I was brushing up on this idea in my other post and i think it deserves a thread of its own.

After i had installed my exhaust, i as able to boost to about 10psi on the stock ecu. at this time i was doing some tinkering with the wastegate, so i decided to run it without a line and it would get about 5psi of constant boost(stock setting with the flap closed at 0psi), not really powerful but very driveable. Next I started trying to build a better intake, i played with stock airbox using various pipe modifications with a stock filter, and while it was nice and quiet and linear, it really didn't add much. Then i did a short ram by using a tiny cone filter, and the boost built a lil faster but i didn't keep it this way because of possible heatsoak. So next i decided to make a custom CAI filter, i used PVC 3" ID, and i managed to fit a pretty big filter at the end of it. I took it for a test drive, boost started building really fast and it would boost creep to about 14-15 and hit fuel cut and then fall back to like 5 and then start building up slowly again. With a 3" turbo back exhaust and the custom CAI, with the wastegate actuator set to where the flap is open by a couple of mm at 0psi, i can hit 9psi with the vacuum line disconnected. Anybody else ever experience similar. I know some people say you shouldn't mess with the wastegate and just get a tune, but in my case its a necessity.

 

How is it a "necessity" that you fiddle with the wastegate? It isn't a ncessity at all. You want to build more boost, but you don't want to pay for an ECU upgrade. That is what more then likely it comes down to and in the end you'll loose out because fiddling with the wastegate will cause problems down the road for you.

If you just saved a little cash here and there you would have money for an ECU upgrade. Also you could get a cheaper upgrade from SpeedTuning USA or Upsolute ($325, $425). While yes that is some money right there it is certainly less then what IPD USA, RICA, BSR PPC charge you.

Take it the ST USA and Upsolute tunes are not as researched and developed as the others, but you get a decent tune for the money. Might run a little RICH on the ST USA tune, but you can work that out.

 

I was just telling the story of when i started running into that problem. Now i'm running a FMIC, ST 17psi, the CAI, and the 3" exhaust. With this setup and the stock wastegate set to where it just slides over the wastegate flap with barely any tension, i get fuel cut problems in every gear. Just to do a test, i unhooked the actuator from the wastegate flap and fully opened it, i was able to still make 4psi of boost. I was just saying i noticed this behavior after i installed the CAI.

 

Interesting observation to say the least!