Are RBs worth building reliability wise

[Blakeo]

I want to build my RB25, what puts me off is they just don't seem to last a long time at a powerlevel of 550-600hp. Seems as soon as you mess with the factory engine, RBs just don't last. Two of my mates who had forged RBs, one was in a drift car which spun bearings more times than he would like to admit and since he's gone to a Ford Barra engine. My other mate had the bore crack.

Is it even worth putting 10-15K into an engine you can't be sure will stand up to the power level because there is so much uncertainty in the quality of parts, engine builder and tuner. As well as the various other issues the car can have. 

Has anyone here had a rb put out at least 600rwhp and last for a long time 5 years/50,000km? Is there anyway to build the 5 speed manual on a budget to handle the 550rwhp, without having to do a low quality conversion kit to a T56/CD009?

[Kinkstaah]

I say no, but something people don't really look into is what problems they are trying to fix by forging a motor.

What are these problems? Were people getting stock motors, and melting pistons, or having pistons fail, and rods bend? (in 2021?)

No?

If they aren't - What good is stronger pistons and rods? Forged motors aren't failing because the forged pieces fail, and they aren't really upgrades for failing bits anyway. There's a enormous thread on oil control to keep bearings alive, but people much prefer to forge a motor and put the money there instead of an accusump or a drysump for some reason. Can't really do much about blocks cracking when IT becomes the weakest link.

320kw is the happy spot for a RB that gets used outside of Instagram, and other parts of the car work well there, clutches, diffs, subframes, the ability to grip the road, turbo lag etc.

When your car is driving around daily, it is making about ~50rkw, so you can go and get 300,000km of driving at ~50kw from a 500kw motor if you never actually use the power, so km/chronological time since rebuild isn't even that accurate a factor if you don't consider how its being used.

Keep in mind that GT3 engine manufacturers rate their 500hp (at the crank) engines for Mclaren, Mercedes, Nissan, Audi, Lambo etc for about 12,000km of race use. And these are VERY expensive, VERY modern, VERY engineered motors with HIGH displacement made specifically for continued high power use. In a category where lasting longer than your competition has a massive competitive edge.

Instagram performance is not real world performance.

[bcozican]

there is no guarantees at all to be honest if you cant afford to rebuild a built engine dont start the first time

 

whether you spend the $ is up to you - the question has come up a few times and yet to make a decision so Id say prob not but its all relative to people and for what purpose

 

reduce you power goals put a head gasket, head studs and cams in run e85 and 20 pst get 500 rwhp and it'll last for a good while if you treat it right

also if youre using just on the street big difference to on the track - total different loads put on the car 

pushing 600 rwhp built or not always going to shorter the life of the engine by a long way - 500  different story

 

No - no gearbox solutions / upgrades that'll worth and are cheap but a stock box will handle it if you treat it 'gentler' especially snap changing between 3rd and 4th

 

Ive been racing Rb's for 13 years from stock rb20 to rb22 stroker, stock rb25 and built rb25 200 hp to 650 hp (most around the 500 - 550 mark)  - I belt them they last... until they dont and you go again

 

 

[BK]

4 hours ago, Kinkstaah said:

Keep in mind that GT3 engine manufacturers rate their 500hp (at the crank) engines for Mclaren, Mercedes, Nissan, Audi, Lambo etc for about 12,000km of race use. And these are VERY expensive, VERY modern, VERY engineered motors with HIGH displacement made specifically for continued high power use. In a category where lasting longer than your competition has a massive competitive edge.

Instagram performance is not real world performance.

Absolutely, you speak the truth here. For comparison to a GT3 engine, a much cheaper V8 supercar engine that costs $150k and makes 650hp at engine, lasts about 5000km and cost at least $30k -$35k to rebuild.

[Dose Pipe Sutututu]

LS swap OR JZ or Barra swap it

[robbo_rb180]

My motor (rb25) has been reliable for the 10years I've had it (Built by Red R Racing in early 2010 by previous owner)I replaced the head with a ported one and did new gasket & studs in 2015, 260-350kw, Lots of track days(drift, sprints & hill climbs), street driving and shenanigans. Run on 98 & e85, sensible timing map, maintained it correctly, Good quality & thought out oil breather setup and not bang them off limiter. Like anything have a sensible goal & maintain it correctly will last a long time.

