Jump to content
SAU Community

Recommended Posts

Okay guys. I am in the process of getting ready to build the living crap out of my RB26 including a 2.8L Tomei Stroker Kit. I had previously considered going with an RB30 however I was under the impression that with the RB30 you lost quite a bit of revs. This was my primary reason for steering away from it as I am very rev happy. As of yesterday I was informed that my understanding was incorrect. You dont really lose much revs. You can still rev an RB30 to 9500rpm and such safely.

This brings me to the reason for this thread. First let me say I am not trying to make this an RB30 vs Stroked 26 war. Also I am not asking what the RB30 is or what it does. I know these things as I have researched it. My question is much simpler then that.

If the price to stroke and build and RB26 is the same as the price to buy a brand new RB30 fully built. Why the hell wouldnt you buy the RB30? I mean with all the benefits of the RB30, torque, crazy power possibilities and if you truly dont lose any revs, I dont understand any reason to not go with an RB30 over a stroked RB26 for the same price.

Of course I may have a narrow minded view and that is why I wanted to ask you guys here.

If it costs the same to build a stroked RB26 and for a new fully built RB30, why not buy the RB30?

Thanks guys.

-Sayajin

Link to comment
https://www.sau.com.au/forums/topic/155543-pros-and-cons-of-an-rb30-engine/
Share on other sites

  • Replies 44
  • Created
  • Last Reply

Top Posters In This Topic

The general rule for a Rb30 bottom end is that its limited to approx 7500rpm.

Which is what I thought as well... however per Ripps Mods,

We're running our forged RB30's up to and over 8500rpm now and they are still pulling hard and smooth, I prefere to give conservitive rev limits to customers although similar internal engines I know of regularly pull 9000rpm+ and 1000hp+ so its up to the individual I suppose.

When you can make over 700whp by 7000rpm with huge torque I prefere to keep the rpm down a bit for long life, its rpm that kills, not outright power.

This made me do a complete double take on my build..... 8500RPM AND an RB30? Why the hell not?

-Sayajin

Well... I mean based upon what I was hearing from RIPS, what I was planning to spend to build the crap out of my RB26 and stroke it to a 2.8L is about the same as what I would spend on an RB30.

That is really where my question lies. Of course I dont expect to be able to rev an RB30 to the same place as a 26. However if I can still rev to 8500 safely on the RB30, it would be worthwhile for me personally.

-Sayajin

yes..we take ours to 8k...we were worried about the oil pump previously but if you ran an external pump then you can probably rev is further without much concern at all. But most people will tell you there is no need to rev it because it makes the same power as a 25 or 26 at lower rpm, but if you can afford and it still makes strong power upto the rpm limit you want then why not.

You live in the US of A go buy a crower strocker kit about the same as a tomei price wise but you get a billet crank. They could probly make you a kit for the RB30 then you could rev the crap out of that too. They can also build a 86*86 stroke*bore get a 20mm spacer and some bore liners and you have a home made OS 3lt kit lol.

I've never understood the "I want to stroke my rb26 so it still revs since an rb30 can't" point of view.

It is primarily the length of the stroke that governs revs (head issues aside). The only real diffference between a 26, 28 and 30 is stroke length. Oh and you pay $5k more for a 28 crank than you would for a larger 30 crank.

Why do people build rb26s? No idea - the only issue with rb30 is the 4wd sump adapter and there are no oil squirters in the block. And rb30 cranks and blocks are significantly cheaper than rb26 ones.

Why do people build rb26s? No idea - the only issue with rb30 is the 4wd sump adapter and there are no oil squirters in the block. And rb30 cranks and blocks are significantly cheaper than rb26 ones.

i think the VL turbo blocks have the oil squirters in them?

i think the VL turbo blocks have the oil squirters in them?

Nope.

-----

There's a few RB30's floating around now that rev plenty hard. If you want a hard reving rb26 you have to do the same mods as you do to an rb30.

r33racer rb25/30 I think his alias is... Plenum, exhaust manifold, ext gate, 256 tomei cams and it full spool in the mid 3000's makes power to 8500rpm no problems. 370rwkw I believe it ended up making.

Then there's Bu5ters and a string of VL's.

An RB30 is a hell of a lot cheaper to build than a stroked Rb26.

How many rev's do you want and how often do you want to rebuilt it? :)

Remember back to the Gibson motorsport bathurst days... They rev limited their Rb26 to 7000rpm for a damn good reason. Longevity.

You also must remember large turbo's need cubes to get them going hard in the lower (less load) gears.

