Six to Four But defiantly not a down grade for Fast.

[fastcorvairs]

OK back on track.

What is the abundant air temperature of compressed air.  Dose it change dramatically from five PSI to fifteen PSI.  Won't one hundred eighty degree air cool two hundred degree air?  Can abundant air temperature cool compressed air down to abundant without some form of chilling it. Has any one ever put a thermometer in the intake of and intercooler to find out just how hot the air is under boost?

[fabr]

Yes they have and it can be a lot of difference.

[fabr]

Air to air will get you close to ambient. No need for chilling unless you want to go lower than ambient. You just don't want 50   degree hotter air going into the intake tract. The intercooler allows more cylinder pressure to be used without detonation due to the cooler intake charge.. Or put another way,it allows higher boost pressure for longer periods of time at the higher boost .

[sandvw]

So does this mean you have heard the motor running?

[chrishallett83]

What is the abundant air temperature of compressed air.

All depends on the ambient air temperature, how much you compress that air, and how efficient your compressor is. If you live in Death Valley and are cramming three bar of boost into an engine using an old 6/71 blower, your intake manifold temps are going to be through the roof.

Dose it change dramatically from five PSI to fifteen PSI.

Probably. The more you compress the air the hotter it will get. You're trying to smoosh three times as much air molecules into the same space, so they get pissy and wriggle around a lot more. It's like cramming four kids in the back of the car for a long roadtrip.

Won't one hundred eighty degree air cool two hundred degree air?

Yeah, a bit. Maybe to 190 degrees...

Can ambient air temperature cool compressed air down to ambient without some form of chilling it.

Yes, how much it does depends on the thermal efficiency of your cooling medium. The more thermally efficient your intercooler core is, the greater the flow restriction will be. There will always be a trade-off, if you want really hot air brought back to room temp, you are going to lose pressure due to the restrictive design of the cooler.

Has any one ever put a thermometer in the intake of and intercooler to find out just how hot the air is under boost?

Only way to test the thermal efficiency of a core is to measure before and after temps. A car magazine I used to read here called Zoom did this all the time, testing different factory and aftemarket cores for comparison articles.

Basically you want a good flow of nice fresh ambient air over a big enough sized core that you'll get good cooling, but without affecting lag or reducing pressures too much. You're bound to lose up to a couple of PSI through an intercooler, but that's offset by being able to run much better timing.

[fastcorvairs]

So does this mean you have heard the motor running?

That would be a no red rider. 

Still waiting on Ron Davis for a radiator. And need to build and exhaust.

[fastcorvairs]

All depends on the ambient air temperature, how much you compress that air, and how efficient your compressor is. If you live in Death Valley and are cramming three bar of boost into an engine using an old 6/71 blower, your intake manifold temps are going to be through the roof.

Probably. The more you compress the air the hotter it will get. You're trying to smoosh three times as much air molecules into the same space, so they get pissy and wriggle around a lot more. It's like cramming four kids in the back of the car for a long roadtrip.

Yeah, a bit. Maybe to 190 degrees...

Yes, how much it does depends on the thermal efficiency of your cooling medium. The more thermally efficient your intercooler core is, the greater the flow restriction will be. There will always be a trade-off, if you want really hot air brought back to room temp, you are going to lose pressure due to the restrictive design of the cooler.

Only way to test the thermal efficiency of a core is to measure before and after temps. A car magazine I used to read here called Zoom did this all the time, testing different factory and aftemarket cores for comparison articles.

Basically you want a good flow of nice fresh ambient air over a big enough sized core that you'll get good cooling, but without affecting lag or reducing pressures too much. You're bound to lose up to a couple of PSI through an intercooler, but that's offset by being able to run much better timing.

Thank's Lett83 lot's of good information here.

[SPEC]

I found this calculator, just in cas someone has the variables on record
 
http://www.jcalculator.com/?c=intercooler_temp_efficiency

[SPEC]

Altho this one might get you in the ballpark faster
 
http://www.turbofast.com.au/tfcalc.html

[fastcorvairs]

Altho this one might get you in the ballpark faster
 
http://www.turbofast.com.au/tfcalc.html

Still have to know the Intercooler efficiency.

[fastcorvairs]

Here's more.

I plan on using a Hobbs switch to activate the intercooler fan.  That way I don't have a fan running all the time while I am just putting around.  Only on boost.   What say you I use for and activation PSI.  Do I need a fan when the turbo is only boosting at say five PSI to nine PSI. Then when it gets over the nine PSI I have the fan come on.  I have heard tell that most subi's boosting only eight to nine pounds don't even need and intercooler.  But when you get over that you do need one.   

[fabr]

Personally I don't recommend any of it. The fan will come on and cool the intercooler too late IMO.

[fastcorvairs]

Ok so the new intercooler fan is in place.  I have 150 SQ inches of intercooler area. The fan is a nine inch.  How many SQ inches of fan area do I have.  How many SQ inches do I have covered with the fan.  The fan is a 740 CFM fan.  Am I hurting the cooling or am I helping?  The fan sits in the middle of the intercooler with about three inches of intercooler surface at each end open.  the nine inch fan covers all the way across the intercooler.  The shroud is about and inch off the intercooler at the radiator end and full open at the back. 

[SPEC]

too late in th night for me to do the math

[chrishallett83]

Here's more.

I plan on using a Hobbs switch to activate the intercooler fan.  That way I don't have a fan running all the time while I am just putting around.  Only on boost.   What say you I use for and activation PSI.  Do I need a fan when the turbo is only boosting at say five PSI to nine PSI. Then when it gets over the nine PSI I have the fan come on.  I have heard tell that most subi's boosting only eight to nine pounds don't even need and intercooler.  But when you get over that you do need one.

Water injection would be a better setup I reckon. Rigged so it only squirts when you're at WOT.

Little 1.5 gallon water tank, pump, injector and kickdown switch under the loud pedal.