MK7 Golf Build

@burpod that was on the previous injectors, and quite some time ago. I think a fresh log with IATs will happen next week, but do know the AWIC is more aimed at stable temps vs lowest possible. I too would prefer them lower though!

burpod said:

if you're IATs are 110f cruising... i would loo

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Ever tried to get a W2A IC on ambient temp, while the water its using is the same as for the engine coolant?
Good luck with that one.
The biggest advantage of W2A IC is also their weakness.
Water has a really high thermal capacity. So you can do a bunch of pulls and you wont notice and increase in
the temperature. But due to the fact, that the waterloop shares the same coolant with the engine,
you get a higher base temp. One cool think I have personal in mind is: use a dedicated source for the water with radiator.
But at this point, I would rather use a normal A2A IC and completely close the loop of the W2A IC, so you dont end up
to cool the coolant with your pre FMIC.

ohhhhh.. i did not realize this air-water used coolant.. do they all?? i've never really looked into them, as i've so far seen no need to do anything other than a simple fmic, never had a problem with intake temps too high they are always nice and low, barely higher than what you get from some mild increase from engine bay heat. seems to me a water-air IC is really only useful for a track car? *shrug*

i was kinda wondering how the heck cruising intake air temps could be so hot! lol. that sure explains it

Capping the inlet from the main bottle and re-routing to a dedicated bottle would not be too terribly difficult. Might be worth some thought before a A2A addition

Yeah, a dedicated bottle and possibly larger/better positioned heat exchanger seems easier to me. Maybe route a squirter from the windshield res to spray onto the heat exchanger for occasional high power bursts.

You're probably familiar with Greg's Pikes Peak racer- he has his cua a2w intercooler plumbed up to a frozen boost heat exchanger:

The AWIC is integrated to the intake manifold so repositioning is not possible. And a very custom piece would be needed if trying to replace entirely with A2A.

I meant the heat exchanger for the intercooler. Basically a little radiator.

Ah! There's possibly some room there, I do have the "hot weather" version that is slightly thicker but that's a good point!

I have no idea where they mount that, but anything that would get more airflow across it would help.

Something like this placed behind the lower grille where there's good airflow might drop IATs a decent amount:

That's not a bad idea at all. The heat exchanger is just a slim radiator that sits sandwiched between the main radiator and AC condenser. My stock MK7 hot weather version is 625mm X 414mm X 27mm (5mm wider and 11mm thicker than the standard). I would be curious if somehow a unit similar in size to say, an upgraded A2A charge cooler for a GTI/R could fit in that same location to keep things simple.

It might also help if I straighten all the fins of the AC condenser because I know they are jacked up and likely blocking a ton of flow. The condenser is very large and blocks nearly the entire charge cooling radiator, so flow there could be improved substantially. I may be pulling the bumper soon anyway when taking the gearbox off (again) to install the input shaft support, so will have plenty of access to straighten all of those.

Edited in because this is likely the better figure to use:
Rough estimate of cooling surface area by measuring core width X depth X twice the number of cooling rows (to account for surface area of top and bottom of each bar). Anyone feel free to mention if my thinking is off.
2086sq.in - MK7 Hot climate
1848sq.in - Frozenboost front mount
2496sq.in - small Mishimoto front mount
3612sq.in - large Mishimoto stock mount location (darn close to stock fitment dimensions and inlet/outlet)
4800sq.in - CTS upgrade

Wow, that CTS exchanger is gigantic. I'd think a separate coolant res with more capacity could achieve the same thing with a somewhat smaller exchanger/radiator. Maybe you could fit something in the airbox area if that's going away. You could even add some ice for dyno pulls and such.

Yeah, it's more than double the size of the stock S6/S7 unit that it replaces, but they claim to only receive a 10F-12F drop in charge temps. That is a big spend for that small a gain! I am only guessing here..but that gain could be small because it is also connected partially to the main engine coolant circuit (like the MK7 Golf), and what coolant is bled off is then draw in from the main circuit adding a little more work for the exchanger to do.
It seems like a dedicated circuit would be an interesting first test either way.

