Charge cooler

[Born2Run]

I saw the japimports cc on ebay but lost the bid. I was wondering the same thing about the st205 throttle body. Would certainly make life a little easier (and we all like easy). Is there a difference between the st185 cc and the st205 cc as I have been offered a 185 for 40 quid. I know the 165 is a lot smaller and not worth the bother but cant find any info on the 185. I would assume its the same as the 165 tho. Can anyone correct me?

[Pitcher]

I dont know about the difference in size between the 205 and 185 but i think i read somewhere that the 185 does not run a dump valve, i maybe be wrong tho

[MR2Mania]

I dont know about the difference in size between the 205 and 185 but i think i read somewhere that the 185 does not run a dump valve, i maybe be wrong tho

I *think* the 185 is smaller.

You're right about the BOV thing, but my recent thinking is that this isn't necessarily a bad thing! I know of a few top engines that are not running one at all, and they've lost nothing for it. In fact, they probably have something to gain (ie no boost leakage, better responsiveness, etc).

I'm thinking of trying a config without the BOV to see how it feels. I've currently got a Turbosmart recirc BOV, as I hate vent-to-atmos valves (they make the car sound like a bus, and I feel they lose you straight line performance, as you've got to fill the whole system again with air).

[MR2Mania]

Incidentally, Born2Run, I was going to say that the ST185CC will be easier to install on a Rev1/2.

[Pitcher]

I thought it was a bad idea to run no BOV because the Turbo slows down due to air passing backwards through the turbo and the Turbo life can be shortened due to this.

[MR2Mania]

I thought it was a bad idea to run no BOV because the Turbo slows down due to air passing backwards through the turbo and the Turbo life can be shortened due to this.

The air doesn't necessarily pass backwards. Basically, the throttle shuts and you get a body of pressurised air that has nowhere to go. The turbo is still spinning up, so it's trying to work against that body of air. This can sometimes cause a sonic effect on the compressor blades.

The issue on whether it causes any damage to the turbo is an interesting one. A mate had been running like this for some time at up to 2bar with no problems. If you run less boost, then the issue is even less critical. Also, how many more GT4 turbo failures do you hear of compared to the MR2?

As I say, it's something I want to try, and personally I can't see any issues.

People like Chris Wilson also recommend doing this.

[Born2Run]

Thanks Dino. Guess at that price I have nothing to lose and as I am not looking for huge power gains and more interested in the temp side of things I am going to have a go. I have a recirculating BOV so will let you know how things turn out. If it all goes wrong you may find me in the queue for one of your systems when they come out.

Rory

[Patrick Gray]

really fantastic thread guys, some excellent reading i have to say. Plucking up the courage to attemp a cc conversion on my REV 3 is getting closer

[Andy F]

Dino
I tried both, with dump, without dump, and to be honest the car always ran better with the DV, having said that it was mapped with!!
It does make a very weird noise when you back off.

[Jimbob]

The ST205 throttle body is defo larger than the ST185. The ST205 also lacks the idle-up/adjsutment lever that is on the Rev2 throttle bodies. It is controlled purely by the internal needel valve and the butterfly bypass.

I'm pretty sure its 74mm.

The TPS is the same though. I can't run one as I am opting to keep TC which will not fit.

Yes the ST205 CC has a dump pipe and I thought it was slightly bigger too.

If you want to be king try and grab hold of one of the TTE ST205 chargecooler cores they are the daddy. They did TTE cores for ST165's as well but not sure about the ST185. The basic difference on the 165 was an extra row inside. Dunno how the carlos sainz and RC cores differ internally? Maybe the same?

I'll have a chat with my celica buddies.

The ST205 pumps work quite cleverly, its easy to mimic with a microswitch or potentiameter on the throttle, or by tapping into the TPS signal. The beauty of it is all the cold water is stored up front (in the actually quite large ) pre-rad. On initiation of the pump the contents empties into the core and cools the charge. The hot water (which will be small in volume) from the core will then mix and water temp will go up slightly.

I can't see why running the pump continously would hurt as It's not often that it doesn't run in a stock set-up anyway. The main contributing factor to pump failure is stopping and starting which are the times the bearings at the point of most wear, of course the pump must be rated for continual use in the first place but I should think the 205 one is? Dunno?

My 2P.

