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Golf 1.8T General Consensus on 09G transmission

HJ38

New member
Location
US
Car(s)
MK7.5 Golf TSI Auto
Long time lurker, first time poster. I've been going through almost all of the 1.8T specific threads on this forum, and firstly wanted to thank all of the people who've documented their builds, their experiences with different tunes, and generally provided information; it's made everything for me a lot easier.
I own a MK7.5 Golf 1.8T with the Tiptronic/Slushbox/09G transmission, and am looking on some more information on how this transmission pairs up with different setup/tunes:
1. IS20 or IS38? From my understanding, the IS20 is generally the most common turbo upgrade for the 1.8T, but with it being a smaller turbo, the torque is more instantaneous and that is what can cause issues with the 09G's torque converter and send it into limp mode, so some people suggest running with the IS38, as the cost difference is minimal, has a better top end, and pairs better with the 09G because the power is more linear (?). Again, this is just my understanding from reading through various FB groups and forum posts on here; if I am incorrect, please let me know, but I'd like your thoughts on which turbo pairs better with the slushbox tranny I have (NON-DSG, just regular auto).
2. What tune? I'm currently running the Stage 1 APR IS12 91 Octane tune on an otherwise stock Golf, apart from wheels/tires. What's my best tune option if I were to go with a IS20/IS38? I'd rather stick with APR, since I've already spent the $600 on a stage 1, and upgrading to their Stage 3 IS38 tune would be relatively cheap, but if jumping ship to something different is better, I'm open to it. If anyone with a 09G transmission and a bigger turbo could comment on their experiences with reliability, power, etc on the following tunes:
Options:
APR Stage 3 IS38 91 Oct
APR Stage 1 IS12 91 Oct (current) w/ JB4 stack (will have to buy the JB4 new for support from George)
Reflect Tuning (cost? experience with them as far as power, reliability, etc)
A different OTS/canned tune?
I'm sure I'm missing something, so are there any better options?

Since I live in California, 91 octane is as good as it gets, but I do have E85 readily available all around me. This isn't a necessity, but which of the above options would best be able to accommodate E85/ some sort of ethanol mix?

I know these are very specific questions for a very niche part of the GolfMK7 community, but hopefully someone could guide me in the right direction considering my situation and the fact that this is a daily driver that needs to be as reliable as can be (lol) but can pull hard when it needs to.
 

ZuMBLe

Autocross Champion
Location
NY
Car(s)
Alltrack 6MT
If you just want to drive the car and enjoy it, the most practical turbo for the 1.8 is the IS20. You'll have plenty of low and and a good deal of mid range. The car will feel sporty and there really are no negatives. You can't go wrong with APR really. You being in Cali means you have strict testing. I'm not sure the IS20 APR tune is carb certified. If it is, I would go with that. If not, just get the Stage 1 91 octane tune. This is coming from a guy with a highly modified 1.8 now. I've spent a lot of time, a lot of money. There is a lot of stress when the car doesn't work right. There is a lot of stress when tuning the car for perfect driveability.

My advice to most people is, APR Stage 1, set it and forget it. If you're the tinkering type, you have a lot of options, none of them are perfect.
 

StorableComa

Autocross Champion
Location
SoCal, USA
Car(s)
17 GSW S FWD
Long time lurker, first time poster. I've been going through almost all of the 1.8T specific threads on this forum, and firstly wanted to thank all of the people who've documented their builds, their experiences with different tunes, and generally provided information; it's made everything for me a lot easier.
I own a MK7.5 Golf 1.8T with the Tiptronic/Slushbox/09G transmission, and am looking on some more information on how this transmission pairs up with different setup/tunes:
1. IS20 or IS38? From my understanding, the IS20 is generally the most common turbo upgrade for the 1.8T, but with it being a smaller turbo, the torque is more instantaneous and that is what can cause issues with the 09G's torque converter and send it into limp mode, so some people suggest running with the IS38, as the cost difference is minimal, has a better top end, and pairs better with the 09G because the power is more linear (?). Again, this is just my understanding from reading through various FB groups and forum posts on here; if I am incorrect, please let me know, but I'd like your thoughts on which turbo pairs better with the slushbox tranny I have (NON-DSG, just regular auto).
2. What tune? I'm currently running the Stage 1 APR IS12 91 Octane tune on an otherwise stock Golf, apart from wheels/tires. What's my best tune option if I were to go with a IS20/IS38? I'd rather stick with APR, since I've already spent the $600 on a stage 1, and upgrading to their Stage 3 IS38 tune would be relatively cheap, but if jumping ship to something different is better, I'm open to it. If anyone with a 09G transmission and a bigger turbo could comment on their experiences with reliability, power, etc on the following tunes:
Options:
APR Stage 3 IS38 91 Oct
APR Stage 1 IS12 91 Oct (current) w/ JB4 stack (will have to buy the JB4 new for support from George)
Reflect Tuning (cost? experience with them as far as power, reliability, etc)
A different OTS/canned tune?
I'm sure I'm missing something, so are there any better options?

