Okay here's the deal, I have the Turbonetics kit and it set to run at 8PSI out of the box, my boost gauge has always read at 8PSI and the other day driving around on the highway, my boost gauge now reads at 10PSI Can anybody tell me whats going on, it started to do that after I had installed the Tsudon N1 exhaust. Is this considerer boost creep or a faulty WG or BOV? Is it safe to drive around with it running 10PSI on the Turbonetics tune? Somebody help me out here

 

bov is fine, wg problems LEAD to boost creep, so im going to have to say your wastegate has a problem.

you are still running the stock tune? was it working fine at 8psi?

 

Not sure about AZ but colder weather will cause your boost to go up. Mine jumped 1-2 psi just with the colder weather.

 

Is your wastegate set to recirculate or is it open dump? Anytime you free up the exhaust side of a turbo it will be harder to control spool with the wastegate.

 

dood, you added an exhaust. You increase airflow a very good amount and decreased back pressure on the turbine which would account for the increase in boost.

 

even i knew that.. when you add an exhaust to your turbo set-up you will see an increase in boost, nothing to be alarmed about

 

Does his car need to be retuned now though? The added PSI won't affect the afr...?

 

ya.. most of the time, when you add an intake or exhaust to a turbocharged car you should get retuned.. however with the unichip it may be hard if he doesnt have someone local to do it.

 

Rasta had similar problems when he went with a large diameter custom exhaust. I wonder if you relocate the pressure hose to the wastegate to closer to the turbo you might be able to get to your old PSI level.

 

I didnt think it would increase the boost though...Guess I should get it tuned soon then. Now just trying to find a unichip tuner

 

It is all good man. Yeah turbo's are very sensitive to exhaust flow. Yank your 1 cat you have left and see what the boost does haha. Also yes the cold weather plays a MAJOR factor in boost down here in Az when going from 110-115 summers to 40-50 degree weather. Now that things have gotten cold the trd tune coupled with the mods I have is just not working out very well. Time for some more playing.

 

[quote="DTRUONG_112"]Since he wastgate is before any exhaust wouldnt it regulate the airflow before any exhaust could effect it? I always thought that if a wastegate was set for a certian psi the simple mods like exhaust cant change that. I will increase air flow, but it shouldnt change the PSI.

I have full exhaust with the stock unichip tune and I dont go above 8psi. I use autometer nexus gauge and every now and the they need to reset to read correctly. What kind of boost gauge do you have.

 

make sure you watch your afr with added boost it may not have the fuel you need.

 

[quote="yamaha16bw"]I have the autometer cobalt boost gauge electric. So your gauge reads at 8psi, then whats up with mines then, its totally freakin me out, I dont even want to get on it amymore to be safe.

 

Do you have a wideband?

 

Wow, alot of bad info in this thread.

My points:
The boost increase is normal with a larger/better flowing exhaust.
Though someone said they did not experience an increase in boost when they installed an exhaust, every car is different and doesnt always go by one rule of thumb.

If you dont have a wideband, you should get one. This is one of the easiest ways to get an idea on whether or not you need to have the car retuned.

In my experience, Autometer gauges are NOT as accurate as they are popular. There are actually reputable builders who refuse to sell or install them on customer cars.

 

The cause could be either the new exhaust or could possibly be some cold weather. If its doing it constantly I would lean more to the exhaust as the culprit. Do you have a wideband in the car? Whats your AFR showing under boost? I would be a little careful with it until you get some to tune it for you. Although theres a couple guys running 9.5 PSI here daily with water/meth installed.

 

it also coul djust be your gauge reading wrong. i started the car up and my gauges didnt kick on (cobalt autometer) and i turned the car off and back on and they kicked on went on the freeway boossted and read 2 psi higher then normal. shut the car off after cooldown and turned it back on to reset gauges and it went back to normal. just watch your AFR gauge if its safe to boost do it and see if thats the problem

 

Does AZ get cold enough to get those "cold weather" boost spikes? I know Ive gotten them but it's 30 degrees here right now.....lol

 

Just some more info to help the guessing game of problems. I have 2 turbo tC's running turbonetics kits at with "full" exhaust and they never go above 8psi. That is unless I want it too...hehe. You should notice much faster spool up time but the boost increase should be so small that you wouldnt notice it IMO.


both of our cars run the stock turbonetics 8psi with stock tune with full exhaust at 11.4-11.7 AFR's at WOT....just fyi