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

[GTRNUR]

Video at last:

http://www.youtube.com/watch?v=dR-LNctPhgY

[BOBBYr34]

Video at last:

Nice car Ian.

Remember dyno numbers mean nothing on how the car drives to me its just a number.

Looking at the curve i have not seen a Gtr that has so much area under the curve so ealry in the rpm. Id love to drive this car.

Will you be uping the boost ?? Will you be trying E85?

Cheers

Bobby

[GTRNUR]

Nice car Ian.

Remember dyno numbers mean nothing on how the car drives to me its just a number.

Looking at the curve i have not seen a Gtr that has so much area under the curve so ealry in the rpm. Id love to drive this car.

Will you be uping the boost ?? Will you be trying E85?

Cheers

Bobby

Thanks Bobby.

Im not concerned about the power figures yet. After all these results are a first dyno run with a street tune, and the engine is far from optimised for power.

Based on the testing and the rich AFRs that were seen, I might be able to rescale the ECU's load bands to allow a little more boost (1.7 bar), which will max the injectors completely. That should see somewhere over 400kw once the cam timing and AFR's are sorted.

Cam timing is going to affect this considerably though, so more boost is still a little ways off. I think that the retarded exhaust timing is colouring the AFR figures, raising EGTs and is why the top end isnt there yet. Once this is corrected it will become a different engine in top end.

E85 isnt an option for me as its not sold at the pump in Cairns, and fuel by the drum isnt very practical. The compression of this engine is too low to make E85 efficent too. ID1000cc injectors and a water injection system are possabilities I am considering though. That would allow me to max the GTRS's and provide some safety at the same time.

The torque does make it loads of fun to drive. Low down power was what this project was all about. I was comparing some dyno sheets today and noticed that I am making the same power (180kw)as the RIPS Stealth R34 does at 4000 RPM (that was one of my goals). I am also only 1000N away from the same peak torque figures as the Racepace Rb29. These two results alone make me feel pretty good about the first dyno session.

[N1GTR]

Ian where are you seeing the rips 34 numbers please?

I love your wheel choice btw, very understated

[sucram]

water/meth works well

you can get OK results from just whacking a "kit" in but for best results you need to do a bit of testing

[GTRNUR]

Ian where are you seeing the rips 34 numbers please?

I love your wheel choice btw, very understated

I came across the info about 180kw @ 4000 in someone's post somewhere, but hadnt seen the dyno sheet till just now. Seems I had read some typically inaccurate forum information as it looks like I need to gain another 10kw. It looks more like 190 @ 130km/h (4000 RPM) on the sheet to me.

Because I am having a sixth sense about this coming... I'll say this to set the record straight now, before some over enthuesastic skyline "expert" says I am trying to make claims that I've built a better engine than Racepace or RIPS. (Not referring to you Steve, I'll just say that I have some fans...)

Fact is I do not do this for a living, and what I have built has really only been made possible because of tid bits of information that RIPS and Racepace, and a few other top level builders have occasionally posted on SAU and GTR.CO.UK. These guys set the records and I have the upmost respect for their work.

Here's the link to the stealth bomber build too: http://www.gtr.co.uk/forum/69822-my-r-i-p-s-rb30-build-24.html

I was going to look at a water/meth kit, and then link it to the boost controller with a 2 nosel system in the intake hose before the plenum. And definatly dyno tune it. I have only been reluctant till now to book dyno time as my last experience with sending an engine away cost a small fortune. I want to make sure that everything is as good as I can make it before I start paying for someone to fix my mistakes.

[R31Nismoid]

200rwkw @ just after 4000rpm is pretty decent mate for those turbos when you consider they will mash out over 400!

[GTRNUR]

Cam gears arrived today and were installed this afternoon. It turns out the intake and exhaust cams were retarded around 7 degrees, which explains a lot of the odd charactoristics I was seeing with tuning the engine.

The GTRS's would start spooling below 2000 RPM because of the retard on the exhaust cam, but were also causing quite high EGT's which were effecting the accuracy of my wideband AFR meter making it appear leaner than it was. So I was compensating with too much fuel as a result when tuning.

The intake cam timing was affecting idle quality, and made the engine pull a near complete vacuum at idle. It also prevented me from being able to get the idle below about 1000 rpm even with the butterflies and idle adjust shut. I had written that off as being a side effect of the displacement increase and additional torque at idle, but it turned out to be all cam timing. The retarded intake cam was also causing the engine to struggle for airflow in top end, and I believe is why the power curve didnt continue to climb after 5000 rpm as much.

I have re-dialed in the cams now to a correction + 2 degrees advance on the intake (9 degrees total change), and correction + 3 degrees retard on the exhaust. (4 degrees total change). The effect has been dramatic already. The car started and idled at 500 rpm, but very very smoothly. After adjustment the idle is now comefortable at 900 rpm and deviates a maximum of around 10 RPM. Very smooth, as I would expect from stock cams. I still havent taken it for a test drive to feel the difference as I want to do another pressure test of the intake system first, just to make sure its all 100%. I am also changing the catch can arrangement and havent made up the new hoses yet.

So all good news so far.

One other piece of news is that I have been invited to an invitation only 1000M event at a nearby airport in 1 weeks time. I am going to be hard pressed to get everything sorted for the event, but im going to try. A few of the other cars are a modified 997 turbo, a Ruf 3.4 911 turbo, and a Lamborghini Gallardo. Rumor has it that CASA has allowed side by side 1000M drags. In testing the 997 managed around 21 seconds for the 1000M.

