New intercooler

**vwthunder** · 03-01-2013, 07:52 PM

Originally Posted by Njay

what the frankenturbo F4h rated to, didn't troy pull 155kw atw with one

Yeah it was around that, graph is somewhere

They didnt give it a proper run and pulled it off the dyno as they couldnt get a AFR reading and didnt want to risk doing damage to the engine. The few little runs they did, well they were only playing

My scangauge reads the intake temp a 1 or 2 degrees over ambient

**Sirocco20348** · 03-01-2013, 08:12 PM

Originally Posted by h100vw

From what I have read though, the pressure drop across the IC is more important. ie do you want the turbo working real hard to produce 20 PSI in the intake when the IC is dropping 5 PSI. So to get the requested boost you are introducing a heap of heat. Effectively negating the boost.

VERY interesting. So is that the 2 values in vagcom: Boost Pressure 'Actual' and 'Requested'. ?

So the engine is requesting for example 20 psi, but with an inefficient intercooler the turbo my actually be pushing the equivilant to 25psi to correct the pressure drop?

Am I on the right track? Sorry for hijacking thread, Im just contemplating what I would do in Lito's position.

What density internal fin design is better from the 2 below?

CX racing core: (probably similar to godspeed as its the same price on ebay)

Treadstone:

**h100vw** · 03-01-2013, 08:38 PM

Originally Posted by Sirocco20348

VERY interesting. So is that the 2 values in vagcom: Boost Pressure 'Actual' and 'Requested'. ?

So the engine is requesting for example 20 psi, but with an inefficient intercooler the turbo my actually be pushing the equivilant to 25psi to correct the pressure drop?

Am I on the right track? Sorry for hijacking thread, Im just contemplating what I would do in Lito's position.

Nope, requested is what the ECU is asking for, actual is what is being seen in the MAP sensor just after the intercooler. There should be practically no split between the 2. Certainly once the turbo is spooling effectively, say over 2000revs.

Your second statement is correct, the ECU works the turbo hard to get the actual up.

Gavin

**Sirocco20348** · 03-01-2013, 09:05 PM

So its kind of a catch 22...

If you have a low fin density intercooler (like the cxracing above), you will have great flow and great IAT on the first pull. But the longer the car is on full boost or the more pulls it does, the crappier it will get in terms of heat dissapation leading to higher IAT and lower power.

But with a high fin density, the flow wont be as great at first to reach full boost and initial power output wont be as high as a low fin intercooler. However, in the long run as the car performs more pulls or full boost , the high fin density will disappate the heat better than the low fin, and therefore maintain higher power figures over a prolonged period of time.

More good reading:
http://www.treadstoneperformance.com...install-84.pdf
http://www.turbomagazine.com/tech/03...p_intercooler/

So i guess it depends on what LITO wants to achieve. If he wants to be king of the dyno, then he's probably better keeping the godspeed, parking the car overnight at the dyno center, warm up the car in the morning, spray the intercooler with water, and then let loose on the first dyno run lol.

otherwise if you track the car i would be ditching the godspeed and going for a more complex fin design for better transfer of heat.

Dynos are pretty stupid by the sounds of things, everyone just brings out there best dyno sheet when they should be averaging all their runs. If someone has a inefficient intercooler, after 5 runs on the dyno their high first run dyno figure will be much lower.