Jump to content
SAU Community

Recommended Posts

Hey guys,

I've had a bit of a look around, but I can't seem to find a definitive answer.

Would appreciate something from the tech-heads preferably, but anything's good so long as it's accurate.

A couple of clients/friends are building a GQ Patrol for the SA Offroad Champs, and the vehicle is going to have a mid-mounted RB25 in it. Under the regs of the sport class they cannot use the standard motor, and would prefer to run a forced 6 cylinder instead of a V8, so the motor is going to compiled from an RB25/30 combination, as the motor must be < 3000cc.

More to the point, the car is being built to a spec is mindful of their budget & class.

That's not the current concern though, currently they'retrying to sniff out some information regarding the factory RB25 flywheel, because the motor was an automatic from a Stagea half-cut. How much does the factory flywheel weigh?

No need for suggestions on aftermarket options either, the guys are machinists amongst many things, and will be manufacturing most of the components themselves for the vehicle build.

While I'm here too.... This is unrelated to the topic title, but - What is the torque/power rating of the standard RB26/GTR transmission?

Cheers in advance for any help,

Rick.

Link to comment
https://www.sau.com.au/forums/topic/402457-rb25-flywheel-weight/
Share on other sites

Not necessarily, things aren't always engineered from an aftermarket point of view, they're engineered to a torque rating.

Every manufacturer wants their vehicles to see out the warranty without paying out the nose for ongoing factory recalls, so things are always engineered or over-engineered to withstand a minimum specification.

The 'X' amount of extra power & torque from the 2.6 litre, plus the increased load on the drivetrain from an AWD format, means generally they'll install a larger clutch, to compensate for that. So the flywheel will be larger, respectively.

That doesn't necessarily mean it's heavier, of course.

But they could have just provided the same flywheel for all models/variants, but I don't know... that's why I'm here! ;)

Stronger clutch, yes. Bigger diameter, no. Therefore bigger flywheel, no.

Face it, the RB26 didn'tmake that much more torque than the 25, and not a whole lot more power. And the flywheel is almost the same (if not the same) between the piddly little RB20 and the 26.

A 10kg flywheel is overengineered by a factor of a bazzillion for an RB26.

(Yes, I am an engineer).

Guys, thank you very much for your time! :)

I do find it interesting that they kept the same flywheel from RB20 through to RB26 though, on all models. Strange indeed.

But I guess they knew what they were doing, and that's all that matters.

See I hail from the Pulsar mob... SR20's are commonly used, and there is a distinct difference in the variants, from RWD to FWD/AWD and GTiR. GTiR is commonly known as the black sheep, because 99% of it is different to other SR variants, and thus usually not interchangeable. The flywheel & clutch is one of those things... Ours are around a 215mm clutch, and the GTiR is around 245mm. Then of course, the flywheels are different to compensate.

So I figured maybe there might be a difference between models in the same fashion, but obviously not.

All the same - I got the information I was after anyway, so thanks again guys! :)

Rick.

Yeah, too true.

That was the idea of finding out... Briant (the owner/builder) wants to machine one up from scratch, but simply wanted to compare the standard TB42DE flywheel, to the RB25DET they bought to throw in the car.

Most of this is R&D, because the RB motor will likely be copping the GQ's FS5R50A transmission. He's a machinist, so making the components is not an issue for him.

Thanks again Elite/Daniel.

Edited by car_fanatica

Yeah no problem.

The RB25DE grenade has a shorter pin than the RB25DET grenade. Turbo models were nodular cast iron, non turbo models and RB30 flywheels are regular cast iron.

If you are going to be making torque/hp, you need to consider an aftermarket flywheel. NPC do the revsolution flywheels at 6.5kgs at approx $400-$450.

The worst thing for that setup is the weight of the car. There is a lot more load on the clutch and drivetrain so it's even more important to consider non-cast iron options when it comes to flywheels

  • 1 year later...

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

    • You see R34 GTRs listed for 200-300k are they really selling for these prices? Kinda seems like the same ones listed all the time. Even with R33 GTSTs looking at gumtree. You have an auto with a bitsa interior for 35k. Another one needs an engine rebuild and asking 24k. And then you have a stock in better than average condition for 45k. Nobody is ever going to pay these prices.
    • Only needed to pull out the seats, center console and gear shifter surround, took a weekend and a fair few beers. You get to look forward to finding all sorts of weird shit under the seats and carpet, I pulled out a Chinese dudes passport from 2003, 220 yen and a condom wrapper 😆
    • Well, turns out not a lot happened from back then to now, between life again, and working on 3 separate other cars (only one of which was mine, and will now be departing the household soon).   So I decided with the whole "don't go outside, it's a cyclone!" Turning in to being not a whole lot, I ventured down to the garage, found a couple of water leaks in the shed (the main one I've already fixed), and then ended up "stuck" as it started pouring rain, and I didn't want to walk back inside in the pouring rain. This meant I ended up taking a look at the Skyline, and trying to work out what past Matt had been upto. I retraced a few things out from scratch, added the rest of the power feeds in that I needed for the indicators, and headlights. Double checked I'd wired a few things up correctly (and worked out how I wired a few things to begin with), updated my sparse notes. Added one of the ground points. Oh, and got really really dusty, as the car is quite dirty. Wrote up quickly what should be left for me to do with the wiring too. Adding the below photos more for my records than anything else. I need to make myself a proper book for the car that details everything, and how I've done it, but for now, this is my records... The third image is my most important one for me, and I need to draw it out into a proper schematic eventually. The last photo is my re-written list, I'd have put it on the white board, except I had to take the white board down to fix one of the water leaks.
    • Can try Maxima. Or random Infiniti models from the same era. Good luck with your hunt, let us know what you find!
    • Shall we... wake you up when September ends?  
×
×
  • Create New...