Andrew Malo

Hello, can you guys tell me if I'm being paranoid. Recently I turbocharged my NB1 daily driver. I have been taking the laptop with me everyday to work watching everything like a hawk and checking the engine bay every time I park for leaks or issues. Mainly I'm worried about my tune set up. I haven't taken it to the person I had do the NA tune because he is not really a miata tuner and doesn't use any knock detection. He is well versed with Honda and LS platforms. I am mainly concerned with my ign map being too advanced. I verified base timing recently and it is spot on. Lots of VEAL and datalogging at 8PSI, then went up to 10. The set up is:
-MKturbo hotside, T3 weenie hut turbo, 2.5" downpipe and 2.5" straightpipe to the back
-Custom charge piping 2.5" from compressor outlet to TB, no BOV, 10-11 PSI
-12x12 intercooler from china racing development
-Rebuilt BP4W, Manley rods, stock pistons
-Flowforce R8 coils
-Flowforce 640cc injectors
-DW200 fuel pump

This is a 4th gear pull to redline from 2500ish rpm


And heres my tables I have been messing with a little bit. IGN map is basically the DIYautotune base map with a bunch of timing pulled out after 100kpa.

Andrew Malo

Update: Car blew the head gasket. When I tried to go to work this evening attempted to start, it was cranking forever. Once it finally started on what I assume was 2 cylinders, excessive amount of white smoke / steam coming out of exhaust. Turbo also had a nice little steam show. It was running fine when I parked it this morning. I'm assuming it popped on the way home this morning when I was pulling a datalog of a 4th gear pull. Felt a slight hiccup at the top of the pull but the log doesnt show anything out of the ordinary.

I was planning on removing the head anyways to replace the valvetrain again because the intake valves are eating themselves (again). But this is the second time the head gasket and valvetrain will have been replaced almost one year apart exactly. The first time was the same issues but it was not turbocharged. This time I will use stiffer valve springs and tell the machine shop to cut the valve faces fat, but what can I do about the head gasket issues? The head was decked and block was cleaned and checked for flatness. Never overheated during driving. ARP head studs. What am I missing here?

der_vierte

Your tune is on the conservative side even for 93 octane. I do not think, that you'll find your answers in lowering ign. timing even more, if your base timing is spot on like you said.

Where did it blow the gasket? What kind of gasket was it? Do you drive it like you stole it, when cold?
I like to check/retorque the head after a few heat cycles. How much tq for the ARPs?

Andrew Malo

Your tune is on the conservative side even for 93 octane. I do not think, that you'll find your answers in lowering ign. timing even more, if your base timing is spot on like you said.
Where did it blow the gasket? What kind of gasket was it? Do you drive it like you stole it, when cold?

I have blown the exhaust side of the head gasket between what I assume is a coolant passage and cylinder 4. I saw the most coolant in that area. It was the MLS OEM Mazda gasket. I typically baby the car until operating temperature if I have to drive it soon after starting, but mostly just start it and let it idle for 10-15 minutes before driving. Even then, I usually hardly go into boost (just for logging and maybe some turbo sounds hah). Mostly because I was still not fully confident with the set up and doing a lot of logging and fiddling with the tune still.

I like to check/retorque the head after a few heat cycles. How much tq for the ARPs?

I checked the head studs around 3 weeks ago when the turbo went on. I checked them in stages from 25, then 40, then to 60ft-lbs. I think perhaps the block has an issue? The last time this happened, it was a similar incident but coolant would slowly drip into cyl 2 after being at operating temp and shutting the engine off.

I am going home now and I am very eager to rip the head off and check the damage. I will report what I find and put some pics.

Andrew Malo

Okay I got the head off this morning. Basically I found the same thing I found the last time I did this job which is... nothing. No visible signs of failure around the offending cylinder (#2). The only thing I could find that is a little weird is a small recessed pocket likely due to corrosion. But it was also there last time I did the head gasket. I'm wondering if this is why it keeps letting go?

How it started

Here is the area I'm a little bit concerned about. Do you think this could seep into the MLS gasket and get into the cylinder?

Perrycountymsm

If you are planning to upgrade the valve springs, I have a bnib set of dual spring 63lbs that I would sell you for much cheaper than what I paid for them at fab9.