Jump to content
SAU Community

Rb25/30 How Long Will It Last?

Tony1981

By Tony1981,
in Engines & Forced Induction

 Share

Recommended Posts

MBS206 Grand Master

MBS206

Posted
Posted

Personally, I'd be going for a stock turbo if you don't want to break things...

I'm running a T04R on the same setup as you, except for ceramic coated pistons, and a flowed head...

I hit 4000RPM and just snap into massive amounts of torque...

Off boost drives really well, but once above 4000RPM it REALLY Hauls ass...

Cubes Grand Master

Cubes

Posted
Posted

I'm not sure a stock turbo on the rb30det is a wise thing for reliability as they choke up way too much.

Mine used to ping so damn easily and ran bugger all ignition timing.

The tune with the GT30 is much less highly strung. The stock turbo was right on knocks doorstep even though we were running next to no ignition.

As a comparison the stock turbo running 12psi tailing off to 9psi saw a peak of 13-14degree's.

Drop the GT30 on and an instant 20degree's through out the rev range.

MBS206 Grand Master

MBS206

Posted
Posted
I'm not sure a stock turbo on the rb30det is a wise thing for reliability as they choke up way too much.

Mine used to ping so damn easily and ran bugger all ignition timing.

The tune with the GT30 is much less highly strung. The stock turbo was right on knocks doorstep even though we were running next to no ignition.

As a comparison the stock turbo running 12psi tailing off to 9psi saw a peak of 13-14degree's.

Drop the GT30 on and an instant 20degree's through out the rev range.

The advantage though of running the stock turbo, is the ability to drop the revs, and still have just as much useable power.

And we know revs also kill motors.

I've heard of a few 26/30 combo setups (Not in australia) running twin RB20 turbos, and cranking out over 300RWKW without blowing turbos.

Cubes Grand Master

Cubes

Posted
Posted
The advantage though of running the stock turbo, is the ability to drop the revs, and still have just as much useable power.

And we know revs also kill motors.

I've heard of a few 26/30 combo setups (Not in australia) running twin RB20 turbos, and cranking out over 300RWKW without blowing turbos.

What sort of rev's are you talking about?

The usual 7000rpm is fine for the rb30det.

With regards to the rb30dett running twin rb20 turbo's.. You've missed my point. :blush:

A 'single' rb20 or rb25 turbo on the rb30det's chokes them up reduces the available rev range. Causes detonation and has them living on the edge. You have to pull a heap of ignition timing out of it and even then it still pings so damn easily as soon as the weather warms up.

Mine with its stock turbo made its peak power at 4400rpm and felt like you hit the brakes at 5500rpm. Definitely not fun nor did it accelerate quick. Possibly with a 3.45:1 diff ratio but with the 4.3:1 diff ratio the lack of rev's absolutely killed its acceleration. The power band was compressed not widened. :(

No point having 110rwkw at 2000rpm unless your towing or pulling stumps. :(

Cubes Grand Master

Cubes

Posted
Posted
Cubes, I am need of a turbo for my conversion and I was thinking something like this would be good,

http://www.turbobygarrett.com/turbobygarre...T30/GT3071R.htm

With a .63 or .82 A/R,

Thats not to small is it?

Definitely don't go with the .6 on the rb30.

I personally wouldn't go any smaller than the GT3076 .82 on the rb30det which is what I went.

Mine recently made 302rwkw on 17psi. 200rwkw by 3.5k and 256rwkw by 4k. The cams really woke the motor up.

I must be dyslexic as I typed 265rwkw at 4k in other threads :S. Its actually 256.

It has heaps of mid range a perfect street setup. I can click third gear from 60km/h and torque away from rb25 and 26's making similar power that are sitting in second from 60km/h's without any problems.

And surprisingly as power is so linear traction problems are very little. Not lag lag lag and then hard snapping power delivery.. Just brute mid range when you put your foot down.

The GT3582r with a .6 rear will push 340-350rwkw spool slightly later than the GT3076r .82 and have slightly decreased throttle response. Which is most noticeable in the lower loading quicker reving gears.

Up from there is the Gt3582r .82 for another 40-50rwkw cams then GT4088r etc etc :devil:

IMO

Tony1981 Explorer

Tony1981

Posted
  • Author
Posted

Mine recently made 302rwkw on 17psi. 200rwkw by 3.5k and 256rwkw by 4k. The cams really woke the motor up.

I must be dyslexic as I typed 265rwkw at 4k in other threads :S. Its actually 256.

Its called a transposition error, you can tell because the difference is divisible by 9, ie...265-256 = 9 or example.........1170 or 1710, diff = 540/60 = 9, whenever the difference is equally divisbled by 9, its called a transposition error, common mistake in bookkeeping - I studied Commerce at UNI :-)

And surprisingly as power is so linear traction problems are very little. Not lag lag lag and then hard snapping power delivery.. Just brute mid range when you put your foot down.

