Turbo Timer Install Write Up, Pics, Questions, etc...

[Mark P]

I had been thinking about installing a turbo timer for quite some time, probably back to when I had my A4 and would look under the hood after a hard chipped run and note the bright orange/red glow of the turbo. After seeing that, there's no way I'd want to shut down my engine leaving oil sitting in that 1500F turbo.

I originally liked the look of the Greddy III in the cupholder location on an A4/S4 with the Symphony radio as the black/whte w/red display matched very well, as does the size of unit for the space:

But I couldn't quite ever make the commitment to get rid of that cupholder. I hardly ever use it, but it's just so cool to have )

Well, then I saw an installation in this location, and that was much more appealing to me:


I saw other mounting locations (dash, glovebox, ashtray, sunshade), but the one shown above was what met my needs. So, then I set out to see what was available (knowing that the Greddy III was one or two models ago and no longer available). I researched and posted all the details I found here:
Turbo Timer Details post

I searched online, but found it for the same, if not less, at a local tuning shop, XX Tuning. I hadn't been able to find any dimensions of the unit on A'PEXi website or elsewhere online. A'PEXi does have their install/operating manuals online though, which is nice. Nonetheless, I had pretty much decided on buying it locally so I could check the size first to make sure it would fit. The price was just a bonus So, I went over to the shop to check it out and unfortunately they were out of stock. Not to worry, they ordered one and had it there for the next morning. Yup, it's gonna fit quite nicely.

When I was searching through the Turbo Timer install write ups that are in the Tech section and in various posts, I wasn't too thrilled with their detail, nor was I with the A'PEXi manuals. Sure, there was instructions on "cut this wire, connect it to this one", but I was looking for more. I wanted to know what these wires were (signals) and why I was connecting to each. So, in attempt to help out, here's what I've found...

Most (verify before you take this as fact) Turbo Timers have a standard color coding for their wiring which is:
RED - Constant 12V
- Purpose: Supply power to the turbo timer
BLACK - Ground
- Purpose: Supply ground to the turbo timer
GREEN - Ignition #1
- Purpose: Supply power from the turbo timer to the car's ignition wire when the key is removed, thus keeping the car running.
BLUE - Ignition #2
- Purpose: Appears the same as GREEN
GREY - Emergency Brake
- Purpose: to shut off the turbo timer (& engine) when the e-brake is released.
I also had a WHITE wire for connection to O2 sensors to determine A/F.

GREEN/BLUE: No where was it explained why there was 2 Ignition wires and what that means to our cars. I never checked, but I assumed they both sent the same signal at the same time. Well, it appears that some cars require two connections (I still don't know the details), but nonetheless, we only need to connect one. Following what others had done, I used the GREEN and did not use the BLUE. I connected the GREEN to the thick (10 AWG) Black Ignition wire that's located in one of the nylon looms to the lower left of the steering wheel column. Be sure to have the steering wheel pushed in all the way when getting to this loom as otherwise it's being pulled outwards and has no slack in it. Also, you'll find two nylon looms next to each other. One is thicker, comprised of a greater number of smaller wires, where the other is smaller, comprised of a half dozen or so thicker wires. It's this latter that contains the Black Ignition wire of interest. The RED, BLUE and GREEN wires on the Turbo Timer are short as they have a plug on them designed for a harness connetion (which most Turbo Timer companies don't make for Audis). Therefore, I cut off this plug and added a length of 14 AWG wire to connect between the Turbo Timer's GREEN wire and the Black Ignintion wire. There's not a lot of room around this Black wire, so be careful how you connect and how you route your wire. Move the steering wheel in and out to see how the wiring is going to move when you're done.

RED: I connected directly to one of the constant 12V posts near the fuse panel. This is the feed that supplies the fuse panel and thus you should add a inline fuse holder if you connect here. That's what I did. (see image below)

BLUE: Not to be used, I cut it shorter, and wrapped the end with tape.

BLACK: I connected the ground to one of the car's official ground locations which you'll find througout the car as bolts in the frame with multiple brown wires going to them. I chose the one that's located on the transmission tunnel, just to the driver's side of the gear shifter.

GREY: The A'PEXi manual stated that the Emergency Brake connection should be to the switched wire that has 12V when the E-Brake is up, and Ground when the E-Brake is down. I tested our E-Brake switch to find that it is floating (doesn't connect to anything) when the E-Brake is up, but does connect to Ground when the E-Brake is down. I determined this would work just fine, and sure enough it does.

With the above 4 wires (RED, BLACK, GREEN, & GREY), the turbo timer will work. That is, it will keep the engine running after you take the key out. It will also shut off the engine if you release the emergency brake. The "problem" that still remains is that this car will not let you operate the central locking system (you can't lock the doors).

