Questions RE: 3SGTE RC Water to Air Intercooler

[Lanius]

As part of the repairs / upgrades to my car, I'm coming into possession of a water-to-air intercooler from an RC version ST185, and have a few questions ...

1\ Is this the same wta i/cooler from the ST205 3SGTE?
2\ How much of an improvement was it over the standard ST185 top mounted air-to-air cooler?
3\ Does it need anti-freeze as well as water?
4\ Is it possible to use ice-packing in the water resevoire of one of these coolers?
5\ What kind of stress would be on the cooler water pump if its wired to run all the time? (I believe the pump alternates on and off according to certain criteria?)

Any info would be greatly appreciated

[Adydas]

this Might help with the pump one.
http://homepage.ntlworld.com/celicagt4/ ... nstant.htm

Note : 165

Naturally it would not last as long before needing a replacement or rebuild to the pump.

I use a full antifreeze in my wta as for St205 been the same i Belive its a yes i would love to know the same thing tho for sure. but im sure its the same unit as it looks the same and operates the same.

i dont think ice into the little bottle would do anything would it?

[GT4 20]

There isn't really anywhere to put ice in as there isn't a reservoir bottle. Try using an additive called 'Water Wetter'. This can increase the amount of heat the water can absorb.
There has been a few discussions about running the pump full time on the GT4OC forum (www.gt4oc.net) and the general opinion has been that it will offer no real benefit - just reducing the pump life as stated above.
Gary

[Lanius]

Thanks for that man, will have a read of the site when I get a chance. Technically speaking, the ice should lower intake temperature more than just normal tepid water, simply because its so much colder. But again, I haven't worked with these intercoolers before, so all I have is theory

Thanks for the info Gary ... does the discussion you mentioned give any details on what conditions cause the pump to run? If its not running all the time by default, does it only come on at regular timed intervals, or only when intake temperatures reach a certain level, or only when the throttle is open ... ?

Cheers

[GT4 20]

From what I understand (and if I'm wrong, I'm open to being corrected), the pump is speed operated. So when the car is moving and goes over say 20km/h, the pump is activated.
Gary

[Malcolm]

you want to use as little antifreeze as possible. straight water will cool better than antifreeze, but it will also cause rust. Water wetter is supposed to be an excellent alternative to antifreeze as it cools better than straight water and inhibits rust.
Running the pump full time is useful for preventing heat soak (the intercooler gets quite warm after sitting at idle or low speeds for a minute or so), good for drag racing etc

[GT4 20]

Running the pump full time is useful for preventing heat soak (the intercooler gets quite warm after sitting at idle or low speeds for a minute or so), good for drag racing etc

Not sure if that is really the case. Remember, that if you aren't moving, even with the pump running, water will still be 'fed' through the pre rad, but won't be cooled. All you'll do is increase the temp of the water in the entire system which will take time to cool down again once you are moving. At least with the pump off whilst stationary, only the water in the WAI itself will be warm/hot. Then, when you move and the pump kicks in, you'll immediately get cooler water into the WAI. Would imagine that would be far more effective and possibly why the Toyota engineers designed it this way.
Gary

[vvega]

i used to run mine full time and i found that my intake temperatures dropped... measured with a probe
you may find the swtich them off to inprove pump life....
they only switch on at 1/4 and above thottle..

v

[YeMs]

maybe if u had a seperate sealed resovoir that u could open? that the water ran into?would need to b lower than the IC itself, but with the top at the same level so it didnt over flow, but with the bottom lower so the water flowed out of the IC. the pump would need to be lowest, and the radiator middle? fill the resovoir with ice and then i guess u would have to fill the system from reasonably empty (displacement of the ice would cause the full system to over flow) and run it from there.

