After spending a month in California we were greeted by 12" of snow in the first 4 days back in Colorado. I took advantage of the snow days to complete some post-road trip maintenance, install some performance goodies, and research some future cooling and lighting upgrades. The Q7 saw 3,000 miles of use during October. 2,400 was the road trip from CA-CO and back and with the Q loaded up with cargo + a roof box and bike bikes hanging off the back there were multiple times while climbing grades that I saw >250F oil temps. I did data log anything so no juicy data but I did notice the engine pulling power/timing when it was hot. I can assume IATs were quite high at times. No shocker there since I was running a dual pulley setup with stock cooling but this was a good nudge for me to research upgraded heat exchangers for the supercharger. I performed an oil change and sent a sample off to Blackstone for analysis so I can see if there are any signs of oil breaking down from the high temps I observed.
- 3,000 oil change and anlysis
- Install 034 Motorsport SC clutch delete
- Flash 034 ECU and TCU software
- Explore cooling upgrades
- Explore lighting upgrades
The weather started in CA and we essentially drove through rain/sleet/snow the whole way home. McGuire's Ceramic car wash doing it's job.
I love the stealth hitch, especially when it's not being used but the hitch receiver does sit pretty low so it can make for some close calls like this.
Removing factory SC clutch. I had a spare clutch so I did this before removing the blower.
Clutch out and snout cleaned up.
I pulled the front bumper off the get a better look at the cooling system so I could take some pictures and measurements.
Here is a better look at the coolers. Front to Back (Left to Right) we have the thinner black ac condenser up front, then the main heat exchanger for the supercharger, followed by the main engine radiator. As you can see there is some room to work with. The OEM heat exchanger (HX) is tall and wide but thin 28"x19"x1.1" Most of the aftermarket HXs are shorter and narrower but thicker, my measurements suggest I should be able to go from a 1" core to one ~2.5" thick with similar height and width.
AFAIK there is no aftermarket HX for the 4M Q7, maybe because the OEM HX on the Q7 is about 5x larger than what's found on the S4, A6, and A7. Merc Racing seems to be a top choice for it's size, price, and evolving features. Poking around I found a Mishimoto (MMRAD-HE-04) HX that looks like it would also be a great option. Here is how these options stack up in terms of cubic inches which I used a crude guide for cooling capacity.
OEM HX (main) 28x19x1.1 = 585
OEM HX (Aux) 10x7.5x1.1 = 82.5
Mishimoto 24.6x19.6x1.9 = 916
Merc High Cap 18x17x2 = 612*
*I've sent an email to Merc Racing and I am awaiting reply but their specs online say "24x18x2.4 excluding piping" which suggests these dimensions include the rather large end tanks and since my cu/in calculations are of the core itself I did my best to estimate until I get confirmation on actual core dimensions.
I know there are considerations like the quality of the core and overall design; single pass, dual pass, etc. but going strictly off these numbers it seems the Mishimoto HX would be the unit to focus on first as it would have the biggest impact on capacity. I have a Pierberg CWA-100 on the way from FCP euro so I'll have increased flow to support a larger HX. I might order the Mishi to tinker with and test fit, if it fits well enough then having some fitting welded on which better suit the Q7 application might be the way to go.
Here is a pic of the OEM HX (main)
Mishimoto
Merc Racing
Oil change, bleeding cooling system, and topping off washer fluid with a winter-ready solution.
Extractor pulled 6.2L, I filled with 6L and then did a test drive where I got the "add a quart of oil message" so I topped off with the last quart. Full at 7L. Extractor gets pretty much all the oil, maybe <.5L is left in there and some oil is consumed so everything checks out.
With the maintenance and the clutch delete installed it was time to flash the 034 ECU and TCU software. I have one test drive on it so far so I'll get some more experience under my belt before I make any observations.
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