Inexpensive Intercooler Improvement Experiment DIY
01-31-2016, 04:29 PM
#31
AudiWorld Member
Join Date: Feb 2014
Posts: 115
Likes: 0
Received 0 Likes
on
0 Posts
There is likely some benefit from a colder denser charge and I think your exploration is a great idea. But yes people need to know that there is other low hanging fruit for more power per se.
02-08-2016, 07:43 PM
#32
AudiWorld Senior Member
Thread Starter
Hooked-in auxiliary intercooler radiator on Saturday. Didn't drive much on weekends and no long highway trips but this week will reveal more.
Preliminary observations are the following....
It's become obvious the stock small front radiator is a great "Heat exchanger" that works well when airflow is abundant such as highway speeds. However, with less airflow across/through radiator there is less heat dissipation... meaning radiators don't cool off as quickly and heat remains longer. The water flowing though the hot/warm radiator picks-up the heat of the radiator if it's not cool enough. So if front intercooler radiator is hot with heat not yet removed (hotter than incoming water from low speed supercharger) then cooler water will heat up.
"Heat Transference".
At low speeds, the intercooler temps are now higher with additional radiator. The low speed doesn't provide enough airflow to cool and the units remain hotter, so as water flows through it heats up rather than cool.
HOWEVER,
At high speeds, the intercooler temps appear slightly lower at maybe a 5 degree Fahrenheit temperature drop but to early to tell for sure.
Although not much of a temp drop, the big impact seems to be a major improvement in heat soak recovery.
In safe area off public road... did high speed accell from stop to kick-in maximum boost.
Pre-extra intercooler radiator
intercooler water temps rose by 40-50 degrees F in 8-10 seconds due the massive heat generated by supercharger.
Cool-down back to original temp before boost run took roughly 40-60 seconds to return to normal. Depending on travel speed wind across radiator.
Post-extra intercooler radiator
intercooler water temps rose by 40-50 degrees F in 8-10 seconds due the massive heat generated by supercharger.
Cool-down back to original temp before boost run took roughly 6-30 seconds to return to normal. Depending on travel speed wind across radiator.
Initial thoughts...
This is potentially a good mod for those who Track their car and need to quickly reduce intercooler temps and reduce heat-soak. Also good for lead-footers that love to see lots of boost on highway runs.
Not so good for cars with majority of driving at city speeds. Not enough airflow to cool down front radiator(s) and water will instead heat-up rather than cool-down.
Preliminary observations are the following....
It's become obvious the stock small front radiator is a great "Heat exchanger" that works well when airflow is abundant such as highway speeds. However, with less airflow across/through radiator there is less heat dissipation... meaning radiators don't cool off as quickly and heat remains longer. The water flowing though the hot/warm radiator picks-up the heat of the radiator if it's not cool enough. So if front intercooler radiator is hot with heat not yet removed (hotter than incoming water from low speed supercharger) then cooler water will heat up.
"Heat Transference".
At low speeds, the intercooler temps are now higher with additional radiator. The low speed doesn't provide enough airflow to cool and the units remain hotter, so as water flows through it heats up rather than cool.
HOWEVER,
At high speeds, the intercooler temps appear slightly lower at maybe a 5 degree Fahrenheit temperature drop but to early to tell for sure.
Although not much of a temp drop, the big impact seems to be a major improvement in heat soak recovery.
In safe area off public road... did high speed accell from stop to kick-in maximum boost.
Pre-extra intercooler radiator
intercooler water temps rose by 40-50 degrees F in 8-10 seconds due the massive heat generated by supercharger.
Cool-down back to original temp before boost run took roughly 40-60 seconds to return to normal. Depending on travel speed wind across radiator.
Post-extra intercooler radiator
intercooler water temps rose by 40-50 degrees F in 8-10 seconds due the massive heat generated by supercharger.
Cool-down back to original temp before boost run took roughly 6-30 seconds to return to normal. Depending on travel speed wind across radiator.
Initial thoughts...
This is potentially a good mod for those who Track their car and need to quickly reduce intercooler temps and reduce heat-soak. Also good for lead-footers that love to see lots of boost on highway runs.
Not so good for cars with majority of driving at city speeds. Not enough airflow to cool down front radiator(s) and water will instead heat-up rather than cool-down.
Last edited by IknowHuhA6; 02-08-2016 at 07:49 PM.
02-09-2016, 07:21 PM
#34
AudiWorld Senior Member
Thread Starter
But it's not all peaches and cream. Sometimes things break.
I've been member of forums where people are rude to people looking for help. So contributions not only need be physical projects. Many times helping to point others in right direction or positive support of others goes a long way. That's what builds a community. The rest is just fun.
02-10-2016, 02:52 PM
#36
yeah I find Audiworld to be pretty good at that, the M5 M6board was also great. bimmerfest is the iffy one (on some model specific discussion)
I just don't do enough DIY these days except the basic oil and brake changes.... hardwiring of V1.....(can post DIYs if needed for those). I can do one when I install my upcoming subwoofer upgrade
I just don't do enough DIY these days except the basic oil and brake changes.... hardwiring of V1.....(can post DIYs if needed for those). I can do one when I install my upcoming subwoofer upgrade
02-13-2016, 08:15 PM
#37
AudiWorld Senior Member
Thread Starter
A week was really not enough time to get enough information but oh well. Here's what I've got so far.
