IS20 Instalation Guide (1.8t)

[Gawernator]

I have one but seems like the perfect excuse to upgrade. Actually I think I trashed mine


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[TwinDad]

If it were me I would ask in the classifieds for a stock one. There's bound to be plenty lying around for cheap from people who have replaced their intakes and don't plan on reverting to stock.

I was thinking of doing that on the local Facebook page. That's how I found the turbo. Realistically it's not going anywhere though. Between the pcv and the intake holding it in place.
On other news I was able to get some logs in. I think my wastegate is a little too loose. I can hear it rattle under low speed throttle and my boost is building slowly. I even got a low speed pull and it wouldn't hit 20 psi until above 3,500. It ended up peaking around 23.6@4,200-4,600 range. Held 22.1@5,000 and 19.7@6,000. Timing advanced to 13. On an earlier log I got 17 degrees of timing advance, but it hadn't fully adjusted yet. Trims were too high. I was 21@5,000 and 19@6,000. I need to get the wastegate tightened up and then drop my target from 5,500 up to see if I can get that 17 degrees advance back

 

[Gawernator]

I knew it let me know if you can’t get it adjusted


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[TwinDad]

I knew it let me know if you can’t get it adjusted


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I figured I'd play it safe and not go too tight. Too tight and it won't work. A little loose and it still runs like a beast. It just takes a little longer for the spool to come up. It's most noticeable on logs starting at 2,500

 

[Gawernator]

Yeah the adjustment is pretty small


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[TwinDad]

I'm going to pick up some tiny wrenches first so I can get one to fit the arm. I used to have a set of ignition wrenches years ago when I did mechanic work. I'm sure they still make them. Does anyone who still has the is20 off the car now what size the arm is. It's got to be in the 2-4mm range.

 

[Gawernator]

I used either a 4mm or a 4.5 I want to say. It’s in my post I believe


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[TwinDad]

I used either a 4mm or a 4.5 I want to say. It’s in my post I believe


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Thanks. I'll go back and look

 

[TwinDad]

For future reference, the is20 wastegate actuator works differently than the is38. When unplugged, the is38 actuator still holds the wastegate closes tight. The APR adjustment process could work with that. The is20 and is12 actuators relax when unplugged and let the wastegate open a little bit. If you tighten the rod to close the wastegate, it will be way too tight once powered up. Gawernator discovered that. You have to push the actuator in all the way and then turn the arm to close the wastegate. You can probably go a little tighter than you think. I did it just till it closed and it's loose a little bit. You can do this to get it close though and then adjusted it tighter once it's plugged in and the key is on. Just leave the downpipe off.

 

[MeltedSolid]

I was thinking of doing that on the local Facebook page. That's how I found the turbo. Realistically it's not going anywhere though. Between the pcv and the intake holding it in place.
On other news I was able to get some logs in. I think my wastegate is a little too loose. I can hear it rattle under low speed throttle and my boost is building slowly. I even got a low speed pull and it wouldn't hit 20 psi until above 3,500. It ended up peaking around 23.6@4,200-4,600 range. Held 22.1@5,000 and 19.7@6,000. Timing advanced to 13. On an earlier log I got 17 degrees of timing advance, but it hadn't fully adjusted yet. Trims were too high. I was 21@5,000 and 19@6,000. I need to get the wastegate tightened up and then drop my target from 5,500 up to see if I can get that 17 degrees advance back

That's not too far off, I'm only hitting 20psi around 3400rpm, but you do have a GTI piggypipe so you should probably be hitting that earlier than me. Speaking of that piggypipe, it really does work! That's almost as much boost as my e30 settings on I assume only 93. I'm definitely interested to see the difference between it and when you switch back to the aftermarket downpipe.

 

[toledospeed]

For future reference, the is20 wastegate actuator works differently than the is38. When unplugged, the is38 actuator still holds the wastegate closes tight. The APR adjustment process could work with that. The is20 and is12 actuators relax when unplugged and let the wastegate open a little bit. If you tighten the rod to close the wastegate, it will be way too tight once powered up. Gawernator discovered that. You have to push the actuator in all the way and then turn the arm to close the wastegate. You can probably go a little tighter than you think. I did it just till it closed and it's loose a little bit. You can do this to get it close though and then adjusted it tighter once it's plugged in and the key is on. Just leave the downpipe off.

Do you have VCDS available? If so, it will be easy to adjust. Assuming Gawernator shared this thread?
http://www.golfmk7.com/forums/showthread.php?t=35012

Ideally, before you took the turbo apart, you mark the position of the adjustment rod/nut/locknut. Then you could have been close to spot on during reassembly.

 

[TwinDad]

That's not too far off, I'm only hitting 20psi around 3400rpm, but you do have a GTI piggypipe so you should probably be hitting that earlier than me. Speaking of that piggypipe, it really does work! That's almost as much boost as my e30 settings on I assume only 93. I'm definitely interested to see the difference between it and when you switch back to the aftermarket downpipe.

I'm on e30 as well. The main difference would be I'm following the stock timing curve. Not sure if you're seeing 17 degrees advance. At 3,700, I'm at 7.5 degrees advance. When I was on the is12, I needed e30 to match APR stage 2 boost settings. I'm guessing this will be the same due to the timing difference. Top end we start getting closer, but I have a lot of advance in the low and mid range over the APR flash

 

[MeltedSolid]

I'm on e30 as well. The main difference would be I'm following the stock timing curve. Not sure if you're seeing 17 degrees advance. At 3,700, I'm at 7.5 degrees advance. When I was on the is12, I needed e30 to match APR stage 2 boost settings. I'm guessing this will be the same due to the timing difference. Top end we start getting closer, but I have a lot of advance in the low and mid range over the APR flash

Oh I see, so overall you're about 3 degrees more advanced than me like normal. I'm curious how much of a difference that makes, if it's worth the slightly lower boost even with a downpipe? Well I assume you'll dial it in more as you go so the difference will shrink and hopefully reverse.

 

[Gawernator]

P.S. depending on your downpipe design you may not need to remove it. Mine has enough flex in the flex joint to where you could simply unclamp it. However I did not even mess with that at all, I simply kept turning the rod 1/4-1/2 turn at a time until the diagnostic test would pass. In the future I would say the best way is to mark the threads with paint or something, I want to say I had about 1 1/2 actuator rod threads sticking out when I took it off my IS12. It makes sense now why APR's video is not correct, it's different for the IS38 for some reason. Also I used a 4" IRWIN needle nose type locking plier from under the car to twist the rod, because it was pretty tight. Once the rod is looser like it should be you can turn it with a small 4 or 4.5mm wrench or even by hand eventually. However anyone reading this shouldn't need to mess with it on the car....

 

[MeltedSolid]

P.S. depending on your downpipe design you may not need to remove it. Mine has enough flex in the flex joint to where you could simply unclamp it. However I did not even mess with that at all, I simply kept turning the rod 1/4-1/2 turn at a time until the diagnostic test would pass. In the future I would say the best way is to mark the threads with paint or something, I want to say I had about 1 1/2 actuator rod threads sticking out when I took it off my IS12. It makes sense now why APR's video is not correct, it's different for the IS38 for some reason. Also I used a 4" IRWIN needle nose type locking plier from under the car to twist the rod, because it was pretty tight. Once the rod is looser like it should be you can turn it with a small 4 or 4.5mm wrench or even by hand eventually. However anyone reading this shouldn't need to mess with it on the car....

Yea, now that we've seen twice that the IS38 is different I'll add something about it to the instructions.