Since I live in California, 91 octane is as good as it gets, but I do have E85 readily available all around me. This isn't a necessity, but which of the above options would best be able to accommodate E85/ some sort of ethanol mix?

I know these are very specific questions for a very niche part of the GolfMK7 community, but hopefully someone could guide me in the right direction considering my situation and the fact that this is a daily driver that needs to be as reliable as can be (lol) but can pull hard when it needs to.
At a minimum for Full E85, you'll need MPI. I just wrapped up my install and am fine tuning a few things before my first tank hopefully this week.

How up to date are you on Cali smog? Being a 7.5 you're probably a few years further out than I am, but I believe the 15s are coming up on smog soon. They scan the ECU for the CAL ID and Number and compare it against their database. So you either have to be stock for your vin, or on a CARB approved tune. Currently the only CARB approved tune is APR stage 1, for whatever vehicle. Not a big deal if you flash back to stock and drive to set readiness before smog, or stay stage 1. JB4 would need to be removed to pass the visual part of smog.

From my experience talking to a local mechanic that I trust, and who has several 1.8T customers FWD and AWD and is APR dealer. Stage 3 is going to give you EPC at WOT for 3 to 4 shift issues. I had these briefly with stage 1 from IE but they were able to correct them in a patch, not sure if APR is aware or willing to patch their software on this one, but is an ongoing issue as of my last conversation with him on 09G IS38 APR tuned wagons.

That isn't to say you can't do an IS38. Reflect would be an option for his custom tunes, I went the OS route but it looks like you're looking for something canned/OTS. Honestly I plan on going IS20 here shortly, and will probably end up on an IS38 in the end, everyone does.. that or hybrid.

As to why they recommend the IS38 with the 09G, Speculation but, I think it's due to the fact your torque comes on much later in the RPM band rather than the near instantaneous torque of the IS20 down low. Torque is what kills transmissions in the end. Though if reports are correct of Is20 09Gs on full e85 handling it just fine. I think you'll be fine with either OTS tune as they tend to be less aggressive than custom or Ethanol only tunes.

Now that Cobb supports the 1.8T, maybe you can get more love than I did when it comes to custom tunes and the 09G.

Let me know if you have any other questions. 09G is a small part of the community as a whole, so info is hard to come by sometimes.
 

HJ38

New member
Location
US
Car(s)
MK7.5 Golf TSI Auto
If you just want to drive the car and enjoy it, the most practical turbo for the 1.8 is the IS20. You'll have plenty of low and and a good deal of mid range. The car will feel sporty and there really are no negatives. You can't go wrong with APR really. You being in Cali means you have strict testing. I'm not sure the IS20 APR tune is carb certified. If it is, I would go with that. If not, just get the Stage 1 91 octane tune. This is coming from a guy with a highly modified 1.8 now. I've spent a lot of time, a lot of money. There is a lot of stress when the car doesn't work right. There is a lot of stress when tuning the car for perfect driveability.

My advice to most people is, APR Stage 1, set it and forget it. If you're the tinkering type, you have a lot of options, none of them are perfect.
Appreciate the advice, I do agree with what you said about just staying stage 1 and calling it a day, and that’s likely what I’ll do: the cost, reliability, and convenience are too good to pass up.
 

HJ38

New member
Location
US
Car(s)
MK7.5 Golf TSI Auto
At a minimum for Full E85, you'll need MPI. I just wrapped up my install and am fine tuning a few things before my first tank hopefully this week.

