MoNoXSizzlE

iTrader: (2)

Had the car on the rollers last night to get tuned. I have the On3 AC kit with a 76mm. I bought a 15 lbs spring from on3 as well. Have the spring on the gate, did a pull & the boost was at 21 lbs for whatever reason. Thinking that they could've sent me the wrong one, I changed the spring to one of the ones that came in the kit which one of the reps at on3 told me it was an 8 lbs. put it back on the rollers and its at 20 lbs of boost. Any ideas?

Stock 5.3, no port on the turbo either so not running a boost controller. No vacuum line on the W/G either, not sure if I need one on or not? Any help would be appreciated.

SteenH

If you don't have a line going to the WG it has nothing to reference.. put the first spring back in, plumb a vacuum line and voila

MoNoXSizzlE

iTrader: (2)

Right on man, thank you. Can I use any type of hose and what fitting for the top of the gate? Where would you recommend routing the hose to?

LT1PWRD

iTrader: (2)

Preferably hoses made for boost with zip ties for security. Or, hard plastic air brake line.
Reference boost from the turbo, not the intake. The WG shouldn't see vacuum. Attach it to the bottom fitting of the WG only, the top just vents to air.
You may need to drill the comp housing for an 1/8" NPT fitting. Then go to the smallest WG spring and start there.

truckdoug

iTrader: (26)

i like these fittings

http://www.ebay.com/itm/252395653679?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

04gtoBMXracer

iTrader: (26)

On3 said not to drill the compressor housing, what is another option? Charge pipe, pre-intercooler?

JoeNova

Just reference it from the intake and don't make it complicated.
I've been building turbo cars for 11 years and have never had an issue with the wastegate seeing vacuum.

RatCityRex

iTrader: (3)

Make sure you run your vacuum/boost line to the lower port on your wastegate.