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IS38 1.8T Info/Discussion

mfennell

Passed Driver's Ed
Location
New Jersey
Has anyone done a Unitronic 2+ w/is38? My setup, just finished this past weekend:

Stock air filter (aFe on order)
Stock air box w/snow guard removed
MST tube & elbow
is38 (duh)
Stock exhaust
Stock intercooler

I know I'm leaving some power on the table but I was a little underwhelmed so I logged a 3rd gear run and was surprised to see boost peak at 1.4bar, barely more than the is12 with the Unitronic 1+ (2.25bar). That's about 21psi.

It pulls really hard eventually and doesn't trail off. I lifted at 6250, unfortunately.
 
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joedubs

Passed Driver's Ed
Has anyone done a Unitronic 2+ w/is38? My setup, just finished this past weekend:

Stock air filter (aFe on order)
Stock air box w/snow guard removed
MST tube & elbow
is38 (duh)
Stock exhaust
Stock intercooler

I know I'm leaving some power on the table but I was a little underwhelmed so I logged a 3rd gear run and was surprised to see boost peak at 1.4bar, barely more than the is12 with the Unitronic 1+ (2.25bar). That's about 21psi.

It pulls really hard eventually and doesn't trail off. I lifted at 6250, unfortunately.

Can't speak specifically to your setup but, in general:

Larger turbos will add less heat to achieve the same pressure (they're not working as hard). Obviously within reason.
Larger turbos won't have the same shocking torque as a small turbo (so it might feel underwhelming when in actuality, it's just smoother).
Larger turbos will obviously be able to support more boost higher in the rev range (since they're capable of flowing more volume).

The difference between the is12 and the is38 isn't HUGE but it's there.

Someone else probably has more relevant/technical data.
 

mfennell

Passed Driver's Ed
Location
New Jersey
Quicker follow-up than I expected from Unitronic. Target is 1.4-1.5 so I'm there. Good points joedubs. The smoothness is probably throwing off my butt dyno calibration.

Probably something to be had with an IC but it was 50F and I only did a single pull.
 

tigeo

Autocross Newbie
Has anyone done a Unitronic 2+ w/is38? My setup, just finished this past weekend:

Stock air filter (aFe on order)
Stock air box w/snow guard removed
MST tube & elbow
is38 (duh)
Stock exhaust
Stock intercooler

I know I'm leaving some power on the table but I was a little underwhelmed so I logged a 3rd gear run and was surprised to see boost peak at 1.4bar, barely more than the is12 with the Unitronic 1+ (2.25bar). That's about 21psi.

It pulls really hard eventually and doesn't trail off. I lifted at 6250, unfortunately.
Their site says it has crackle/pops/bangs/overrun - does it? How is it?
 

Sparky589

Go Kart Newbie
Their site says it has crackle/pops/bangs/overrun - does it? How is it?
That's interesting. I remember APR claiming they wouldn't run the crackle tune since unlike the 2.0, the 1.8 doesn't come with the necessary temp sensors to ensure cat health. Since Unitronic is normally to more conservative of the two, wonder what they know that APR doesn't.
 

mfennell

Passed Driver's Ed
Location
New Jersey
Their site says it has crackle/pops/bangs/overrun - does it? How is it?
I haven't noticed it. Maybe it's just subtle with a stock exhaust? Alternative: the marketing department just got it wrong. The page also mentions the "EU-style startup overrun", which I haven't noticed.

To Sparky's point, I found some old posts on Vortex saying you shouldn't run the cackle file with a stock cat, even in an R, which presumably has the sensors.
 
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tigeo

Autocross Newbie
I haven't noticed it. Maybe it's just subtle with a stock exhaust? Alternative: the marketing department just got it wrong. The page also mentions the "EU-style startup overrun", which I haven't noticed.

To Sparky's point, I found some old posts on Vortex saying you shouldn't run the cackle file with a stock cat, even in an R, which presumably has the sensors.
It could be - I know they've had wrong info on their main site before. Someone with the tune should reach out to John and ask.
 

mfennell

Passed Driver's Ed
Location
New Jersey
By someone, you mean me but I'm glad it doesn't have it. :)

I checked this morning - definitely no extra noise on overrun.
 

tigeo

Autocross Newbie
By someone, you mean me but I'm glad it doesn't have it. :)

I checked this morning - definitely no extra noise on overrun.
I'm guessing it's just a mistake on their web description, possibly just a copy/paste from the R or GTI tunes.
 
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