Building A Responsive Rb30det

[Danzzigger]

Hey all, I was wanting to do some research for the future when I turn 21 (finally get my full license) - I've got one yr left.

So basically I was wondering what is involved in creating a rb30det responsive engine. When I say responsive I mean boost comes on really low, and the engine loves to rev. Somewhat like a f1 car but obviously not quite as responsive as that. Now I've read a few threads in regards to it, like 'I want my skyline to revv' and 'Getting your r33 to do 12's' (or something similar to that), but I was wondering if there was a little more insight into doing it to a rb30det as the capacity is another .5L and they tend to rev less. However saying that, the .5L gives the engine a lot more torque and from what I can understand torque is were responsive engines dominate. f1 cars are high tuned v8's and they are very responsive (and have torque). - Correct me if this observation is wrong though.

So basically the goal of the engine is;

Reliability

Boost doesn't come on hard - easier to drive / control

Loves to revv when you want it to - can plant foot in high gear even at 2000 - 3000rpm and still get a good response

For a power figure, that's not really my goal, but lets say 200rwkw if that doesn't compromise response.

Now this will be a street car (most likely a r33) so reliability is highly sought after, I'm not going to do anything that will compromise that.

These are the suggestions I've heard from others about modifications for a 'responsive engine';

Lightened pully's

take off clutch fan and put on elec radiator fans

lightened flywheel

changing gear ratio's

raising compression

new turbo, like a hks gt2530 (I think that's the one)

r34 smic

Carbon tailshaft

Now I don't really want to go too much into a debate on some of the items like the inter cooler, flywheel and carbon tailshaft (I've read enough from the 'i want my skyline to revv' thread).

When I make this motor I'm looking to use it in multiple cars, so when I outgrow the r33, I might move onto a 240z or something. So I want to focus mainly on the engine, less on things like gear ratios, fmic's etc. However saying that, I'm willing to make an improvement on the car if it gives me a substantial gain.

So this is where I need some suggestions, what should I do, and where should I start. Firstly, should I not even bother with the rb25det engine, but instead get a rb26 head and build upon that? - the rb26 has a forward facing plenum stock, and is good for a large amount of power. If I ever want to go fmic, which I will later I'm sure (might not be in this car, but if I go with the 26, it probably will be), the forward facing plenum reduces the amount of piping (less heat), so more power and response. So I need to settle on that first as it will determine my next move.

Good things about getting a rb26:

forward facing plenum stock

twin turbo's

bigger combustion area in head (most likely will never be used though)

Have a cool gtr stamp on the top of the engine

Bigger injectors (room for improvement)

compared to r33 rb25, the computer can be remapped

Bad things:

If I'm to do it in a r33 I'll need to swap looms - How hard is this, how long does it take?

need to go with a fmic (or is the stock a smic?)

Lots of other things wont bolt up so easily I imagine - piping etc

larger cost

more time involved

Car no longer looks stock

So a issue I'd have with the rb25 would be engine management after I've done my mods if I don't go with the rb26. Instead would a r32 rb25 be a option? - how do these bolt up? are the wiring looms the same, any other differences?

The plan is to have this engine ready to pop into the car as it will be driven daily, and I won't be able to afford to keep it off the road for a long time. (so the engine will be built up outside the car)

Also I forgot to mention that I'm really after getting a good tune, everything comes down to tuning, efficiency, power, reliability, so this is something that will not be missed.

Oh yea and legality, trying to keep myself under the radar if possible - how difficult is it to get it engineered?

I leave it at that, hopefully your understanding what I'm trying to achieve. Hopefully we can produce some good ideas.

Thanks for your time

~Danz

Edited October 4, 2009 by Danzzigger

[paulr33]

you could get that out of a properly setup rb25 for response and power

you wouldnt need to bother with a rb30det for 200rwkw and response

a mild gtst setup correctly with the right mods and driver

will be responsive from 2000rpm and make 200rwkw no problems

[bradsm87]

A single GT2530 is waaaay too small for a RB30DET. It would choke the engine up in the higher revs big time. Also U'd be looking at a fair bit more than 200rwkw even with awesome response.