Thats exactly what I am looking for, for the moment I am running an N/A RB30 5spd, and old uni'd half-shafts and 27spline'd stub axles, dont want the power delivery to come slammin on at 4000rpm!!!

Tony1981 Explorer

Tony1981

Posted
  • Author
Posted

Just curious about manifolds as well Cubes, those turbo's dont have internal gates and I cant fit in a high mount manifold - absolutely no way does it fit under the bonnet of my Z,

Are you modding the stock low-mount and sticking a blow-off valve on top?

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Rezz
      Video Edit Programs

      By Rezz · Posted

      For something a little more serious, Davinci Resolve is about the best there is for free video editors. No expiration dates or watermarks, completely free.
    • Shoota_77
      Shoota's R33 GT-R RB30/26

      By Shoota_77 · Posted

      Well, it's taken me until the last week of 2024 to actually do something on the Skyline but I consider it a good head start to 2025's efforts! I managed to justify (to myself anyway...) my purchase of the lift table. It made taking the rear subframe out a lot easier than it would have been without anyway! Everything is out and stripped down ready for a clean then powdercoating.  She's pretty grubby under there but pretty good condition for a 38 year old Japanese tin bucket. 12 years of zero street time have obviously helped that... I need to decide which of the factory suspension arms I will keep and replace so I only get what I'm keeping powdercoated.  Baby steps but it's a start!  
    • The Bogan
      NC MX5

      By The Bogan · Posted

      Turbo gods, some assistance and recommendations please I'm looking into a turbo kit for my 2.5 from MX5 Mania >>>>> https://mx5mania.com.au/products/copy-of-mx-5-nc-2-5-litre-engine-conversion-turbo-2005-2013 Power wise I would like about 200kw atw, and of course dose noises, apparently if you keep a stock 2.5 under around 200kwatw the engine and drivetrain will not hate life even when ragging on it a bit Max RPM on the 2.5 is around 6500rpm The turbo MX5 use is something around the disco potato size as  packaging room for the turbo is pretty limited, which will, I believe, give me my power goals I want and not have the turbo either under, or oversized, but the rear housing bit is confusing  It comes with either a 0.64 or 0.86 From my understanding, which so far is based off googling, so make of that what you will 0.64: spools faster = good Makes more EGT heat on boost = bad Less topend power than 0.86 = I'm only looking for 200 atw so that point may be mute????, I don't know, hence my questions  0.86: Spools a "little" slower = how much slower??? remembering 6500 is my max rpm Makes less EGT heat = good Makes a little more power up top = again, power goals is only around 200 Also, this is a street car, so there will not really be any long track sessions, in saying this I would want it so it was happy with at least 3 hot laps at Wakefield Park if the need arises  I already have a fancy pants triple pass radiator, and a oil cooler with thermostat will be getting installed as well Thanks for any information or recommendations you have 👍, and of course, the comments about me wasting money on drive in drive out modifications, or any other snide remarks about my manhood for owning a MX5 🤣    
    • The Bogan
      Mistakes were made, my R34 Story

      By The Bogan · Posted

      Tape some wool onto the vent then take it for a drive I did this to my reverse cowl and was instantly unhappy, as anything over about 60kph would have the wool enter the engine bay, thus just adding underbonnet pressure and stooging my coolant stack, it did let alot of heat out when stationary though, which really didn't help once the car was moving, with the reverse cowl you could watch the coolant temps cheap up the faster you went on the hwy, I assume it would be alot worse doing track day speed With the vented bonnet (just after the radiator and about 1/3 up the bonnet) on my old R33 the wool on the leading edge sat at about a 45° angle as air poured out of it From looking where your vents are, and their size, I believe you should be fine at speed and air should be evacuated from the engine bay, I think it will be a night and day difference when stuck in traffic though for removing the trapped heat, and not sitting there cooking when parked up after driving around... #convection  Post wool tuft pics and data for science  This beastie is one nice and unique rig, enjoy
    • GTSBoy
      How much roughly to convert stock r32gtr to single high mount turbo + ecu and tune

      By GTSBoy · Posted

      It is possible to do this stuff for "cheap". But you need to be able to get deals on all the bigger items, and it really helps if you're fully capable of doing your own work. As soon as you're paying retail for new parts, or buying "kits" because you can't fabricate necessary bits and pieces, and if you really need someone else to take the reins of doing the work because you don't have the space/time/skills/confidence to  rip deep into the car and put it back together in a working fashions.....then you pay. And these days, pay means a lot of money. You'd think things would get cheaper, but they don't. They just seem to keep getting more and more expensive.
×
×
  • Create New...