The Black Rat will be run in and tune checked this week by Dan at Simply Tuning before he heads off to support some teams in BMW at the Bathurst 12 hour next week.

Dan’s main focus these days is on 8hp transmissions, complete with e-clutch setups (auto with a fully functional proportional clutch).

If ever I do a transmission swap again, it will be along those lines. K24 + NC + 8hp.

 

Everything appears to be working. The run-in was perfect, and it is making over 400hp (on a different dyno so no meaningful back-to-back comparison). It's not leaking any oil which is a huge relief.

The transmission needs a run-in period of about 300 kilometers (180ish miles) to allow any shedding from the gearset and bearings to be changed out before the gearset sees heavy use. It's done about 70 kilometers so far, so a few hours left to go before an oil change and then it is ready to lean on. I can hear the Os Giken diff is also breaking in with a few clunks in tight low-speed turns.

This video is a run through 1st 2nd and 3rd at part throttle. The tires are a bit old and are probably contributing to the lack of traction at the top of each gear.

 

Jesus that thing looks like it has effortless power. Good work! I'll be interested to see if you are able to get it to hook up.

 

I'm very interested in more videos as you break it in. Looks fantastic!

 

Sounds pretty angry, got earplugs?

 

Not long after that last video was recorded, it started showing symptoms of low fuel pressure, and the priming sound in the tank was less of a crisp on-puuurrrr-off affair, and more of a gushing splashing sound. Sure enough, on extracting the pump and hanger, the submersible rubber hose connecting the pump to the hanger was very decayed and split. I am not exactly sure how it was starting or running at all.

Before pulling it all out, I had logged some short drives that showed that it was suffering from lean spikes with any boost. I had also checked the fuel pressure at the rail, which was struggling to get to 45 when priming, and was holding none after the prime pulse.


The attachment and mix-n-match of hose vs barb sizing was something I was never happy with when installing the pump the first time around. This time, I have used one of those fancy Radium hangers that has a reservoir attached to the foot of the pump bracketry. It will be interesting if this helps at all with the fuel surge issues common to these cars.

Oddly, the hanger that I have and the tank that I have will not accept the Radium hanger using the 'NB8B' bracket extension. When I discovered this, I measured both side by side, and the Radium configuration for NA8 appears to match what I have and what I replaced. Maybe this is due to some differences between USDM and JDM/ADM market cars?


I am studying this year and next, and the coursework adds up to about an extra two days/week work on top of my day job and family responsibilities. This is what the institution told me at the outset and 'surely not' was my naive internal monologue - but they weren't joking, and consequently, time for playing with cars is in short supply.

 

This is the offending bit of ‘submersible’ hose

 

All back in place using the Radium hanger