Boost Difference

[lrover2]

Here is my weeky dumb question. My boost seems unstable. When I floor the car from a stop I get 15 lbs of boost. If I floor the car from 30 miles an hour I get 15 lbs of boost. With me so far? If I floor the car from a stop and the tires slip I get 18-19 lbs of boost. If I floor the car from 50 mph I get the 18-19 lbs. What gives? How am I supposed to know what I have the boost set at.
I am running race fuel right now so I dont knock but what happens when I am not running high octane?

 

[blackbuick87]

I am still learning about these beasts so dont take this for Gospel but it sounds like a problem with the wastegate ar the puck. Could have a vacuum leak somewhere also

 

[lrover2]

Well I just put a new wastegate and the TH downpipe so I am pretty sure those are ruled out. As far as the vacuum goes I guess I will keep replacing lines. Thanks

 

[NC87GN]

Believe it or not, some chip makers vary the boost table in there chip. I have one aftermarket chip from red armstrong that went from 19# to 17# along a given rpm band. At the time my car would knock at the top of third and fourth. Fixed the knock problem at the top of third. However, your problem sounds like a wastegate solenoid on its way out. If the car is high mileage you might want to replace both the wastegate actuator and solenoid. Good maintenance...

 

[Intercooler]

If you are going to the stock solenoid it may be bad. Hook it up tuner style and see what you get.

 

[lrover2]

Not sure what tuner style is. I have the vacuum line hooked directly to the turbo coming from the wastegate. I am a little naive to this world of turbos but I am here to stay so lay it on.

 

[PsychoBuickBoy]

Tuner style is like you had it before, with the bleeder valve.

 

[jojo]

Ok heres what i did:

I bought a boost controller from turbosmart.com.au it is a pretty sweet piece. When you do this you bypass the solenoid all together. All you need to do is to get two nice new vaccum lines, and one goes to each end of the controller. And the other two, one goes to the actuator and the other directly to the little nipple coming out of the turbo, (still not sure what that thing is called) And all i did was adjust the the actuator rod to about 17 or 18psi then adjust the boost from there with the little round dial that comes on the boost controller. Its pretty neet to, because it makes a little clicking sound every time you turn it to adjust the boost, up or down. But i do understand what you are saying about the inconsistent psi of boost, because mine does that now, it flickers when i floor it between 21 and 23psi of boost on my VDO gauge. Dont try this at home just kidding, my boost is set high for the simple fact that i dont run anything in it xcpt 100 octane unleaded 46psi of fuel pressure and about low 800s or so on the O2s so i will probably be turning the boost up another pound or two with no spark retard.

hope this helps

jojo

 

[lrover2]

So your saying that I go back to what I have been told has been a non accurate way of setting the boost? I should just hook it back up. It has been a pain (literally) burning my hand everytime I adjust the wastegate.

 

[jojo]

Im not sure what you were told. But when you put a boost controller on there, all you have to do is adjust the rod one time, roughly between 15 and 17 or 18 psi. and from then on adjust the boost with the boost controller, and you will never burn your hands again I still have my old actuator on there and havent had a problem yet.

jojo

 

[lrover2]

No thats the way I had it before but I was told its not a stable way or accurate to set the boost. It seems like the only way my setup is going to work for me though. Hey physco is your GN running yet?

I am going to have to call Nick and see what to do about the smoke. It seems to be getting a bit worse. I CANT TAKE IT ANYMORE! Maybe I will just pretend its turbo dust and its a good thing. hehehe.

 

[PsychoBuickBoy]

Yea, give Nick a call on the smoke. The tuner method works for some (I do it) and others have lots of problems mainly because of vacuum leaks. I had the ATR bleeder valve on before and it sucked, boost all over the place. I replaced it with a kit from Turbonetics and it is great. I actually have an extra one (Turbonetics sent me 2, shhhhh don't tell!). We will try it on yours this weekend and see if it works better. Got my converter in the mail today so tranny is going back in this weekend!

 

[lrover2]

If you need any help putting it in let me know. I want to be there when you get the monster running again. It should be interesting with the new IC and turbo. Now remember I didnt put the external wastegate on so will that kit work with my setup?

 

[PsychoBuickBoy]

Yes, it will work with your setup. It will be easy enough to throw on and see what happens. Do you know what kind of chip you have? Like someone mentioned before, some of the chips have variable boost levels through out the gears and such. I have a bunch of chips laying around but they are all for 42.5 lb injectors. I have another buddy comming over to help with the tranny this weekend but your welcome to come by (should be fun).