Wiring up a Turbo Timer in GU 3 litre Patrol

Submitted: Tuesday, Mar 19, 2013 at 18:01
ThreadID: 101188 Views:3178 Replies:3 FollowUps:6
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Hi Guys: I have just built a Turbo Timer kit from Jaycar electronics. It is called an Adaptive Turbo Timer and appeared in Silicon Chip Magazine in 2007. Kit no. KC5451

The timer monitors engine load through the MAF sensor and determines how long the turbo must run at cool down.

It all seems to work, and is adjustable for maximum cooldown and sensor input, and you can monitor it's progress via 3 LEDs. It is supplied with extra outputs to operate another relay to defeat the immobiliser when you turn off the ignition to allow the cool down idle.

There is a couple of senarios of how to wire it in but it is a general kit for all makes and models and I need a bit more detail to accomplish this task in my 3l GU.

I have tried a couple of wires after consulting the Nissan wiring manual but so far no success.

Any help or direction will be greatly apreciated.

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Reply By: Ross M - Tuesday, Mar 19, 2013 at 20:02

Tuesday, Mar 19, 2013 at 20:02
Can you explain why the timer reads the MAF sensor. It is airflow and doesn't measure load as far as I know. Can't see how it can. I cannot see why load is important at all.

However, the temp of the turbo is important and I would imagine some sensor, probably a NTC sensor similar to a water temp sensor would be the/an item it would use to sense the turbo temp with the NTC sensor positioned near the turbo in the engine bay and set/tested to a preset level.

Usually they just keep the "ignition" wires connected via the timed relay to accomplish the time out period, maybe extended by the sensor temp as sensed, if fitted.
Personally, I wouldn't be connecting to the MAF sensor wires unless you know the unit is completely happy with an alternative electrical path which is connected to the ECU.
I would want to know alot more about it's function before I connected it as I see it as totally unnecessary to have that connection.
To walk away and have the vehicle running with you not there is illegal and the vehicle is regarded as you still being in charge of it although you are gone. If anything ever happens because of the vehicle running in your absence then you are gone.

Insurance and legal issues arise.

Ross M
AnswerID: 507161

Follow Up By: pop2jocem - Tuesday, Mar 19, 2013 at 20:10

Tuesday, Mar 19, 2013 at 20:10
Yes, quite right Ross. I must admit I am a little bemused by the concept behind a turbo timer. As you pointed out it is illegal to leave the vehicle running so why not just let it idle down for a couple of minutes while you make sure your hair is combed and the nail polish is dry. (;-))

I'm assuming here that drying the nail polish is why some drivers, male or female like to hang one arm out the window while the vehicle is in motion.

FollowupID: 784343

Follow Up By: 503 - Wednesday, Mar 20, 2013 at 01:09

Wednesday, Mar 20, 2013 at 01:09
Hi Ross: Thank you for your input.

The MAF sensor is used because it has high co-relationship with engine speed and thus assumes that high engine speed probably means that the turbo is working hard too. The integrated circuit monitors the voltage from the MAF and compares it with a threshhold voltage many times per minute and uses this info to work out how long the engine needs to idle for cool down, giving more weight to the last 25% of the data stored in any 5 minute block.

This is a fairly crude and very brief overview as to how it works but you can get the general idea.

It is supposed to be an "intelligent turbo timer" only allocating cool-down time if the engine has been working hard, overcoming the annoying habit of engine run-on even though it hasn't done any work. ie starting the car and backing it out of the garage then turning the engine off!

I do take your points but in essence by monitoring my EGT and scan gauges along with the ability to adjust the threshold voltage that the unit uses it is easy to set up and surprisingly accurate in its automatic allocation of time reqd to get down to 175 degC, which is my temperature of choice.

I just have to get it working with the Patrol ignition circuit now.
Thanks for the description of what is reqd it is very helpful and makes great sense.

warm regards
FollowupID: 784365

Follow Up By: Ross M - Wednesday, Mar 20, 2013 at 15:13

Wednesday, Mar 20, 2013 at 15:13
I can see the relationship of the MAF and the theoretical speed and load inputs BUT I can't see how it can then tell how hot the turbo IS or how hot it will remain hot for, OR how long it needs to run at idle to allow the required cooldown amount.