[Twolitre]

Sometimes in my old ST165 after driving round town I couldn't touch the top tank without burning my hand yet on a long drive at night, pop the bonnet take the cap off the IC and the water inside was cold, obviously the colder the water flowing through the core the colder yout intake temps will be.
In awnser to your questions it makes a huge difference over the stock pos top mount and all_fours is correct a little bit of anti-freeze is neccessary if not redline water wetter. The pumps can be rebuilt, or otherwise just find another one if yours shits itself.
Ps. the pump in stock form is throttle related like Vvega said, I think it varies betweeen generations but basically it comes on for 30 seconds or so under throttle then turns off.

[Malcolm]

Running the pump full time is useful for preventing heat soak (the intercooler gets quite warm after sitting at idle or low speeds for a minute or so), good for drag racing etc

Not sure if that is really the case. Remember, that if you aren't moving, even with the pump running, water will still be 'fed' through the pre rad, but won't be cooled. All you'll do is increase the temp of the water in the entire system which will take time to cool down again once you are moving. At least with the pump off whilst stationary, only the water in the WAI itself will be warm/hot. Then, when you move and the pump kicks in, you'll immediately get cooler water into the WAI. Would imagine that would be far more effective and possibly why the Toyota engineers designed it this way.
Gary

If you have a fan running then it will dissipate heat while stationary, keeping the water at approximately ambient temp, and even if you don't have a fan running the heat exchanger will still radiate heat out of the water, just not at the same rate it would if a fan was running. Toyota engineers tend to be more concerned with reliability than maximum performance, which is why Toyota has such an excellent reputation for reliability. They could have the pump and fan running full time and have no problems with heat soak but then they would have people destroying ringlands and blowing headgaskets because their IC water pump has failed and they had no idea, kept driving it with super high intake temps and detonated the sh*t out of the engine.
But each to their own, I know I will run the pump in my AW11 full time and if it craps out I will replace it or rebuild it, but that's just my way of doing things

[Lanius]

Awesome, thanks for the replies everyone, much appreciated.

VV ... when you say the intake temps dropped, can you tell me roughly how much they dropped by? Was it quite a significant amount? I think I'd rather have the pump running full time, and then have it repaired / replaced if and when it craps out, and enjoy the advantages of the lower intake temps.

Can anyone tell me if its the ECU that tells the intercooler pump how and when to run, or is it controlled seperately?

Water Wetter will be on the list of purchases next payday ...

[Malcolm]

in an RC there is a seperate intercooler ecu, not sure about st165's or st205's.
if you want to make your fans run full time when racing etc, then just unplug the sensor in the bottom corner of the radiator, or the plug going into the aircon pipe, by the diagnostic connector in the corner of the enginebay by the firewall. Either of these will turn both fans on whenever the key is on, until yoiu plug them back in again

[Lanius]

Excellent, can you tell me whereabouts the i/cooler ECU is located? Just want to make sure that I get it when I get the engine etc pulled from the front cut.

[Lanius]

viewtopic.php?p=289390#289390

[Malcolm]

From memory it's somewhere behind the radio. Personally I wouldn't bother with it, there's a good chance it wont plug in anywhere on a standard 185 anyway.
BTW are you getting a gt4 RC front cut?

[vvega]

the all have the intercooler computer
it sits just behind the glovebox near the top of the heaterbox

if you run te pump full time it will throw a code
but there are ways to get around this

they droped to over100 dgrees to a nice semy constant 20-30 on a mild day

the best watercooling in the world will struggle to get within 6 dgres of ambiant temperature

adding a icebox would not be difficult you just put it inline in the system

v

[vvega]

thats 100 dgrees whe idling at lighs for excessive times or in kfc drivethough
even mild highwaydriving saw it getting up there because its simply not running

oh and you know if its broken because it sends a code up on diagnostics

it sences current draw thought the motor and if is not working or is to much will bring on the check engine light
if your car dose not do this then your i/c computer had been played with

it will also throw a code if the water is low in the intercooler system

[Malcolm]

but he's not putting it into a GT4 RC, it's just a standard GT4, so it doesn't have any of those measures in the factory ecu for the w/a intercooler, because it doesn't normally have one