I've got what looks to be an old school HKS turbo timer it only has 5 buttons on it 1 for 30sec , 1 mon, 3 min, and 5 min. Now my questions is sometimes it doesnt wanna stay on the full time i set it to. Yeah i know some got by the rpm's or something but i drove like 2 miles and it stayed on the full minute and the again i drove 20 miles and it stay the whole minute. I didnt run hard on either trips. I'v got stock boost and pretty much everything stock except for my "pop off valve" which brings me to my next question what the hell is it? i never herd of it till i bought this car (ive had it like 3 days) and i cant find anything on teh internet about it, a friend told me its the same thing as a waste gate but not on the exhaust side. Does it control my boost? anything helps. thanks!

 

Look at the case, does it say "TIMER" on it?
No, it cannot control boost.
It might be able to show boost levels.


-Ted

 

Yes, its says "HKS TURBO TIMER" above the buttons.

 

It did it again this mornign ran hard and only like a 10 second hold. I dont wanna blow this turbo. Anyone?

 

The Turbo Timer just lets your car run at idle for a little while to cool down your turbo after you've run it hard. You can do the same thing manually by just not boosting at all for about a minute before you park and turn your car off, or when you park, let the car idle for a a minute and then turn the car off.

The "pop off valve" usually known as a blow off valve or "BOV" or air bypass valve, doesn't limit boost, it relieves extra boost when when you let off the gas.

The wastegate is what controls maximum boost.

 

pop off valve and bov are not one in the same. I will let someone more knowledgable speak about the differences between them.

 

a blow off valve lets the boost out when you let off the throttle to prevent compressor surge. a pop off valve bleeds off boost in an over-boost situation to prevent you from blowing your engine. it is pretty much a back up for the wastegate. it by no means is meant to replace a wastegate, because it will let out metered air which will cause the engine to run rich.

as for the turbo timer, check to see if the wiring is loose or sit in the car and watch it. does it have a visible countdown to shut off? does anything visible abnormal happen when it shuts off before the time you've told it?

 

Well when its set, it only shows one number, when its set at 30 sec it shows only an H, for 1 minutes its says 1 etc. And it doesnt count down its just keeps that number. I tested it and it works on 30 sec 1 minute and 3 minutes but I didnt have time to do the 5 lol but I assume it works but yeah when it counts down it keeps that original number that it started with.

 

wow weird, I've never ever heard of a pop off valve then. Sounds like it could be useful... why the hell did they have to name it so close to blow off valve though!

 

popoff valve? hmm never heard of it