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I'm seriously contemplating a 1ltr micra engine with an rb26 head, surely they'd be on a par and cheap to tax and insure, I definitely see a gap in the market ha
 

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Very strange, our comparison from RB26 to RB30 with no changes other than the block looks almost identical and as the "experts" pointed out, it is clear there are no gains to be had by doing nothing but increasing capacity and you can REALLY see it fall on its ass up top.............as you were..........

Where's the sarcastic smilie when you need it.

That's funny rob your now contradicting your self you have allways said just by swapping a 2.6 to 3.0 there won't be no peak power gains
 

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Remember this comment to rk tunning when he stated on Pupsi tread that he wasn't impressed with his rb30

Firstly, I'm in favour of this discussion 100% so don't get me wrong here, but:

You must ask yourself:

Q: What did R.I.P.S actually supply for your old car?
A: A shortblock only.

Q: What was bolted to the top of the shortblock we supplied?
A: Exactly what it had on the 26.

Q: Did we have any input into, or did we supply any of the parts that went onto the shortblock we supplied?
A: NO.

Q: Did we have anything to do with the install or mapping of the engine?
A: NO.

Q: Was it commented on that the head and/or cams were no-where near worked enough/big enough to make full use of the larger capacity bottom end?
A: Yes it was, by the person who was mapping it.

Q: Does a shortblock really have ANYTHING to do with actually making power?
A: NO, not really.

Q: Did it make considerably more torque than it use to?
A: YES.

Q: Was the oil pressure, compression and build quality to a high standard?
A: YES

Q: Is it possible that because the power curve is much smoother/wider it just doesn't give the top end punch it may have had before but it is in fact still accelerating just as fast if not a bit faster?
A: I'd say so.

Q: Was the customer service I gave, build time (2 weeks), shipping time (3-4 days) and overall value for money top class?
A: I believe so.

Q: Do you seriously think that by just bolting in a RB30 bottom end and changing nothing else, giving it a re-map the thing will majicly turn into an absolute monster?
A: Of course not, thats just silly isn't it.

A big hit in the top end may feel cool and really quick but side by side the same peak powered RB30 will be quicker in acceleration, around a tightish track or on a drag strip.

If there's anything I've missed feel free to add/comment.

Rob
 

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So, does having a larger 'air pump' allow you to operate outside of the compressor curve and peak performance? Because there are some clear BS claims in this thread.
 

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I'm seriously contemplating a 1ltr micra engine with an rb26 head, surely they'd be on a par and cheap to tax and insure, I definitely see a gap in the market ha
That sounds like a great idea. Perhaps you have found the future of Skyline engine development.
Obviously some people will argue the point but I reckon there will be massive hp gains and because the engine weighs less thee will be a huge performance advantage. I must be right, I read it somewhere on the internet so it must be true.
Gotta go, mum says I need to get in the bath...
 

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So, does having a larger 'air pump' allow you to operate outside of the compressor curve and peak performance? Because there are some clear BS claims in this thread.
Rod ratio effects volumetric efficiency. The RB30 has a rod ratio of 1.79, the OSG30 has a rod ratio of 1.61. The optimum is reckoned to be 1.75. Making the Nissan RB30 the best on that area.

Rod ratio effects volumetric efficiency due to a longer dwell at top dead center.
 

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Rod ratio effects volumetric efficiency. The RB30 has a rod ratio of 1.79, the OSG30 has a rod ratio of 1.61. The optimum is reckoned to be 1.75. Making the Nissan RB30 the best on that area.

Rod ratio effects volumetric efficiency due to a longer dwell at top dead center.
Volumetric efficiency of the 'pump' aside Andy, how does it make the attached compressor perform outside of its curve and rating?
 

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Remember this comment to rk tunning when he stated on Pupsi tread that he wasn't impressed with his rb30

dan all that highlights though mate is the head was a restriction for the rb30, it must of been and hindering top end power it still would of made the same or more power than it did on an rb26 bottom end with a big chunk more of low end grunt.

if I was building a motor from scratch for an older skyline and the engine was fubared then I would no question build an rb30, if I was going stroker I would 100% go rb34, you don't even need massive revs with a big capacity motor you can make massive power, good boost threshold with a sensible rev limit.
 

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Volumetric efficiency of the 'pump' aside Andy, how does it make the attached compressor perform outside of its curve and rating?
which motor has done that matt ? I must of missed it ?
I think ive just realized your referring to the hks t51r kai run from marks car, I can tell you that mark trapped 151 mph yesterday at santa pod so although the kai maybe rated at only 800hp marks is definitely flowing a site more than that mate ;)
 

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which motor has done that matt ? I must of missed it ?
I think ive just realized your referring to the hks t51r kai run from marks car, I can tell you that mark trapped 151 mph yesterday at santa pod so although the kai maybe rated at only 800hp marks is definitely flowing a site more than that mate ;)
Carl, I think you're forgetting Mark's car weighs A LOT less than a standard car.