How up to date are you on Cali smog? Being a 7.5 you're probably a few years further out than I am, but I believe the 15s are coming up on smog soon. They scan the ECU for the CAL ID and Number and compare it against their database. So you either have to be stock for your vin, or on a CARB approved tune. Currently the only CARB approved tune is APR stage 1, for whatever vehicle. Not a big deal if you flash back to stock and drive to set readiness before smog, or stay stage 1. JB4 would need to be removed to pass the visual part of smog.

From my experience talking to a local mechanic that I trust, and who has several 1.8T customers FWD and AWD and is APR dealer. Stage 3 is going to give you EPC at WOT for 3 to 4 shift issues. I had these briefly with stage 1 from IE but they were able to correct them in a patch, not sure if APR is aware or willing to patch their software on this one, but is an ongoing issue as of my last conversation with him on 09G IS38 APR tuned wagons.

That isn't to say you can't do an IS38. Reflect would be an option for his custom tunes, I went the OS route but it looks like you're looking for something canned/OTS. Honestly I plan on going IS20 here shortly, and will probably end up on an IS38 in the end, everyone does.. that or hybrid.

As to why they recommend the IS38 with the 09G, Speculation but, I think it's due to the fact your torque comes on much later in the RPM band rather than the near instantaneous torque of the IS20 down low. Torque is what kills transmissions in the end. Though if reports are correct of Is20 09Gs on full e85 handling it just fine. I think you'll be fine with either OTS tune as they tend to be less aggressive than custom or Ethanol only tunes.

Now that Cobb supports the 1.8T, maybe you can get more love than I did when it comes to custom tunes and the 09G.

Let me know if you have any other questions. 09G is a small part of the community as a whole, so info is hard to come by sometimes.
At a minimum for Full E85, you'll need MPI. I just wrapped up my install and am fine tuning a few things before my first tank hopefully this week.

How up to date are you on Cali smog? Being a 7.5 you're probably a few years further out than I am, but I believe the 15s are coming up on smog soon. They scan the ECU for the CAL ID and Number and compare it against their database. So you either have to be stock for your vin, or on a CARB approved tune. Currently the only CARB approved tune is APR stage 1, for whatever vehicle. Not a big deal if you flash back to stock and drive to set readiness before smog, or stay stage 1. JB4 would need to be removed to pass the visual part of smog.

From my experience talking to a local mechanic that I trust, and who has several 1.8T customers FWD and AWD and is APR dealer. Stage 3 is going to give you EPC at WOT for 3 to 4 shift issues. I had these briefly with stage 1 from IE but they were able to correct them in a patch, not sure if APR is aware or willing to patch their software on this one, but is an ongoing issue as of my last conversation with him on 09G IS38 APR tuned wagons.

That isn't to say you can't do an IS38. Reflect would be an option for his custom tunes, I went the OS route but it looks like you're looking for something canned/OTS. Honestly I plan on going IS20 here shortly, and will probably end up on an IS38 in the end, everyone does.. that or hybrid.

As to why they recommend the IS38 with the 09G, Speculation but, I think it's due to the fact your torque comes on much later in the RPM band rather than the near instantaneous torque of the IS20 down low. Torque is what kills transmissions in the end. Though if reports are correct of Is20 09Gs on full e85 handling it just fine. I think you'll be fine with either OTS tune as they tend to be less aggressive than custom or Ethanol only tunes.

Now that Cobb supports the 1.8T, maybe you can get more love than I did when it comes to custom tunes and the 09G.

Let me know if you have any other questions. 09G is a small part of the community as a whole, so info is hard to come by sometimes.
Thanks for you detailed and quick reply! Smog is pretty far away for me, so that shouldn’t be too big a problem. It does seem like to do this properly, I’d need to go MPI, upgrade fueling, and tinker to a point where it no longer is a reliable daily, and since I don’t want to do the installs myself, it’ll come to cost more than it’s worth in the end after the dust has settled. Thanks for your advice, it helped me get a better understanding of the whole picture. Let me know how your turbo swap goes!
 

ZuMBLe

Autocross Champion
Location
NY
Car(s)
Alltrack 6MT
Appreciate the advice, I do agree with what you said about just staying stage 1 and calling it a day, and that’s likely what I’ll do: the cost, reliability, and convenience are too good to pass up.