People with efame only show the dyno runs & the one time they go to powerskids/roll race they don't tell you it failed after one day of being thrashed and banged off limiter.

if building a competitive race car/motor they are always pulled & inspected and parts replaced at service intervals as per an engine builders specs. 

 

[SKYMAGGOT]

4 hours ago, bcozican said:

there is no guarantees at all to be honest if you cant afford to rebuild a built engine dont start the first time

 

whether you spend the $ is up to you - the question has come up a few times and yet to make a decision so Id say prob not but its all relative to people and for what purpose

 

reduce you power goals put a head gasket, head studs and cams in run e85 and 20 pst get 500 rwhp and it'll last for a good while if you treat it right

also if youre using just on the street big difference to on the track - total different loads put on the car 

pushing 600 rwhp built or not always going to shorter the life of the engine by a long way - 500  different story

 

No - no gearbox solutions / upgrades that'll worth and are cheap but a stock box will handle it if you treat it 'gentler' especially snap changing between 3rd and 4th

 

Ive been racing Rb's for 13 years from stock rb20 to rb22 stroker, stock rb25 and built rb25 200 hp to 650 hp (most around the 500 - 550 mark)  - I belt them they last... until they dont and you go again

 

 

Which cams you using?

[GTSBoy]

I would suggest that RBs are becoming sufficiently rare now that the old days' behaviour of beating them to death are unsupportable.

Unless you can afford to keep a stock of blocks and heads that will get you up and running again without having to pay someone COVIDtax/US enthusiast prices for theirs when you desperately need it, or you can afford to just not put the engine back together and thus give up on the car, then you either spend a lot of money building it absolutely properly (to prevent the inevitable bang) or you just don't lean on it that hard (~300rwkW sensible limit expressed above) to also prevent the inevitable bang.

[bcozican]

24 minutes ago, SKYMAGGOT said:

Which cams you using?

Poncams initially as it was an easy and good option and was a case of this + this + that = 'x' power as a tried and true method then I just kept carrying the over into each new engine

 

Recently 272 Kelfords are in and have the best options / service imo

 

[SKYMAGGOT]

16 hours ago, bcozican said:

Poncams initially as it was an easy and good option and was a case of this + this + that = 'x' power as a tried and true method then I just kept carrying the over into each new engine

 

Recently 272 Kelfords are in and have the best options / service imo

 

Cheers, I was looking at the Kelford 262 9.3 or usual poncams but don't know enough about ramp rates, overlap etc & seems to be not much posted about results for the Kelfords 

[Unzipped Composites]

4 minutes ago, SKYMAGGOT said:

Cheers, I was looking at the Kelford 262 9.3 or usual poncams but don't know enough about ramp rates, overlap etc & seems to be not much posted about results for the Kelfords 

 

Kelfords are definitely the go, forget shitty old Jap cams. Speak to Kelford about your aims for your build, they can give you guidance on the most appropriate profile.

[bcozican]

5 hours ago, SKYMAGGOT said:

Cheers, I was looking at the Kelford 262 9.3 or usual poncams but don't know enough about ramp rates, overlap etc & seems to be not much posted about results for the Kelfords 

I dont know about any of that either and dont care to - get the car to 80% right before worrying about being so specific what I concentrate on

272 recommended by them for me Im running bigger hp, squential, no vct for a time attack car that should be never off boost

but as said all that is taken care of from kelford now anyway - contact - get recommendation - install 

[Dose Pipe Sutututu]

On 10/06/2021 at 2:59 PM, GTSBoy said:

I would suggest that RBs are becoming sufficiently rare now that the old days' behaviour of beating them to death are unsupportable.

Install this

[Blakeo]

On 6/10/2021 at 7:12 AM, Kinkstaah said:

I say no, but something people don't really look into is what problems they are trying to fix by forging a motor.

What are these problems? Were people getting stock motors, and melting pistons, or having pistons fail, and rods bend? (in 2021?)

No?

If they aren't - What good is stronger pistons and rods? Forged motors aren't failing because the forged pieces fail, and they aren't really upgrades for failing bits anyway. There's a enormous thread on oil control to keep bearings alive, but people much prefer to forge a motor and put the money there instead of an accusump or a drysump for some reason. Can't really do much about blocks cracking when IT becomes the weakest link.

