S4runner

I have a 2000 Audi S4 and recently I just installed a boost gauge that's showing me why I'm probably blew my k03's so many times. My car has a giac chip,bov's,piggie dps, evo intake,borla exhuast, stage 2 stuff. I just purchased piggie's standalone mbc and tcc to kill boost spikes. Is that the way to go, I heard from other's yes, and others no because it will make it worse. So now I'm stuck whether or not to put this in. Can someone just help me out with this because it's making me nuts. THANKS

Gator Al (Al)

In my experience, boost spikes were caused #1 by leaks, and #2 by a bad N75.

noSup4u

what would be appropriate to log to determine if the n75 was bad? i assume you can measure its signal somehow, but then would you compare that to requested and actual boost?

S4runner

so your saying I wouldn't need a mbc and tcc to check for leaks and a bad n75. Even if that was the problem should a mbc and tcc be used

Gator Al (Al)

Worked for me.

Gator Al (Al)

though I was tempted when things were flaky.

Do a pressure test, fix any leaks, and if you're still overboosting, replace the N75.

Things should work at least OK without an MBC. I've never experienced throttle cut. Under the right conditions, my boost can spike as high as 24, but it always settles to 20 or slightly lower.

Flyboy

seems to be before throwing solutions at it. Try logging blocks 114 and 115 with VAG-COM, that will show boost and N75 duty cycle.

noSup4u

i hit 24

stock ecu im at 13.

it also flutters... graph of actual looks literally like /\/\/\/\ between 20's and 14ish for a 3rd gear highway pull.

Gator Al (Al)

Got a spiffy new laptop, new port on the car...

I'll send yet another email now.