[Nonecure]

I have been running the same Shiv tune for 10 months and it has been great, now my car pulls weak. The tune is over boosting and causing throttle closures, so I flashed a basic OFT stage 0 tune and took these logs. Even when the boost finally catches up to the target, it still feels weak. Any ideas what is going wrong? I am not throwing any codes.

http://www.datazap.me/u/nonecure/3rd...log=0&data=1-3

[j1gilles]

Vacuum or boost leak?

[Nonecure]

I was over boosting with the prior tune, would a boost leak do that? Does the vacuum control the waste gate? If so, that sounds like a logical possibility.

[stanlalee]

Your azz became use to it. There is nothing abnormal about the log including not meeting target until about 4000rpm (there is still plenty of boost from 2650rpm). Based on the IATs you must have an upgraded intercooler. Run a more aggressive tune and tune out throttle closures if you get them. That is as clean of an unmodified Shiv stage 0/1 log I've seen especially in the 4000rpm range.

[Nonecure]

Originally Posted by stanlalee

Your azz became use to it.

lol, your probably right. I have had this car and a tune (Cobb then OFT) for almost 2 years and I swear that it feels weaker than it used to, especially before 4k. It feels like turbo lag from hell, or running way too rich and bogging down.

I'm glad to know the log looks ok, but my azz says it doesn't. I guess it is time for a custom tune. I will first try the stage 1 ots map since the stage 0 seems ok. I was running a custom tune that was made for someone with the exact same bolt-ons. The logs were good and it felt good for 10 months, so still contend something changed.

[j1gilles]

Originally Posted by Nonecure

I was over boosting with the prior tune, would a boost leak do that? Does the vacuum control the waste gate? If so, that sounds like a logical possibility.

-A stuck wastegate could do that or vacuum leak.

[j1gilles]

Originally Posted by stanlalee

Your azz became use to it. There is nothing abnormal about the log including not meeting target until about 4000rpm (there is still plenty of boost from 2650rpm). Based on the IATs you must have an upgraded intercooler. Run a more aggressive tune and tune out throttle closures if you get them. That is as clean of an unmodified Shiv stage 0/1 log I've seen especially in the 4000rpm range.

-I'm confused?? How is it "OK" to not hit target until 4k RPM? What do you mean "tune out" throttle closures? Throttle closures are the ECU's way of protecting the engine so I would look to see what is causing the closure and correct the issue...

[BuellsterR1]

Originally Posted by j1gilles

-I'm confused?? How is it "OK" to not hit target until 4k RPM? What do you mean "tune out" throttle closures? Throttle closures are the ECU's way of protecting the engine so I would look to see what is causing the closure and correct the issue...

It's "OK" because there is still plenty of boost prior to hitting 4k. Nonsecure is only 1-2psi off target from 2,500 - 4,000 rpms and this is relatively normal from all the logs I've seen including mines when target boost is initiated at 1,500 rpms.

I don't believe Stanlee was implying tuning the throttle map but instead, tuning out what is causing the closure like you stated. You guys are on the same page, just not at the same time..

The log looks good to me.

[j1gilles]

Originally Posted by BuellsterR1

It's "OK" because there is still plenty of boost prior to hitting 4k. Nonsecure is only 1-2psi off target from 2,500 - 4,000 rpms and this is relatively normal from all the logs I've seen including mines when target boost is initiated at 1,500 rpms.

I don't believe Stanlee was implying tuning the throttle map but instead, tuning out what is causing the closure like you stated. You guys are on the same page, just not at the same time..

The log looks good to me.

thanks for the clarification.... I guess Im just use to the flash I'm running hitting target almost immediately and then staying on it.

[stanlalee]

Originally Posted by j1gilles

thanks for the clarification.... I guess Im just use to the flash I'm running hitting target almost immediately and then staying on it.

Yep my OFT stage 1 typically behaves the same way (as have other logs I've seen). While not meeting requested 12psi at 2500rpm, and 16psi after 3000rpm can hardly be considered "low" or anything that would suggest it should be sluggish. Those are still strong stage 0/1 boost numbers by any standard. As for throttle closures what he said..The closures are caused by overshooting boost target (on OFT stage 0/1 that occurs precisely around 4000rpm). Tune out the overshooting and the throttle closure will go away. The problem with that is you have to have skills that most of us (me included) don't have to fine tune boost control. With forum help I've been able to tune out overshoot at will but with the basic changes the curve is not nearly as smooth as it could/should be. IMO either way they are more bothersome to look at on a log than actually bothersome/noticeable on the road.