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Old 06-20-2007, 03:10 PM   #1
Scooby Specialist
Member Sales Rating: (4)
Member#: 50072
Join Date: Dec 2003
Chapter/Region: South East
Location: TN
2017 STI
WR Blue Pearl

Default AEM Tru Boost electronic boost controller

I've been using the AEM tru boost boost controller for the past five months so I figured I'd do a little write-up on it.

I bought the tru boost to compliment my external waste gate and in hopes of having more consistent boost performance because the stock BCS sucks. I paid around $280 shipped buying this new through eBay. It is by no means fancy but it's actually very consistent, easy to install, and not at all difficult to get used to.

Reading vacuum in inHg (inches of mercury), usually -18 idle, -21 cruising:

In The Box
For info on what's included check out this forum post. At the bottom of the first post is a link to the PDF manual that lists the box contents.

It of course includes everything needed to install the gauge but you will most likely need to buy more vacuum hose for the solenoid and probably have some zip ties handy. Also included are interchangeable black and white gauge faces.

The instructions are pretty straight forward. You'll connect the gauge to power and ground, run a couple wires to the solenoid and a hose to a vacuum source. I suggest using the place where the stock boost gauge connects. There are diagrams for internal and external waste gates.

The solenoid is a three port so you'll be using two fittings and a sintered muffler. Since they don't include enough hose I bought 6 feet of 1/4" inner diameter hose because I had to fit it over the EWG fittings. If using hose that big you might wanna use some clips/clamps (not pictured) to secure the hose the the solenoid fittings and a reducer fitting at the compressor housing. Also, notice the instructions for the EWG usage; you will use a T-fitting at that cross section and you will use both the top and bottom ports of the EWG. I'm at 45% duty cycle pushing 18.5psi in 3rd gear on my VF22 so that configuration should give you plenty of room to boost.

Also note that there are two positive wires in the wiring instruction, I just put them together on the same tap on the radio's power wire. I suppose one is for the gauge power and the other for the solenoid.

As for placing the solenoid, I zip tied mine to the cruise control box. You should probably avoid putting it near extreme heat but I'm using my stock heat shield and after running the car and checking the heat in that area I feel that the heat shield is working great and the solenoid is in no danger.

This shows where I used a T-fitting:

Used a reducer here, no pills required for aftermarket BCS:

Using both ports on the EWG:

** Check at the bottom for the extras I used for the installation.

It'll take all of 5 minutes to get accustomed to using the Tru Boost, reading the instructions helps but I'll go through the basics.

Enabling the solenoid. Choosing your boost setting.
- By default the gauge will display "OFF" meaning that the controller is off and you're using waste gate spring pressure. To turn it on/enable the solenoid hold the LEFT BUTTON for a few seconds and release, it should now display "A"; repeat that procedure and you'll be on "B" setting, next you'll be back to the "OFF" setting where it'll be running at waste gate pressure. If you want it to work, I suggest having it on "A" or "B".

- SPr (Spring Pressure): They previously called this "crack pressure" and probably for a good reason. DO NOT put your spring pressure in this setting! I have a 13psi spring, I set SPr to 13.0 and it caused a HUGE lead-in boost spike. I now have it set to 4.00 and boost comes on properly without a spike.

When tuning, watch the gauge (or graph if you're on a dyno). If you're trying to hit 16psi but it spikes to well over that and then settles back down, you need to lower your SPr value.

- Boost settings "A" and "B": This will of course be in duty cycles, NOT PSI! Don't set it to 20 and expect 20psi.

- SEn (pressure sensor): If you're not using their add-on pressure sensor (E), make sure this is set to "I" or the controller will not function.

- FUL (gauge scale): If you're pushing a max of 20psi then set this to 20psi or 21 or whatever. It'll adjust the scale of the display so when the LEDs light up then 20 will be at the end of the scale. I actually never notice the LEDs since the readout is right there in plain numbers.

Since the tru boost isn't exactly fancy it doesn't have independent gear settings for boost, you'll set a duty cycle and it'll vary ~1psi through the gears.

More importantly though is that it's very consistent. I've been running at 45% duty cycle since I got the car tuned in February and I haven't had to make any adjustments for the 30-40F change in temperature. It is still hitting the same boost it was then.

I'm satisfied and I'd recommend this to others looking to ditch the stock BCS because the price is good at less than $300 and it functions extremely well. I'm very happy because of the five months I've been using it I've had no crap from it and through various weather conditions it has continued to boost the same amount it was boosting the day it was tunNed.

Extras I Used For Installation
- 13400 (optional) hose clamps - Link - Green and Red "HELP!" box
- 47308 assorted vacuum connectors/fittings - NoLink - Purple "VACU-TITE!" box
- #### assorted vacuum Tees - NoLink - Purple "VACU-TITE!" box
- 6-feet of 1/4-inch inner diameter vacuum hose (could probably go smaller if not using EWG)

PDF user manual at the bottom of the first post here:,17959.0.html
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