HELP! Blew engine, and am now paranoid. Need help/opinions.
 

So, I blew the engine in my Miata after turbo install (melted 3 of 4 pistons while tuning via tunerstudio). My setup was a stock 99 engine (with mazdaspeed cam) in a 96 Miata using stock 96 fuel system/injectors and the 96 sensors. I was running all flyin miata intercooler piping/intercooler/manifold/3" catted exhaust. My turbo was a rebuilt s13 t25 (8 psi wastegate). I have a MSPNP for a 96-97 from DIYAuto. Here are the maps I was running at the time of death (I don't know how to turn the maps in tunerstudio to thumbnails, so I took pics of my screen, literally):

https://www.miataturbo.net/attachmen...ine=1371162221

https://www.miataturbo.net/attachmen...ine=1371162221

https://www.miataturbo.net/attachmen...ine=1371162221

So, I am now rebuilding the engine with Carrillo A rods, Supertech 8.6 pistons, Supertech +1 valves and springs. Planning on also running a 2560 turbo and 550 RC engineering injectors with FM dual feed rail and Walbro 190 pump. I'd like to run 15-16 psi.

From what I could tell by researching, I thought those maps were safe (the timing map is what FM issues with their 01 Hydras). By looking at the maps, does it look like my injectors were overwhelmed (stock 96 with 155K)? Do I need less timing? More fuel? This has been a very costly mistake, and I definitely want to build it right this time, and do not want to go down this road again. Please help, I just want the car to stay together.

Thank you,

Jason

Those maps look a little hot to me for an initial tune. Sure they maybe the optimal settings with the right fuel and if everything is calibrated properly, but if there are sensor issues, you could be in serious trouble. I have not seen as many maps as others here with more ECU experience, but even so, it stands out as a bit risky for the maiden voyage. Also, I think you have some fuel system limitations that make matters worse.

Next time around, have a much more conservative tune, and work your way up once you know all the bugs are worked out, and all components are adequately matched.

Way to little injector capacity and the spark map is a bit aggressive for starting out (what's with the huge jump 1000-2300?). Injectors were, most likely, your main problem.

Don't buy RC injectors buy something ev6 or ev14 from Deatchwerks or Injector Dynamics, the better spray pattern will substantially improve how your car runs.

As was said above, use a very conservative spark map to start out and get your fuel and reliability nailed down, then make more power with your spark map.

** rescale your spark map, you don't need the 100 column and the rest could be redistributed more evenly.**

I ran a stock 97 fuel rail and pump with 600cc injectors feeding a gt2560 at 18psi on a stock 97 engine for close to 4 years reliably, you don't really need a fuel rail IMO.

I agree that it wasn't getting enough fuel and had too much spark advance. Your AFR target table SUCKS.

Stock injectors?? Really?? You stupid or something??

Don't bother with the fuel rail or fuel pump. But do get properly sized injectors please.

You could have the most awesomest fuel map, it would be perfectly worthless if you do not have the injectors to deliver the intended fuel.
Translation: you were running too lean for the amount of boost you were feeding the engine.

I second the suggestion to use EV14 injectors.

Well, from what I had read, the stockers should have supported 8 psi. Live and learn.

I'll look at injectors other than RC, thanks.

Anyone have spark and AFR target maps they'd like to share for me to start out with (unfortunately my MS is a 8x8 AFR target map)?

Thanks,

Jason

Stock injectors and excessive timing.

On the my afr targets, where do you see the problems?

Thanks,

Jason

Question for all the guys replying that timing was too aggressive. When I first started my MS3x I used Brains 1.6 460cc base map. I started a thread and asked if the timing was conservative enough to make it to the dyno. Brain replied it was very conservative. But it looks more aggressive than jrmotorsports55's where peak torque would occur. What areas of his map are too aggressive, high load high rpm? What should a stock short block miata be targeting for timing?

https://www.miataturbo.net/megasquir...x-start-72267/

https://www.miataturbo.net/attachmen...c2cb91e8_c-jpg


Also jrmotorsports55 was this on 91 or 93 octane?

The taper from 12.7 to 12.0 between 100 and 156kpa means you're running too lean for my tastes. 12.7 at 100kpa is fine, but it needs to be 12.0 by 128kpa and 11.8 by 156kpa. It's not a big issue, but combine that with aggressive timing and pump gas and you'll melt pistons over time.

I was running 93 octane.

Thank you for the explanation on the afr targets. Do you see any other issues with the fuel map?

Thanks,

Jason

Many people dont get the idea behind the afr chart... its a wish list... just because you "wish" to tune for 12.0 doesnt mean you ARE running 12.0. In other words if ur fuel map is shit... thats what you'll be running until the autotuner has had a chance to correct it.

Did you even bother to check if the injectors were exceeding 80% duty cycle?

Next time turn on "include AFR Target" and use the TS built in table generator for your AFR table as a starting point for tuning with VEAL.

I hope you understand now why we harp on learning to tune with MS before turbocharging. You will make mistakes!

Sorry to hear that man. I'm pretty new myself and the hardest thing for me was trying to not rush the turbo build and checking everything twice before the "first" run. Like everyone else stated, the main problem that I see was you using your stock 96 injectors and your spark map was a little too aggressive for the first run. Here's a link to my post from last night. It has my current maps on there if you would like to see. It's by no means highly tuned but I have been driving it reliably for almost 2,700 miles now @10psi(knock on wood). Well good luck on your build and getting bigger injectors.

https://www.miataturbo.net/mspnp-55/...9/#post1021289

I get that, and I did try to gradually work it on to boost to allow it to correct. Guessing I didn't wait long enough, and it looks like even though I read that my equipment could have handled the boost I was running, I overwhelmed it.

Now I just need a solid starting point for the new engine, as I do not plan on making this mistake again.

Thanks,

Jason

I agree! Tuning N/A was definitely easier and also fun. Before turbocharging I was running a stock 1.8 with RX7 550cc injectors. My friend looked at me crazy when I told him. Well it worked!

Your timing is very hot. Do you happen to have a log while tuning?

No logs unfortunately.

Jason

A bit of levity, to lift your spirits:



Q: How do you make a plumber cry?

A: Murder his family.




A horse walks into a bar. The bartender says "Why the long face?" The horse replies "My wife was just diagnosed with terminal cancer."



Q: Why can't a T-rex clap?

A: Because they all died during the Cretaceous–Paleogene extinction event c. 66,000,000 BC.



Q: What's worse than biting into an apple with a worm in it?

A: The holocaust.



Q: Why did the six year old girl drop her ice cream?

A: She was hit by a truck.





You don't have to be a parent to understand the horror of walking into a room to discover that the baby has crawled out of his crab and onto the pottery wheel that you forgot to turn off. And while the baby is spinning around and around, the dog is sitting there all calm, like a person, gently using his paws to shape the baby's soft cartilage head into something a bit more modern.

It might be the classic tale of bad parenting, but let's see where the dog is going with this.





Also, both your AFR and timing maps look fine to me. I'm with the crowd which suspects that you may have simply been exceeding the capacity of the fuel system, and wishes that you had a log showing actual AFR while in boost at high RPM.