Saving a 2008 Mazdaspeed 3

Thanks StreetSpeed6, but currently the stock BPV I have appears to test out fine. I will let you know if it comes up as a possible issue after reassembly.

So despite not believing the turbo was knackered, I sent it off to a local turbo rebuild shop for analysis. Got the call yesterday from the shop and the tech informed me that the turbo was in need of a rebuild. He found metal pieces in both the journal bearing and the thrust plate feed area. Add in the fact the oil feed gallery was plugged, it would explain why the turbo wouldn't spin up fast enough to provide more than 4psi of boost. He did confirm that all the rest of the turbo, including the wastegate checked out fine.



At this point, it was decision time. Do I go with a rebuild, an OEM replacement or a CST 4? In the end, given my vehicle situation, it made the most sense to have my current turbo rebuilt. For a reasonable price, my stock K04 will be getting overhauled along with a new CHRA, turbine and compressor wheels. While a CST4 would be nice, the cost plus time/effort/risk of daily driving a vehicle in the process of tuning outweighed the install and drive aspect of a stock turbo. Also given that the general goal for this speed is stock-ish, constrained by being reliable on major stock components, a CST4 may be in the cards down the road. Going with the K04 will also allow me to get up to speed with Mazdaedit and get some extra power out of the K04 before taking on the CST4.

I will however, be adding a catless downpipe, HPFP internals and Corksport injector seals while I am in the car for reliability and longevity reasons. Not too far in the future will also be a FMIC setup.

 

Glad to hear you found the issue.

Why a cst4? There are far better options out there.

 

CST4 is a banger for stock block setups

 

The CST 4 rose to the top due to price, performance and stock location installation reasons. The goal is to stay within the confines of the stock fuel system and stock block. I.e. no need to go with a massive turbo, which would snowball into auxiliary port injection, larger, louder exhaust, suspension upgrades etc. Unless there are other options I haven't found in my searching, the CST 4 and BNR are the main two that fit those first 3 requirements.

 

Fair to me $50 is worth going bnrs3 over cst4. Edit: you'll probably break even with shipping lol

 

I have had the Beta #4 corksport turbo for like 70k miles without a problem. Highly recommend.

 

and your car is a broken piece of shit so that is like 700k miles on a normal car

 

Hahahahahaha, that hurts.

 

The truth usually does.

 

Today was a good day. Got the turbo back from the shop. It needed a new CHRA, compressor and turbine wheels and was completely overhauled. the catless downpipe also showed up. Once I get the Corksport HPFP and injector seals, I should be good to get reassembling!

 

That is seriously like the cleanest ko4 I have ever seen. Rebuilt or brand new

 

How much did that k04 rebuild run you?

 

Make sure you use OEM DP Gasket the one ebay sends is straight trash.

 

It was close enough as makes no difference to $450 out the door. Full rebuild with new CHRA, turbine and compressor wheels, balance, etc. It was through a local shop so no shipping either.

Thanks. I was looking at the downpipe gasket that came with the downpipe and the gasket I got from the turbo shop and I am leaning towards OEM mazda gaskets. The gaskets I took off the car look to be a higher quality than the ones I have now. I REALLY don't want to tear this apart again due to a cheap gasket failure.

Also, Aside from the Kozmic oil feed line on Edge, are there any other good oil feed lines? I can probably clean mine, but given the particulate that was in the turbo bearings, I am inclined to replace the whole feed line. I'd like to keep it as a braided stanless line however.

 

If I were in your shoes, I would stick with the OEM oil feed. The way that line has to curve up from the center of the block to the top of the turbo, its rigidity keeps it from flopping around and getting damaged. Not to mention that with the OEM ExManifold you have that little support bracket too.

I would just clean the hell out of it. Run some carb cleaner and compressed air through it several times in both directions and call it a day.

 

Finally got around to working on the Speed again during the Quarantine. Mainly worked on getting the Manzo downpipe installed and getting actual HPFP internals installed. HPFP internals were installed fairly easily and the HPFP is staged for when the turbo is installed.

Also, I think I found a major contributor for my boost issues....


Primary cat was empty, as I assume one of the P.O.'s hogged it out. When I pulled the secondary cat, a couple heavily blackened pieces of honeycomb came out. That prompted me to shine a light down into the secondary cat and find that the front side was fairly broken up. Oddly enough, the back side of the secondary cat still looked OK. In short, a clogged cat mot definitely contributed to my boost issues.

 

Made some more progress lately as well. Pulled the intake manifold to put the brass fitting for the brake booster connection along with installing CS injector seals and a new PCV valve. I am also doing a bit of a valve clean while I am this deep into the engine.



I did pick up a catch can, but am debating on whether or not to install it. I would need to hunt down a suitable check valve to use it as right now it would get full boost pressure if plumbed between the intake and PCV valve.

Lastly, I did replace the starter as previously the car seemed to crank over slowly. It was another one of those snowball "while you are in there" jobs.

 

Make sure to take a look at the starter signal wire while you are there, it can get corroded and cause lots of issues with the car not starting randomly and it needing wiggled. People usually cut it off and put a new end on it.

 

That's not a bad idea. I have to do some other wiring "fixes" before the manifold goes back on anyway.

Also, I see lots of people advocating for a catch can. However when I researched, it looks like the PCV plate on the side of the block is supposed to act as a catch can by OEM design? Is a second catch can really that beneficial?

 

You mean an actual catch can? Yes it stops so much blow by on your valves. You'll be surprised how much comes out of it if you're doing any sort of city driving