Any logs on stock tune with is20?

[00Zero]

I was just wondering with as cheap as used is20 are is it safe on a stock tune and is there any power to be had with the higher flow at the same boost?

Another road, again with as cheap as is20s are at 4lbs boost over stock (jb map1) would an is20 be a better upgrade than a cheap intercooler. If one was worried about iat / longevity and not huge numbers?

Has anyone gotten a hold of compressor maps for the two?

Thanks

 

[jimlloyd40]

You must have a is12 right now I'm guessing. But an IS20 wouldn't run properly without a tune.

 

[odessa.filez]

You must have a is12 right now I'm guessing. But an IS20 wouldn't run properly without a tune.

why?

 

[jimlloyd40]

why?

The ECU has to be tuned for a specific turbo. You can put an IS20 on but it won't run properly if the ECU isn't programmed to control it properly.

 

[tigeo]

The ECU is tuned to meet targets and doesn't know or care what turbo is attached...it will adjust parameters accordingly. You won't gain a thing running an IS20 without a tune (or JB4).

 

[odessa.filez]

The ECU is tuned to meet targets and doesn't know or care what turbo is attached...it will adjust parameters accordingly. You won't gain a thing running an IS20 without a tune (or JB4).

Suppose we run an is12 on JB4 map2, then run an is20 on JB4 map2.

Any gains with the is20? why or why not?

OP: I'm running stock intercooler, JB4 on map 2, map 1 during the summer on is12. I think it's fine for street, as my logs for straight pulls look okay.

At autocross after a few runs, heat soak waiting for my next run will impact my throttle response and increase severity of trim spikes and timing correction. Debating myself on the best cure for that.

 

[tigeo]

Suppose we run an is12 on JB4 map2, then run an is20 on JB4 map2.

Any gains with the is20? why or why not?

OP: I'm running stock intercooler, JB4 on map 2, map 1 during the summer on is12. I think it's fine for street, as my logs for straight pulls look okay.

At autocross after a few runs, heat soak waiting for my next run will impact my throttle response and increase severity of trim spikes and timing correction. Debating myself on the best cure for that.

I don't believe map 2/JB4 with an IS20 will do anything different vs. an IS12 - maybe the boost curve looks slightly different b/c of the slightly larger turbo taking a touch longer to spin up/produce the requested boost? Map 2 is taking the stock boost the ECU requests and adding a few psi if I recall. Folks running IS20 with JB4 are doing custom map 6 to gain the extra power from the larger turbo which involves not only more boost but more fuel delivery for that extra air to meet the ECU's required lamda value.

 

[TwinDad]

Suppose we run an is12 on JB4 map2, then run an is20 on JB4 map2.

Any gains with the is20? why or why not?

OP: I'm running stock intercooler, JB4 on map 2, map 1 during the summer on is12. I think it's fine for street, as my logs for straight pulls look okay.

At autocross after a few runs, heat soak waiting for my next run will impact my throttle response and increase severity of trim spikes and timing correction. Debating myself on the best cure for that.

It really comes down to torque targeting from the stock ECU. The is20 has the capability of making more power at the same boost, but the stock tune has the ability to remove boost as it senses the torque target met. That is why with an is20 and jb4, the absolute targets works better than additive. Additive only adds to the ECU request. That is map 2. It's additive. So if the ECU is cranking out 11 psi in the is12, it might dial that back to 8 psi if it senses the target is already being hit. So the additive is on that lower target boost number. If you run a map 6 with absolute value of say 20, the jb4 will force it to add boost until it hits 20. I've had my jb4 only is20 run on map 0. Stock tune. It feels really slow compared to the map 6. Like really slow. Maybe slightly more power than stock. Negligible though

 

[odessa.filez]

I don't believe map 2/JB4 with an IS20 will do anything different vs. an IS12 - maybe the boost curve looks slightly different b/c of the slightly larger turbo taking a touch longer to spin up/produce the requested boost? Map 2 is taking the stock boost the ECU requests and adding a few psi if I recall. Folks running IS20 with JB4 are doing custom map 6 to gain the extra power from the larger turbo which involves not only more boost but more fuel delivery for that extra air to meet the ECU's required lamda value.

thanks for hashing this out. I'm not an expert by any means.

My understanding is the fuel delivery is not controlled by JB4, unless one alters fuel rail pressure through FOL. I see folks doing that to compensate for E85..Am I wrong?

