Trango

So I just finished my center vent boost gauge, which I'm somewhat satisfied with. Once I finished with it, I went and made a quick highway run, where I confirmed that, at nearly WOT (or pedal floored, translated whatever the pedal is telling the motor), I am getting 20psi until my boost cuts to almost zero.

Is this the symptom that an MBC helps, or is there something else going on here?

Is this the fun of tuning a 2.7?

Thanks
Bob

Trango

Ummm sorry wrong forum. PS Anyone want to help install an MBC in Boulder?

DocWyte

But you're probably running into throttle cut, the mbc may help if you use it to limit boost to 17psi or so...

Nigel (no more S4)

4psi will trigger it on most software. Like I've said previously though, APR K03 software does not like being tweaked for K04's.

An MBC won't stop throttle cut, it'll just limit the spike to whatever you settle on (<20psi). If you want to run 20psi on K03 software, you need an MBC (standalone) and a TCD, and a custom 1600mbar one at that. An MBC in parallel on APR K03 code won't allow you to run that much boost, because the N75 is still controlling it.

An MBC install can be done by a monkey on acid, and as you did you're own turbo swap, you'll have no issue. Literally take the wastegate hoses from the N75 (bottom and left side) and plug them into the MBC. Leave the N75 connected eletronically so as to not trigger a CEL, and with the 2 remaining connections (that you just took the wastegate hoses off), loop them back to each other with another hose. TCD install is a little more complex because you have to solder, but I have install instructions for that if you decide to go that route.

And BTW, I picked up a hoist, so I'm good.

Trango

Seriously Nigel, I have read so much about MBC in conjuction with N75, that it's somewhat confused *this* monkey on acid.

This is what I was thinking.... the ECU sees too much boost, and then shuts her down. So, on WOT, my power curve looks like a playground slide - sharp uptick (stairs) when the turbo finally spools, and then gradual let down as I start building "normally aspirated" power but lose turbo charge.

I think, as you've suggested, I will just go standalone MBC, and try it with the APR. I mean, I'd rather my tax return go to something else than another part for this vehicle. And soldering is no worry if I need the TCD.

Thanks again, and let me know if you need a night or so of help as you yank or reinstall your engine.

Best
Bob

Trango

...but I have the APR chip already in my junk, and allroad ECU's aren't swappable because of an immobilizer issue, so I'm just going to give it a whirl (free, after all) and see what happens.

DocWyte

Why is 17psi not an option? Just set the mbc for it.

LaserAvantS4

on mine
i'm prety sure cause i have MBC running parallel

Nigel (no more S4)

mbc only is a little quirky driveability wise. You'll see what I mean. Never tried it on APR code though, so good luck.