Not much fun if you have to wait until the end of second until things start really happening.

5k for built RB30

15k for built RB26, i know what i'd be doing

note: price may not be 100% accurate, or even close for that matter... lol

a mate was telling me about a place he came across that offered rb30 single cam turbo engines that would rev to 10,000 all day every day, he also mentioned for just the engine your looking at $19,000 no turbo, so anything is possible if you have stupid money

5k for built RB30

15k for built RB26, i know what i'd be doing

note: price may not be 100% accurate, or even close for that matter... lol

Not sure where you have your prices mate, but they are horridly wrong.

Why even post if you dont know... kinda pointless

the rev issues with RB30's appears to be that around the 7500rpm mark (standard crank, mains cap, sump, block, oil pump) the system hits a harmonic which essentially distorts the geometry of the whole lot and means you break things. there are a number of ways around this, all things being equal:

1) billet mains cap

2) change the sump to something else - stronger, stiffer

3) dry sump it

4) forged, lighter rods and pistons with crank counterweight lightening

5) billet crank

6) block stiffening (grout filling, girdles etc)

basically the stiffer you can make everything, the higher it will rev. if you can avoid that nasty harmonic (apparently it's very "focal" and if you rev past it quick enough, it goes away above 7500!) then you are in safer territory.

having said that, revs are bad. revs create massive wear on bearings etc, not power. i'm not sure why anybody would want to build an RB26 just so that it can "rev hard". use a bigger capacity engine, fit a larger turbocharger and enjoy the off-boost response. fit taller diff gears to space out the gears and allow the turbo time to work in the first two gears. chasing revs simply for the sake of it is a bad idea.

shoosh neill....my dream: an rb30det with to4z 10rpm redline.....words cant express how im feeling right now thinking about that.

See no need to go overboard, something like that is great...but not godlike.

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

    • The nature of my commute has changed. Way back then it was traffic lights all the way, for ~28km. It sucked. When they finally stitched the expressway together I can do a good 15+km of it at a steady 80-100 with no stopping. That alone has gotten me down to flat 10s. Prior to that it was mid-high 10s. I can't remember the delta that I saw when I got the idle down. It was only ~150 rpm, because the idle speed was never terrible, but for the delta in consumption to be noticeable it would have had to have been at least 0.2-0.3 L/100km - which is not to be sneezed at when it comes for absolute free.
    • If you're claiming the issues are not skyline specific, then either the USA is living in the 90s / early 2000s, OR you have the issue of "survivor bias". Which is you're mainly hearing and listening to those with terrible experiences, and haven't found the guys who have cars with good decent builds and no problems. It happens in AU too, that plenty of people keep having issues, and they keep going to the workshops that are known to be shit "because I read on the internet". Even worse, are those who keep posting on the internet as though they know for a fact what something is, when they've never touched/looked at said item in their life, and again are making assumptions, based on something they read, or because it's a certain way in other cars. It's even funnier when those same people debate the facts with the people who've lived and breathed this stuff for over 15 years. Example, I've had someone tell me you can't do something with a Skyline, because they read it on the internet, except I can tell they're wrong, as I did that exact thing back in 2008 with my Skyline.
    • The funniest part I saw, was someone would bitch and moan on FB about something, Andy would be the one to respond, asking for more info, if he could contact them, what the engine setup is, what their config file was, and 95% of the responses were people just going "der! It doesn't work" and Andy going "What doesn't work?" And then going "The firmware!" And they'd go around in circles as no one could ever give information, and Haltech couldn't fault things on the bench, (especially when people wouldn't give any specifics).   Many moons ago, when Andy was back at e420c stage, he reached out to me, and asked me to test different plug and play looms for him (already had an e420c in the car on his V1 PNP loom). And he kept asking me, as I was competent enough to be able to give him some specific feedback on what was/wasn't working, how to replicate the faults etc, and work through things with him. Most people are terrible at answering the questions they're asked, or being able to provide quality feedback other than "it doesn't work".
    • I say it often, none of this stuff is really Skyline-specific per se. But in general there's not a lot of people who actually know what they're doing. A lot of people charging like they do. Agile software development probably isn't the greatest idea for an engine controller.
    • Incidentally, I also put v3 of the tune on the car and did an oil change from 5w20 to 5w40 to see how it affected oil pressure in the mid to high end. I'm still happier with the thicker oil and will stick with it, but clearly the system is happy with 55psi even if I'm not! It's well within the service manual specs...but they are very open
×
×
  • Create New...