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Discussion Starter · #1 ·
I've been playing with my boost tables and I sometimes have fluxuating boost in 5th gear. The needle will bounce from 19-16 or so and back and forth. I decided to zero out all the turbo dyamics tables. I did a 5th gear pull and watched as the boost seemed to creep uncontrollably. The needle went straight past 20psi. AFRs were still okay but I let off. I put the stock (for a fxt) turbo dyamics tables back in but modified the values, bringing the values closer to 0 all around. The result was boost control was back in 5th. I still have some spiking I'm trying to get rid of though.

Moral of the story... boost creep may not be boost creep. As often said here, supposed boost creep may be able to be tuned out.
 

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I talked about this almost a year ago ...

http://www.iwsti.com/forums/showpost.php?p=349030&postcount=8

I've been to where you are testing now and worked those tables a lot. Guess what, you can still get boost creep :) Ask me how I know - lol.

If you feel you must experiment with this stuff yourself, focus your effort on the turbo dynamics NEGATIVE. This is what helps to pull wastegate duty cycle OUT when boost is higher than targeted. These tables definitely help (although a lot of so-called tuners don't even touch them :(). However, some people can still get true boost creep even with these tables modified.

You definitely don't want to zero out the negative table. That would actually hinder your chances at controlling creep.

t
 

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Discussion Starter · #3 ·
Well, my case is a bit different than yours. My turbo dynamics tables are the tables used in the Cobb AP ST2 maps! That's for a TD04-13T... I'm running a TD05-16G. By looking at the WGDC maps for the 13T and the WGDC map I'm using on the 16G now the difference is pretty major. Where it took 90+% WGDC to get 15psi I can get 15psi using 50% or so WGDC. So the correction table definitely had to be reworked since the corrections were too large. I'll play around with the negative correction a bit and see what happens.

I've been looking at some of the logs that you guys put up and I think you're getting your turbos so spool earlier than mine does. You guys are seeing 18psi around 3000 and I don't see that until almost 4k. Different turbos yes, but I would think the TD05 would out spool the VF39. Maybe I just need to be more aggressive with the WGDC down low? Does it make sense to run higher wgdc to force faster spool then back off to control the boost?

WolfPlayer said:
I talked about this almost a year ago ...

http://www.iwsti.com/forums/showpost.php?p=349030&postcount=8

I've been to where you are testing now and worked those tables a lot. Guess what, you can still get boost creep :) Ask me how I know - lol.

If you feel you must experiment with this stuff yourself, focus your effort on the turbo dynamics NEGATIVE. This is what helps to pull wastegate duty cycle OUT when boost is higher than targeted. These tables definitely help (although a lot of so-called tuners don't even touch them :(). However, some people can still get true boost creep even with these tables modified.

You definitely don't want to zero out the negative table. That would actually hinder your chances at controlling creep.

t
 
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