Forced Induction Superchargers | Turbochargers | Intercoolers

AEM Tru-boost questions & boost duty cycle

Thread Tools
 
Search this Thread
 
Old Apr 24, 2009 | 05:16 PM
  #1  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default AEM Tru-boost questions & boost duty cycle

Ok I got this thing and I'm about to install it. Reading the instructions before I do I read something about scramble boost, what the hell is that? It says to hook it up to a grounded switch, okay umm where can I find one? Also would it be a necessary to hook up the alarm? And can someone explain to me what the boost duty cycle is. And if there is someone that has one how do you set it up (programming part of it)

I don't know if I can do this because it has been years since I read the forum rules but here is the manual for the boost controller
Attached Files
File Type: pdf
AEMTBC.pdf (338.2 KB, 940 views)
Reply
Old Apr 25, 2009 | 02:17 AM
  #2  
DeltaT's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2005
Posts: 2,404
Likes: 1
Default

A grounded switch is simply an on/off switch with one side connected to your orange wire and the other connected to a good ground, like your frame or engine block. With the switch in the ON (Closed) position, the orange wire will have a connection to ground. With the switch OFF (Open) position, the orange wire will not be connected to ground and therefor not active.

The instructions say you do not have to hook up Orange (scramble) or Grey (alarm) for the thing to work.

It sounds to me like scramble boost is a way to set a brief (0-25.5 seconds) of overboost. I wouldn't play with this until you are comfortable with the normal operation.

Boost duty cycle is set from 10-90%, and is a measure of how much of the time per On/Off cycle of the boost-controlling solenoid the solenoid is Open (or ON). Let's say it cycles once per second. If it were open for a half second then closed for a half second, the duty cycle would be 50% (half the time on, half the time off). 10% would be open for a tenth of a second and closed for the other 9/10's of a second. But it usually pulses faster than once per second. Maybe something like 20 times per second. But the duty cycle still stays the same as the percentage of the time per cycle that the solenoid stays open. Higher duty cycle = more air can move through your solenoid.

For the programming, follow the charts very carefully on Page 7. It's all a combination of button pushes. Start with pushing both buttons and the gauge should respond with "PRG" to show that it has entered Program Mode. After that, the gauge will display the messages shown in parentheses after the commands on Page 7, like (A), or (b), or (UnI) or (SCb), etc. That shows you where you are in the programming tree.

Does that help?

Jim
Reply
Old Apr 25, 2009 | 04:55 PM
  #3  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default

yes thank you, but the programming is still a little fuzzy to me. what do I really have to mess with to actually set it up for let's say 10#'s of boost.
Reply
Old Apr 25, 2009 | 09:27 PM
  #4  
52172's Avatar
TECH Junkie
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (2)
 
Joined: Jul 2003
Posts: 3,489
Likes: 1
From: Buellton Ca
Default

My tru boost is set at 72 duty cycle and it has a 6 lb spring in the wg and it equalls 10lbs of boost on the dyno and on the street under load it is more like 12 lbs of boost.
Reply
Old Apr 25, 2009 | 11:25 PM
  #5  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default

so how does the math work out?
Reply
Old Apr 25, 2009 | 11:36 PM
  #6  
52172's Avatar
TECH Junkie
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (2)
 
Joined: Jul 2003
Posts: 3,489
Likes: 1
From: Buellton Ca
Default

Originally Posted by The Fugitive
so how does the math work out?
It never works out you just got to start with a conservative duty cycle and build from there. Just set your tru boost to duty cyle 40 and hit it and see what boost you will hit I know it won't go very high. Then start adding 4-5 to the duty cycle and your boost will slowly go higher in a safe increment.
Reply
Old Apr 25, 2009 | 11:44 PM
  #7  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default

so in the program mode what do I do with the bar graph thing?

Last edited by The Fugitive; Apr 25, 2009 at 11:52 PM.
Reply
Old Apr 26, 2009 | 01:26 AM
  #8  
DeltaT's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2005
Posts: 2,404
Likes: 1
Default

I'd set the bar graph to about 5psi more than you expect to see. That way you can see if you are over your target. What boost do you want? What wastegate spring do you have? Did you have the car running before you got this thing?

Jim
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Apr 26, 2009 | 01:38 AM
  #9  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default

Originally Posted by DeltaT
I'd set the bar graph to about 5psi more than you expect to see. That way you can see if you are over your target. What boost do you want? What wastegate spring do you have? Did you have the car running before you got this thing?

Jim
not sure how can I check to know what kind of spring is in there? Actually I don't even know the size of the wastegate or bov. So I would just assume it is a 5# spring. I am not sure I think I may go with 8-10 psi figure I could do that to be safe with a stock LQ4. But I am getting engine and turbo installed at the same time.
Reply
Old Apr 26, 2009 | 02:16 AM
  #10  
eviltwin_1987's Avatar
TECH Fanatic
iTrader: (18)
 
Joined: Sep 2006
Posts: 1,002
Likes: 0
From: Nor Cal
Default

with a 9psi spring in my wastegate i could only make 7.6psi With my tru boost on 30% duty i made 9.4psi with the same wastegate spring
Reply
Old Apr 26, 2009 | 02:27 AM
  #11  
The Fugitive's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 563
Likes: 0
From: Reno, NV
Default

does the type of turbo matter? I have a 67mm
Reply
Old Apr 26, 2009 | 08:58 AM
  #12  
mightyquickz28's Avatar
TECH Addict
20 Year Member
iTrader: (8)
 
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Default

I asked all these same questions when I bought my AEM Tru-Boost and was told to RTFM (Read the f**king Manual). Nice, eh? At any rate what they are saying (now) is true as far as the target psi. You'd think it would be 'Read the PSI, if it is over what I want, start bleeding off the pressure'. But, at least with this one, if not all of them, that's not what happens.

You should,

a. Find out what spring you have in your Wastegate(usally has a paint stripe on it which denotes what PSI it is rated to be from the Wastegate manufacturer). Put in a 7 psi WG spring if you don't already have one.

b. Put your duty cycle low just like the prior fellow stated. If it exceeds your desired target, reduce the duty cycle value. If it's too low, bump up the designation. Take it for a drive. Repeat till the PSI delivered is what you want.
Reply




All times are GMT -5. The time now is 02:43 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE