Jump to content
SAU Community

Recommended Posts

i'm just after people opinons on this,

I'm up for a rebuild at the mome and don't like to do things half arsed lol, narrowed down my choices to 2 setups

a gt3040R on a worked 25 or a gt3540R on a worked 25/30

i will be looking to get proengines to do the build regardless but does anyone know of them doing a rb25/30det before? and at what sort of cost?

as far as i'm aware there still in a transition state at the moment so i don't want to bother them just yet lol

and basically what i'm after is more than 300rkw with as little lag as possible

budget 15g but of course would like to stay below that by a fair margin if possible :)

Link to comment
https://www.sau.com.au/forums/topic/135212-rb30det-worth-it/
Share on other sites

  • 1 month later...
  • Replies 49
  • Created
  • Last Reply

Top Posters In This Topic

okay no reply's but justing letting ppl know that'll i'll be able to tell you all if it's worth it :)

not going all out cos i picked up a standard just built 25/30 for a damn good price picking it up this sunday, my cars currently at autotech having the 25 pulled, it will be interesting when's it back together with the same set up as what was on the 25

I guess it will show straight away what differnce the extra .5L makes, i'm thinking bigger turbo will be a definant requirement and is first on the list to be done

figures are one thing, but what i was meaning it will be real interesting to actually feel the differnce in the exact same car with same mods on to primarily standard motors except one 2.5 one 3l i'm looking forward to it

Edited by Slither

I would love to go the 3 litre. and if the rb20 should die i will be doing a rb25/30 budget build. you will dfinatly feel the difference.

mainly the torque as soon as you put your foot down even at low revs.

Booo, truck engine.

Shouldve done a 26 so it can rev its ass of :)

lol not so actually can still be pushed till around 7500 standard, with full rebuild 8000+ should be reachable I'm going back to factory 7000 just to play it safe, will be interesting to have full boost a 2000 with stock turbo I'll miss reving her out tho till i get a much bigger turbo that is :no:

speaking of which i've heard of trojan doing some no name turbo for a good price that's meant to be surprisingly effective apparantly the burgendy 300+ r33 they did had it anyone heard of this?

Let me know how it goes as i'm just about to pick up an RB30 block for mine. The old RB20 is on its way out so hopefully i'll have the new engine built by then. :ninja:

hook me up with a good price on the gt35 kit and you can even drive it :P

Edited by Slither

Longer stroke + bigger cc's=more torque for anRB 30.

Torque balances power [hp,kw]. The longer the stroke the greater the torque, the less you can hurry the motor [revs].

The shorter the stroke the greater the power, the more you can rev the a#se off it.

But consider torque vs power as the ability to push through a brick wall. A rev happy motor will get to the brick wall quickly, and whack it hard, but it will dissipate its energy quickly.

A torque laden motor will reach the wall much more slowly, and will hit the wall 'gently' but will continue through the wall and out the other side.

Torque is work, power is energy.

Its power that makes you go fast, its torque that fights the headwind.

This is like a tractor pulling a stump out with 80hp vs a car trying to do it with 600hp. Older tractors [the common grey fergie type] are usually two to four cylinder diesels with 50hp small bores, and long stroke crankshafts. F1's [senna, Schumacher] cars are short stroke and [in relation] big bores.

Manufacturers try to find a balance based on expected use for each motor.

I've probably gone overboard here, but you should get the picture now.

Not everything that revs is powerful.

my datto revs to 9k but doesnt make good power until after 4.5k. Its a combo of bore/stroke, if id stayed 1.6L i couldve made 10k revs but it doesnt offer any benfit to 9k in the 1.8L. doesnt bother me as its for track/hillclimb where you revs its arse off all day but itd sauck to drive all day around town.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • @joshuaho96 Hmm considering the drama you've seen/experienced, have you looked into getting a built complete long motor shipped from Australia?  Considering the AUD is basically monopoly money when compared to the USD, at a glance this seems like a good option?
    • Bloody Skylines, they put you through the bloody wringer! Stick at it! Stunning drag strip BTW! Where is it? Can see part of the name on the slip and probably should just Google it!
    • I mean the other day I had to walk someone through diagnosing why their timing belt was walking off the cam gears. At least one of the issues was a bent tensioner stud. Local mechanics have found runout on the CAS mechanism causing weird failures. I'm also no saint here I've documented some of the things I've had to learn the hard way. Something I discovered recently is that my CA emissions catalytic converters weren't even welded correctly to align the downpipe to the main cat and they tossed the support bracket that goes from the transfer case to the downpipe to support everything there. I spend a lot of time chasing down these decidedly unsexy problems and the net effect is it feels like I never actually get to the original objective (flex fuel, VCAM, oil control, cooling, etc).
    • At times with how you make everything sound, all I imagine Americans doing when they see a gtr is standing there looking at it and bashing it with a gun like how a caveman would with a club and hoping it fixes itself 
    • I think this is just a product of how the US market works for this stuff. Shops are expensive and there's no real way of knowing what kind of results you're going to get, people don't really have the institutional knowledge. I have heard too much at this point to really put faith in anybody "full service" except maybe DSport and they aren't really a full service kind of shop. If you go to the right place I have no doubt they'll get it right for you. Some locals have set it up right but the cost really is nuts and even now they're still fighting issues. And you know I'm a crazy person who thinks things like twin scroll, relatively short low-mount cast headers, PCV recirc to intake, recirculating BOV, right-sized for ~400 whp, MAF load, validating all of that to a standard comparable to OEM test programs, etc are relevant. For what it's worth, multiple local owners at this point have been stuck in a perpetual cycle of blowing a motor -> getting someone to rebuild it -> some missed detail causes the bearings to wipe and spin just outside of break-in mileage or drop valves or some other catastrophe -> cycle repeats. I usually only find out about this because I'm perpetually helping random friends with diagnosing car troubles, Skyline or otherwise. The single turbo stuff if I'm honest is mostly secondary, it just doesn't seem to achieve the numbers in the ~2000-3000 rpm region that I would expect given the results I've seen here or in Motive's videos. I don't really know what we're missing here in the US to be causing this. Lots of people like to emphasize the necessity of finishing the project first and foremost, but I'm not made of money and I can't afford to be trashing a 15k+ USD engine build with any regularity. Or spending my relatively limited garage time these days unable to triangulate problems because too much was changed all at once. Also, even if it isn't a catastrophic failure I would consider spending the cost of single turbo conversion with nothing to show for it to be pretty bad. 
×
×
  • Create New...