That has been my experience. Someone at your level can put a stock N54 into a reduced power mode in 6 laps on an 80 degree day. I’ve been right seat passenger for that at Buttonwillow.
The stock S4 is overengineered in this regard. If you’re tracking the tune you need the CPS, so the real cost of a tune is about $5k.
he already did. They banned him for it lol.
Now there’s a topic I’m interested in.
Anyone with experience on a stage 1 for track work?
CPS needed?
At stock power levels, I have zero heat issues on the road course. But with a stage 1, I have no idea what to expect.
I’ve done 4 DE’s on APR stg 2 with stock cooling and intake/exhaust upgrades, no real problems I can tell, other than PT mentioned I was getting more timing pull than normal while logging at the strip. But haven’t followed up on that question.
Yeah I’ve got tons of videos of stage 1 with CPS. I observe about a 40 degree difference in surface temperature between the engine loop and the supercharger loop at the end of a run. I only recently went stage 1+.
https://www.youtube.com/watch?v=n14-4y8KWpY&list=UU8gCFr_1QUiWIIBuNpkqPVw
Hey west, thanks for the vid.
When you state that you observe a 40 degree difference in temps between engine loop and sc loop by the end of a run, are you referring to with CPS or without?
If it’s with CPS, do you know what the deltas are? IE: what is the observed improved temp difference between both loops?
I’ve posted about it in the past on AZ. I don’t have the data from the ECU because there isn’t a sensor in the SC loop. Put I use my hand held pyrometer to measure the difference in coolant temp between the overflow reservoirs, the hot output lines, and the heat exchangers. One notable difference is the engine loop is pressurized, whereas the SC loop is at 1 ATM.
I’ll see temps like 160 F on the engine loop and 120 F on the supercharger loop (measured at the reservoir and at the metal piping). On the radiators I’ll see 95 on the heat exchanger and 115 on the main radiator. This is after a 25 minute track session. I’ve only seen the two systems achieve parity one time, on a particularly brutal 115 degree ambient day where I’d been running the car on track repeatedly.
On stock system or CPS?
That’s pretty darn good if it’s stock system 
The CPS. The stock system runs both at 160 F.
The N54 record for the moment is actually 829HP (Motive 900 ST w/ supp port-injection) on a stock block with open deck etc. http://www.bimmerboost.com/content.php?5325-The-BMW-N54-horsepower-record-stands-at-829-wheel-horsepower-thanks-to-a-Motiv-Motorsport-single-turbo-upgraded-335i
@West-tard:
The S55 is not an N55 with largers turbos. It has a factory dry sump, closed deck block and, based on the logs from 1/2mi airstrip races, VASTLY BETTER boost cooling than the 3.0T, even with CPS- it held IAT to under 125F in 70-80F weather in 25psi 1/2 mi pulls on Terry Burger’s M4.
Lol as always as you have a $2000 CPS on your car that someone else installed, brakes, weight reduction, etc, but lets compare that to a bone stock 335 and poke fun at them.
I managed to drive my 2014 S5 in street traffic for a few min in 84’F temp, mashed the gas 2-3 to 90mph on a highway on-ramp and managed to hit 82.5C on my IATs- with stock boost which bled down to 6psi because of the heat. I’m sure if I would have pushed it harder I would have managed to limp it as the IAT was skyrocketing.
FAIL.
I have an APR CPS system with a temperature sensor about six inches from the CPS radiator outlet and a P3 gauge. My main engine coolant temperature is always about 200F. The CPS coolant temperature is always within about 5F of ambient air temp. The only time I’ve ever seen higher on the CPS coolant was after back to back 1/4 mile runs during which the CPS temp climbed into the low 90’s with ambient temperature about 70F.
The S4 cooling is sufficient for my road course needs. The M3 has a very impressive engine. The rest of the car isn’t perfect so I’ll never buy it.
1 wheel drive 900 HP is the silliest thing I’ve ever heard on the Internet.