hi/low switch with hks actuator

[amatthews45]

Hello everyone

Well after the last 2 hours googling and downloading the hks manual maybe 9 times! I am still havent figured out how to plumb this all in.

I know you put the t peice in the joiner between the actuator and the turbo.

That bit goes to the hi setting but what happens with the low?

I dont have a dump valve or efi pipe

Logicly my mind cant put this to rest becsuse I am not sure how the low boost setting will work not being plummed in.

Someone please finsh my puzzle

Alex

 

[davehart]

I don't think you can run hi/lo with the HKS unit, just the one boost setting

You need to set the pressure using the adjuster on the actuator, lengthen it or shorten it.

 

[amatthews45]

Oh you can I know that

Just a quick google tells you that its possible.

Lots of people dont and say its useless

But I will make it happen

 

[Guye]

It's been years since I have seen the stock hi/lo boost lines. The way how the stock system work was by allowing a small amount of boost pressure to push against the diaphram/spring when hi mode was selected, resulting in a higher boost pressure required to open the wastegate. The other line was the boost reference from the compressor housing itself. The hks actuator only has one port for boost reference and the final pressure is dependent on how long or short you set the actuator arm. Sadly, I don't think that there is any way to retain the hi/lo function using a hks unit. JAM actuators allowed for arm adjustments but still retained the stock two port setup. So with such a unit you'd have both higher than stock boost levels with use of the hi/lo function. If I am wrong and someone has figured out how to retain that with the hks actuator I am sure they'll share how.

 

[Guye]

The only way I got hi/lo functions with an hks actuator was to use an aftermarket ebc like the profecB spec2. It would be most interesting if you figure a way to use the stock plumbing to achieve the same thing.

 

[amatthews45]

Yeah thats the kinda repsones I had so far and had expected. But I have seen postive stuff online to show it can be done. The hks csme with a t peice to allow it to keep the hi/low function.

I can plumb in the high but uncertain what to do with the low

 

[Guye]

From the tgtt archive http://www.toyotagtturbo.com/forums...ctory-hi-lo-boost-with-a-aftermarket-actuator The answer is in this thread and the other from the link within. Yet again tgtt teaches me something even after all this time lol

 

[amatthews45]

So theres the answer in there but the pictures are not clear

I still not sure what goes on with the low part on the solnoid!

 

[davehart]

Well I never It is possible after all.

Although, why would you want to keep the hi/low with a HKS unit? Most folk put one on so they can ramp up the boost.

 

[davehart]

Yeah thats the kinda repsones I had so far and had expected. But I have seen postive stuff online to show it can be done. The hks csme with a t peice to allow it to keep the hi/low function.

I can plumb in the high but uncertain what to do with the low

From that picture it looks like the hard pipe that goes down the side of the timing cover is just left redundant with the new hose bit going to the t-piece.

 

[amatthews45]

You can still up the boost to near the fuel cut limit.

I dont plan to run higher boost than that so no need to spend money on a boost controller.

If and when I decide to go for bigger power I need to think about forging/turbo set up and a good fpr.

I think the low side goes to the efi pipe just had a idea I might see if I can put the low pipe into a short route pipe.

 

[steo800]

I've not seen it mentioned in the above links or in this thread but I remember there was a brass restricter you got with the actuator that had to be put into one of the pipes.

I reckon it was the "P7" pipe on the first link above.

I always preferred it without the stock hi and lo though, or if your worried about fuel consumption, an EBC is best, turn it off and you'll get lower boost than stock ebc

 

[amatthews45]

Brass ristrictor eh! Will have to look that up

What pipe you reckon that was on? The low?

Dont want a controller yet really wanna keep the high/low button will drive me mental having it there useless

 

[amatthews45]

If you are referring to the brass restrictor it goes in the short length of pipe from the turbo housing to the supplied T piece, this in turn goes to the actuator spout. I found that with this in place the car produced far too much boost so I took it out and now it runs perfectly.

Found it

So it goes between actuator and the turbo near the t peice?

 

[Guye]

Found it

So it goes between actuator and the turbo near the t peice?

BY

I wouldn't think so. If you put a restrictor in the boost reference hose it will require an even higher boost pressure to open the wastegate. The turbo will spool even higher than what the arm lenght setting without the restrictor would have been

 

[dac69er]

the hks actuator manual clearly shows how to plumb it all in.

the brass restrictor is used to even out the boost control to reduce spiking. i will be honest, i didnt notice any real difference with or without on the ct9. it can pretty much go anywhere, but i would tend to put it just before the actuator.

as for the hi/lo control itself. its pretty worthless with the hks actuator. difference is about 2psi between the 2 settings.