Do I need a retune?

[Darknight]

Okay well I just found out that one of the vacuum lines going from my boost actuator to the boost bypass solenoid has been off ever since I added stage IV ported blower, 6 lb lower, and got a tune on those.

What I'm wondering is, with the pink line (top outlet on the boost actuator) not being connected while being tuned, will this affect my air to fuel now that the line is back on?

Will it require a retune?

I have read from others that, at full boost if the boost actuator isn't working right (basically it will open more and more with more boost if the boost actuator isn't working to keep it closed against the force of the pressure of the supercharger) will let air by therefore not allowing that air to be taken into account with the air to fuel.

Any ideas?

 

[pitstain]

WOW you got me stumped there, do you have a wideband a/f gauge? and what is your max timing set at?

 

[Darknight]

WOW you got me stumped there, do you have a wideband a/f gauge? and what is your max timing set at?

My max timing on 93 octane is 17, and no I don't have a wideband a/f gauge. I had RWTD tune he is willing to look at it again if I want. But its still a 3 hour drive one way, and want to make sure that I need a retune before I go that far.

 

[Darknight]

Also would having that messed up cause a loss of power at the time of dynoing it for the same reason (some loss of proper air flow)?

 

[02Lightningbolt]

Dude be on the safe side and retune also yes that would cause a loss of horsepower.

 

[Bird]

With the line off the top port of the actuator, the bypass valve is closed all the time - boost is 'on' all the time. Hooking the line back up will allow the engine to only run boost when needed and if the load tables and the MAF transfer functions were adjusted correctly, you should be OK as long as the lower vacuum line was hooked up when tuned. The purpose of the lower line is to allow the vacuum felt in front of the throttle body when WOT to be applied to the underside of the bypass diaphram and hold the valve closed during WOT. Check your boost during WOT and see if it starts falling off after going WOT.

Bird