Reducing IAT's on the 1.8TSI

Haven't really seen a good discussion about this yet but is there any reliable/definitive way to reduce the IAT's on our 1.8TSI's? Based on the research I've done so far, the Golf R FMIC is good for maybe 10% more efficiency and given how difficult the installation is, you might as well spend the extra money on an aftermarket one. There is already a good thread discussing intercoolers here:

http://www.golfmk7.com/forums/showthread.php?t=16070

Another thing that you'd think could reduce IAT's a bit is a cold air intake. I've been doing a bit of research on all of the various CAI's available and there is a ton of conflicting information about which ones actually help / work better than the OEM one. I remember seeing a thread about modifying the stock snowguard by cutting holes through it so your stock intake gets more of a ram-air effect but now I can't find it (doh) but I'm leaning towards doing some modifications to my factory intake. Based on my experience with turbo Subaru's and intakes being a big no no unless you want a tuning nightmare i'd rather stick with OEM in this regard unless there is an actual proven CAI that performs better but I've yet to find anything definitive outside of a bunch of marketing garbage and outrageously priced pretty cf intakes that likely do little to nothing than generate more swishy sounds.

This leads me to my last question/point. APR's website specifically mentions "we recommend an intake and intercooler be installed" on the new IS20 1.8TSI tunes. Either this is marketing BS to get you to buy more of their products or perhaps there is a legitimate reason to consider supporting mods in the IAT department.

Anyone have any thoughts?

While a CAI can help a bit (pulling hotter air than necessary is never desired), the IC is still doing the lion's share of the work since the turbo compresses the air to a very high temp and then the IC has to cool it down. The IS20 upgrade will actually help with this (it will produce a lower turbo outlet air temp than the IS12 for a given PSI). The only real viable options are aftermarket IC and methanol injection. The Golf-R IC is a bit better than the one used on the TSI and GTI, but not by much. The Golf R IC is not an FMIC by the way...

Methanol injection alone can get you near ambient. Aftermarket intercooler will give you the usual benefits. Look in the intercooler thread in GTI forum.

R intercooler is within the margin of error for benefit. Probably not worth it even if it was free because the install takes some effort.

Stock intake is pretty good. But aftermarket is maybe a little better as long as it doesn't suck in warm air.

"APR recomends." Yes they do. But quite a few very successful turbo upgrades have been done on stock intercooler. And then think that your upgraded turbo will be blowing cooler air than the original..........

A proven intercooler is always a worthwhile upgrade. Nessesary upgrade? Depends on the car and the upgrade and how far you want to go.

TSI, GTI and R have an okay intercooler capacity wise and it's pretty good pressure drop wise. Its not like the Mustang Eccoboost where you have a flow and heat problem.

The intercooler thread gives me a headache but I found a thread about the rev9 specifically:

http://www.golfmk7.com/forums/showthread.php?t=23452

Looks to work somewhat well, drops this guys temps by about 20-25F consistently over stock. Its hard to find this kind of data by reading the other intercooler thread since there are so many options out there.

I also just took off the top of my "snow shield" thing and its identical to the GTI's in that it blocks all airflow going directly from above the grille into the airbox. I might do the dremel mod to mine to give the factory airbox more of a ramair effect. I also have another thought in mind for modding the snow shield that i'll make a video on when I get around to it.

I removed the snow catcher and added a K&N, but I'm not a big fan of modifying the stock airbox. Here is one of the threads where some of us gave opinions on this.
http://www.golfmk7.com/forums/showthread.php?t=33179

At a minimum. Rev9 looks like the cheapest option. Take it a step further with water methanol.

toledospeed said:

I removed the snow catcher and added a K&N, but I'm not a big fan of modifying the stock airbox. Here is one of the threads where some of us gave opinions on this.
http://www.golfmk7.com/forums/showthread.php?t=33179

Click to expand...

ah, thats the thread! No wonder i couldn't find it, its in general discussion.

Thinking of doing the cutout on the snow guard for mine though. Not sure why the gti's have the cutouts on their grille. Mine does not but I only plan on hacking up the snow scoop not my grille.

The GTIs grille is not cut out either. I did mine. I would say it's worth it. It is drawing air directly from outside vs the engine bay. The stock vent pulls from air that gets mixed in the engine bay some. Plus it comes across the top of a hot radiator. I also blocked off the center of the stock plenum. This way air still gets into the engine bay, but I'm only getting air from the outside. If it didn't work, they would not have opened it up in the R

How easy is it to swap out that part? I'd like a cutout for spring through fall and closed for winter. It appears simple, but sometimes looks are deceiving.

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Faceman said:

How easy is it to swap out that part? I'd like a cutout for spring through fall and closed for winter. It appears simple, but sometimes looks are deceiving.

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Click to expand...

Just a few torx bolts.

Faceman said:

How easy is it to swap out that part? I'd like a cutout for spring through fall and closed for winter. It appears simple, but sometimes looks are deceiving.

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Click to expand...

I've had mine cut out fduring a nor'easter blizzard and through all of the spring rains. No issues at all

I completely took out that stupid airbox, all fully open now with a CTS Intake. I went on a joyride last night with some city driving mixed in, pulled over to see if the intake was hot to the touch, was still cool. Filter and pipe. Seriously just take the thing out, it's like 4 torx bolts.

This is an extension of what BlueBalls posted for his GTI's intake over here: http://www.golfmk7.com/forums/showthread.php?t=33179

His instructions use a drill and razor blade to cut out the 3 sections of the snow guard in front of where the factory airbox inlet is. I used a dremel and it is NOT pretty and I will clean it up when I get some coarser sandpaper (lowest grit I have is 800 far too fine). But looking at the design of the snowguard, it still has the giant opening from the engine bay which would only cause hot air to be sucked into the factory box. Initially I was going to tape off the backside of the snow guard with some aluminum duct tape I had but then I figured it wouldn't hold up to the engine bay heat and doesn't really have any thermal properties anyways so I took a different route. I took some garage flooring pads that I had laying around and cut inserts out that I can slot into the snow guard to separate both sections. The foam is quite rigid and once the top snaps on it doesn't move at all. I used 2 back-to-back to help with thermal separation although I might look into getting some foam insulation board from the hardware store to try out but I'm not sure it will have enough give to snug in quite right.

Snow Guard dremeled out:

Foam inserts cut to size:

Foam inserts slotted in snow guard:

Foam inserts snugged into place by the top:


Snow guard installed, now directing outside air directly into the factory airbox with no engine bay air:

I did the same thing with the foam. I used a round sanding drum on the dremel to smooth everything out

TwinDad said:

I did the same thing with the foam. I used a round sanding drum on the dremel to smooth everything out

Click to expand...

I wish I could use my sand drum bits. The metal grinding bit is stuck in my dremel's chuck to the point of absurdity so I might need to get another dremel or just do it by hand