Would you guys be willing to help troubleshoot an F2T install?
 

Little bit of backstory:

I've got a buddy that has an MX3 with an F2T swap. (2.2 SOHC 12v turbo motor, same as i run in my MX6.)

Last year at the GRM $2012 Challenge it was just running on a chipped stock ECU, mild boost. He bought a DIYPNP, had a buddy build it, and installed it. He's had TONS of problems since then. The unit has been in to DIY, tested good, and now it seems to be close, but he's fighting a massive misfire at any more boost than 10psi at 4500rpms or higher.

At first i was thinking ignition setup, as he was running some pretty crappy plug wires, and these cars are sensitive to that. However, now he's running pretty much the same ignition setup i run up to 25psi or more, and still fighting the same issue.

He thinks it may be a shielding issue.

Would you guys be willing to give him a hand if i get him to come on here and post some logs? He's a bit noobish in the MS department, as am i, and he's been trying to figure this out for a good 8+ months now. I figure if anyone can help, it'd be you.

I think he really doesn't want to get dickstomped by the MX6 running band-aids again. :bowrofl:

plug gap? which plugs and heat range?

Same as me: .030" and ZFR7F11s. Worth mentioning that i can run as much gap as .040" without blowout issues at 20psi. We're both running stock ignitors and MSD coils.

Worth mentioning that i run a bigger turbo as well. This dude has been through the wringer with this car. He's replaced the fuel pump, no change. Thought maybe his injectors were going static causing weirdness, moved up to RX7 460s, no change. He's changed every bit of the ignition, no change.

At this point, i have no idea if it's an MS tune issue, or something mechanical. The only "mechanical" things i can think of at this point would be 1) wheel pickup wire needing to be shielded or 2) sub-par job grinding a tooth off the dizzy wheel.

I'm curious about this swap, Did he have to use custom motor mounts for this swap or did a combination of factory mounts work for this setup?

He actually bought the car already swapped. I BELIEVE from my extensive experience with both chassis and every permutation of motor that came in them, that you could get it done with probably only one custom mount if you were hell-bent on keeping the better H-type trans. (This one did, and i'd recommend it.)

Would be substantially easier to keep it with a G-type trans, but it won't handle near the power.

This particular car goes a bit farther than that. It's running 1G MX6 hub/spindles, and as such, 1st gen MX6 suspension, brakes, the whole 9 yards. It's a VERY cool car. Weighs something like 2300-2400lbs, and once the MS is sorted, should be a rocket.

It's this car. (Mine is the MX6, obviously.)

https://www.miataturbo.net/attachmen...ine=1380900625

I know this is going to sound stupid and noobish, but isn't there some default boost cut set for 10psi in the firmware? I thought I remembered reading that somewhere, and seeing something like that when I still had my DIYPNP :dunno:

Oh man i'd be shitty.

He can build 15psi before 4500rpm, though... it just cuts at 4500rpm. Would that be a symptom of that?

I'm honestly not sure, I know there is something like that in the DIYPNP and it seems to catch people from time to time. I don't have the unit in front of me, and its literally been a year since I touched one. It's something to consider though, I'm pretty sure it limits via spark cut too.

I hope I'm not leading you on a wild goose chase, but I felt it was worth mentioning.

Also: inb4log :party:

Yeah I told him I made this thread so hopefully he'll show up soon.

Turns out he was unaware of this boost cut, so... that may be something. I told him to get on here, it's only a matter of time before i say something inaccurate, and i don't have the logs.

Hello everyone. I can take logs of anything you need me to, I'm pulling my hair out with this thing... as Ben says.... I've swapped Coil, Ignitor, Cap & Rotor,Plugs Wires, Fuelpump... All with no change. pulls pretty good til 4500 then It begins to misfire at over 10psi. Any help will be greatly appreciated.

Do you know how to find boost cut settings, Dan?

Nope

Me neither. :P

In tunerstudios, click "advanced" then "over boost protection".

It's a simple single box with either Kpa or psi displayed. Set it to 2-3psi above your target boost, they often spike during onset. Good luck.

That's definitely something to consider.... It runs great til ~4500 then feels like it just hits a wall. Free revs to redline with no issues.

I'm not using electronic boost control, just a Manual Boost Controller. I don't see any thing with overboost protection options. just boost control settings.

So from the main tunerstudios page (dashboard), you're clicking on the big "advanced" button, and you don't see an "over boost protection" button?

https://www.miataturbo.net/attachmen...ine=1381023219
Nope.

1 tab to the left, extended. 3rd from bottom should be overboost.

Its set to"None" :-/

https://drive.google.com/folderview?...Hc&usp=sharing

There is a link to Log Files and my current MSQ

If you haven't already, make sure your engine grounds are good (direct from block to ms).

I had problems similar to yours until I did that.

Happened to me when I set up my turbo, the car was randomly cutting off when under full throttle. It turns out is was the overboost protection set too low.

But it should be a throttle sensitive thing, not RPM sensitive. Here's another thing to check: Does he by any chance have configured the ECU to use launch control? Mine was set up initially in such a way that when the car reached a given temperature IIRC it would automatically cut-off at a certain RPM. Turns out the clutch switch wasn't connected to the ECU and caused the car to cut-off when certain conditions were met (launch control turned on).

Also, I know you've probably gone back to basics and eliminated this, but check the spark plug condition and gap. It plays an important role when you're running boost.

I'll check the grounds, and make new ground points on the engine. The plugs are gapped at .028 and are brand new as well as the plugs which are switch are a step colder. I haven't installed a clutch switch yet as I'm trying to keep it simple til I get to the bottom of the problem.

Wouldn't the overboost protection be ran off the boost control portion of the board? Im just running a standard internal wastegate ans a manual boost controller.

I'm not running any boost control features at all, and yet the overboost protection still works. It simply makes the engine cut off when a certain level of boost is achieved!

There's electronic boost control, and then there's over boost protection. They are two different features. Not running over boost protection and relying on your mechanical devices to keep boost in check is asking for a blown engine. That'd be like saying you don't need a rev limiter because you have a throttle pedal.

I really have no idea what TS you're running, when I open it up it looks much different than mine, which explains your issues finding the over boost protection, as you have it under the "extended" menu. It's sorta weird, because you have a "experimental" option under the "advanced" option that's about Vanos debugging. Which is a BMW feature. WTF. (Oooooooh, is this a MSII?? OOOOOOOOHHHH.)

Anyways. If it were me, I'd try turning over boost protection on, and setting it to 2-3psi above your target max boost for now. But as others have said, that's more of a throttle pedal thing, not an RPM issue, but it's worth trying and going from there.

The grounds are probably a good thing to check for sure...

Especially since this motor was swapped... who knows what that dude did.

Diagnosis found!!! Replacement turbo enroute, I discovered by accident the turbo is one of the B6T Upgraded Ballbearing from Corksport not for a F2T. The Hotside is too small and choking the engine over 4500 and anything above 10psi. Thanks for all help!