I really miss the days when I was stage 1 and just drove the car. My car currently has a Vortex on it, and I can say I've probably gone too far. It's become more of a race car and not a really good "appliance". I really liked the car when it was an "appliance" that I got in and used.. I went stage 1 at 800 miles and really felt like that's the way the car should be from the factory. Probably feels even better for you cuz my car is much heavier than yours. If you can do the IS20, I'd do that to widen your power band. After the IS20, you're really just moving the power band up the rev range which makes the bottom less usable.

I've had 5 turbos in my car now, tune my own car, drive in NYC traffic, and road trip in my car often. I think I have a pretty good idea of what the different levels are like. :)
 

StorableComa

Autocross Champion
Location
SoCal, USA
Car(s)
17 GSW S FWD
Thanks for you detailed and quick reply! Smog is pretty far away for me, so that shouldn’t be too big a problem. It does seem like to do this properly, I’d need to go MPI, upgrade fueling, and tinker to a point where it no longer is a reliable daily, and since I don’t want to do the installs myself, it’ll come to cost more than it’s worth in the end after the dust has settled. Thanks for your advice, it helped me get a better understanding of the whole picture. Let me know how your turbo swap goes!
No need to upgrade fueling beyond MPI unless you want to run straight ethanol, and that is normally around the IS38 area. There are reports you might need to upgrade fueling to max the IS20 on E, but even that would be a drop in LPFP, so nothing too crazy or HPFP switch needed. A mild tune I don't think would have an issue on Full E and IS20.

Honestly my car has been pretty reliable so far, and don't see why anything with a non kill tune and any OEM turbo wouldn't be. Yes MPI and stuff can add new hardware to have issues with, but the setup itself is simple enough that if tuned for properly shouldn't be a new source of issues. Cars come with MPI stock ROW, granted smaller injectors, but same idea. I think you start hitting reliability issues when you start tuning for max power, or go big turbo setup where you're putting more stress than normal. Seen lots of IS38 Wagons running around, so I'd say they're pretty reliable if you do basic maintenance.
 

Sparky589

Go Kart Champion
Thanks for you detailed and quick reply! Smog is pretty far away for me, so that shouldn’t be too big a problem. It does seem like to do this properly, I’d need to go MPI, upgrade fueling, and tinker to a point where it no longer is a reliable daily, and since I don’t want to do the installs myself, it’ll come to cost more than it’s worth in the end after the dust has settled. Thanks for your advice, it helped me get a better understanding of the whole picture. Let me know how your turbo swap goes!
Bolded the most important part. I'm with Zumble here 100%, and I didn't even go anywhere near as far as he did on modifying my 1.8. The cost of labor for the benefits gained won't be worth it in my opinion. For what it's worth, I actually learned how to work on cars with my Golf, and even with literal thousands saved in labor over the years I'm still not entirely certain if it was all worth it. I've kept my car intentionally more as a daily, but every now and then I sit there and traffic and ask why I went down this rabbit hole for what is ultimately at the end of the day an appliance I want to comfortably get from point A to B in.

Thinking back on it, I'd say the last time I was truly confident and happy with the car was back on Is20 with stock fueling with a downpipe. You'll pass readiness with an Is20 and the stock downpipe on the OEM software, and I don't think there's a smog tech in California that can eyeball the difference between the 18 and 20's housings. Still if I had to pay for the installs, knowing what I do know I'd have personally stuck with stage 1, which is entirely trouble free and in the case of APR already CARB certified so you'll never have to worry about emissions.
 

ZuMBLe

Autocross Champion
Location
NY
Car(s)
Alltrack 6MT
but every now and then I sit there and traffic and ask why I went down this rabbit hole for what is ultimately at the end of the day an appliance I want to comfortably get from point A to B in.

Yea, I think 1.8 guys are generally not trying to build race cars, so I try to give advice accordingly. I too find myself wondering why I spent so much money and time on the car. It's a hobby and I like new setups which I can tune. But really, its not cool when the MPI fuel rail you just installed spews fuel all over the engine bay when you're about to go out, and the only thing that prevented a huge fire is probably my GF's sense of smell. We had to cancel our plans that night. Or the crazy sounds and vibrations the car makes when you install the stiffer mounts that everyone tells you is the best thing ever. Or when a tuner convinces you a 4 puck clutch is streetable and you live with it for like 2 years with the car shaking when you engage the clutch wrong, and making crazy sounds when slipping. Learn from this dummy here. Don't repeat my mistakes.
 

