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


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thanks mate - proof is in the pudding with my setup & although i might be biased, paul (piggaz) was very impressed as well as my tuner (jim @ crd) who says that the power delivery is like running 500awkw from a rb26 :(

i wonder what cams rob @ rips recommends lol

I do not know what N1 is on about as he criticised your set up and then said "lot's of good results with 280° cams" and suggested Ian buy 280° cams? :P

Yes, I wonder indeed...

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There is a lot of good results with 280's out there, personally I'm over spending on this motor.

Cam changes are a little way off yet. I want to see how it goes with standard cams first, but at the most I figure poncams will be the go. I still want it to sound and idle as close to stock as is possible, and i want peak torque around 5000 rpm still, much like a stock engine.

The re-sleeving the slave cylinder will be done in 2 days aparently as the shop doing the work is busy. So Im getting to have a break from cars for a bit.

I totally understand about being over spending the money too but anything good does tend to hurt the wallet a little.

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I do not know what N1 is on about as he criticised your set up and then said "lot's of good results with 280° cams" and suggested Ian buy 280° cams? :P

Yes, I wonder indeed...

Well, further investigation and you'd find all the top results on 280 cams have bucket loads of RandD and perfectly matched supporting mods.

I'm not recommending anything for Ian, he will no doubt try different sizes and pick whichever suits his motor best :(

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I think cam choice is more about the applicaiton you have in mind for the car too. In reality I drive on the street, and on occasion on short sprint tracks (gocart tracks with tight corners), so low end response is what im after. I'd love to get to drive around some of the decent tracks you guys have access to in Sydney and Melb (and get to hold 3rd gear for more than 2 seconds), but thats a long way from where I live. So there is no point in setting up for that sort of track.

While I have a power goal in mind which is easier to achieve with bigger duration cams, from what Im told I can achieve that figure with just the turbo's im using, so the additions i'll be making will be focused on building more low end torque instead. Given the choice I'd have gone with -5's or 2530's but the GTRS's were too good an offer to pass up at the time as I was able to get rid of a lot of my old R33 GTR parts in trade as part of the deal.

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This one

http://www.skylinesaustralia.com/forums/in...t&p=4726549

If you ever win lotto try back to back against 260 procams :ermm:

stevo - u have hurt my feelings & stabbed me in the heart :( im gutted brother (only joking)

what dont u like about my graph? a lot of it has to do with the way it is tuned, i.e. it can be tuned for mid range or top end.

maybe u dont like the fact that i made 930nm & u made how much, 700nm :P

WOOOO - i'd pay that 1 (tongue in cheek mate)

another plus with big cams....they sound FAT!

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I do not know what N1 is on about as he criticised your set up and then said "lot's of good results with 280° cams" and suggested Ian buy 280° cams? :P

Yes, I wonder indeed...

well jim @ crd likes 280's & rob @ rips likes 280's - that is enough for me :(

these 2 legends have build more gtr icons than most, worldwide

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stevo - u have hurt my feelings & stabbed me in the heart :D im gutted brother (only joking)

what dont u like about my graph? a lot of it has to do with the way it is tuned, i.e. it can be tuned for mid range or top end.

maybe u dont like the fact that i made 930nm & u made how much, 700nm :P

WOOOO - i'd pay that 1 (tongue in cheek mate)

another plus with big cams....they sound FAT!

Your peak torque trumps mine, agreed, but I think you'd beat me by a greater margin with some changes.

Don't forget mines in for another tune this month, willbe good to compare then

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Update!

Today I finally got motivated again and re-installed my re-sleeved master and slave cylinders. 2 hours of stuffing around bleeding and adjusting later and the clutch works like a treat!

Thanks to a little tech support from Paul at red R racing diagnosing an adjustment issue with my throttle stop switch, the car now idles much better (as its not hunting on the map sensors), and also it doesnt flood the engine after a rev. The corrections for the larger injectors dont seem to match the requirements of the engine though, so Im still tweaking those a little. Not that it will matter as the new ecu arrives next week which will change everything.

I put about 80km on the engine this evening, just cruising around town and up and down the tallest hills I could find in the tallest gears and keeping the revs low. It runs awesome and I think it will come close to meeting all my goals based on what ive seen today. The engine makes positive manifold pressure of around .15 bar at 2500 rpm and is at .4 bar at 3000. This is with a doey as hell ignition curve and 13:1 afr's too. Engine temps topped out at 71 degrees when driving, and oil temps at 89 as it was last time. External oil cooler is going to have to be installed before the first dyno session.

From 2500-3000 the engine has that same urgency that the 26 had from around 3000-3500 as it just begins to surge onto boost. Driving and short shifting at 3000 rpm still feels quite zippy. You get to hear that all familiar slow and deep sounding spool of the large turbo's happening from around 2500. No aparrent choo-choo train noises so I think there is no shuffle issue there to deal with.

Low end torque is nice too. The engine happily cruises at 60km/h in 5th gear at 1650 rpm, and at 80 in 6th at 1800 rpm, with 200mmHG of vacuuum.

Oil sample and plug check tomorrow morning, then the testing continues.

That is all for now.

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Minor update.

Solve the issues I was having with idle stability. Turned out to be a leaking gasket on the throttle bodies... of course the one at the back not that it made any difference to fix. I must say, removing and re-fitting the plenum on a gtr engine is a right prick of a job. But its all sorted now and pressure tested to 30psi with no leaks!

Note to self: Pressure test the next engine on the floor BEFORE installing it in the car.

Note 2: Use HYLOMAR on EVERYTHING! Fricken tomei rubber coated metal BS gaskets wont seal reliably without it.

With that issue solved ive started to put some KM on the engine. Just over 200k's now, and have used 1/2 a tank. All in round town (in traffic) driving between 60-80k's, as well as up and down the tallest hills I can find. The engine has no noticable blow-by at all. I havent pulled the plugs and compression tested for a week but im pretty sure its getting close to being bedded in nicely. Oil samples are continuing to come up clean touch wood. Ive got quite a collection of samples on the shelf in my loungeroom now :thumbsup:.

Thats all for now.

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Nice work Ian; as an aside I met the guy who built that RB29/30 in Adelaide (one with the RB30 crank modified to fit in RB26 block) the other day, nice guy and pretty clever!

Mark99 off the forum? He was quite helpful and fourthcoming with information for me when I initially started with this project. That is a rare thing considering everyone in "the industry" keep their secrets to themselves.

Of course that is perfectly understandable really... Its the only way one has a chance of earning some money back after all thats spent on R&D.

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Mark99 off the forum? He was quite helpful and fourthcoming with information for me when I initially started with this project. That is a rare thing considering everyone in "the industry" keep their secrets to themselves.

Yes it was a bit of a "small world" moment as I went to a mates house and he happened to be there!

His engine was slightly smaller (2.9) than yours but he had some extensive head work. Would be good to see a comparison made.

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Note to self: Pressure test the next engine on the floor BEFORE installing it in the car.

Note 2: Use HYLOMAR on EVERYTHING! Fricken tomei rubber coated metal BS gaskets wont seal reliably without it.

i know what u mean, ive never got those metal gaskets to seal either. now i just buy gasket paper and make my own. no more problem.

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