Updated picture of how it looks now is attached. That is all.

[Beer Baron]

good luck mate. was great to chat again the other day. I'm not surprised how drastically the cam timing changed the engine characteristics. with that much retard in the inlet it's no wonder it was doing some slightly funny things. It must feel pretty crisp and awesome now.

I think you'll do pretty bloody well at the 1000M event.

[GTRNUR]

Update!

The Eboost street is now removed in favour of a AVCR limited edition. I've also installed a new catch can setup with -10 speedflow black nylon hose and a large catch can, but Im not 100% happy with it as it really detracts from the whole "keep it stock looking" goal. It works well though.

Thanks to the cam timing changes and the boost now not falling off in top end anymore, the power delivery is much more smooth and its cleanly pulling to 7500. The low end response also improved vastly, and it responds every bit as revvy as a 2.6 when its above 4500, except that if your in any gear below 4th the car just wants to lose traction.

I have re-tuned the engine again with the two boost levels se to 1.3bar and 1.7bar. High boost now completely maxes out the fuel system. 16.2ms around 5000 RPM, you can practically watch the fuel gauge drop. I have no idea what the power figures are at this stage. Safe to say its a fair way over 500hp to the tyres though. Every 0.1 bar over 1.2 seemed to produce exponential gains.

It feels better to drive in traffic now too. Its like a stock engine, except that the around town cruise rpm is 1800 in 5th at 60km/h or in 6th at 80km/h. When going on a long drive I have tried to change into 7th before I realised I didnt have a taller gear. It just cruises so effortlessly.

I got my dates wrong with the Wings and Wheels car show (http://www.inghamwingsandwheels.com.au/), and the 1000M event. Its actually this coming weekend, so I should have some pretty interesting video of some LEGAL top speed runs and super car racing come Sunday. I'll be having a shot at a techart enhanced 997 turbo, but I am told there is now a Murcielago and a Gallardo coming as well. Should be a hoot!

Ordered a Nismo dash on the weekend which should be here in a few days. Mechanically I think I am very close to having the car finished now. I will be starting on some cosmetics with the interior soon, perhaps a carbon fiber insert style steering wheels as per Tangomatt's car. Im also going to be on the lookout for a Nismo Rtune bonnet and Nismo front bar.

Updated picture attached. That is all.

[045HOW]

Sounding better than perfect!

Keen to see more vids!

Good luck on the weekend!

[Marko R1]

this is the great thing about fitting an rb26/30 in an r34 or r33 for that matter...it fits a lot nicer than in a r32.

your engine bay looks great!

[045HOW]

this is the great thing about fitting an rb26/30 in an r34 or r33 for that matter...it fits a lot nicer than in a r32.

your engine bay looks great!

But its not a 26/30, its a stroked RB26.

[Marko R1]

But its not a 26/30, its a stroked RB26.

still have the additional height though

[robbo_rb180]

great work on this project ian.

how did you go at the wings & wheels show?

[GTRNUR]

Wings and Wheels was a pretty good weekend all in all.

The Lamborghini's didnt show up though. The general concensis is that they were on the side of the road in a cloud of steam 1/2 way to Townsville.

A Ferrari 430 showed, but didnt go on the airstrip. Which was understandable... as the airstrip surface had been recently re-laid. While it was dead flat, the new stone hadn't yet been pressed into the surface so it was more or less like driving on a dirt road. Then it started to rain just as we pulled onto the airstrip! There 600hp viper that was there didnt get any traction at all in any gear.

The euro car club and myself had a go though. The quickest car was the 997 turbo, but the driver said the car was all over the place with the stability control fighting to keep traction. In the video it is the car in front of me. He didnt know his speed though as he was too busy fighting for control.

My run was just as pointless. I launched at 3000 rpm and immediatly lost traction reving to 7500. Changed to 2nd, lost traction again and then noticed the boost had dropped to 0.8 bar. I thought I had partially blown off an intake hose, but the boost controller had just shut down because of a spike caused by how quickly the engine rev'd up. So I continued accelerating through 4th and a little in 5th to about 1/3'rd track and then rolled to the end. I managed 203km/h before backing off. Today I remembered I could do a recall on the settings for the last maximum boost achieved, and it had actually spiked to 2.3 bar for a moment in 1st gear, which explained the controller shutdown.

The we were offered a 2nd pass on the runway this afternoon. I opted to pass so I could film and not risk more stone chips. I got a ride in a police car which was positioned at the 1000M mark where they setup a Lidar system to monitor the car speeds. The best speed captured was 193 my mates M3. That speed was at 1000M minus the range of a Lidar, not at the 1000M mark. They didnt get an accurate speed on the 997 turbo due to the angle from the road side.

Here's the video of my run anyway.

http://www.youtube.com/watch?v=yvwnWA9F_r8

[Robi33]

... Wait. Please don't tell me that was on the past weekend? I was in Townsville and didn't even know.

[robbo_rb180]

yep, it was at ingham.

i would have gone if i wasn't away for work.

shame about the weather would have been good to see what the car is capable of.

[snozzle]

Just took me an hour to read through this thread and i must say i am very, very, VERY impressed! Keen to see a dyno graph with the cam timing alterations too!!

[GTRNUR]

yep, it was at ingham.

i would have gone if i wasn't away for work.

shame about the weather would have been good to see what the car is capable of.

The weather wasnt really the problem, it was just icing on the cake. The real issue was the runway surface. Check out the picture. I wasn't kidding when I said it was like driving on a dirt road! Seeing the MaxxG stunt plane in action was worth the look though.