Rotaryturbo

Hello everyone,
I recently added a boost machine to my already GIAC chipped and intaked 2003 TTQC. I love the BM to death. Thanks Steve. After adjusting it and setting it for around 22 psi I have noticed that in 5th and 6th gear while rolling down the highway when I step into it the boost climbs to about 24-25 psi and then drops clear back to around 11-15 psi and then climbs back up again. At first I thought it may be my factory DV so I changed it this evening to a 007p but it still does it. I don't want to really turn the boost machine down as that feels more like just bandaiding it and I will have less booost in the lower gears as well then. Since the boost onset **** on the BM adjusts for onset wouldn't raising that also make the boost more prone to spiking?

Also when I am WOT in 4th gear at around 5000 rpms and up the car will have minute surges where boost won't move but you can feel the car almost miss as if it is loosing power and then gaining back almost instantaneously.

Thanks for the help,
Ben

TTschwing

GIAC's are a little more sensitive to adjustment, but you're in ranges that others are running without problems. Higher boost is asking for more fuel and a weak MAF is not delivering. Have a VAG? A check of block 32 will tell the tail and I would expect you'll see a CEL soon. If not, trying dialing down 1/2 turn and see how it runs. You can also disconnect the MAF and the car will default to prebuilt fuel maps. (You'll ge a CEL with this too) but you'll have fuel. Set the onset to 1-1.5 turns or until you just feel it start to get snug...That'll smooth transition.

Rotaryturbo

Ouch sucky. Just replaced the MAF about 4-5K miles ago but after what I have read that could definately happen. I will try adjusting the transition some more as I am only at 3/4 a turn and I may try disconnecting the maf too. Thanks

TTschwing

Those symptoms shout MAF. Know anybody with a VAG? Could also be a coolant sensor. If you don't have a newer green one spend the $6. Everything needs to be at 100% to run high boost.