Sloza's Mazda Builds

[Sloza3]

Hello all! I figured I should post somewhere to document my builds and issues and how I fixed them for me to look back on and hopefully someone else to help use to keep their car alive when I run into silly issues. For some background I have been building/tuning small motors and race bikes for about a year, then moved to a MZ3 and now am on the mazdaspeed platform due to an accident in that car. I am trying to research as much as I can and learn I am studying mechanical engineering with a hope to get into the automotive field.

My 2007 Mazda Speed 3:
I bought this car for 5100 in July of 2025 with 153k miles, I had a throttle body go out on me, and then the connector went out(expensive fix at the dealership to figure out I wired the new pigtail in wrong), then my clutch master cylinder went out, and the in September I blew the engine at 156k miles(Oil pump chain skipped a tooth and I spun a rod bearing). I swapped the engine myself with one out of a cx7 from japan imported through JDM Seattle with about 50k miles on it. Now I am at about 158k miles and have started tuning myself with Versatuner. As this tuning process goes on I will update, post logs, and try to explain what I am doing for yall to judge me(hopefully while being told why I'm wrong)!

Mods:
Autotech HPFP Internals
BNR s2 Turbo
Fidanza Aluminum Lightweight Flywheel
Flexible Turbo Oil Feed Line
Grimspeed 3 Port EBCS
JBR Turbo Inlet Pipe(yuck)
Self Tuned with Versatune
XSPower 50/50 Blowoff valve

 

[Sloza3]

Alright, some more has been done now, in the last 2 weeks I've replaced my turbo with the BNR s2 as well as done the spin-on oil filter conversion(very worthwhile). I wish I would have taken more photos of the process to share with yall but I was trying to rush through it so I could have my car back. I am still in the beginning stages of my tune for it so I'm still under boosting quite a bit but its looking promising to me. Attached is the comparison dynos, low on power but with about 1-2psi less boost.

Later tonight ill come on here and add the photos from how the turbo install went wrong(I had the oil return gasket spin so it was making puddles)

I'm working out the kinks in the current tune around the wgdc but should be finished within a week or so and then I can start to have a bit more fun with the car as well as actually turning up the boost.

This chart is comparing the Versatune OTS 91 octane tune with a stock k04 to the spring pressure BNR s2 tune

 

[Sloza3]

So I got a bit pissed off at my tune and forgot to upload on here lol. Im struggling with my WGDC jumping up high during spool(about 5% over the base table) and then dropping like a rock down to 0% after like 3300rpm so I have been researching on the forums and trying to use chatgpt to point out any patterns. I finally gave up and zeroed out all my adjustment tables and then added them back in.

I think what was happening was my ECU thought my BNR S2 spooled like the k04 and expected an overshoot on load so it pulled wgdc in an attempt to save it before it happened. I am thinking this because I restored the BCS DC load error adjustment tables first with the values from the 93 octane grimmspeed interrupt OTS tune and my WGDC drop came back.

After a couple days of comparing the OTS tunes versatune provides with mine I realized I had forgot to adjust the Accel/Decel load multiplier per gear tables and that was the load limit I was hitting. As of now I am slowly increasing the multiplier until I have a solid 5% or higher WGDC like I have set in my base map. Chatgpt wasn't really much of a help, outside of finding me the cobb tuning guide for the speed which is nice.

 

[Enki]

... Chatgpt wasn't really much of a help...

Big fucking surprise. AI can't give answers that don't already exist, and will struggle to identify the cause of complicated issues like stuff regarding tuning.

At any rate, a perfectly acceptable solution to this is to just zero the WGDC table, adjust your comps and limits (especially correction limits) appropriately, and do pull after pull in the same gear the same way a number of times until load is where you want it. From there, you can plug in the WGDC numbers you're seeing into the table and call it good.

Alternatively, you can do what I do and create a few zero comp flat WGDC tabled maps (I do 20, 40, 60 and 80, and run them one after another until I get close to the boost level I want, and will skip any higher WGDC maps), flash and run them, then build a WGDC table off that, correcting later where needed.

 

[Crazycanadian]

So I got a bit pissed off at my tune and forgot to upload on here lol. Im struggling with my WGDC jumping up high during spool(about 5% over the base table) and then dropping like a rock down to 0% after like 3300rpm so I have been researching on the forums and trying to use chatgpt to point out any patterns. I finally gave up and zeroed out all my adjustment tables and then added them back in.

I think what was happening was my ECU thought my BNR S2 spooled like the k04 and expected an overshoot on load so it pulled wgdc in an attempt to save it before it happened. I am thinking this because I restored the BCS DC load error adjustment tables first with the values from the 93 octane grimmspeed interrupt OTS tune and my WGDC drop came back.

After a couple days of comparing the OTS tunes versatune provides with mine I realized I had forgot to adjust the Accel/Decel load multiplier per gear tables and that was the load limit I was hitting. As of now I am slowly increasing the multiplier until I have a solid 5% or higher WGDC like I have set in my base map. Chatgpt wasn't really much of a help, outside of finding me the cobb tuning guide for the speed which is nice.

I'd be interested in seeing your tune.. I've got a thread about my Speed6. I've slowly been diving more into my tuning strategy.. It sounds like you don't fully understand how all the tables work together and whats in play and when..

 

[Sloza3]

Big fucking surprise. AI can't give answers that don't already exist, and will struggle to identify the cause of complicated issues like stuff regarding tuning.

At any rate, a perfectly acceptable solution to this is to just zero the WGDC table, adjust your comps and limits (especially correction limits) appropriately, and do pull after pull in the same gear the same way a number of times until load is where you want it. From there, you can plug in the WGDC numbers you're seeing into the table and call it good.

Alternatively, you can do what I do and create a few zero comp flat WGDC tabled maps (I do 20, 40, 60 and 80, and run them one after another until I get close to the boost level I want, and will skip any higher WGDC maps), flash and run them, then build a WGDC table off that, correcting later where needed.

Thank you for the advice!! I think that I have found myself following the first strategy you suggested accidentally but now I know im on the right track.

As for using AI, I assumed it wasn't going to be much of a help but I figured it was worth a shot since maybe the answer I was looking for was on a forum post I hadn't stumbled across yet, probably won't be using it much more in the future

 

[Sloza3]

I'd be interested in seeing your tune.. I've got a thread about my Speed6. I've slowly been diving more into my tuning strategy.. It sounds like you don't fully understand how all the tables work together and whats in play and when..

I meant to respond to this yesterday but didn't realize there was a post cooldown, whoops. I read through your thread though and it's really interesting! Definitely some new info there

I am still very new to EFI tuning and tuning in general, though I have been trying to do as much research as I can, so you'd be 100% correct, I don't know how different tables interact fully.

Below is the last edits I've done to my tune, I've currently got it set to around 11afr whenever I'm WOT in an attempt to be safe if my mafcal is off, though I may lower that to about 10.5 if I start to see more deviation as the load starts rising(ofc correcting the mafcal but just as an extra buffer if something happens) I am also tuning at about 5000 feet ASL so my barometric pressure is pretty low here. I also lowered the rev limit down to 6500 as I never rev higher than about 6000 anyways and figured it wouldn't hurt to have that lower than stock.

 

[Enki]

One thing you probably don't know about DI is that it can be dangerous to be too rich.