Intercooler radiator

[Adamantium]

Need a bit of help here.

Being new to the car (not even got it yet really) I’d like to understand the tuning potential.

I’ve bought an eventuri intake and a fluid damper with 3.08:1 drive ratio for the supercharger.

I’m going to get a storm developments s-tronic remap and a Litchfield engine remap.

Right now I’m looking at chargecooling with some questions.

Primarily I want to know if the chargecooler itself can be upgraded? Am guessing not since a) no one talks about it and b)I’m sure I read somewhere that it was integrated into the supercharger.

With that in mind, has anyone here got updated the chargecooler rad, if so, which kit and why?

I’m looking at forge but that’s because I know the company from previous tuning. I can’t really tell if there’s much between the options from an outright power point of view as cooling of the water seems to be less directly power critical as say cooling and pressure drop across an air/air intercooler.

So I’m a little out of my depth. Any advice/opinions welcome.

 

[arad85]

This should help you understand: https://www.goapr.com/products/cps_30t.html

I have one of these, but got it as part of a package when APR tuned my car so didn't "see" it as an upgrade. Dippy doesn't have any uprated cooling and from his FIS Control package doesn't seem to need it. For a 3x pulley multiple, and driving on UK roads (and not racing) I suspect that you would only see a need for it very occasionally. The ECU will keep the engine safe and you'll just lose some power...

 

[lincoln_dj]

From reading around I've come to the conclusion it's not needed for most tunes (up to, say, 480hp). I'm upgrading mine, probably to the Forge one too. But mainly for peace of mind / reliability in keeping temperatures down.

If you're tuning further then I guess you'll need the upgrade, but then you start getting into melting the OEM cat territory and spending £££ lol

 

[Adamantium]

Lincoln,

If you’re going for the forge, hold fire. Might be able to get a better deal on two.

I don’t think there’s any extra power to come, that would only come from a better chargecooling HX which seeing as it’s part of the supercharger, is not going to happen without some major modding that I’m not looking to do.

I’ve read that the ecu pulls a lot of boost am timing as the IATs climb - even on a standard car this should happen.

I wonder if dippy can log ignition timing?

My FIS control arrived yesterday and is being fitted along with my Carplay interface probably some time today. Will have a tinker to see if there’s another indicator available.

 

[Adamantium]

In addition to the above, I’d actually like to know why the kits consist of much more than just a radiator core?

Surely it’s the core that’s adding the volume so why is it necessary to divorce the coolant and provide a dedicated header tank (I appreciate these two come as a package).

What’s wrong with just a much bigger capacity radiator. Just the extra volume alone will massively improve the consistency of the cooling effect, then add it the larger cooling area and it’s a double benefit.

So why the rest and why the cost?

In addition, I’m not entirely convinced that you want or need a better flowing pump than stock. At higher flow there’s more time in the chargecooler core to heat up but there’s also more time in the radiator to cool down. You need some flow of course but so long as the water isn’t staying moving so slow as to not be replenished quickly enough to keep temps down, I’m not sure what the point in it being any faster is.

I can see an argument if the rad has excess efficiency compared with the chargecooler then the faster flow will improve charge cooling without necessarily reducing heat rejection from the water to the air.

Then I have an issue with dual/quad pass. The flow rate through the rad volume is defined by the pump. If you have a single pass that had four times the cross sectional area of a quad pass the same volume of water flows through the rad in the same amount of time.

Eg. 1 litre does one pass in one second or 250cc does four passes in one second, either way, what difference?

Someone point out where I have gone wrong as why else do they make multiple pass cores?

 

[Dippy]

I don’t think there’s any extra power to come, that would only come from a better chargecooling HX which seeing as it’s part of the supercharger, is not going to happen without some major modding that I’m not looking to do.

I’ve read that the ecu pulls a lot of boost am timing as the IATs climb - even on a standard car this should happen.

I wonder if dippy can log ignition timing?

Bear in mind that the CREC engine has a revised supercharger and supposedly the intercoolers are improved. However since it is relatively new and wasn't fitted to US or Canadian S4/5s, there isn't a lot of data on it.

Part of the reason I liked the FIS-Control MMI is that its easy to access the measurements instead of having to drive with a laptop. But the downside is that it doesn't do logging. I am relying on IAT and "IDE09983 Torque limitation due to high intake air temperature". The latter is always 100% and so if I ever see it drop below 100% whilst IAT is high, I'll know that the ECU is holding back. Of course if it is a BS measurement then I can still see boost and ought to see that reduced if its too hot.

But I do have "IDE00149 Ignition angle of current cylinder: actual value" available to monitor.

In addition to the above, I’d actually like to know why the kits consist of much more than just a radiator core?

Surely it’s the core that’s adding the volume so why is it necessary to divorce the coolant and provide a dedicated header tank (I appreciate these two come as a package).

What’s wrong with just a much bigger capacity radiator. Just the extra volume alone will massively improve the consistency of the cooling effect, then add it the larger cooling area and it’s a double benefit.

So why the rest and why the cost?

In addition, I’m not entirely convinced that you want or need a better flowing pump than stock. At higher flow there’s more time in the chargecooler core to heat up but there’s also more time in the radiator to cool down. You need some flow of course but so long as the water isn’t staying moving so slow as to not be replenished quickly enough to keep temps down, I’m not sure what the point in it being any faster is.

I can see an argument if the rad has excess efficiency compared with the chargecooler then the faster flow will improve charge cooling without necessarily reducing heat rejection from the water to the air.

Then I have an issue with dual/quad pass. The flow rate through the rad volume is defined by the pump. If you have a single pass that had four times the cross sectional area of a quad pass the same volume of water flows through the rad in the same amount of time.

Eg. 1 litre does one pass in one second or 250cc does four passes in one second, either way, what difference?

Someone point out where I have gone wrong as why else do they make multiple pass cores?

I admit I haven't researched this much but I can tell you what I know (mostly from reading posts on Audizine).
The B8 had two rads. The B8.5 was revised to just one.
There does seem to be disagreement as to if the charge cooler needs to be divorced or not. I don't think I have seen anyone provide any proof that it is better. Same regarding the pump.
There are expensive kits and they there are people who have just replaced the rad with a bigger/better one from a different make/model of car. It does make me wonder if its a bit like the air intake situation - there are expensive kits which look nice, then there's the simple hose & filter option.

 

[Adamantium]

Didn’t realise that about the crec - great to hear.

 

[lincoln_dj]

Must admit, reading all that and having a think, just a bigger surface area should suffice. Air is being forced over the heat exchanger by a fan anyway...

 

[Adamantium]

Only when the fan is on.

I’m not sure why there are complete kits around and not just a much bigger rad with everything else being equal.

The jury remains out on if you need to divorce the system.