A simple temp sensor located near the turbo will always do it every time with no variations.
Every vehicle will be different with relation to the airflow around the turbo and the heat dissipated by the turbo during the cooldown period.
Therefore the MAF involvement , while a trendy/unique way of sensing, really won't mean anything as it can't tell if the turbo has cooled down or not.
It is the turbo you are trying to protect isn't it?
The involvement of more electronics will only complicate things and I wouldn't be placing my trust in it to save a turbo.

Simpler the better, or just wait a minute or two.
I used one for 25 years and usually just waited until time passed meant cooling had occurred, the timer only ran sometimes but I didn't rely on it.

Ross M
FollowupID: 784415

Reply By: Member - Bentaxle - Tuesday, Mar 19, 2013 at 20:37

Tuesday, Mar 19, 2013 at 20:37
Thommo check with AKSNISS on >www.patrol4x4.com/forum/< he should be able to point you in the right direction. I am exeedingly wary o flinking anything to the MAF sensor as they have the potential to cause more problems than anything else,, like blowing motors.

May the fleas of a thousand afghan camels infect the crutch of your enemy and may their arms be too short to scratch.

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AnswerID: 507164

Follow Up By: 503 - Wednesday, Mar 20, 2013 at 00:07

Wednesday, Mar 20, 2013 at 00:07
Thanks Mike, I appreciate your guidance.

I have taken a jumper from the MAF sensor and compared the results with the Scan Gauge read out before and after and can see no difference, volts for given RPM according to the genuine Nissan Manual.
It really is very easy to keep your MAF honest thru the use of ECU talk and the real time voltage readout from it.

Engine - ignition ON engine stopped Maf voltage approx 1.0 volt
Engine idle- normal op. temp Maf voltage 1.6 - 2.0 volts
Engine idle - 4000 RPM Maf voltage 1.6 - 2.0 to approx 4.0v

FollowupID: 784362

Reply By: PeterInSa - Tuesday, Mar 19, 2013 at 20:45

Tuesday, Mar 19, 2013 at 20:45
Pulled the TT out of my Cruiser, after the following experience.

Up in Cooktown camped under the trees in a tent, (Tandem Van back at Mareba) following morning pulled down the tent and just about ready to go. Decided to start the TD Cruiser and warm up the motor ( only had the vehicle for 3 months). Opened the drivers door and started the engine from outside the vehicle, the vehicle happened to be in reverse gear, engine started and started to go in reverse. Margaret saw that the rear door was up and rushed to close the door, she was behind the vehicle as it was backing into a tree. I turned the ignition off, but with the TT the engine kept going so did the vehicle in reverse.

The penny dropped and I hit the TT cut out button, vehicle stopped and Margaret sqeezed herslf out from the back of the Cruiser and the Tree.

Have not sold my TT or given it away, because to me they are dangerous.

AnswerID: 507167

Follow Up By: jacent - Wednesday, Mar 20, 2013 at 00:01

Wednesday, Mar 20, 2013 at 00:01
Hi mate I have a boggard turbo timer and it will only engage the delay shut down if the car has been running for over ten seconds so in your situation if you started the car and it was in gear you would just turn it off as per normal with the key, not sure what brand you have but this should of been something yours should of had? With your handbrake applied even with the car in gear it should of stalled anyway? I don't believe they are unsafe as long as you use them sensibly. I always rock the gear stick before turning the key if in your situation but I can see how you can get busy trying to pack up and overlook this. Glad no one got hurt and can see how the scare made you remove yours.
FollowupID: 784361

Follow Up By: 503 - Wednesday, Mar 20, 2013 at 01:37

Wednesday, Mar 20, 2013 at 01:37
Hi Peter:
Thanks for taking the time to reply.
That was indeed a close call, but as "jacent" pointed out that wouldn't have happened if you had an "intelligent" T/Timer.

Thanks again for sharing this incident with us. It highlights a very dangerous practice which I'm sure most of us are guilty of doing at some time or another, starting the car from outside the vehicle through the open doorway.

This is exactly what killed outdoor legend "Malcolm Douglas".

He stopped close to a tree. When he tried to start the vehicle standing outside but inside the door it lurched forward, still in gear, and he was crushed between the door and vehicle as the door pushed hard against the tree.

We should all learn from this!

Thanks again
FollowupID: 784366

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