I was recently working on my girlfriends corsa and the radiator from the 1.4 looks like a spot on size

Time for Dino to set me straight

James

[Born2Run]

This has been a great thread. Gone from being a cc virgin to an almost virgin, lol. James, your reply has raised some good points. What other pumps are available. Just had a look at my engine and the question of the BOV became immediate. I assume the cc connects directly to the turbo so does the BOV connect to the CC. Cant seem to find any decent pics of how it all connects together. I am sure it will all become as clear as mud when I start the project. I am never one to shy away from a bit of experimentation so look forward to getting all the bits and seeing how they all connect.

Rory

[Jimbob]

As long as you have a ST185 CC then it connects to the CC body.

If using a ST185 you need a T-piece like baileys supply as a fitting fit. The BOV will fit onto this.

James

[MegatronUK]

The ST185 RC/CS intercooler is the same size as the ST205 - and looks virtually identical. The ST165 is approx 1/2 the size.

[Born2Run]

Thanks guys. I am getting there slowly but surely.

[Mark Edwards]

I was going to say, has anyone tried to fit the ST205 pre-rad? From memory, it's not too big a unit, so *may* fit

Too big mate, i've got one and it doesn't fit between the foglights and is quite thin too.

[Mark Edwards]

The ST185 RC/CS intercooler is the same size as the ST205 - and looks virtually identical. The ST165 is approx 1/2 the size.

Incorrect i'm afraid. The ST185 cc is noticably smaller than the ST205 one (though not a great deal) and also doesn't have the take off for a bov either.

[Jimbob]

Thought so

[MR2Mania]

The ST205 pumps work quite cleverly, its easy to mimic with a microswitch or potentiameter on the throttle, or by tapping into the TPS signal. The beauty of it is all the cold water is stored up front (in the actually quite large ) pre-rad. On initiation of the pump the contents empties into the core and cools the charge. The hot water (which will be small in volume) from the core will then mix and water temp will go up slightly.

Hmmm, this is an interesting theory, and you'll find people who agree and disagree with this. Personally, I think it depends on the application, and since we're talking about the MR2, then let me give my thinking on this...

We all know that engine bay temps get silly when sat still in the MR2. If the pump is not running (ie no water flow), then the chargecooler is absorbing a fair bit of heat. Now, say the pump is triggered by your throttle position. The pump starts pumping water around. Now, assuming that you're using 19mm ID hosing, the volume per metre run of this is about 285cc (ie 0.285 of a litre). If the rad is up the front, you could have about 4 metres of hosing between the rad and the pump. If the pump pushes out 14 litres per minute, it takes the water 4.5secs to reach the CC, by which time you've been on boost for a little while! Hence why I say you design the system to suit the application.

I personally would rather have the pump running constantly, especially if the pump is reliable enough to be run like this. Not only will the CC not get heat soaked, but it will also ensure that the CC is getting cool water constantly.

I can't see why running the pump continously would hurt as It's not often that it doesn't run in a stock set-up anyway. The main contributing factor to pump failure is stopping and starting which are the times the bearings at the point of most wear, of course the pump must be rated for continual use in the first place but I should think the 205 one is? Dunno?

OK, by that logic, if the majority of the wear happens when the pump starts and stops, then BECAUSE the ST205CC pump is likely to have done that several thousands of times in it's life (more so than a pump that has been running more constantly, ie on/off with the igntion), then this is probably why I have seen them fail so often.

Nevertheless, I note that Fensport advertise the stock ST205CC pump SECOND HAND for £85+VAT (see here http://www.fensport.co.uk/partsfiles/st205mech.htm) whereas the pumps I use cost £95 all in NEW, and are designed to run continuously for 2 YEARS!! Also, they weigh probably less than 10% of the ST205 pump (a reasonable weight saving).

Hence why I say that sometimes you're not always saving as much as you think (or in this case, not saving at all!).

[MR2Mania]

The ST185 RC/CS intercooler is the same size as the ST205 - and looks virtually identical.

Apart from the throttle body side outlet, right, which would be about 64mm?

[MR2Mania]

Dino
I tried both, with dump, without dump, and to be honest the car always ran better with the DV, having said that it was mapped with!!
It does make a very weird noise when you back off.

Mate, can you humour me and try this out again when she's up and running again, and fully mapped? Maybe let me have a go myself in your car, to make sure (I have to think of SOME excuse to get behind the wheel! ).