My car is street tuned on 16lb and was wondering if i need a retune if I were to run a lower pressure, say like 8-9lb. If I dont need a retune, will i need it when i turn it back up to 16lb?

 

shouldn't need to if tuned by a real professional.

 

No. When it is tuned for 16psi, it is also tuned for the boost pressures below 16psi (for instances like part throttle). During the tuning process, your tuner will start at wastegate pressure and work up from there to your desired boost pressure, scaling the differences in between. Unless you went straight to 16psi (meaning your WG has a 16lb spring without a boost controller), there should be a fairy solid tune for lower boost pressures.

 

Depends how it was tuned. If it was tuned with just the wg spring at 16psi then it would be difficult for the tuner to run lower psi to be able to tune at those lower levels. A good tuner could attempt to interpolate to fill in the columns in between but you need to ask the tuner.

If it was tuned by increasing levels of boost by either replacing the spring or mbc or ebc then those load columns would be tuned.

 

Guy I bought it from said 6lb wastegate spring and the controller is set to 10lb, so does that mean 16lb of boost?

 

it means 6psi is the lowest you set it and its running at 10psi. its probably tuned to 10psi unless he actually told 16psi is what its tuned for do not increase boost.

 

no it means 10psi. hes using a boost controller to increase boost pressure over the wastegate spring pressure.

 

Ok, well when i go WOT in 3rd, the boost gauge doesnt go into the boost side of the gauge, it stays at zero but at idle its like -15psi. I definitely feel the turbo so could the gauge be broken or wired wrong?

 

Does the boost gauge move at all? Does it ever go into positive pressure?

 

technically actually it should be between 20-24 inhg at idle..

 

try a different gauge

does the blow off valve make any noise?
does the turbo make any funny noises? check it for shaft play

what kind of turbo setup is on the car? brand, etc... if it's an eBay kit it's very likely the turbo has failed

 

Ok nevermind, my friend gave me a spare one and now it works. My first turbo honda so Im new to this and dont know much yet. Thanks to everyone