I'd suggest 9.5:1 compression pistons with a 52 Trim GT3076R 1.06 running about 10psi. I reckon that's the closest to the V8 kinda feel u'll get. Won't hit boost like a light switch and will make a lot of torque even off boost. Would prob make about 280rwkw.

Edited October 4, 2009 by bradsm87

[_Ryan_]

new turbo, like a hks gt2530 (I think that's the one)

r34 smic

a 2530 is choking an rb25, and you want to put one on an rb30?

if you want response, RB30 block, rb26 head and inlet/ITB's, and a 3076

[VB-]

you want to build an RB30DET and put an R34 SMIC on it???

Edited October 4, 2009 by VB-

[paulr33]

yeah some contridicting terms and matches here

given your knowledge, experice and what you want do this

r33 GTST

+ FMIC

+ good cold air intake

+ fuel pump

+ apexi powerfc

+ heavy duty clutch

+ splitfire coilpacks

+ 3" turbo back exhaust

+ 255 wide rear tyres

+ aggressive tune

get a good power tune and tons of ignition timing all over the map

learn to drive and you'll find it almost unbeatable on the street

it will make an easy 200rwkw and have plenty of response if tuned properly

that vs your rb30det will save headaches, $, time, effort and risk if get you EPA'd

the cost difference between above and an rb30det setup is probably 10k all up at least?

or an even better and more cost effective option is to buy someone else's modified R33 already

there are dozens that have had complete builds on them done and all the expensive stuff brought

and the owner is ready to offload for a fraction of the price. check out Dezz's R33 GTST

it has everything you would ever want in a GTST and its for sale, by far more cost effective

[Danzzigger]

Thanks for the replies, I don't know much about turbos and stuff so when people list of names and sizes it doesn't mean much to me untill I actually see the thing. Sorry, I didn't realise a gt2530 was so unfitting for a rb30det.

the main reason I've always wanted a rb30det is because its a good base for the future, I'll soon get sick of 200rwkw and want more. And when I do, I know the bottom end isn't going to be a problem, from what I've heard the rb30 has to be the best over engineered bottom end from the rb series. I've heard of people pulling 500 - 600hp completely stock. Like I said, I'm wanting this engine to later on go in another car, but perhaps your right and I'm best off just modifying the stock rb25det. Problem is and paulr33 highlighted it in the last post is that when you try and sell your car with all the blood sweat and tears that you put into it, no one gives a shit and wants rock bottom dollar. So I'd rather put all my effort into a engine I can take back out, and then stick the stock one back in.

I maybe naive, but I was under the impression that the rb30det conversion wouldn't cost that much more than modifying a 25. Custom engine mounts - I can weld something up. Use all the 25 or 26 stuff around the motor as the rb's are basically the same. The engine management remains the same due to the same head, just bigger capacity. I haven't read up on what exactly is done in a conversion (I'm not going to read a 300page thread), I have seen a couple engines though, and one in a hr31.

And I'm not going to be going into the effort of ITB, thanks for the suggestion though - would sound sick too .

I like where bradsm87 is going with the raising the compression and then sticking the bigger turbo on. Raising the compression would be something I'm definitely after doing. I wanted to shave the block cause it's worth much less than the engine, and if I stuff it up, it'll only cost me 50 bucks, small price to pay.

If I stay with the rb25det and stick on a larger turbo, won't I be loosing that response that I'm after?

I'm taking all responses in and trying to analyze what's the best approach, so thanks for all the replies so far.

~Danz

[bradsm87]

Thanks for the replies, I don't know much about turbos and stuff so when people list of names and sizes it doesn't mean much to me untill I actually see the thing. Sorry, I didn't realise a gt2530 was so unfitting for a rb30det.

the main reason I've always wanted a rb30det is because its a good base for the future, I'll soon get sick of 200rwkw and want more. And when I do, I know the bottom end isn't going to be a problem, from what I've heard the rb30 has to be the best over engineered bottom end from the rb series. I've heard of people pulling 500 - 600hp completely stock. Like I said, I'm wanting this engine to later on go in another car, but perhaps your right and I'm best off just modifying the stock rb25det. Problem is and paulr33 highlighted it in the last post is that when you try and sell your car with all the blood sweat and tears that you put into it, no one gives a shit and wants rock bottom dollar. So I'd rather put all my effort into a engine I can take back out, and then stick the stock one back in.