You can not lock the doors because the signal wire that goes to the central locking system "knows" that the car is still running, and therefore won't allow this operation. So we need to change the source of this signal wire. The wire that needs changing is the Blue/Black wire connected to the back of the fuse panel to fuse #6 (Central Locking). This wire gets 12V when the car is running. We need to change this so it no longer gets power while the turbo timer is controlling the engine. By simply removing fuse #6, there is no longer any signal going to this wire (no need to cut it). Now make a connection to this wire and connect it to Accessory Power. Accessory Power is controlled by the key in the ignition, so as soon as you remove the key, Accessory Power no longer has power. This is what we need. I connected directly to the main Acc Power post (labeled 75x, yellow), next to the fuse panel, next to where I connected constant power earlier. Likewise, an inline fuse is needed on this wire as you've removed that 5 amp fuse that previously protected this circuit. (see image below) Now you will be able to lock your doors while the turbo timer is keeping the engine running.

Main connection posts for Constant Power and Accessory Power:



Pictures along the way (these pics are all on my website):

Drilled a hole for the wiring:


Here's the area under the armrest:


Don't be scared by the mess:



Installed:

Closer:

Very Close:


I haven't "mounted" it yet as I wasn't expecting the supplied double stick tape to adhere very well to the felt-like surface of the "pen holder" bottom. Knowing this ahead of time, I just made sure that the hole for the wire was snug enough to keep the unit in place. I suppose I could try the tape or scraping the felt away (it's more like "spray felt" than an actual piece that can be peeled up), but it's pretty good just the way it is, so I may just leave it alone.


Observations:
1.) The turbo timer supplies power to the Ignition wire as power is being removed from this wire due to taking the key out. Therefore you may notice a slight "blip" in the engine at this moment when the turbo timer is detecting this power drop and reacting by supplying power to this wire to keep the engine going. This is normal.

2.) If your car is off and you turn the key to Acc Power position, power is apparently in the ignition wire as well. Therefore, if you now remove the key from the ignition, the turbo timer will begin supplying power since it thinks the engine was running (all it knows is that it sees power being removed from the car's ignition wire, and thus steps in to do its job)

3.) When the turbo timer steps in to keep the engine running, I get both an ABS and an ESP light on my dash as well as a loud beep 3 times. I do not recall reading anyone else's posts/write-ups which discussed this, so I'd be interested to hear from anyone else with a turbo timer installed to whether or not they get this as well. I assume it's because the ignition wire has power, and the ACC Power does not have power. This combo is not normally encountered, and thus I think reason for the lights and beeps. After the 3 beeps, the lights go off and no more beeps. The beeps are quite loud though, and it's annoying to hear everytime I remove the key. I did note, that this occurs also in situation described in #2 above, so it's not related to whether or not the engine running - it's merely when Ignition continues to have power, but ACC 12V does not.

A'PEXi Turbo Timer Operation:
The two main controls I was interested in was the ability to turn it off at a gas station, garage, etc, as well as to easily add time to it's countdown for just a given shutdown. Well, the A'PEXi has a little joystick. To permanantly turn off the unit, just hold the joystick to the left for one second, and then "OFF" shows on the display. If you take the key out and the turbo timer starts it's countdown and now you want to stop it, you do the same thing - hold the joystick to the left for 1 second, and then the engine shuts off. To add (or subtract) time while the turbo timer is counting down, move the joystick up or down and it will add or remove time from its countdown.

A'PEXi did a very poor job of documenting how the "Auto time calculation" is performed. You can either use Manual or Auto mode. In Manual mode, you set a time that the turbo timer will use to countdown every time the car is shut down. In Auto mode, you set a minimum and maximum value for this time period, as well as a "calcualtion rate" of low, normal or high. SOMEHOW (not documented), it determines how long (somewhere between your defined min and max) to keep the car running. I'll assume they go based on how long power had been in the Ignition wire, but I haven't tested out the Auto mode yet.

Another reason I was looking to install a turbo timer was for at the drag strip. After a run, I like to keep my car running for a little while, as I've found that to cool the engine quicker than just shutting it down. However I don't want it to run too long, nor do I really like to walk away with the key in the ignition, so this is the perfect solution. I'll set it for like 5 mins or so and be able to walk away with the engine running, doors locked, hood up, etc.

Overall, I'm very happy with the outcome. I took some additional time beforehand for my own piece of mind so I knew how and why all the connections were being made. The A'PEXi unit is quite nice, fits well in this location, and is easy to operate. I didn't hook up the O2-A/F wire, as I wasn't sure where the best location was to get to this, but I may revisit that in the future, enabling this novelty feature.

[Polar]

[Chaka]

but do you have dual turbo timers baby!!!!

[Imolsify]

however, i don't have those symptoms in my car.

• http://forums.audiworld.com/s4/msgs/1304426.phtml

[mpwolf]

Something like this in the instrument block (17):

00849 - S-contact at Ignition/Starter Switch -D-
31-10 - Open or Short to Ground - Intermittent

[Kitch]

But not EVERY time. No idea what causes it, no VAG codes or issues otherwise, but it is annoying. Wish I could figure it out. cause it does bother me a bit.

[Mark P]

[Driving Excitement!]

[Kitch]

[Mark P]