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was hoping maybe someone in this forum could possibly chime in:

I've had my JB4 in for I'd say approximately two months with the only modifications to the car being lowering springs, BMS intake filter, JB4, and Corsa Centerline exhaust. I initially felt the JB4 didnt provide me with the results I wanted, but on occasion I would get extremely noticable performance improvements which would get my head out of the mud. However, my question lies more in "why is my power gain intermittent and what can I do to fix it?" I thought at first it was temperature (sunny florida) but I've experienced these issues on cold nights when the car feels like its 'sluggish' and was feeling a lot more energetic the previous day in similar environment. What I want to ask though is #1: Is this something I should expect from a piggy back? My experience with performance tunes has been strictly that of either dyno tuning or using a canned tune and #2 I have read about 'torque limiters' on this vehicle and I dont exactly understand how that works. Is the vehicle cutting power due to the torque being created by the supporting mods and tune, and/or is the low(er) tread my rear tires are starting to get to possibly inviting a loss of traction that the transmission reacts to by killing some power?

Sorry for the rant, its just bothersome when I take the car out looking for a little spirited driving and try to bang through the gears and I dont even feel my head go back into my seat once.

Any advice is awesome!
 

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was hoping maybe someone in this forum could possibly chime in:

I've had my JB4 in for I'd say approximately two months with the only modifications to the car being lowering springs, BMS intake filter, JB4, and Corsa Centerline exhaust. I initially felt the JB4 didnt provide me with the results I wanted, but on occasion I would get extremely noticable performance improvements which would get my head out of the mud. However, my question lies more in "why is my power gain intermittent and what can I do to fix it?" I thought at first it was temperature (sunny florida) but I've experienced these issues on cold nights when the car feels like its 'sluggish' and was feeling a lot more energetic the previous day in similar environment. What I want to ask though is #1: Is this something I should expect from a piggy back? My experience with performance tunes has been strictly that of either dyno tuning or using a canned tune and #2 I have read about 'torque limiters' on this vehicle and I dont exactly understand how that works. Is the vehicle cutting power due to the torque being created by the supporting mods and tune, and/or is the low(er) tread my rear tires are starting to get to possibly inviting a loss of traction that the transmission reacts to by killing some power?

Sorry for the rant, its just bothersome when I take the car out looking for a little spirited driving and try to bang through the gears and I dont even feel my head go back into my seat once.

Any advice is awesome!
93 octane helps a bunch, Run two tanks before coming to a conclusion.
 

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As I'm perusing other forums (n54tech), I noticed some people experienced a similar problem to mine where power remained inconsistent with the jb4 on the 2.0 giulia. I have since added a centerline corsa exhaust and EC v2 intake and the best 0-60 I can record is a measly 6.2 seconds compared to my friends giulia that has similar mods but no tune and he does 5.2 seconds. Is anyone else experience this? my 335i with jb4 and mhd back end is a monster, but this is starting to get a bit bothersome. If necessary I can take more logs than the last time I posted some, but even then the consensus was they looked 'ok' which on the road they are very much not
 

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What did your car do before the JB4 0-60? 6.2 is def slow... I do notice that my car is slower while warming up, IE the turbo and transmission won't kick as hard until I get the temp dial half way up.

Also, if you are not posting logs while asking for help...
 

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These are 3 logs. The IAT is RIDICULOUS for 70 degree F nights and at sea level (Florida). Just trying to find a resolution. I want to love this car, but punching it and barely even moving in my seat is somewhat depressing.
 

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I did respond to peoples questions, thanks. And for some reason it's not posting the logs (saved in CSV files) and I'm currently looking on how to convert them. It's not bitching, its genuine concern for a possible underlying problem. I'm simply addressing a problem that I observed was listed in an alternative thread that never had a resolution posted and was hoping maybe someone had a first hand experience with a similar problem. Stating the IAT's are ridiculously high seems like a valid statement, as the logs show 258 temp at WOT. Going to post logs as soon as I can figure out how to properly attach them, as it said they were and obviously they did not.
 

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If you have the phone app you can graph it and screen shot it and post it

Also our IAT temp is post turbo but pre intercooler... But your number look odd. Do you have the newest jb4 firmware (I think IAT was rescaled at one point)
 

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I did respond to peoples questions, thanks. And for some reason it's not posting the logs (saved in CSV files) and I'm currently looking on how to convert them. It's not bitching, its genuine concern for a possible underlying problem. I'm simply addressing a problem that I observed was listed in an alternative thread that never had a resolution posted and was hoping maybe someone had a first hand experience with a similar problem. Stating the IAT's are ridiculously high seems like a valid statement, as the logs show 258 temp at WOT. Going to post logs as soon as I can figure out how to properly attach them, as it said they were and obviously they did not.
hmm, keep trying to post. Your IAT def is high. I just looked at my log from the past 2 weeks, I never get over 175.
 

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I'd like to believe whatever safeguards the ECU has built into it possibly are causing the drastic loss in power due to the IAT's but I'm extremely unfamiliar with how this ECU handles it. That being said, all signs point to the IAT's being the problem (in my opinion) but I'm not sure on what would be causing them. Location of the IAT sensor? I changed all fluids hoping it was a cooling issue but no change observed. This is why I referenced 'torque limiters' I've looked into from other members previous posts as well as on the Supra forums where they have a similar issue of the ecu cutting power due to torque demands.
 

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If you have the phone app you can graph it and screen shot it and post it

Also our IAT temp is post turbo but pre intercooler... But your number look odd. Do you have the newest jb4 firmware (I think IAT was rescaled at one point)
I will double check my firmware, I purchased the jb4 approximately 3 ish months ago and it could be my user error that I assumed it was the most updated firmware.
 

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yeah, I would say you are on the correct path. If the engine starts getting the air to fuel ratio out of whack... I'll let the smarter people chime in :)
 
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