I maybe naive, but I was under the impression that the rb30det conversion wouldn't cost that much more than modifying a 25. Custom engine mounts - I can weld something up. Use all the 25 or 26 stuff around the motor as the rb's are basically the same. The engine management remains the same due to the same head, just bigger capacity. I haven't read up on what exactly is done in a conversion (I'm not going to read a 300page thread), I have seen a couple engines though, and one in a hr31.

And I'm not going to be going into the effort of ITB, thanks for the suggestion though - would sound sick too .

I like where bradsm87 is going with the raising the compression and then sticking the bigger turbo on. Raising the compression would be something I'm definitely after doing. I wanted to shave the block cause it's worth much less than the engine, and if I stuff it up, it'll only cost me 50 bucks, small price to pay.

If I stay with the rb25det and stick on a larger turbo, won't I be loosing that response that I'm after?

I'm taking all responses in and trying to analyze what's the best approach, so thanks for all the replies so far.

~Danz

U need to use different pistons to acheive the compression u want and leave the deck height standard otherwise it'll throw the cam timing out heaps. Think about it, as u shave the block, the timing belt isn't getting shorter so the cams turn around. Also U need to get the exact right turbo setup for 9.5:1 pistons to work well. U need a large a/r turbine housing and a turbo that'll flow what u want efficiently on low boost.

Edited October 5, 2009 by bradsm87

[bubba]

I haven't read up on what exactly is done in a conversion (I'm not going to read a 300page thread)

[bradsm87]

Also a side mount intercooler will be no good. What U want is a FMIC mounted with the outlets at the top under the radiator support where the air con evaporator goes and very short piping straight to the turbo on one side and straight to the throttle body on a forward facing plenum on the other side. Very short piping = good response.

[Lazy-Bastard]

He only has 1 year before he gets his opens....not nearly enough time to read a 300 page thread and actually arm himself with some knowledge....

[BrianV8]

bahhh i wanna build a 30

[Rolls]

read more before you start forking out, basically all the info you need is already here. 200kw with response = stock 25 with stock turbo. 250kw with response = stock 25 with a gcg highflow. Then when it blows up build your rb30 because you will be armed with a lot more experience and knowledge, that and you will know how to drive a car with some power.

[Danzzigger]

He only has 1 year before he gets his opens....not nearly enough time to read a 300 page thread and actually arm himself with some knowledge....

Thanks for the sarcasm.

If i want to learn about how a rb30det can go into a s13, s14, s15, r31, r32, r33, r34 and any other car the engine can go in, and all the other information it provides, I'll read it. However at this point in time I just want to know simply what is possible, and what is worth doing. Minutes of other peoples time can save days of my time and for that I am really appreciative for anyone who gives me some kind of information or suggestion.

I know it may sound selfish, but it's as if I'm reading the whole dictionary just in case I want to use some superfluous word one day (and that's not evidence that I have in fact done that ).

If the information is more direct and informative to what I need I'll read it no problems, many times over... Like the rb30 guide on the first page, that's fantastic.

Anyway I've said enough.

U need to use different pistons to acheive the compression u want and leave the deck height standard otherwise it'll throw the cam timing out heaps. Think about it, as u shave the block, the timing belt isn't getting shorter so the cams turn around. Also U need to get the exact right turbo setup for 9.5:1 pistons to work well. U need a large a/r turbine housing and a turbo that'll flow what u want efficiently on low boost.

Ok at first I didn't understand what your talking about but after some googling I've got an idea what your on about. From what I can visualize in my head is when you shave the block, the belt looses its tension on both the left and right side, for every mm you take off, you loose 2mm of belt. So considering that the tensioner is on one side of the rb (lhs isn't it?) so therefor it advances / retards the timing. From what I understand if the tensioner is on the lhs, the rb's rotate clockwise if your standing in front so the cams will open close later so there for its advancing it. If the tensioner was on the rhs, it would retard it wouldn't it?

