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Discussion Starter · #1 ·
In my quest to find out what my 2014 GT-R has had done to it by the previous owner, I ordered some Skura 3 inch intakes and AP with Cobb tunes from Kaizen. It has a at minimum a HKS mid pipe, but I am going to take some better pictures and send to Kaizen to see if has any other exhaust mods. Unfortunately, I can't ask the previous owner what has been done.

So, this last weekend, I went to put the intakes on and surprise, it already had Cobb 3 inch intakes. I liked the red powder coated ones anyway, so I put them on. Luckily I did as one of the Cobb's bracket was broken and was rigged using what appears to be some type of insulation tape. Anyway, that issue was resolved, but during this, I realized that it most likely also had a tune on it. Of course it did. Without knowing anymore, I decided it was best to start from scratch. So, I loaded the stock tune, then loaded the Stage 2 Big SF map. I by no means a expert, but it looks to me like its running rich, but also the duty cycle on the injectors seems low if it had stock injectors. I have an indication, on the gas door it has an X and E85 written in black, that it had an E85 tune. So, I am thinking the fuel pumps and injectors were probably upgraded.

It does not seem to want to get above 15 lbs of boost. I have tried all the boost maps and the highest it gets is 15.3. Is it possible I need to get a map update from Cobb?
Going by the duty cycle at WOT, is that a good indicator of bigger than stock injectors?

I attached a data log from the AP. I only had time to do one quick run this morning. I would appreciate any feedback on reading what this log says and helping decipher what exactly has been done to this car. Thank you.
 

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injectors are pretty easy to see if they are stock or not, the OEM injectors are blue

If this is the cobb stage 2 ots tune then its likely still stock injectors bc the STFT at idle is
100% which indicates that the scalar is not off

Wastegate duty is 100% only up to 4k rpm to help out with initial spool but it drops off pretty hard after that which is why the boost is so low
 

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Discussion Starter · #3 ·
injectors are pretty easy to see if they are stock or not, the OEM injectors are blue

If this is the cobb stage 2 ots tune then its likely still stock injectors bc the STFT at idle is
100% which indicates that the scalar is not off

Wastegate duty is 100% only up to 4k rpm to help out with initial spool but it drops off pretty hard after that which is why the boost is so low
Any suggestions on how to resolve the wastegate dropping off or why its dropping off so rapidly?
 

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Any suggestions on how to resolve the wastegate dropping off or why its dropping off so rapidly?
You need to raise wastegate duty cycle higher up into the rev range. With that being said, the stock turbos will always taper off pretty hard up top so dont expect much more
 

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Discussion Starter · #7 ·
You need to raise wastegate duty cycle higher up into the rev range. With that being said, the stock turbos will always taper off pretty hard up top so dont expect much more
I just want to get the most out of it reliably that I can. I will check the injectors and see if they have been changed. This is all good information. Thank you.
 

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The tune is way off from where it should be. You are running a Cobb stage 2 + Big SF correct? If you want to shoot me an E-mail I will help you setup the logger a little better and see if I can't help you figure out what's up with the car. My E-mail is in my sig. below.
 
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