't conducive to high HP FWDers. I might even just run an S1 if it'll get me where I need to be without stepping outside its efficiency.

The only reason that I would consider a full OEM replacement of the K04 would be for serviceability when I'm not near my home dealer that's mod-friendly and will happily install any parts I give them (I live in an apartment complex where major car work is frowned upon). That way, I could go to any Mazda dealer if something comes up within the turbo warranty.

@Maisonvi makes some gorgeous shift knobs. I'm not ready to replace mine just yet because Stage 0 always comes first for me.

I got this beast for the princely sum of $3200 including TTL plus a worn out Volvo S40 that was pretty much ready to be a parts car, so I'm still not mad that I've had to do some minor stuff. The people at the dealer were actually kind of shocked at how clean it is.

 

Welcome and feel free to ask questions if you have any. Sounds like you have a solid plan and a safe goal for a stock block. Good luck and glad you joined!

 

Thanks! Good to be here. This is actually my first Mazda ever. I don't even mind the hilariously bad fuel economy because it's fun to have people ask me what I get and I tell them 21-22 average xD. They're usually thinking about 30+ haha

I'm sure it'll drop when I'm at Stage 0 and can drive her hard again!

 

BNR S2 or S3 are excellent choices! I wouldn't even worry about the mazda warranty on the turbo...chances are the warranty would be up before it smokes (just) BNR would far outlast it. Even if they are "mod friendly"

 

Awesome, thanks for the input! S2 it is!

 

Good choice, it'll provide more oomph than the K04, very good match for the stock block for OEM ish turbo with a little more pep. I'd recommend a 3 port ebcs, upgraded hpfp internals and intake to match it, however at the very least the 3port with a tune will help control boost better

 

Internals are already scheduled to go in before the turbo, as well as a new BPV (the PO JB welded mine back together, but it works fine and holds boost on the K04), a TIP, catted downpipe and vented OCC. A 3 port sounds good, so I’ll add it to my list. When my VVT solenoid starts getting wonky, I might look at mild cams but that’s a big maybe.

 

I also picked her up today after getting the suspension work. It’s so nice to have a quiet and tight car! You can definitely tell I went with cheapish coil overs for now (they’ll be replaced with the B12 pro kit when these blow or I’ll have them revolved properly if the housings are still good) but the car is back to being sharp and agile! And my CV axle is nice and quiet and smooth. I went with a DTA one at the advice of the folks on here in the parts that don’t suck thread.

 

Nice! Also careful with cams some seem to make doodoo power, you'd be better if tossing in a BNRS3 even on the stock block if you're trying to maximize it than touching the cams from what I've seen. Just let the tuna know you want to keep the stock block and will tune to it, especially if you're going with someone like freektune

 

I'll nix the idea of cams, then. Thanks!

I scored a lightly used JBR PMM and TMM today as well as lightly used Autotech internals and a JBR intake and TIP. Got a great price on all of them! My RMM definitely looks like it's been upgraded but I have a lot of driveline lash still, so I need to fix that.

I'm not sure if I'm going to get out of the comfort zone of the S2 trying to push about 325 WHP - and I can't find any real dyno maps on that, so I think I'm going to bite the more expensive bullet and spring for a CST4. Or would most people recommend a BNR S3? I know I'll need a tune regardless and the CST also comes with the 3bar MAP, which I'll need anyways so it's a better value. My research indicates that they had some hiccups at the beginning but are generally fine now. Has that consensus changed? I'll likely put a turbo blanket on there and a nicer firewall heat shield instead of the ugly sauce, sharp sheet metal heat shields.

Since I really only wanna dig into that rat's nest once if I can help it, I'm putting in a downpipe while I'm there. If I can't find a catted long pipe for a reasonable price, I'll run a decat DP and cat my midpipe.

Does a better turbo manifold really do anything? I've seen answers for both sides. If so, I'll slap it in while everything is removed back there. Hell, it may be easier to unbolt the DP from the MP, unbolt the turbo manifold, and slide everything out as one unit, if it's possible. I've heard good things about the TurboXS manifold for its price and I can get it locally ceramic coated to help protect the welds and metal (plus reduce heat!). Though this thing looks pretty beefy and nicer than the TXS:
https://www.ebay.com/itm/JST-Turbo-...IOnTopCombiner&_trksid=p2047675.c100752.m1982

FMIC is planned for a later date or will go in if I do a turbo manifold since lining stuff up with the TMIC might be a PITA.

