Project Rb31dett. The Development Of My Open Deck Rb Engine And The Quest For More Torque!

[Marko R1]

you might be interested in my mates setup as he also has WMI - i'll send him a link to your thread & i'll let him explain it to you

[N1GTR]

So Ian do we get to see this up close in Sydney before the Nats?

[GTRNUR]

So Ian do we get to see this up close in Sydney before the Nats?

Absolutely!

I am currently in a hotel in Ballina. I've driven 1958km in the last 2 days. The car is running flawlessly.

My last long drive prior to this was to Townsville and back (~700k round trip), and my cruise speed was around 90-95km/h. Thanks to the inaccurate speedo which made my economy 8.3lt/100. I now think that I must have lost a recepit from that trip.

So far I am averaging 13.88lt/100. I have a GPS speedo now which is far more accurate. I suspect that I have used a lot more fuel since getting past Mackay as well. The 110km zones and motorways where everyone does a bit more than 110 uses a bit more fuel. The camshaft timing is different now as well so that might be a factor.

The water/methanol kit arrived monday morning just before I departed. I will be in Newcastle tomorrow around 1-2pm visiting people and then move on to Sydney later in the day. This will give me all of Thursday to install it before the cruise out to Shepparton on Friday. Marko, I'll appreciate any wisdom your able to offer with the setup.

See you all Thursday!

[zebra]

Holy long drive Batman...I remember doing Tweed - Cains in like 4 days and that was enough

[Marko R1]

Absolutely!

I am currently in a hotel in Ballina. I've driven 1958km in the last 2 days. The car is running flawlessly.

My last long drive prior to this was to Townsville and back (~700k round trip), and my cruise speed was around 90-95km/h. Thanks to the inaccurate speedo which made my economy 8.3lt/100. I now think that I must have lost a recepit from that trip.

So far I am averaging 13.88lt/100. I have a GPS speedo now which is far more accurate. I suspect that I have used a lot more fuel since getting past Mackay as well. The 110km zones and motorways where everyone does a bit more than 110 uses a bit more fuel. The camshaft timing is different now as well so that might be a factor.

The water/methanol kit arrived monday morning just before I departed. I will be in Newcastle tomorrow around 1-2pm visiting people and then move on to Sydney later in the day. This will give me all of Thursday to install it before the cruise out to Shepparton on Friday. Marko, I'll appreciate any wisdom your able to offer with the setup.

See you all Thursday!

great to hear that you use your car & not afraid of putting kms on it

i was leaning on my mate to offer you advice on the WMI - i personally have had no exposure to it.

oh & say hi to paul! i spoke to him a few days & he'd mention that he was looking forward to meeting you!

he has a PhD in GTR engineeering haha

[TiTAN]

So far I am averaging 13.88lt/100. I have a GPS speedo now which is far more accurate. I suspect that I have used a lot more fuel since getting past Mackay as well. The 110km zones and motorways where everyone does a bit more than 110 uses a bit more fuel. The camshaft timing is different now as well so that might be a factor.

with decent sized turbos you should be seeing better econ than that. my 3L with GT35 will do 9-10L/100km on the highway(at 110). is it running rich? my cruise afr is around 15.5

[GTRNUR]

with decent sized turbos you should be seeing better econ than that. my 3L with GT35 will do 9-10L/100km on the highway(at 110). is it running rich? my cruise afr is around 15.5

Do you have an EGT probe as well? At 100km/h and 15.5 afr my EGT's are a nice 800 degrees. Get up to 110(or perhaps I mean "motorway speeds...") though and the EGTs would easily be hitting 850 degrees which is too hot when the sensor is in the dump pipe. It would have combustion chamber temps around 900 degrees. So to maintain an egt of 800-810max i run the afr's at 14.7.

The other factor that could be effecting my economy is that I am enjoying the sub 20 degrees air temps. At full load the engine is drinking a calculated 3.9lt/minute. 1lt in 15 seconds!

[TiTAN]

no i dont have EGT sensors and my wideband is in the front pipe about 30cm from the cat.

[Rolls]

Do you have an EGT probe as well? At 100km/h and 15.5 afr my EGT's are a nice 800 degrees. Get up to 110(or perhaps I mean "motorway speeds...") though and the EGTs would easily be hitting 850 degrees which is too hot when the sensor is in the dump pipe. It would have combustion chamber temps around 900 degrees. So to maintain an egt of 800-810max i run the afr's at 14.7.

I always thought you'd be seeing those temps on full load. How can you get EGT's up around 700+ on cruise?

I get that leaner = hotter, but surely you are burning maybe 5% of the overall fuel you are burning at WOT, where does all the heat come from?

[Roy]

If I had of known that it was your Nur at Winton I would have come and had a look/chat rather then rubbing my brake pads on concrete trying to get rid of my glazing problem.

How did the car go?

[GTRNUR]

Update!

