Name that Intercooler!
Trending Topics
01-21-2005, 09:34 AM
#9
Rennlist Member
Thread Starter
I guess I am wondering how much of an upgrade would I really be getting. I know going from stock to Kokeln is HUGE but would I just be throwing a lot of money after minimal returns in this scenario?
01-21-2005, 09:50 AM
#10
Rennlist Lifetime Member
In the world of intercoolers there are only two times you will receive huge gains. One is when the intercooler is too small volume wise to pass air through. Meaning you have modified everything but the intercooler and it has now become a bottle neck.
The other scenario is the intercooler core has gone beyond its efficiency temp. Meaning that it has become heat saturated. The stock intercooler goes down hill rather quickly after 88 degrees ambient. The car has seals which make the flow increase through the intercooler, but at the time it hits 88 it becomes an interheater, not cooler.
So at the end of the day if the core is efficient and able to handle the flow you will receive zero gain in HP and huge dividends in insurance. It is all about keeping things safe. The biggest marketing scam in this market is intercoolers add hp, no they don't. They do however keep you from loosing it. That and holeing a piston
The other scenario is the intercooler core has gone beyond its efficiency temp. Meaning that it has become heat saturated. The stock intercooler goes down hill rather quickly after 88 degrees ambient. The car has seals which make the flow increase through the intercooler, but at the time it hits 88 it becomes an interheater, not cooler.
So at the end of the day if the core is efficient and able to handle the flow you will receive zero gain in HP and huge dividends in insurance. It is all about keeping things safe. The biggest marketing scam in this market is intercoolers add hp, no they don't. They do however keep you from loosing it. That and holeing a piston
01-21-2005, 11:16 AM
#13
Rennlist Member
Thread Starter
In your expert opinion (I write that as I am thumbing through this month's excellence with a certain yellow TT on the cover)... with a K27, Andial Fuel Enrichment System, custom fab exhaust, machined heads, polished and magniflux crank, reground cams, recently adjusted valves and a reseal job, do you think there is much to be gained with the Kokeln? Maybe I am just missing this whole concept.
A friend of mine has one on one of the cars in his shop and has offered to let me flip the two and see if I see any difference (particularly in lag)... is this even possible without retuning the car for the different intercoolers?
Thanks!
A friend of mine has one on one of the cars in his shop and has offered to let me flip the two and see if I see any difference (particularly in lag)... is this even possible without retuning the car for the different intercoolers?
Thanks!
01-21-2005, 01:04 PM
#14
Rennlist Member
Another Option, Food for Thought
Hi:
I see that you have been getting a lot of good advise. Here are a couple of thoughts I will add for your reference.
An intercooler is a heat exchanger. The main characteristic of which you are interested in is it's "approach temperature" or how close to the ambient (outdoor) air temperature the intercooler/heat exchanger can bring the air inside the intercooler back too after it has been heated up inside the turbo, etc. You can never do better than that (unless you have a refrigerated system). Typically, if you can get to within 10- 20 F of ambient you have a pretty good heat exchanger and air flow system.
Several factors affect the approach temperature of a heat exchanger/interccooler including size (heat transfer area), flow rate of cooling air to draw the heat energy out, material of construction (heat transfer coefficient). Since 911 intercoolers are air to air, a properly channelled air flow is critical to good heat transfer. Similarly the more heat transfer area you can provide (read size) the better. Finally aluminum has an excellent heat transfer coefficient and is light and so makes a good material of construction . All of this will impact your approach temperature.
Finally, the idea of intercooling is to be able to get more molecules of air into the combustion chamber. Theoretically then you can add more fuel molecules and generate more power. So the key element is that if you can keep your approach temperatures low and the cooler the day the more power you can make, i.e. a large, well designed intercooler with lots of air flowing through it is the best solution. Naturally there are many other factors affecting how much power you can SAFELY make but a well designed and large intercooler is a good thing.
I have attached a photo of my Strosek 911 which has a very large well designed unit by David Hart of Proto Tech in Ft. Lauderdale FL. It also has a very high flowing deck lid to keep plenty of air flowing through the cooler. I do not know how this compares to the Kokeln unit. It looks well made as too but a little smaller than my unit.
I hope that this was helpful. I did not mean to state the obvious if you already understood some of the basic thermodynamics of heat transfer but just wanted to help you out if I could.
Best regards and good luck!
I see that you have been getting a lot of good advise. Here are a couple of thoughts I will add for your reference.
An intercooler is a heat exchanger. The main characteristic of which you are interested in is it's "approach temperature" or how close to the ambient (outdoor) air temperature the intercooler/heat exchanger can bring the air inside the intercooler back too after it has been heated up inside the turbo, etc. You can never do better than that (unless you have a refrigerated system). Typically, if you can get to within 10- 20 F of ambient you have a pretty good heat exchanger and air flow system.
Several factors affect the approach temperature of a heat exchanger/interccooler including size (heat transfer area), flow rate of cooling air to draw the heat energy out, material of construction (heat transfer coefficient). Since 911 intercoolers are air to air, a properly channelled air flow is critical to good heat transfer. Similarly the more heat transfer area you can provide (read size) the better. Finally aluminum has an excellent heat transfer coefficient and is light and so makes a good material of construction . All of this will impact your approach temperature.
Finally, the idea of intercooling is to be able to get more molecules of air into the combustion chamber. Theoretically then you can add more fuel molecules and generate more power. So the key element is that if you can keep your approach temperatures low and the cooler the day the more power you can make, i.e. a large, well designed intercooler with lots of air flowing through it is the best solution. Naturally there are many other factors affecting how much power you can SAFELY make but a well designed and large intercooler is a good thing.
I have attached a photo of my Strosek 911 which has a very large well designed unit by David Hart of Proto Tech in Ft. Lauderdale FL. It also has a very high flowing deck lid to keep plenty of air flowing through the cooler. I do not know how this compares to the Kokeln unit. It looks well made as too but a little smaller than my unit.
I hope that this was helpful. I did not mean to state the obvious if you already understood some of the basic thermodynamics of heat transfer but just wanted to help you out if I could.
Best regards and good luck!
01-21-2005, 01:19 PM
#15
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
One thing when looking at intercoolers is the construction and design. Typically they will follow in two type.. Design cast tanks and Hand made sheet metal tanks.. The companies like Garrettson, Kokeln, and all of the factory coolers use cast aluminum tanks that are welded to the cores. It allows smooth transitions for the air flow, in and out of the cooler. I would take these methods of constructions and design over a sheet metal tank, with sharp angles and welded end caps. Yes the overall size may be larger, but in the end the flow through the the engineered cast units in the long run are better...