People are saying you can just get some cam gears and then you have plenty to play with, I thought this is what you meant with gears, but wasn't 100% sure. So considering that you could leave the bottom end stock (would rather leave the block alone) and just shave it. Then do all my work on the 'brains' of then engine, at the top end. I'm just seeing that cracking open the bottom end to swap the pistons will be costly and time consuming. Shaving seems the best alternative if it means I just need to run some cam gears to fix the problem and a different belt.

What are the advantages / disadvantages? I would most likely be putting adj cam gears on to get the tune I'm after anyway.

I was thinking about it today and I think the best approach is to go with the 26 head as its got more advantages than disadvantages. Has the front facing plenum like we are after, has the twin turbos, which would be great for response and it's no added cost. No VCT modification required so thats a bonus.

[joeyjoejoejuniorshabadoo]

do you want to spend 20k? or less? cause that's what it'll cost when its all said an done.

remember you need other bits like clutch, diff, wheels, tyres supension etc

i have a responsive 300rwkw from an RB25 with an HKS 2835 pro s and a bunch of other shit... and i've been through ~30k and that's withOUT a rebuild

[Danzzigger]

read more before you start forking out, basically all the info you need is already here. 200kw with response = stock 25 with stock turbo. 250kw with response = stock 25 with a gcg highflow. Then when it blows up build your rb30 because you will be armed with a lot more experience and knowledge, that and you will know how to drive a car with some power.

I'm not into blowing up engines, I'm into doing things the right way the first time. I mentioned at the start of my thread that I want a reliable engine, and where possible I want to do this bang for buck - blowing up engines seems like a bit of a waste.

gcg highflow is something I haven't heard before though. Just googled it, something about a company transforming the stock turbo so that it can take a good 260rwkw? This sounds like a very good option as the stock turbo is quite small (good for response) and using something existing will bring the costs down. Do you know of the top of your head how much something like this costs, and what they do?

As for controlling power, I don't want to say that I know what it's like because I don't. However I drove my brothers r33 stock gtst on my L's and I could begin to feel the limitations towards the end. stock rb25det's are around 125rwkw stock (correct me if I'm wrong), so that's why I'm saying I'd be happy with 200rwkw. However this is really not what I wanted to focus on, I want response not a kw figure.

Seems like people keep suggesting to stick with the 25 and not bother with the 30. This does make sense in many ways, and it might be what I end up doing. But I'm just wanting to see what other options are available in achieving a rev happy engine.

You can tell I love my rb30's Driving a 31 atm, I just hate the electronics on the thing, the block / mechanical side of it goes hard though.

[aDrew_C]

Doesn't matter if you plan to do it on the cheap, the costs will add up and there's a lot of unexpected costs. If you aren't building it yourself, it will cost more than $15k, minimum. For the power you want it's not worth it, you will get the response out of an RB25 for that type of power with a highflow and the whole thing will cost you under 10k for all supporting mods and tune. If the engine lasts a year or three, great, not the end of the world. Build it then when you have the experience and can decide if the extra power is worth that kind of money.

Get over the idea of having to get a built engine. It's not necessary for under 300rwkw.

[Rolls]

I've got an R32 with a rebuilt rb25det, gcg highflow making 220kw at a 6k rev limit due to the fresh rebuilt. IT IS A HANDFUL ALREADY, when I get it tuned it should make 250kw+ and rev to 7.5k. It is ridiculously responsive and makes great power by 3k, you do not need a 3L unless you are aiming for big stupid power and personally anything much over 230kw on the street is stupid power. If you do get more than this and haven't had a solid few years with 150kw-200kw cars you WILL wrap it around a tree or kill yourself.

Starting with a 25 and a highflow + supporting mods (ecu, injectors, fuel pump, clutch) will set you back maybe $6k and will keep a stupid grin on your face for ages.

You can tell I love my rb30's Driving a 31 atm, I just hate the electronics on the thing, the block / mechanical side of it goes hard though.

If you already have a 31 just turbo the single cam motor, thatll make a solid 150-200kw with loads of response. Probably be more fun than a standard 25det even.

Edited October 5, 2009 by Rolls

[joeyjoejoejuniorshabadoo]

fwiw a stock RB20 will rev harder than a 25 or 30... and you can get 200rwkw pretty easily

[Guilt-Toy]

CHEAP - RELIABLE - FAST

You can only have 2.