PCV replacement with vented OCC is also on my list.

I do want to be fully bolted with everything I can be, so is there any real benefit to running an ST or other alternate intake manifold? I think my throttle body is being weird (twice since I've owned it has it just randomly stopped responding until I jiggle its connector) so I'll order the CS one once it dies or ends up giving me more issues.

I don't necessarily want to chase numbers - I want a responsive, well-balanced GT car.

 

Shirt version: BNRS3 with supporting mods:intake, hpfp, ebcs, intercooler, map sensor sure. Downpipe preferably turboback. Will give you quite the responsive and powerful car on stock block. Then of your want more Manifolds and build motor with rods and pistons.

LongBLong version:S3 is a wicked turbo especially with the latest revision, your research on the CST4 I believe is correct. From what I've seen generally the BNR gets recommended more from other forums users with decent support for the CS.


Exhaust manifold upgrade will balance out exhaust pressures between cylinders and far improve responsiveness on the turbo. You'll notice the biggest improvement if you also upgrade the intake manifold if doing exhaust manifold. Now keep it mind that means you'll have a vcts code and EGR and if you have to do frequent emissions then be prepared to swap parts....
Good call on DP, CPE and Cobb both make long catted ones, they'll cost you a pretty penny but they're good, cat will be a choice point and I don't know how much it's with an exhaust manifold upgrade from a performance standpoint of you have one however from a engine longevity it should still have a place. If you can get away without a cat it'll give you more flow for sure.

As for eBay EM, don't recall which ones last but all seem to crack eventually, also upgrading exhaust manifold typically means no.

At the end of the day tossing on the BNRS3 or CTS4 with supporting mods will give you a response car. Doing the manifolds will certainly make it even more responsive but you're also spending alot of money at that point and should start saving for a block talking just rods and pistons as just doing those can sustain good HP.

 

So I’m either going to have to source an engine or I’ll have a very complete parts car to sell. My poor beast was diagnosed has having - I’m not sure what exactly it’s called - but kind of like crank walk. Basically, the crank moves under boost and eventually the friction washers eat into the block and destroy the engine.

My symptoms were very difficult shifting and you can see the crank move when you depress the clutch. Anyone ever had this happen? The master tech at the dealer said it’s not uncommon on the Speeds and CX-7s.

You know it’s never good news when said master tech looks at your car for less than five minutes and then asks if you want a hug before or after he tells you the news lol.

 

Really take your time deciding what your course will be given your diagnosis. I’m not questioning what the master tech told you, just impressing that these are amazing cars with fantastic potential. If you’ve loved it this much so far, imagine what some extra coin invested in a new engine would mean for you 5, 6, 10 years from now. My Speed3 has 260k on the OG engine and I would definitely invest in a new engine if I had to.

(Just being an existential dumbass over here who really loves this peppy beast)

With regards to your difficult shifting, can you expand on that a little more? Shifting in these cars can be a pain to get used to. It took me over a year to keep from grinding into 2nd, 3rd, or honestly any other gear and that’s with growing up driving a manual. It wasn’t until I installed the JBR SSP (short shift plate) that I hit every gear darn near 95% of the time with minimal effort.
In the end though, tbh, I don’t know enough about crankshaft issues to give you both sides of the issue. I am, however, in love with these cars.

 

Didn't want to necessarily start a new thread for this, but wanted your take. My original K04 needs to be replaced (pretty sure the seals are gone). I'm looking at the BNR S1 vs. a remanufactured K04. I'm 100% stock and don't really want too much more power. Just want to make my '13 a little more responsive around town while keeping everything else stock.

 

If I were you abd were switching out turbos I would done a s2 because there isn't a difference in spool time at that size turbo really and an s2 would give you a little better power and retain stock qualities. Just my take on that Then you get a bit better turbo with same spool up and no dreaded ko4 smoking issues soon after installing.

 

Yup S1 is a good option probably the only non OEM turbo I wouldn't re tune with, while the S2 says it doesn't need a tune personally I'd be adding some hpfp internals and a little tune to just to be safe. BNR also does stock remans for a good price

https://bnrsupercars.wordpress.com/mazdaspeed-3-6-cx-7/