Tune review R32 GTR Link G4+

Hello,

I am a beginner with tuning, so I had taken my GTR to a tuning shop in Japan and the car runs, but badly in my opinion. I later learned that this shop has a bad reputation for tuning. At idle the map drops from 1000 rpm to around 200-300 then goes back up in a repeating cycle. It also happens when I take my foot off the gas or slow down. This happens more frequently from a warm start. I checked my plugs, coil packs, throttle sensor, and changed the coolant ECU sensor and O2 sensors. The engine was rebuilt and broken in before going to that particular tuner.

Also my fuel pump is very noisy when hooked up making a constant whine with direct 12v, but silent when on the factory wiring. I was wondering if someone could review my tune file and log showing the map dropping to see what is going on.

Mods

Link G4+

Garret 5s

Nismo air collector

Hypertune 11mm fuel rail

Bosch EV14 1150cc injectors

R35 coil packs

HKS sequential bov

Sard fuel regulator

Nismo fuel pump

Hello, the base idle values are so far from where they need to be that the engine almost stalls before the ECU can use the PID system to bring idle back up.

I've attached your file with the base idle values set closer to what the logged values are once the engine stabilizes in your log.

There is room for improvement in other areas as well, but hopefully that helps you get working on idle improvements.

Mike,

Thank you so much! I uploaded the modified file and the idle has definitely smoothed out. I'll have to take it for a test drive later at night, the summer days here in Japan are brutal. I am running a bit rich I think, so I think that will be the next objective. Maybe that's why my pump is constantly whining, I was getting 13.96 AFR at idle. Also, I cleaned the buildup off my spark plugs again (did it a few months ago). Here is the idle log file after uploading.

Update: I took the car out tonight and the car idles beautifully.

I'm glad that gave you an idea of the type of changes you'll need to optimize idle and got it working better in the meantime.

That tune has a lot room for improvement, so keep working at it, and you'll have it running well soon.

Assuming your engine still has the stock ITB's then your fuel table set up with RPM Vs MGP is likely never going to give great fuel control. GTR's usually need an alpha-N fuel setup like our GTR base map.

Your difference in fuel pump noise is because the stock set-up has a 3 speed fuel pump controller, they run the stock pump at about 6V at idle.