Intercooler efficiency

[aus jd 2703]

pretty much im running a st205 intercooler and have been told conflicting stories of how efficient these are.
im trying to get as close to 300awhp eventually but am at 216awhp dyno proven. i have been told that going to a front mount (good quality pwr or similar) would at this stage net me 5awhp. no big deal but they also said that right now if i push much harder i will run the chance of detonation due to intake temps.
now a few months ago (back in summer) i got curious and put a thermo couple right before the throttle body.
now at idle it was always at ambient and when i boosted to red line it would hit 50-55'c so around 25-30'c over ambient. my question is this. is 55'c high intake temp?
and would the 205 ic be a restriction at 300awhp both flow and not effectively cooling?

[boxh34d]

******I have no experience with the ST205 WTA cooler******
As a general statement, it depends what your turbo outlet temps are. If the pre IC temps are 150deg C, then 55 deg after the IC is not too bad on a 30deg day, but if pre IC is only 80 deg C, then it's not that great.
In the same token, if you have 5 psi of pressure drop across the cooler, then it's not much chop either.

You really need to compare both sides of the cooler (both pressure and temp) to work out where you are.

[senior fred]

I have asked this question on the Alltrac forum - FM intercooler V top mount & top mount water cooled. The conclusion was, there is no conclusion. Everybody that replied had different ideas, so I'm back where I started.

But I did note some interesting comments to think about FM intercoolers down side - Longer travel for the compressed air = lag time. As FM sits in front of the engine radiator & air con.system means less air gets through. Air to air system, +ambient temp of the day. Hot summers day = hot air

One guy who has a ST165 uses the standard water to air intercooler, but has fitted a bigger heat exchanger with a electric fan behind it. He pulls 360 neddys out of his stock/rebuilt engine. Another guy in GB does the same, ST205 WTA with a motor bike radiator as a heat exchanger.

So get a cheap supercheap elect. fan and put it behind your heat exchanger and see what happens

[senior fred]

I almost forgot. At the same time as question on intercooler, the question of hooking up the water pump to the WTA to run full time. I have even a wiring diagram for that.

Very debatable. Some people believe you should leave the pump alone. The down time when the pump is not operating allows the heat exchanger to soak more heat out of the coolant.

I dunno about that one.

[boxh34d]

Yes, front mounts have a bit more piping, but in the real world, it is pretty negligable.
They do rob some radiator efficiency due to adding restriction and prior heat soak to the air going through your rad. Do you actually have a problem with water temps, and has anyone else seen any issues due to this reason (alone)? I doubt it.

The whole thing of air to air meaning that hot day = hot air is true. But, it is equally true to WTA units as well. One way or another, your exchanging heat from your boosted air, to the outside atmosphere. Therefore, you can't really get your intake any colder than the ambient air, unless its a drag car running a closed system throuh an ice box etc.

Air to Air does have some minor (very minor) negatives, but they are cheap and simple, and often quite efficient.

Do some testing on your system, and make a decision from there.

[RONA]

Yes, front mounts have a bit more piping, but in the real world, it is pretty negligable.
They do rob some radiator efficiency due to adding restriction and prior heat soak to the air going through your rad. Do you actually have a problem with water temps, and has anyone else seen any issues due to this reason (alone)? I doubt it.

My Caldina similar car/engine setup would get quite warm after about 4 laps on the track and I dare say a fair bit of that was due to the lack of air flow caused by a front mount taking up a fair share of real estate up front. Back off and temps dropped back instantly.

As for the actual intercooler argument, ST205 stuff is getting old these days and quite a few people have cracked cores running 18+psi of boost which can equally lead to engine issues. Front mounts are fairly cheap, simple and allow bigger head room for the future. I had shit tonne of piping on my old setup on the Caldina and still saw 18 psi by 3000rpm on a standard turbo, 300awhp would not be out of the realm of a similarly responsive aftermarket turbo.

[JustenGT8]

For 300awhp just stay with the stock cooler. Do everything you can for thermal management in that evil engine bay though. On mine i put an extra shroud over the turbo, plenty of insulation on the cooler itself. The good quality adhesive types with the reflective coating are ideal. Do the underside big time. Do the constant pump conversion, it makes a clear difference for the better. Add some water wetter to the IC coolant,, that also helps quite a bit.

Do all that and you'll have a pretty decent system consistency wise.

you intake temp figure align with what i used to see...around that 50 deg C. I also added water injection to mine (a small aquamist setup) and that brought the intake temps down another 20 deg C to around 30deg...almost ambient it was that effective.

The problem with these coolers at high hp..more like 300awkw..is they are a bit short and the air doesn't get the chance to scrub heat to the cooler. They also split as mentioned previously.