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Discussion Starter · #1 ·
I tried searching but could not find anything on this subject. So, I recently had Sound Performance put an aem tru boost controller and exhaust on my car. The controller is set to 75% of the waste gate and should be boosting at 18psi. The problem is sometimes it spikes to 19 and even 20.3 psi when I really get on it especially at 120 plus mph. I set the boost setting to 69% and even then it still shows 18 psi at times. Anybody else had this problem? How bad is it for the car to overboost that much and what can I do to fix this?
 

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try adjusting the crack pressure, i had mine at 0 and it held boost like a champ and then my tuner was showing me some other options on it and he set it at 10 and i was overshooting the boost, so i put it back to 0 and it was fine again.
 

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spr is your wastegate spring pressure. the setting you are looking for is gAE.
From aem forums.

SPr = CRACK PRESSURE! "Crack pressure" is what they call it in the instructions and I think what they mean by that is the pressure at which your waste gate begins to crack open so SPr seems to have little to do with the actual spring rating and more to do with the pressure at which the spring begins to give. When I had SPr set too high I could hear the waste gate open on its own and then shut as the tru-boost took over. Of course that went away once the tru-boost knew to kick in earlier.

:dunno: SPr = Crack pressure, so set SPr to 0? That would fix the spiking problem?

What is gAE?
 

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From aem forums.

:dunno: SPr = Crack pressure, so set SPr to 0? That would fix the spiking problem?

What is gAE?
i have my spr on like 5 ...im pretty sure lowering it will reduce/eliminate the spikes...at least thats what i read from those threads i posted above from the aem forums... if thats the case i dont see why there is a need to raise it ever, maybe something thats done in higher boost applications
 

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if you look in the AEM manual for the tru boost on page 7, i has a menu on how to navigate the settings, and at the wastegate crack pressure setting, it says ( gAE )................i thought that this might be what the abbreviation was on the actual unit since the rest of them are correct, sorry for the confusion. let us know how it works.
 

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Discussion Starter · #13 ·
The spr was set at 2.00 so I turned it down to the lowest setting which is 1.00 and the car will still overboost when I get on it. I still have it set at 69% and it will read 19psi when I check the peak hold. Any other suggestions?
 

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Discussion Starter · #15 ·
rmm downpipe
boost logic exhaust
ETTC speed for sale
Tru Boost
greddy turbo timer

I have a BCC but it is not installed. SP said I didnt need it when they did the BPU because they did some other mod that allows it to boost more.
 

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Thanks! I was having this issue, now I have to lower my spring "crack" setting. Mine would spike to 21 and then go down to 17....
 

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i had many issues with my tru boost in my past two tuning attempts. AEM doesnt care to help, i cant get anyone by phone or email so for what its worth, im getting rid of this thing, its cost me way too much time and money. save yourself some hassle and scrap it. just my two cents.
 

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Discussion Starter · #18 ·
In order to get this thing to work at 18 psi without any spike, I had to lower the duty cycle to 67%. It doesnt spike now unless its cold outside.


i had many issues with my tru boost in my past two tuning attempts. AEM doesnt care to help, i cant get anyone by phone or email so for what its worth, im getting rid of this thing, its cost me way too much time and money. save yourself some hassle and scrap it. just my two cents.
I am feeling the same way. Just curious, what boost cotroller and guage will you go with instead?
 

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I run the AEM Tru-Boost... I like it alot...

I would not get rid of it. Read the book for the truboost its on the aem site. It is hard to get them on the cell but on email it is very easy.
 

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^^^i like it too...

thing is i also have AEM ems, and im trying to figure out if i want to continue controlling boost independly of it with the Tru Boost, or wire solenoid into the EMS and control it that way

not sure which is better

my only gripe with the Tru Boost is the scramble boost does not stay engaged when i flip the switch for it, it turns off at a max time of like one minute(whatever you set it to)...id like for it to stay on
 
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