Might as well start by straightening out those condenser fins and see if that helps. Another advantage I can think of with separate cooling circuits besides larger res capacity and the ability to cool below ambient(maybe) with ice on occasion, is you could use a pretty lean coolant blend for everyday driving. Like maybe 20% antifreeze, 80% water most of the year. Since water is a better heat transfer fluid, that itself would help a bit. You'd need to be mindful of very cold weather obviously, but you could carry a quart or two of antifreeze in the car for those times.

I've thought the same about coolant/water ratios, and a dedicated circuit would be far easier to manage...it's a good callout for sure. The Hyperkuhl product would be interesting to try as well with a dedicated circuit.
I also updated post #252 above since figuring the surface area is the better number to look at for these units. Just how much difference is at play when going from stock positioning to a front mount is key. I really like the idea of the larger Mishimoto unit I have listed, good price, and near stock dimension and location of inlet/outlet. Though, if thinking about a dedicated circuit, the inlet/outlet on opposite ends probably makes more sense based on where I think an extra reservoir would most easily fit.

Heat exchangers can be tricky to evaluate based solely on surface area or volumetric measurements. If I had to guess, the actual cooling capacity of the exchangers you listed would be somewhere between the volumetric and surface area figures, relatively. I've seen a video comparing the cooling efficiency of a2a FMICs and the Garrett intercooler they tested had 150% the cooling of another with nearly identical external dimensions. Mishimoto has a good reputation, I'd imagine their coolers are well engineered.

adjat84th said:

I've thought the same about coolant/water ratios, and a dedicated circuit would be far easier to manage...it's a good callout for sure.

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On the separate circuit, the radiator and pump only needs to keep up with cruising heat load.
Mine on the compound golf I only had a 1st gen prius inverter rad and pump that I scored at the junkyard, and a couple winters ago, even right after several hard pulls, with the aluminum IC core welded directly to the aluminum manifold bolted directly to the aluminum head, the IC was still ice cold, probably only 20f temps outside too, not crazy cold.
The thermal mass of the water sucks down a LOT of heat that the rad can dissipate over time. The IC itself also acts as a radiator most of the time, as your charge air doesn't heat much above ambient when you're not making significant boost.

Over the past couple weeks I added the input shaft support for 02Q 6spd. Regret not installing when I had the engine out
I couldn't find much out there that shows any difference in torque rating between the external brace that requires drilling holes in the casing (what I installed), and the input shaft insert that needs to be pressed in. But, it's all together and can't tell that anything was done to it!

Also, will be using CUAA 90mm MAF sensor and discovered via a local MQB get-together that the Integrated Engineering intake for GTI/R works near perfectly for what I have setup on the car. It's a 5" filter that mounts to a velocity stack/reducer to 3.5" (90mm). Minor tweaking to the air filter connection, and then adding a 3.5" aluminum hose joiner to complete the connection vs hacking up their tubing in the kit. Also had an appropriate connector to join the 2.5" TIP elbow, and hoping to have mitigated any "steps" within the track that could hinder airflow. A 2.25" to 3" reducing elbow would be the perfect solution, but would need to figure out a PCV connection somehow..still pondering a solution for that.
My only concern with the intake is that I REALLY don't want the added noise, haha

That's ready to go on once we update the file, which is dependant on one last piece to the overall puzzle of this build. Hoping to have that in a couple of weeks to start pushing above the 100mg/st mark.

