Tbh your asking an awful lot of the standard cooling system. You've doubled the horsepower now it's time to balance everything else up!!

Get a vented bonnet, larger capacity rad. Put good coolant + water wetter in it and make sure its bled properly. The icing on the cake would be blocking all the air gaps around the water radiator, moving oil cooler from the typical position in between the inter cooler and water radiator and getting a good undertray.

 

A vented hood could help you quite a bit especially if the ambient temperatures are cool like you. By the way, watched your track vids. Those tracks look pretty cool. I should definitely check them out the next time I visit my brother in Sweden. Funny, I'd think someone from Sweden would be the last person to have overheating issues

 

The problem is I don't like aftermarket shit. I am not going to change my Honda rad for a alu one made in China, without knowing that it works
In my first post I asked for a good rad that works, but the problem is that all I read about have made a dussin other chanes to there cooling system at the same time they uppgraded the rad, either that or they drive their cars on the street.
Like I wrote, I tested on my last car to change to a Koyo radiator and splitted original hood. but there was almost no difference.

 

When you had a radiator before what fans did you have? Did you also have a lower temp thermostat? The problem is that you can do these changes to get incremental improvements with your cooling but the bottom line is you're boosted and running on track. Even NA track guys are seeing hot temps enough that they're adding oil coolers so it's not surprising you're seeing really hot temps with 11psi of boost. There's no real solution here other than to back off after it gets too hot for a lap or two before getting on it again. There are some boosted time attack cars but those guys do maybe 3-4 lap at a time (one warm up, 1-2 hot laps, 1 cool down).

 

Oh and you dont have to buy cheap aftermarket stuff if you don't want. There are plenty of very high priced high quality Japanese made ones if that makes you feel better about using it.

 

I don't mind buying expencive and only cry once. But I still need to know what to buy. Mugen,spoon or other high end rads?
It have to be somone with close to my setup who hade the same problem, who bought a good radiator and fixt the problem.

I could always convert to E85, so the problem would solve itself. But I do not like the E85, so I will try without.

 

Buy a nice aftermarket hood for yourself. I personally like the J's type-V. Also, get in on the group buy for the radiator that's being made; the thread is somewhere in the R&C forum.

 

The Way I read it you've got a host of issues and no one change is going to fix it.
#1 Large intercooler blocks air to radiator makes already poor radiator design worse
#2 Water Recirc pipe from head back to T-stat housing recirculates hot water without putting it through the radiator. This on an already taxed cooling system just adds to the problem. The issue is removing this pipe means relocating the T-stat or removing it.
#3 The Radiator design , not the rad it's self, but it's the design. Unfortunately all the aftermarket Aluminum Rad's keep the same design, you've gotta change it to a crossflow design which means getting one made, which is what I did.
#4 removing the air from the engine compartment, be it venting the hood or whatever you gotta get the air out to let new air in though the rad. On the particular car here we had issues here it already had a vented hood so we removed the hood and it bought us about a 1/2 a lap more distance before coolant temps hit critical.

Had a car here that would hit 230f in less then a lap. Between solving all of the above (no one of those did it) the car now hangs in the 190's for multiple laps.

 

For maximizing airflow through the radiator by blocking off the flow paths around it, just use some foam like this;
http://www.motoiq.com/magazine_artic...erheating.aspx

I have found the Koyo to work exceptionally well. While I am still NA, I can track in 95F/35C, stock hood, with oil cooler, and the coolant temperature doesn't move from 90C.

In your case, you are makind double the power which equals double the heat you need to reject. Even NA S2000s really need an oil cooler as I easily hit 270F/132C oil temperatures before backing off with the same 95F/35C ambient temperatures. The temperatures would have gone higher had I not slowed down. You are making double the power, so you are seeing the results of that with the stock cooling system.

For your situation, I would recommend an oil cooler mounted off to the side, similar to an Evo, 911, GTR, etc.... you'll need to make some ducting to it and cut a hole in the fender liner to give the air a place to escape.

 

Thank you for your answers and advice, I will start with the least hard to do, and the cheapest and work my self true the list.