The second newly installed intercooler radiator from the chrysler crossfire donor sits atop the stock unit. That means it sits behind the solid piece of the grille's mid section. It appears the second radiator is not getting enough air across it to dissipate the heat. So instead of cooling the water further it's actually warming up a little the cooled water out of first stock radiator; Or rather keeping a warm temperature as the water passes though it.
I still see potential so I need to find a way to divert air up to second radiator.
If I had an RS style open honeycomb grille this would solve problem but I'm not really interested in that grille, and not going to entertain idea of buying another grille.
So now it makes sense why Audi kept intercooler radiator wide and short, and not tall. And instead provided a small additional radiator behind driver side ACC sensor location. The engineers wanted to make sure there was airflow across the units to dissipate the heat. Very impressive. I love that mindset.
The second newly installed intercooler radiator from the chrysler crossfire donor sits atop the stock unit. That means it sits behind the solid piece of the grille's mid section. It appears the second radiator is not getting enough air across it to dissipate the heat. So instead of cooling the water further it's actually warming up a little the cooled water out of first stock radiator; Or rather keeping a warm temperature as the water passes though it.
I still see potential so I need to find a way to divert air up to second radiator.
If I had an RS style open honeycomb grille this would solve problem but I'm not really interested in that grille, and not going to entertain idea of buying another grille.
So now it makes sense why Audi kept intercooler radiator wide and short, and not tall. And instead provided a small additional radiator behind driver side ACC sensor location. The engineers wanted to make sure there was airflow across the units to dissipate the heat. Very impressive. I love that mindset.
Last edited by IknowHuhA6; 02-13-2016 at 08:22 PM.
02-14-2016, 09:49 AM
#38
AudiWorld Super User
You could move intercooler #2 up into the air stream or install some "brake duct" tubing.
02-14-2016, 10:10 AM
#39
AudiWorld Senior Member
Thread Starter
Yeah good point. I'll take a look later today if moving auxiliary radiator up is possible but I think there's A/C fittings in the way higher up. Then I have challenge to find better way to support it since it was sitting atop stock unit. Trying to keep from modifying past point of not being able to return to stock.
Ducting would help but now that adds more pieces for not much airflow since air volume is limited by area of duct. Probably more complicated for the return it would provide, but still good idea.
Thinking maybe I'll add some aluminum sheet metal painted black and curve one or two sheets to direct air upward to auxiliary location while not robbing stock lower unit of air. Even if this doesn't stay as permanent solution.... this will help me determine if my observations of needing more air to be efficient are true, or If I just fail at hypothesizing. LOL
Ducting would help but now that adds more pieces for not much airflow since air volume is limited by area of duct. Probably more complicated for the return it would provide, but still good idea.
Thinking maybe I'll add some aluminum sheet metal painted black and curve one or two sheets to direct air upward to auxiliary location while not robbing stock lower unit of air. Even if this doesn't stay as permanent solution.... this will help me determine if my observations of needing more air to be efficient are true, or If I just fail at hypothesizing. LOL
04-02-2016, 07:17 PM
#40
AudiWorld Senior Member
Thread Starter
Update:
So I've finally had time to circle back to this mod. I moved the auxiliary intercooler higher up to be in direct path of airflow, instead of sitting directly on top of stock unit where it hid behind my installed S6 grille's solid closed area and didn't receive any direct air.
I need to top off the coolant and let air bleed out of system better over next day or two before I get accurate readings. But just on the drive home today I did go into high boost just out of curiosity. Intercooler fluid temp readings went from 98 degrees up to 120 degrees during boost right after exiting heat exchangers in the supercharger. But readings at the sensor after exiting the second intercooler remained almost unchanged, meaning the heat was able to be dissipated better. Temps remained somewhere around 103 degrees.
So I'm hoping now that the aux. intercooler is getting direct air, it will work more efficiently. As said before, I suspect this won't drop temps any lower, but it looks like it well help improve and reduce heat soak, allowing combustion temps to remain cooler to remain and return to normal after hard runs.
I'll get better readings during the week to compare against previous.
So I've finally had time to circle back to this mod. I moved the auxiliary intercooler higher up to be in direct path of airflow, instead of sitting directly on top of stock unit where it hid behind my installed S6 grille's solid closed area and didn't receive any direct air.
I need to top off the coolant and let air bleed out of system better over next day or two before I get accurate readings. But just on the drive home today I did go into high boost just out of curiosity. Intercooler fluid temp readings went from 98 degrees up to 120 degrees during boost right after exiting heat exchangers in the supercharger. But readings at the sensor after exiting the second intercooler remained almost unchanged, meaning the heat was able to be dissipated better. Temps remained somewhere around 103 degrees.
So I'm hoping now that the aux. intercooler is getting direct air, it will work more efficiently. As said before, I suspect this won't drop temps any lower, but it looks like it well help improve and reduce heat soak, allowing combustion temps to remain cooler to remain and return to normal after hard runs.
I'll get better readings during the week to compare against previous.
Last edited by IknowHuhA6; 04-02-2016 at 07:33 PM.