Cool. Did you consider doing both the insert and the external brace on the 02Q? I just watched a YouTube vid from a shop that did that to a project car. I'd love to have the IE short runner intake manifold for my 07K. They don't give them away, unfortunately.

adjat84th said:

but would need to figure out a PCV connection somehow

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I'm increasingly becoming a fan of just dumping that out atmospheric rather than putting it into the intake post-MAF

After knocking the piston rings out of a single cylinder twice and ending up with a gallon of oil in my CCV catch can both times, it is pretty obvious how a lot of runaways happen... starting with blowby from broken rings or cracked pistons

turbobrick240 said:

Cool. Did you consider doing both the insert and the external brace on the 02Q? I just watched a YouTube vid from a shop that did that to a project car. I'd love to have the IE short runner intake manifold for my 07K. They don't give them away, unfortunately.

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I did, but I couldn't find anyone that did both nor any reason to suggest they're both needed. My take is, the brace will for sure keep the shaft from moving at all. The only other thing I considered was the "case brace" that literally holds the entire case together. One of the suppliers for said brace, only recommends it above 700Nm torque, which I should be under on this setup.

[486] said:

I'm increasingly becoming a fan of just dumping that out atmospheric rather than putting it into the intake post-MAF

After knocking the piston rings out of a single cylinder twice and ending up with a gallon of oil in my CCV catch can both times, it is pretty obvious how a lot of runaways happen... starting with blowby from broken rings or cracked pistons

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I'm not sure exactly how much of a real effect it has, but I've seen/heard mentioned before if running to atmosphere you're technically asking the piston to return to BDC with crankcase pressure of at least 1bar whereas if PCV is plumbed to intake you have a vacuum so piston has <1bar to push back down against...in theory.
I did also install a catch-can to try and keep as much oil from coating the CAC, so will have to keep an eye on how quickly it fills up. I've not noticed much oil consumption on the engine yet since I've changed it early (especially with how low lambda was on prior tune), but there is always some oil in the TIP/charge piping when I take it apart.

Right on, I'm sure it'll hold up great with the external/internal brace. I bet drilling the hole in the case was a bit anxiety inducing(if that's the one you did) Here's the video I mentioned. He was reinforcing the 02Q as part of an AWD conversion. I really like the content on this channel:

Yep, saw that one. The shaft insert they use is a weld-in style vs pressed in. It had me thinking I could install something like that very easily without removing the gearbox, but no other insert that I came across wasn't press-in style so I figured there was good reason for that.
SQS makes a completely solid full input shaft, but only works with their dogbox kit.

And drilling the holes was indeed anxiety inducing, I may have drilled (no, I definitely did) about 10mm too close the the 4th gear. I was able to salvage the situation by grinding down the internal part of the support to mirror the other side of it (though slightly thinner even) so that it cleared the gear while installed. I got lucky, and ended up with the brass rod now touching the input shaft 10mm closer to the gear it's meant to support. So fingers crossed that lasts forever, I'd like to not pull the gearbox again for a long long time.

Can the bitdi cuaa charge cooler manifold be used on the 150bhp model for better cooling

I believe in my notes they use a different part number gasket, so could be not worth the effort.
I think doing a dedicated front-mounted radiator (in the bumper), and a dedicated reservoir so that it's fully separated from the engine loop could show some real value in temp drops. That is the route I'll go.
Also, not a bad idea to get your AC condenser replaced if it looks anything like mine with 107k miles of use.

adjat84th said:

I believe in my notes they use a different part number gasket, so could be not worth the effort.
I think doing a dedicated front-mounted radiator (in the bumper), and a dedicated reservoir so that it's fully separated from the engine loop could show some real value in temp drops. That is the route I'll go.
Also, not a bad idea to get your AC condenser replaced if it looks anything like mine with 107k miles of use.

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No probs I've used a cuna model charge cooler pump has it's bigger and more flow, I tried to fit a cwa50 pump but couldn't get it to work, I'll look into this route

Well, that's good info to know!
I still have CRUA pump running mine, but know for sure my AC condenser is blocking a good bit or airflow to the radiator. It's on my list of things to replace because the fins are not traditional radiator fins that are easier to straighten and fix. That, with a dedicated front-mount cooler will show some interesting data that I'll be sure to log before and after.