Hey. You broke into my garage.
7
Talk me in or out of a JB4 unit for an IS20 swap.
- Thread starter stuntnuts
- Start date
Hey. You broke into my garage.
TwinDad
Autocross Newbie
- Location
- Fort Lee, NJ
It has better timing though. Timing is a lot like stock where the APR timing is down 6-8 degrees at peak boost
4MotionWagen
Ready to race!
- Location
- Michigan
Pushing more boost and sacrificing timing under 4500 rpm is how they make torque from my understanding. That is why they start dropping boost above 5000 rpm to get the timing advance back.
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I my opinion based on experience:
If one were to put an is20 and run max jb1 settings, they would probably pick up some hp. Especially top end as the is20 is blowing more cfm, cooler, more dense are at the same settings.
But. To get the real benefit of the bigger turbo and be safe, the JB4 is what you need. It has more control and control authority over the key parameters you need to make the bigger turbo work. Most importantly the ability to bring boost up to levels above is12 tune.
Only up to a point. You reach a ceiling that is below the point where you're really taking advantage of the bigger turbo. With the, JB1 you are limited to like 5 or 6 over stock boost request max. The is20 can go another 5 or 6 or more over that, or more if you have a tight full mod setup. 2-4 is a good starting point.
The limit is a safety so people don't try hitting 30psi @ 7000 and make shrapnel.
And even if you could do something with the JB1, the JB4's extra authority over boost control and AFR is important for safety, power and driveability.
To get the best answer on this, ask George directly, or wait for him to chime in.
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toledospeed
Go Kart Champion
- Location
- 3rd rock
I agree with Ton's comments. BMS has also never supported the IS20 with the JB1, so there are obviously reasons for this. If anyone were to run the JB1 with an IS20, I would only run the stock map or very modest settings (+3) as a temp solution until it was upgraded to the JB4. The JB4 upgrade is only $125, so in the grand scheme of things, it would be silly not to do things properly.
This is good advice.
George Smooth
Drag Race Newbie
- Location
- South Africa
The JB4 has a larger range of enriching the AFR due to the connection direct to the O2 sensor. In general with the more flow and higher power level its recommended to run richer mixtures.
OK, next question...
How many different "maps" am I going to have to set and run? I drive this car daily, year round, in the Northeast. So it sees below 0 degrees F in the winter and it sees 95 degrees F in the summer. Will I need a separate "map" for various times of the year?
What about octane?
My ideal situation would be to dial it in to my liking and leave it alone. It is not something I want to, nor have time to constantly log/tweak/optimize, like a lot of the more knowledgeable members on here. It is also not something I want to constantly have to monitor to feel comfortable driving around.
If I don't sound like a "good fit" for a JB4 to you, you won't hurt my feelings if you let me know.
BTW, the IS20 has arrived.
How many different "maps" am I going to have to set and run? I drive this car daily, year round, in the Northeast. So it sees below 0 degrees F in the winter and it sees 95 degrees F in the summer. Will I need a separate "map" for various times of the year?
What about octane?
My ideal situation would be to dial it in to my liking and leave it alone. It is not something I want to, nor have time to constantly log/tweak/optimize, like a lot of the more knowledgeable members on here. It is also not something I want to constantly have to monitor to feel comfortable driving around.
If I don't sound like a "good fit" for a JB4 to you, you won't hurt my feelings if you let me know.
BTW, the IS20 has arrived.
You can definitely set a map and forget about it. The people here who tweek are doing it for fun and to squeeze the last bit of power out.
What is the best gas you can commit to run? This is the question for every tune.
TwinDad
Autocross Newbie
- Location
- Fort Lee, NJ
If you use the JB4 app, you can save and name maps. This way you can run a winter map, summer map, 100 octane etc.