Sorry, I know you’re not asking me, but my un-divorced AMS system gets IAT’s to the low 50’s C when ambient is around 80F. That’s after 5-6 hard back-to-back third gear pulls (my normal testing method).
Having a W220 MB S600 and trying to bleed it’s intercooler loop makes the S4 seem like a piece of cake. That car is a nightmare.
One guy with a W220 MB S600 finally figured it out…fill the intercooler loop in from the bottom-most point. Here’s the post, and if you’re interested, this thread has a LOT of information on the myriad of intercoolers and intercooler pump upgrades you can do. This applies to our cars, and for those inclined, an interesting read. The take-away bit is that if the system is started with any entrained bubbles, you will get foam that will take forever to get rid of.
To apply to our B8 S4…on a divorced system…I would add a tee for filling to the passenger side of the intercooler at the very lowest point. I’d guess this would be hose 11 on the drawing below. Run the hose up to the top of the engine bay and leave it there, cap/clamp it when you’re done filling. I would suggest to check to see if the bleeder screws can be replaced with small valves during the fill, so that clear hose can be attached to help see bubbles.
To fill a divorced system:
-Open the bleeder screws at the back of the supercharger and reservoir cap
-Fill from the bottom until the res is almost full, then close it
-Keep filling until the bleeder screws are leaking.
Use a container/funnel with a bottom drain to fill it through the new tee, and enough hose to raise well above the car to pressurize it.
I’d strongly consider going divorced - on an undivorced system you’d have to pinch-clamp the top of hose 23 on the drawing below to isolate the intercooler loop during the fill. I have a big front cooler and the old small APR res, and did the “just keep filling” technique, but it’s my wife’s car now, so I’m not too worried about the intercooler loop and air bubbles. Maybe later on if I find myself dailying this car again.
http://img.photobucket.com/albums/v668/Ookane/Coolantloop.png
Bleeder screws on the back (anyone…what thread is it?):
https://c1.staticflickr.com/7/6230/6239411734_799f0202be.jpg
Here’s my idea for an upgraded intercooler. Cut the end tank off at the back and make 2 straight through passes of cold water instead of the OEM designed twice heated pass. Removal of the end tank would give you clearance of the throttle body. I think it would be 25-35% more efficient. What do u think? Maybe GIAC or 034 or AMS could make up a prototype?
http://audirevolution.net/addons/albums/images/385902510.jpg
I’m confused, you are saying intercooler, but the intercoolers (there are 2) are inside of the blower. The stock heat exchanger for the cooling system is single pass. The AMS one is triple pass
http://amsperformance.com/amsperformanceimages/16/Alpha_Audi_S4_Heat_Exchanger_02.jpg
Just the intercoolers (inside the blower)
Take a peak at the study guide, pg35 shows a close up.
Ah OK, I see what you are saying. I wonder how hard it would be to fab the back-end of that. Like you said about clearance and then I wonder how possible it is to disconnect the bleeder screw section for one pass to the other.
Your idea is interesting, essentially, make the heat exchange process more complete between the compressed air and the coolant. You would still need the larger front heat exchanger and the additional fluid could only help.
Yeah you would definitely still need the upgraded heat exchanger and likely the pump too. From a production standpoint, not sure if it would be practical to modify the OEM core or to produce new design from scratch. Probably be a pain to bleed but would certainly need some provision there. The end take is essentially a 90 already, so there should be enough room. Probably wanna oversize the feed tube and reduce the tubing of the parallel circuits to keep even flow (suddenly wanna listen to pearl jam lol) coming from all passes…
I don’t see it being hard to manufacture, and install would involve removing the SC, swapping the intercoolers, and repiumbing the now four parallel circuits. I’ve been thinking about it the last couple days and I can’t discredit the idea. I’m attracted to AR because this you guys seem to discuss engineering more intelligently. I figured bring the idea here as first step. Hell maybe some one will pick up the ball and run with it…
With all the talk about stage 3, there’s been a lot of talk about heat soak. I keep looking at the OEM intercooler and saying there has to be a way to improve it, with out increasing the size.
Thanks for the response…