146 replies to this topic

[Winstar]

 

 

The intercooler vs chargecooler debate fascinates me. If anyone's done any efficiency calculations I'd be interested? Otherwise as an (ex) engineer I'm probably still capable of working it out by myself if presented with enough data.   The interesting thing is mass flow of air through the RHS turbo ear and through the intercooler and the mass flow of air through the chargecooler rad at the front. Haven't seen any evidence on here of anyone measuring that?   Without wanting to be critical I find it interesting that there's lots of talk about IC and CC efficiency when what people mean is effectiveness. Without knowing the mass flow of the ultimate cooling medium you can't work out efficiency and you can't optimise effectiveness.

LMAO I spent years working designing vehicle thermal management systems (VTMS) and I've given up commenting on this as there's just no point as everyone has an opinion none based on fact or real test data (even those selling the stuff) As for mass low rate then my CFD model of a VX with ears but no blockage for the IC predicts at 45m/s (~100mph) there is just enough flow to cool the charge for 300 bhp. You'll find efficiency and effectiveness are generally used interchangeably when people talk about after coolers even at oem level.  

  With thanks to Winstar my charge intake temps have dropped from nearly 100degrees constant to 45 peak and astonishingly quick recovery rates.  

  Would you like to explain how you did it?

Most of it is covered in Chris' Barcelona 24 prep blog. http://www.hofmanns..../archive/201108

Edited by Winstar, 08 September 2016 - 07:52 PM.

[NDT]

 

 

The intercooler vs chargecooler debate fascinates me. If anyone's done any efficiency calculations I'd be interested? Otherwise as an (ex) engineer I'm probably still capable of working it out by myself if presented with enough data.   The interesting thing is mass flow of air through the RHS turbo ear and through the intercooler and the mass flow of air through the chargecooler rad at the front. Haven't seen any evidence on here of anyone measuring that?   Without wanting to be critical I find it interesting that there's lots of talk about IC and CC efficiency when what people mean is effectiveness. Without knowing the mass flow of the ultimate cooling medium you can't work out efficiency and you can't optimise effectiveness.

LMAO I spent years working designing vehicle thermal management systems (VTMS) and I've given up commenting on this as there's just no point as everyone has an opinion none based on fact or real test data (even those selling the stuff) As for mass low rate then my CFD model of a VX with ears but no blockage for the IC predicts at 45m/s (~100mph) there is just enough flow to cool the charge for 300 bhp. You'll find efficiency and effectiveness are generally used interchangeably when people talk about after coolers even at oem level.  

  With thanks to Winstar my charge intake temps have dropped from nearly 100degrees constant to 45 peak and astonishingly quick recovery rates.  

  Would you like to explain how you did it?

Most of it is covered in Chris' Barcelona 24 prep blog. http://www.hofmanns..../archive/201108

Good stuff. Thought it would refer to inter cooler flow not charge cooler though.

[harboged]

 

 

 

 

The intercooler vs chargecooler debate fascinates me. If anyone's done any efficiency calculations I'd be interested? Otherwise as an (ex) engineer I'm probably still capable of working it out by myself if presented with enough data.   The interesting thing is mass flow of air through the RHS turbo ear and through the intercooler and the mass flow of air through the chargecooler rad at the front. Haven't seen any evidence on here of anyone measuring that?   Without wanting to be critical I find it interesting that there's lots of talk about IC and CC efficiency when what people mean is effectiveness. Without knowing the mass flow of the ultimate cooling medium you can't work out efficiency and you can't optimise effectiveness.

LMAO I spent years working designing vehicle thermal management systems (VTMS) and I've given up commenting on this as there's just no point as everyone has an opinion none based on fact or real test data (even those selling the stuff) As for mass low rate then my CFD model of a VX with ears but no blockage for the IC predicts at 45m/s (~100mph) there is just enough flow to cool the charge for 300 bhp. You'll find efficiency and effectiveness are generally used interchangeably when people talk about after coolers even at oem level.  

  With thanks to Winstar my charge intake temps have dropped from nearly 100degrees constant to 45 peak and astonishingly quick recovery rates.  

  Would you like to explain how you did it?

Most of it is covered in Chris' Barcelona 24 prep blog. http://www.hofmanns..../archive/201108

 

 

Thanks! However, I was also hoping for some information on how to make the intercooler work better as I wish to run approx 250 hp with an intercooler and also keep the power on the race track.

 

But I now drive a "stage 1+" and on the race track with an ambient temperature of only 22 degrees I saw an IAT of 84 degrees, so I can only imagine how high it will be on a warm day and if I tune the engine further.

 

I'm planning to try venting the air after the IC out and also seal the inlet to the IC better, but maybe that will just improve things marginally and will not be a solution to the problem. I guess the way to go in that case is the water injection route.  

[siztenboots]

the problem is the map you have has not been setup to adjust load when intake temps increase , via map KFTARX instead it will compensate for the less dense hot air by increase charge pressure to meet desired load, which will quickly push things out of the optimal efficiency. Next thing to happen is knock as you are running hot charge, bad ignition.

[siztenboots]

example, intake air temperature compensation map for rpm and requested load from stock factory Audi RS6, this represents the latest best practise advice from Bosch.

 

btw courtenay, mmg , have left it all set at 100, same as factory default. But on a stage 2, 100% is now over 250bhp and you have no more engine safety threshold, hence why there have been the engines with damage.
 

[harboged]

the problem is the map you have has not been setup to adjust load when intake temps increase , via map KFTARX instead it will compensate for the less dense hot air by increase charge pressure to meet desired load, which will quickly push things out of the optimal efficiency. Next thing to happen is knock as you are running hot charge, bad ignition.  

 

Thank you very much for the info. I understand what you mean but I doubt there is anything I can do about it because I don't think anyone here in Sweden map these engines with the standard management system and I assume there is nothing I can do myself. Perhaps summer 2017 will be a trip to UK to get my car tuned and do a lot of trackdays over there

[siztenboots]

Bear in mind the sensor value for intake temperature (tans) , is a delayed lower figure so you should failsafe map load earlier. 10 seconds is the time to get to 63% of a change in sensor value. Brands Indy would be a good test to see the delay effect.
 

thermal time constant t₆₃ is 10 seconds max for the temperature thermistor
Response time t10/90 ms 1.0ms for the pressure sensor
 
based on this very useful data sheet for all things motorsport sensors, http://www.farnell.c...eets/312695.pdf