• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

What do you all think of these boost numbers???????

I was thinking how that works backwards. People that put on Turbomasters may use the 3-bar to prevent codes because it actually reports less boost that is there. So if using a 3-bar with the stock system it would report low and the PCM would actually push the vacuum up to achieve higher boost. Because 7psi might be 2.5V reported back to the PCM on a 2bar sensor, but 11psi may be 2.5V on the 3 bar. The PCM would recognize 11psi as 7 psi in that scenario. same as installing a boost fooler pretty much.

a 3 bar sensor apparantly looks the same, different part number, all 6.5 trucks use the 2-bar sensor.

So you may not have any real issue, or perhaps a weak solenoid or a tiny vac leak in one of the lines. Installing a boost fooler or 3-bar boost sensor may actually get you up to where you would want though. That or a performance PCM program.
 
boost sensor= map sensor on top of intake next to IAT? I am wondering if this is what is causing my overboost (having a 3 instead of a 2)
 
Because 7psi might be 2.5V reported back to the PCM on a 2bar sensor, but 11psi may be 2.5V on the 3 bar. The PCM would recognize 11psi as 7 psi in that scenario. same as installing a boost fooler pretty much.
Click to expand...


Sounds better than a boost fooler and a very "easy" way to increase stock boost.....anyway to know how much PSI will increase with a 3 bar map/boost sensor?....2, 3, 4 psi over stock setting?....would this be a "Fixed" deal, or you get what you get?
 
Louis, just bite the bullet and get a tow tune for the tow truck;)

No need for a boost fooler then.
 
NVW said:
Louis, just bite the bullet and get a tow tune for the tow truck;)

No need for a boost fooler then.
Click to expand...


Yea, 10-4 on that.....way more advantage than a boost increase via TM or vac pump.....but I was just curious as to how much of an increase, would it be predictable/reliable and why no one has ever suggested such a simple idea....You got to admit, swapping out a boost sensor/MAP for a reliable increase in boost (Without coding, mind you) is a very interesting and "why didn't anybody else ever think of that" modification.
 
gnel said:
I just installed a boost guage and here are some numbers. Hard acceleration from a standstill it will spike to 6 then quickly settle at about 4. Hard accel from about 45 mph it goes about 4 to 4.5. cruizing most speeds on level ground 1 to 2. Uphills 3 to 4. This is a stock vacuum setup. I have 25 inches of vacuum from the pump and 15 from the boost relay to the accuator. Thanks for any replys. g
Click to expand...

15" @ idle or when running down highway, if that is on highway that is low vac, should be 20" or 15-20" as WG vacuum is being reduced by PCM to modulate the boost. Cracked line or bad WG solenoid ?

gnel said:
This might be a dumb question. Could it be the wastegate accuator? I am getting 15 inches from the solenoid to the accuator but before I could not manully move the accuator bar at idle and now I can. Its stiff but movable. Sorry if these questions are tiresome. Thanks g
Click to expand...
No if you are able to make good boost with direct boost applied to the WG actuator then you have a leak in the vac plumbing (hard to see sometimes in the nylon "hard-line") other vac system leak (check all connectors /lines) or bad WG solenoid.

Also possible a bad MAP sensor as mentioned before, I had one go bad high before that was limiting boost as PCM thought I was making 35 psi boost, and my fooler was hiding that info from the PCM, I don't know how long it was bad as I didn't know/find it until removing the fooler to install my 1st version of reflash, you need a scan tool that can give boost reading the PCM see to know this or just swap out for another MAP sensor.

Word of warning baro sensor looks exactly like the MAP sensor, part store may give you the wrong part, so make sure it's the one that goes on the intake manifold, the 2 are "keyed" differently and are not supposed to not fit the opposite connector but can be "made to fit", test the fit before leaving part store if possible.
 
Last edited:
buddy said:
I think its been mentioned in the past, but a boost fooler is adjustable and cheap.
Click to expand...
X2 and with adjustable fooler you can better tune for performance with a stock setup, even the 3 bar MAP can code with the right conditions you may code, I ran with fooler for years until my vac system started acting up, then I went TM & fooled, & eventually going reflash.
 
Thanks everybody for all the replys. It was a vacuum leak after all. The PO had soft rubber lines on it and one of them leaked. My boost is fine now. Now I need to make a new thread about my "road trip" with the inlaws. RIP old IP. This will be a new thread. Thanks again g
 
You must log in or register to reply here.
Back
Top