320kw is the happy spot for a RB that gets used outside of Instagram, and other parts of the car work well there, clutches, diffs, subframes, the ability to grip the road, turbo lag etc.

When your car is driving around daily, it is making about ~50rkw, so you can go and get 300,000km of driving at ~50kw from a 500kw motor if you never actually use the power, so km/chronological time since rebuild isn't even that accurate a factor if you don't consider how its being used.

Keep in mind that GT3 engine manufacturers rate their 500hp (at the crank) engines for Mclaren, Mercedes, Nissan, Audi, Lambo etc for about 12,000km of race use. And these are VERY expensive, VERY modern, VERY engineered motors with HIGH displacement made specifically for continued high power use. In a category where lasting longer than your competition has a massive competitive edge.

Instagram performance is not real world performance.

Thanks Kink for taking the time to reply properly, I understand what you mean. My main reason is just excessive blowby causing dipstick to blow out under boost even with a well ventilated breather setup. I'm not sure if new rings/bearings will fix it due to the age of the motor and the bore possibly being out of round. 

On 6/10/2021 at 8:14 AM, bcozican said:

there is no guarantees at all to be honest if you cant afford to rebuild a built engine dont start the first time

 

whether you spend the $ is up to you - the question has come up a few times and yet to make a decision so Id say prob not but its all relative to people and for what purpose

 

reduce you power goals put a head gasket, head studs and cams in run e85 and 20 pst get 500 rwhp and it'll last for a good while if you treat it right

also if youre using just on the street big difference to on the track - total different loads put on the car 

pushing 600 rwhp built or not always going to shorter the life of the engine by a long way - 500  different story

 

No - no gearbox solutions / upgrades that'll worth and are cheap but a stock box will handle it if you treat it 'gentler' especially snap changing between 3rd and 4th

 

Ive been racing Rb's for 13 years from stock rb20 to rb22 stroker, stock rb25 and built rb25 200 hp to 650 hp (most around the 500 - 550 mark)  - I belt them they last... until they dont and you go again

 

 

Fair enough, amazing how in all of these years there isn't a good solution for a H-Pattern gearbox onto a RB. The T56/CD009 conversions I've seen are bunky, generally the t56 ones I've seen aren't aligned the best and seem to have a whole host of issues. 

On 6/10/2021 at 8:26 AM, Dose Pipe Sutututu said:

LS swap OR JZ or Barra swap it

Come on Dose, why you have to do this haha. I'd love to JZ/Barra swap it but there's easy 10-15k in the swap which could be better used in upgrading the RB. 

On 6/10/2021 at 11:28 AM, robbo_rb180 said:

My motor (rb25) has been reliable for the 10years I've had it (Built by Red R Racing in early 2010 by previous owner)I replaced the head with a ported one and did new gasket & studs in 2015, 260-350kw, Lots of track days(drift, sprints & hill climbs), street driving and shenanigans. Run on 98 & e85, sensible timing map, maintained it correctly, Good quality & thought out oil breather setup and not bang them off limiter. Like anything have a sensible goal & maintain it correctly will last a long time.

People with efame only show the dyno runs & the one time they go to powerskids/roll race they don't tell you it failed after one day of being thrashed and banged off limiter.

if building a competitive race car/motor they are always pulled & inspected and parts replaced at service intervals as per an engine builders specs. 

 

 My factory motor has been making just over 400rwhp for over 3 years now, as you mentioned they are reliable at this power level. 

I've seen JZs hold 600rwhp on the stock bottom end for years, its just RBs have so many inherent design problems and a weak block it puts me off taking the car to the next level especially due to the cost of a built motor and the hot side setup. 

[Butters]

Running 600+hp on an rb26 for 13 years(100k stock bottom end), albeit low km's.

 

The block cracking seems to have a relationship to the 4wd setup. So hard to compare to JZ. Video tests do suggest JZ is king though.  So are you RWD or 4Wd ?

The stock gear will hold a lot.

Oil pump gears for limiter lovers.

Rods and oil drain for rev's

Sump for track

 

You really should see the condition of some of the engines that die(poor oil changes) or the abuse they have taken (100s of track days on limiter).

Regular oil changes, solid tune. RB's live a long time.  I plan on running my stock long motor at this level with 4wd as a weekender, so let you know how I go

 

GTSboy point is really relevant here though, gone are the days of a $1500 rb25 you didn't care about beating up on.  The $$ on this gear now is more than ever.