Rob's chart has always been a very good guide:
 

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Carl, I think you're forgetting Mark's car weighs A LOT less than a standard car.

Rob's chart has always been a very good guide:
im not sure matt, if its 1400 kg all in then that makes it 817 whp according to that plot, it will make more at the hubs than the wheels anyway, either way its still way over the 800 crank hp that turbo is supposedly rated to im sure mate, how do we even know what these hks turbos flow when they don't even supply any compressor maps all ive ever done is go by the garrett equivelant.

I think a t51r kai is based around a gt4294r which is rated to 850hp so could well flow abit more with the hks mods to it I suppose.
 

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im not sure matt, if its 1400 kg all in then that makes it 817 whp according to that plot, it will make more at the hubs than the wheels anyway, either way its still way over the 800 crank hp that turbo is supposedly rated to im sure mate, how do we even know what these hks turbos flow when they don't even supply any compressor maps all ive ever done is go by the garrett equivelant.

I think a t51r kai is based around a gt4294r which is rated to 850hp so could well flow abit more with the hks mods to it I suppose.

What did marked car a 1/4 mile in? Surely his car weighs less than 1400 must be closer 1300kg?
 

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What did marked car a 1/4 mile in? Surely his car weighs less than 1400 must be closer 1300kg?
he did 9.5 at 151 mph yesterday, need total weight with driver and fuel, also bare in mind that is in circuit trim with circuit slicks on and I don't think that was at full power either.
 

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That's funny rob your now contradicting your self you have allways said just by swapping a 2.6 to 3.0 there won't be no peak power gains
Wrong again. You're not very good at this game are you. I have never said that, why would I, it isn't true,

I have always said if you swap nothing but the bottom end you will get small gains in peek power but big gains in response and torque as shown by the BACK TO BACK dyno graph in this thread or is it a fake?

With regards to Pupsi's thread, I said "does the shortblock really have anything to do with actually making power" NO.

Pay special attention to this bit..........That doesn't mean a bigger bottom end won't make more power than a smaller bottom end with everything else being equal, that means that in any given engine combination, regardless of its size, the short block has very little to do with the power that engine is going to make because for all intensive purposes it is just an air pump.

Please don't try and twist my words to try and suit your own misguided thoughts on the subject.

You have had testimony from people who have been there and done that many times and not one agrees with you.

I have done nothing but build 100s and 100s and 100s of RBs over the last 12 or so years (20s, 25s, 26s, 30s, 32s, 33s) and I can tell you for a FACT when done right the bigger the capacity the better your end result will be, it really is as simple as that.

But, you clearly know better so you stay with a 26 and I'm sure you'll be very happy.

Rob
 

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I honestly don't know of anyone who has had a RB30 that would or has gone back to a 26.

If they were as rubbish as some are led to believe surely the 100s of people that were dumb enough to try a RB30 at least some of them would have found out how slow revving and under powered they were and would have gone back to a RB26 yet you NEVER hear of it, I for the life of me can't figure that one out. :chuckle:

:popcorn:
People just believe in the hype and propaganda that certain people promote. :popcorn:

I would never buy an RB30 because it something that was never designed to be used hard.

Secondly it is a massive waste of time, money and messing around to get things working for little benefit vs the money spent.

If one day I feel the need for more torque I will buy a Tomei 2.8 stroker kit :thumbsup:
 

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People just believe in the hype and propaganda that certain people promote. :popcorn:
You do. LMAO.

Nismo this, HKS that. Only the best for you.

Which head studs did you end up buying, milk chocolate or toffee. Lol
 

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You do. LMAO.

Nismo this, HKS that. Only the best for you.

Which head studs did you end up buying, milk chocolate or toffee. Lol
I bought some from billys hardware shop :chuckle:

Not really a fan of bodge jobs, if you can live your life bodging and cutting corners or being a bit of a cowboy in everything you do in life and good luck if that is the impression you want to give about yourself...

I have always believed in and if you take the effort to do something do it properly and to the best of your ability or do not do it all. Rest is false economy and wasted effort.

As for Nismo or HKS products in relation to what? You can add RIPS to that list as their fabricated items are in the same price/quality league as the Japanese companies you mention.

I am done with this thread as it is getting rather boring now. :rolleyes:
 
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