looking at buying a hks turbo timer the little slim one whith separate control box and harness, was just wondering i take it once you've taken the keys out you can't arm the alarm until it has switched off, say for instance someone jumped in car as its on a 9 min cycle and drove away they'd presumably only get 9 mins up the road am i correct?

 

errr no, the turbo timer is usually earthed out by the handbrake being pulled, once let off the car will cut out. clifford G5 alarms can be armed with turbo timer on if a special box is installed

 

Sleiper: The best solution to the turbo timer is not to fit one. Seriously. On an Impreza with a water-cooled turbo they are an utterly pointless trinket that is more likely to heat your bits than cool them down.

The best way to cool your engine and turbo down after some stick is to drive off boost (at medium engine speeds) for a couple or three minutes, park up, and then switch off immediately. Leaving the engine running on a timer will make it start to heat up again - as there'll be no airflow through the radiator and engine bay to cool it.

 

ok nice one mate thats cleared it up, cheers will put the money to something else

 

Splitpin explain why you would NOT want to cool a water cooled turbo down?? Are you aware of the temperatures exceeded in a turbo mate?? Funny how my wrx import clearly says on the door on a subaru warning sticker, please allow car to idle for a minute or so before shutting down after heavy highway driving. Then again, I presume Subaru could be wrong here.

 

If you litterally pulled on your drive from caining your car for a sustained period then you might want to cool it down but as most do the last few miles to home quite slowly it gives the turbo sufficent time to cool down so not needing the cooling down period once there.

 

Yeh I do that most of the time, I probably have mine set on all the time incase of emergencys.. either for example a police pull after a harsh acceleration and they ask to turn the car off, or a time when you are in a rush and don't wish to sit in the car for a minute or so. Convenience more than anything I guess.

 

Eh? Whose post were you reading? At no point did I say that you would NOT want to cool a water cooled turbo down, all I said was that turbo timers are not the best way to do it.

Go read my post again. What I did say is that leaving your car idling at standstill is an ineffective way of cooling the engine and turbo down, and that a more effective way of doing so is to drive around off-boost at medium engine speeds.

The reason I said that is because when you leave the car idling at a standstill on a timer, the water pump is rotating very slowly and there is no airflow through either the radiator or engine bay - until your coolant temperature rises to 97 degrees celsius and your fan kicks in.

The mere fact that your fan kicks in after you leave your car idling at a standstill for a few minutes on a hot day shows you why turbo timers are a bad idea. The reason why the fan doesn't run when the car's moving is because the airflow is doing a better job.

If, on the other hand, you do as I suggested and drive around off boost but with some revs for a few minutes, you get loads of air through your radiator, loads of air passing through the bay to cool the exhaust and turbo directly, and you get your water pump circulating coolant through the entire setup at nice high speeds.

Have you only been around here for five minutes or something? Seeing as you asked, I run an EGT gauge, and have been known in the past to run an extra temp sensor on my datalogging system just to test out this very scenario, so yes, I probably have more knowledge of the issues we're discussing here than most people you're likely to meet.

It would not be the first time. I can send you some very boring datalogs if you'd like to see the proof of the pudding.

 

Lol... your attitude is quite amuzing mate, but to be fair to you, your right about the cooling, I didn't make it clear though, I mean they aren't pointless at all, they do their job if needed, if you CANT drive around medium revs for a bit, or you stop somewhere un planned after giving it some, it is a convenience. Yes you are right the BEST way to cool it down is to drive around off boost keeping revs say 2-3.
It isn't a game or a war .. I was just stating something do you not think that the fact you and someone had differences before on here says that although maybe not meant, you come accross quite aggressive and rude?

edit - forgot to add idling has its place to let the spindle slow down from say 140,000 revs to 20-30k therefore preventing them spinning without oil for as long...

 

No, they are a pointless trinket. There is a fundamental problem with any turbo timer, precisely because the control system is time-based and therefore far too arbitrary to be consistently effective.

The only thing that'd be a genuine, consistent help in this area would be a device linked to EGT/coolant/oil temp that could calculate an optimum switch-off point based on sensor feedback.

Not really. If you do stop dead after giving it full stick, how do you know what the "right"/optimum amount of time to set your timer is? This is the fundamental issue with anything that runs simply to a (basically random) user controllable time. You never know how long is "right", and, as above, the moment you lose forward motion, and reduce the coolant and oil circulation to idle levels you are fundamentally compromising the entire engine cooling system.

My posting style works exactly the way I want it to. I'm not here to agree with everyone, I'm here to offer advice and opinion where I feel I can. It's up to the reader what he/she makes of it.

 

I am going on presumption like myself, that you know the EGTs, coolant temps and oil temps... Thus on my car I feel 1 minute, is 'normally' apart from on hot days, long enough to let oil and egts cool enough... in the summer longer is needed though.