 

 

[Unzipped Composites]

I also think it would be wrong to say that RB's are weak or inherently flawed. Their oil control issues and block strength aren't a design flaw, they did exactly what they were designed to do when being used for what they were designed to do. Really it's the fact that they are quite a solid base that we are discovering their limits, because people are trying to push them to 600-700-800+ horsepower. Go and try that with a Toyota 2ZZ, the crank starts walking around at 500hp and you can't stop it. There's plenty of motors that legitimately can't handle it at all, the RBs sort of can but you're asking a lot of them.

 

At the end of the day, there's just no guarantees either way. You might build a 600hp engine and have it last 15 years, it might last 2 months - there's no way to guarantee it. So you're playing an odds game, you're rolling the dice. And if you aren't comfortable rolling the dice with the amount of money that it costs to play the game, then the best advice anyone can give is to not do it. Don't go to the casino and put all your money on Red if it will hurt too much when you land on Black.

 

Just ask Laine@bcozican, he's the sort of man that stands with his back to the table and barely even checks what colour the last throw landed on before rolling again 🤣🤣🤣❤

[joshuaho96]

The group A RB26 motors supposedly only ran max attack 700 hp in qualifying and dropped boost to get closer to 600 to actually survive the race. Those are engines that only have to survive one race before getting completely rebuilt. Nissan claims the Zexel group A R32 GT-R that did the 24 hours of Spa was running 550PS. So ballpark that's what the block was "designed" for. 540 horsepower or so for 24 hours of racing before rebuilding the whole thing, with everything around the block up to spec for 24 hours of endurance racing as well.

Personally I don't want to blow up an RB considering the cost of parts these days so it's easier to just keep power goals conservative and focus on reliability/driveability but some people just want to make these engines go further so the parts are out there to make it happen. Big power builds may not last very long but they can work, if they didn't you wouldn't see 6/7 second RB powered GT-Rs.

[Butters]

@joshuaho96 has a good point. Likely designed for around that 600hp range. 

 

The only thing to consider is technology has moved a long long way in 30 years. 

Better turbos, fuels, ecu, materials and machining give us more than what it was designed for  

[Unzipped Composites]

Yeh I dunno, keep in mind that what Nismo were doing with the cars and what Gibson were doing with the cars was quite different.

It's well known the Australian GTR's were making more power than the Nismo GTR's, Australia had the strongest Group A series in the world and they needed the power to compete. Nismo were making bank selling 500hp engines to private racers, and they owned the Japan Group A series. So for them developing the car further just meant spending more money, and they were already winning so why do it.

Here the Nismo-spec cars wouldn't have won, Gibson had to push them further and develop the cars more, and Nismo were too expensive so they were only a small part of that. Gibson were developing a lot of parts themselves as well as getting stuff locally and from America etc. But Nismo and Nissan still supported that development, and they developed the stronger blocks for them etc. The motors weren't getting completely rebuilt after every race, reliability was an important consideration for them and they had an obscene budget to do it.

You also have to wonder if they were capping power at 650 because that was the limit of the engine or because of other factors, ie. Old school turbo tech, old school ECU's, old school dyno tech, tyre restrictions meaning the old school tyre tech couldn't get it to the ground, terrible aero also making it difficult to drive any faster, etc. Is it a case of they pushed the engine as hard as it could go, or is it they pushed the entire package to the limit of what would make a fast Group A car? We know Skaife said they were horrific cars to drive, would having 800hp with bigger, laggier turbos have made them faster or slower?

So it's sort of difficult to say what power they were 'engineered' to handle vs what power they were developed to handle for Group A racing vs what power they can handle after 30 years of aftermarket development, etc. 

[BK]

On 11/06/2021 at 11:39 PM, Blakeo said:

amazing how in all of these years there isn't a good solution for a H-Pattern gearbox onto a RB. The T56/CD009 conversions I've seen are bunky, generally the t56 ones I've seen aren't aligned the best and seem to have a whole host of issues. 

Dunno what you're on about as there are upgraded H pattern gearsets for the stock case which will handle 600hp all day and have been for years.

The stock gearset will only take so much, so if you break it, you upgrade it. No decent driveline solution is ever cheap mate.