R32 Sedan - Grip and Drift (have my cake and eat it too build)

[CRSKmD]

Just now, Dose Pipe Sutututu said:

Post cat should read leaner vs. pre cat O2.

so what do i trust. The dyno one of indeterminate age or my new one?

[CRSKmD]

Checking a video I took of another run can see quite a different AFR Graph.

Edited July 14 by CRSKmD

[Kinkstaah]

Sorry yeah - My post was a mess and I attempted to fix it.

In my example both sensors are post-cat. I realized later that I had literally pulled the motor apart and we saw no evidence of any knock and everything was sweet, so my WB was likely accurate (enough!, if anything the engine looked a little rich)

In your example I'd want to recalibrate both sensors. I realize this is not possible in the real world.

Best you can do is:

1) Calibrate current sensor
2) Calibrate a brand new sensor in same location (do you have an older one to compare to? Or is this a new purchase)

Observe any changes in readings.

I always thought it was 1M, I am clearly out of date. Mine is likely 2m+. I didn't want to have to choose one bank over another in my application.

[MBS206]

1 hour ago, Dose Pipe Sutututu said:

Post cat should read leaner vs. pre cat O2.

I'd be thinking it's the other way around.

Less of an impact when rich compared to lean, but definitely in a lean condition the cat specifically uses up a lot more free oxygen.

When rich it's grabbing oxygen from other places to like NOx, but it still gets converted to CO2 and H2O.

[CRSKmD]

Current state of the 32

On 18/06/2025 at 2:46 PM, CRSKmD said:

Unfortunately I only managed 45mins of track time over 3 sessions (20min, 20min, 5min) out of my allotted 90mins before my gearbox let go. Something related to shifter fork resulting in 3rd being neutral quickly followed by all gears neutral, then it being lock in two gears at once and unable to move. Optimistically there were no bad noises. But I am yet to pull box out and diagnose.

Had a mate help me pull the old box in the driveway to get to the root cause of the shifter issue and as expected it was shifter fork related. However, it was not the fork breaking like last time but instead the OEM keyway which had been cut off the stock fork and welded onto the billet fork I had made ~2 years ago. I was surprised to see the OEM keyway have such harsh corners which are a stress concentrator and just asking to be the weak point. 

At the same time this box was rebuilt with the billet selector fork I had my spare box rebuilt to the same speak. Fingers crossed it won't have the same failure as it already in the car.

Couple other things left to button up while the car is on stands including a wideband/controller and addressing some power steering leaks that have popped up.

[MBS206]

That's some really horrible design with the way it's cut/shaped!

Is there much damage to the box that failed in? IE, new fork and you can go again, or is it a total rebuild again?

Id be trying to build that piece from scratch, and getting some reliefs added in the corner to hopefully stop breakage, and then swapping boxes ASAP, and then doing the same to the currently good working box.

I'm assuming hard shifts have not been friendly to it!

[CRSKmD]

yeah I was shocked when I checked my spare OEM on and as below that's how they come from Nissan. (side interesting note new NEO gearbox and replacement park lack the brass bush on the tips and its just all alloy)

unsure about damage to the box currently back at 1110 to be pulled down/inspected and selector fork replaced as he built it previously and given the never before seen failure on his billet forks he is replacing it under warranty.

He said he has used always OEM the keyway tab without issue for years so it could be an unlucky coincidence.
I did talk to him about the sharp corners and stress concentration too.

Re: hard shifts i got 7+ years out of the OEM one and the fork itself failed not the keyway. so could be bad luck as I said or an age thing + heat cycles in box and during fabrication of billet?