Back from the SAU Nationals. 7061km in 10 days.

I decided to take the in land road back home via the Newall/Leicheart highways as it cuts a fair amount of KM off the trip. 3800km via the coast so I could stop by at Newcastle, Sydney and Wollongong. The way back was 2770km.

I did the return trip in 3 days. Shepperton-Goondawindi (1200km), Goondawindi-Mackay(1003km), and Mackay-Cairns(737km).

Sorted out the fuel economy EGT issue while on the way back as well by re-scaling my RPM and load maps a little so there wasnt load cell interpolation at the cruise speed. Averaging a speed of 110-115km/h I am now getting 10.6lt/100km. It gets a lot better at around 95km/h as the injector pulse drops another 0.6-0.7ms. EGT's are now 690-710 max at cruise speeds between 110-130 or so.

For the most part the car performed well. I had 3 issues. The catch can overflowed again (time to buy a Nismo return to sump can), and the engine developed 2 exhaust leaks after the first track practice session.

The oil cleaned up easily enough, but the exhaust leaks werent able to be fixed on the day. My EGT sensors had worked loose, probably due to the EGT's and metal expansion etc. But the bad leak is either between the manifold and the turbo, or somewhere on the dump pipe on the front turbo. So its a turbo off job to fix it.

Im not too fussed about having not experienced more track time. I got to do over 200km/h on the main straight before the kink in front of the pits which was fun, and I had one attempt at doing a fast lap, but experienced brake fade at the end of the second part of the main straight. After that my testicles shrank a bit. I tried a cool down lap but then the session ended.

Was great to finally meet many of you and put faces to names. Appologies to those that I didnt get to catch up with.

[GTRNUR]

If I had of known that it was your Nur at Winton I would have come and had a look/chat rather then rubbing my brake pads on concrete trying to get rid of my glazing problem.

How did the car go?

Hi Roy, sorry I missed you. I spent the show and shine morning freezing my ass off and looking at everyone else's cars. Sadly my car's not a real NUR, I just bought the number plate for when I do own one. I'd like to upgrade to a Vspec2 Nur Mspec in a year or two. Either that or add a diffuser and N1/Nismo parts to "vspec convert" the current car and give it a re-spray.

GTRRKT and the Midori R34 Vspec2 Nur's were there of course.

[Roy]

I only got back from my Sunday night drinking session at 6.30am so I wasnt even in a state to drive my car to the SNS. I rocked up, looked around then went Ten Pin Bowling and some beers. I didnt realise the SNS finished at 2pm so missed people as well.

I will say AWESOME work on driving down for the event. Makes a mockery of people on the east side of Melbourne complaining its too far to get to Calder

[GTRNUR]

Thanks Roy. I like the idea of next year being closer though. Lakeside raceway in Brisbane would be nice but i'll settle for Sydney.

Pulled the front turbo off the engine today. It turns out that the exhaust leak was just the dump pipe to turbo gasket having 1/2 blown out. Interesting that this was enough to cause the boost to not go over 1.6kg/cm to the 1.75kg/cm that it is supposed to reach. Perhaps it produced just enough turbulance in the exhaust flow to upset things.

I'll be pressure testing the intake side of the engine again prior to reassembly anyway, just to make sure its not anything else that I've missed.

Sorry Paul, I won't be changing to -5's just yet!

[N1GTR]

Recovered yet from the big drive?

Next years SAU Nats is already being planned, trust me it's worth the drive down (or truck and fly maybe?!)

[TiTAN]

has a venue been picked/narrowed down choices?

[zebra]

Yep

[N1GTR]

That's all for another thread, but yes all done with the exception of one section of the event.

lol Zebra, there's no way you would know whats happening behind the scenes.

[zebra]

Haha I never said I knew...well I know which town and which track...which is all I care about lol

[GTRNUR]

Recovered yet from the big drive?

Next years SAU Nats is already being planned, trust me it's worth the drive down (or truck and fly maybe?!)

I think that transporting the car next time would make a lot more sense. Also it allows me to work during the time the car is being transported which covers those costs. It had to be done once though, and all in all I enjoyed the journey. The engine sure proved itself.

Recovered? Nope. My body clock is shot to bits. I keep waking up at 5:30am in the morning. And I am supposed to be on holidays!

I have just finished putting the car back together. I found a split hose to be the cause of the boost drop off from 1.75kg/cm to 1.6. And the exhaust dump pipe gasket explains why my ears were still ringing 7 hours after I got home and out of the car! I pitty the poor people I overtook on the highway on the way back. Must have been defening at 6000 rpm!

My catch can was empty too. So it seems that it works provided I am not doing any cornering. I can't help but think the reason it filled was that long 3rd gear left turn(turn 3 I believe), which was done at around 4000-5000 rpm. During which no oil drains to the sump because its all in the right side cam cover away from the drains. I am definatly adding a return to sump system on the next engine.