Sparky589

Go Kart Champion
As an aside, during the pandemic I went and bought a '94 NA Miata to finally learn stick on and have something to hoon around in while the world was frozen in place. It cost me ~$4k which is honestly less than what I've sunk into my Mk7 and this piddly little ~100whp matchbox whose only real option is the diff in the rear is more fun to blast around when I feel like it than the Golf. I've taken my Mk7 to track days, I've sent it down the quarter mile more times than I care to count, and despite effectively having triple the wheel horsepower, the Miata by virtue of being a dedicated sports car is more fun when I feel like it. Not to mention that with the Miata being a bit of a shitbox, I'm not constantly worried if it explodes or gets in a scrape. I don't fully regret what I've done with my Golf, as it was a willing and patient partner for me bumbling through developing a sense of mechanical competency while working on it.

But seriously, that APR stage 1 is $500. Price to performance nothing will match what it'll give you. Keep the car livable, enjoy the GTI levels of performance, and if you were serious about spending the kind of money to get to a genuine performance build installed at a shop, I'd say go and buy a cheaper weekend car. Granted I had the space to make a second car work, I completely get that not everyone is as lucky. But even if you can only swing for one car, a stage 1 with a rear sway bar, a decent set of tires, wheels, and a softer dogbone insert is all you need to be ~90% as fun as the Golf I drive today without having to really sacrifice anything when it comes to comfort.
 

Billfromnj05

New member
Location
NJ/NY
Car(s)
18 golf
I am also like the OP. Same car and always lurking to see info about modding the 1.8 so ty all that contributed to this thread. I always planned and just doing a stage 1 just to give it more pep and fun to drive!

Sorry to thread jack

But now that Cobb supports us now is it easier to get an AP and use one of their maps or just go the APR route?
 

ZuMBLe

Autocross Champion
Location
NY
Car(s)
Alltrack 6MT
I am also like the OP. Same car and always lurking to see info about modding the 1.8 so ty all that contributed to this thread. I always planned and just doing a stage 1 just to give it more pep and fun to drive!

Sorry to thread jack

But now that Cobb supports us now is it easier to get an AP and use one of their maps or just go the APR route?
If you don't plan on getting a custom tune, just get the APR tune.
 

joedubs

Go Kart Champion
If you just want to drive the car and enjoy it, the most practical turbo for the 1.8 is the IS20. You'll have plenty of low and and a good deal of mid range.
Having gone the opposite way (big hybrid, smaller hybrid, and now on an is38) I can say that for me, there's no way I would be happy with the is20 on the 1.8. As it is, the is38 sacrifices a lot up top (knowing what a hybrid was "reliably" capable of).

That said, I do my own work and tuning so I've never paid a dime for labor. An is38 is a $1000 upgrade and worth every penny. When you start adding labor and tuning, the bang for buck drops dramatically.
 

HJ38

New member
Location
US
Car(s)
MK7.5 Golf TSI Auto
Yea, I think 1.8 guys are generally not trying to build race cars, so I try to give advice accordingly. I too find myself wondering why I spent so much money and time on the car. It's a hobby and I like new setups which I can tune. But really, its not cool when the MPI fuel rail you just installed spews fuel all over the engine bay when you're about to go out, and the only thing that prevented a huge fire is probably my GF's sense of smell. We had to cancel our plans that night. Or the crazy sounds and vibrations the car makes when you install the stiffer mounts that everyone tells you is the best thing ever. Or when a tuner convinces you a 4 puck clutch is streetable and you live with it for like 2 years with the car shaking when you engage the clutch wrong, and making crazy sounds when slipping. Learn from this dummy here. Don't repeat my mistakes.
Yeah, as appealing it all seems to push what is really an economy car to be almost a low 12 second car, especially with mine being a MK7.5, it’s too expensive and nice of a daily to stick all these mods into. Stage 1 gives me the bit more power I need, so I’ll keep it at that. Thanks for the advice yall
 
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