 |
|
See also: General Notes - Performance Data - Potential Risks
Notes:
This article assumes that the user is familiar
with the rewards and risks of a boost controller. Furthermore, it merely
represents my experience and opinions, and should not be taken as a
definitive work.
The work described here was undertaken by
Graydon Stuckey, with erratic
assistance and more frequent interruptions from me. All errors contained
in this article, however, are mine, not his.
There are two major components to an HKS EVC-IV
boost controller:
- The controller unit
- The valve actuator
This page will deal primarily with the
installation and setup of the actuator, as the actual operation of the
controller unit is fairly well covered in the manual HKS
supplies.
ACTUATOR INSTALLATION
The only components which were not supplied by
HKS were a couple of hoseclamps and brass T-joints for the air hoses.
These are readily available at any decent hardware store.
- Remove the airbox, and then remove the
airbox housing (note: in the process, you'll have to remove a couple of
large clamped air hoses and the MAF leads). The housing itself is
attached by a single bolt at the top, and slots in via two pins in its
base. This gives you easy access to the turbo and wastegate.
- Disconnect the hoses to the wastegate
frequency valve (WGFV, Checkered
arrow above). With both hoses and the
electric plug to the WGFV removed, the WGFV will be sealed.
Remove
the large U-shaped plastic duct shown above. It connects to the airbox,
the turbo cold-side, the intake manifold and the bypass valve.
- Mount the EVC valve actuator to a firm
surface, preferably not hot, as close as possible to the wastegate (WG).
For our purposes, we mounted it to the front of the airbox housing, as
shown above. Note the following hoses:
Orange: HKS signal line, with filter, will be T'd to the
bypass valve line
Yellow: HKS output line, will go to the top of the
WG.
Blue: HKS input line,
with filter. Will be T'd to
Green and Red hoses.
Green: Audi hose, will go to a tap on the cold-side of the
turbo.
Red: Audi hose, will go to the tap on
the lower part of the WG.
Gray: HKS power and signal leads.
See step 6.
Note: the T for the
Blue, Red and
Green hoses is
not from HKS.
- Choose a location for the input hose
(Green). We have now tried two locations (see above). The
stock location (2) offers, in my opinion, a good overall balance of low-
and high-end boost. An alternative (1) on the outlet of the cold-side
spool generated better low-end boost, but restricted the high-end quite
severely.
- Reinstall (loosely) the airbox housing.
Connect the Gray wires from the actuator (see
step 3) to the HKS wiring harness, and route them behind the
airbox housing.
Connect the Red, Yellow and
Green hoses.
The Green
hose will go to whichever tap you chose
in step 4 above. The
Red hose will go to the
stock tap on the lower part of the WG. The Yellow hose will go to the top of the WG. It's probably best
to unscrew (carefully) and rotate the upper WG so as to minimize the
length of the Yellow hose (which will in turn increase the rapidity of the
EVC's effect).
- Connect the Orange hose to the
(HKS) T and insert it into the approach to the bypass valve, as
above.
- You can now reassemble the air filter, clip
it into the housing and then re-bolt the housing to the car. Re-attach
the MAF lead. Re-install the U-shaped pipe, and re-attach it to the
airbox, turbo, manifold and bypass valve. Check that all clamps, hoses
etc. are secure.
The actuator installation is now
complete.
CONTROLLER INSTALLATION
All that's left now is to hook up the
controller unit and calibrate it. The location of the controller is
entirely arbitrary, the only restriction being the length of the wiring
harness. It should be accessible within the cockpit, at least for the
passenger. Suggestions:
(Simplest) Drill a hole through the firewall in
the vicinity of the glove compartment and route the cable through it (then
seal the hole back up). Hook the controller unit up to the harness, and
power it from the (switched) wire for the glove compartment light. The EVC
head unit can then sit out of sight in the glovebox. In any event,
calibration is most easily accomplished with a driver and a calibrator in
the car simultaneously.
(Better) Again, route the cable through the
firewall, but mount the controller unit in the space beneath the ashtray.
Note, you cannot use the ashtray light as a power-source because it is
activated by the lighting system, not the ignition.
Installation on my S4, with my
Davtron digital
intercooler gauge to the right of the EVC head
unit.
CALIBRATION
In general, the calibration instructions HKS
supplies are quite straightforward. A couple of notes, however:
- Unless you own a drag strip, performing all
the tests in 3rd gear will be hard. Second gear works fine. Likewise,
"up and down" the same stretch of flat road is acceptable, rather than
having to circle back, off-boost, before starting again.
- Initial tests indicated that the setup
described here is good for boost of up to +1.45 bar. I would suggest
carefully reading the boost and performance sections of Scott
Mockry's website before deciding what
level of boost you wish to run. Personally, I have high-boost set to
+1.25 bar and low boost set to +0.80 bar.
- Performance improves rapidly as the EVC
"learns" the boost curve. After 10 or 15 runs, it will have assimilated
most of the info it needs.
- Carry out the calibration as close to
"normal conditions" as possible (i.e. if you live in Arizona, don't
calibrate it in Alaska).
- During calibration, back off at redline.
You don't want to "teach" it bad behavior.
- In my experience, not much (i.e. <10-15%)
"offset" is required on an S4/S6 AAN motor with a K24 turbo. If the EVC
seems unable to reach the boost level you want, check everything else
before cranking max boost to +1.8 and the offset to +150%.
- What if it all goes wrong during
calibration? Brilliantly, the method of setting the unit up from scratch
is covered in a "note" on the second page (great place to start). Power
the unit down. Wait (cursing under your breath) for a few seconds, then
press and hold the Mod button. Still holding it, press and hold the Alt
button. Still holding both of them, press the Sbc button. The unit
should beep and then get ready to start learning again.
- Sometimes, during initial calibration
(specifically, the first two runs, "-L-" and "-H-" respectively), the
unit will record a run that you'd rather forget about (e.g. you're at
5,000 rpm when you see a cat in the road, and back off, but the unit
just "learns" that your turbo runs out of oomph after 5k). You can't
always use the resetting technique described above. Don't get mad at the
unit (I did). Power it down, turn off the ignition, wait a minute, turn
back on the ignition, and then use the reset procedure described in the
bullet above.
Other Modifications:
|
