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.

 

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.)

 

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

 

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

 

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?

 

Nope.

 

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