Does more turbo flow mean boost target is achieved more quickly?

The fact that posting their custom maps post-is20 install seems inconclusive except perhaps people doing the is20 want more powaa in the first place. I can't recall anyone posting up before after on either a stock map or a jb4 standard map.

Anyhoo, if I ever get around to installing my is20 (hopefully in Jan), I'll log map2 before and after. Won't be as good as a dragy but jb4 log does capture mph.

 

[TwinDad]

I was just wondering with as cheap as used is20 are is it safe on a stock tune and is there any power to be had with the higher flow at the same boost?

Another road, again with as cheap as is20s are at 4lbs boost over stock (jb map1) would an is20 be a better upgrade than a cheap intercooler. If one was worried about iat / longevity and not huge numbers?

Has anyone gotten a hold of compressor maps for the two?

Thanks

The is20 will work fine on the stock tune. It won't be much faster if anything at all. I've run it and it felt ridiculously slow compared to a map 6. I never ran it vs an is12 to compare. As far as the map 1 thing, read what I wrote above. As far as what makes the best power, an is20 with a jb4 on map 6 is better than an is12 on a stock tune and an intercooler. Both on a jb4 with a map 6, is12 with intercooler and is20 without, the is20 will still win unless the is20 starts to see IAT above 100 and the is12 stays below 80

 

[odessa.filez]

Stock tune. It feels really slow compared to the map 6. Like really slow.

Having seen some of your map6s, I believe you

 

[jimlloyd40]

Suppose we run an is12 on JB4 map2, then run an is20 on JB4 map2.

Any gains with the is20? why or why not?

OP: I'm running stock intercooler, JB4 on map 2, map 1 during the summer on is12. I think it's fine for street, as my logs for straight pulls look okay.

At autocross after a few runs, heat soak waiting for my next run will impact my throttle response and increase severity of trim spikes and timing correction. Debating myself on the best cure for that.

An intercooler for heat soak.

 

[odessa.filez]

An intercooler for heat soak.

intercooler would help

I assume IC gets heat from the turbo. IC is helpful especially when car is moving, but at ax it's only 30-60 seconds.

But when sitting on the grid, no turbo air but heat reflecting from radiator, from intake reflecting iat as high as 180F, from other underhood components. No ambient air except for possibly drawn thru radiator fan.

at some events where the wait time is 15 minutes and you can park, turning on the ac to get radiator fan running, lifting hood and shutting it down seems to cool off the stock ic reasonably.

other events, the wait is shorter, a grid might be 'rolling', so no hood up allowed. iat at idle can be 180f and then 155 throughout the run.

I've thought about fmic with a sprayer, fans to hit the stock location intercooler, and of course water injection (meth is a no-no at SCCA but water is ok).

 

[danbfree]

The market is flooded with used JB4's, you can get one for $200, I know I'm in $500 total for used JB4, used IS20 and $30 turbo install kit... Just to add what TwinDad/John mentioned, the JB4 tricks the ECU into seeing less boost/power being made and that's why it can overcome the MAP torque targeting these modern T-DI engines use in their ECU's and you can dial in the boost curve to match the bigger turbo vs. just adding boost with the preset maps. Also, since the IS20 is bigger, you will actually run a little cooler running it with a JB4, since it's bigger so it's more efficient so it will make more power at the same boost as the IS12. Since you were thinking of staying conservative anyway, you can tune the IS20 to be faster with more pull on top while at the same time running cooler than an IS12 so heat soak won't be quite as bad.

 

[kyLman]

The market is flooded with used JB4's, you can get one for $200, I know I'm in $500 total for used JB4, used IS20 and $30 turbo install kit... Just to add what TwinDad/John mentioned, the JB4 tricks the ECU into seeing less boost/power being made and that's why it can overcome the MAP torque targeting these modern T-DI engines use in their ECU's and you can dial in the boost curve to match the bigger turbo vs. just adding boost with the preset maps. Also, since the IS20 is bigger, you will actually run a little cooler running it with a JB4, since it's bigger so it's more efficient so it will make more power at the same boost as the IS12. Since you were thinking of staying conservative anyway, you can tune the IS20 to be faster with more pull on top while at the same time running cooler than an IS12 so heat soak won't be quite as bad.

I think you just sold me on sourcing a used IS20. Where can I find info about which rev to get? Or is that only applicable to IS38?