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Parts For Budget Forged Rb25


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Why did you use "budget" in the topic?

I guess because im not getting a "fully" forged motor. Also wasnt even going to think about touching anything in the head (anytime soon). Im not getting a workshop to do any work apart from the running in process and tune. I am getting the motor assembled and installed privately.

I used the term a bit loosely i guess. Aswell as the "forged" part, lol.

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Luke,

There are 3 ways to go about this.

1: Buy a second-hand engine, drop it in, and swap all of your upgrades on to it.

2: Replace the crank.

3: Buy another engine that's tired. Pull it down, replace everything with the items we discussed over whatever period of time. Once complete, you will have a very capable engine.

The downside to option 1 is that you have no idea as to what you're getting.

The downside to option 2 is that you will have to spend money replacing all of the bearings and of course, the cost of the crank itself. Add to that the labour/machining and costs of gaskets and it would not really be a viable way to go.

There's no downside to option 3 as you will eventually have a fully rebuilt and capable engine. The price of all the goodies and labour can be spent over a period of time at your leisure so it won't be a great burden on your finances. You can keep pussy-footing your car in it's present state and hope for the best.

Another way to go with option 3 is to just rebuild it using stock parts. This way you know that the engine going in will not give up any time soon. If you can get hold of a set of 26 rods and pistons, the cost would be less than forged items, but you will be limited with the power cap. For the extra grand or so it would cost to forge it, and increase the power cap is entirely up to you. Would 400hp be enough? That's your real question.

There's nothing stopping you from driving what you have now, but with the harmonic in the state it's in at the moment it will only be a matter of time before the engine lets go.

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Luke,

There are 3 ways to go about this.

1: Buy a second-hand engine, drop it in, and swap all of your upgrades on to it.

2: Replace the crank.

3: Buy another engine that's tired. Pull it down, replace everything with the items we discussed over whatever period of time. Once complete, you will have a very capable engine.

The downside to option 1 is that you have no idea as to what you're getting.

The downside to option 2 is that you will have to spend money replacing all of the bearings and of course, the cost of the crank itself. Add to that the labour/machining and costs of gaskets and it would not really be a viable way to go.

There's no downside to option 3 as you will eventually have a fully rebuilt and capable engine. The price of all the goodies and labour can be spent over a period of time at your leisure so it won't be a great burden on your finances. You can keep pussy-footing your car in it's present state and hope for the best.

Another way to go with option 3 is to just rebuild it using stock parts. This way you know that the engine going in will not give up any time soon. If you can get hold of a set of 26 rods and pistons, the cost would be less than forged items, but you will be limited with the power cap. For the extra grand or so it would cost to forge it, and increase the power cap is entirely up to you. Would 400hp be enough? That's your real question.

There's nothing stopping you from driving what you have now, but with the harmonic in the state it's in at the moment it will only be a matter of time before the engine lets go.

Nail on the head mate, this is exactly what i've been thinking. I cant see into the future but i would put money on me getting bored from 400hp, would be a matter of time. This is why i am leaning towards replacing with forged pistons and rods then ill be sweet for when that time comes.

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Haha Luke, my advice for if you're getting bored with 400rwhp... Get out on the track more! I can imagine you will get bored with whatever power you have, because street driving is boring, plain and simple. But out on the track, different story. When I got out to Collie awhile back, I found I had to turn the boost down because at 400rwhp the car was too much for me, I'm shit! Haha. And Collie isn't as technical as Barbs, so I can't wait to see how I'm going to go there.

The track will really put you to the test and give you some real fun, on the street you can't really have any fun no matter what power level you've got. I'm itching for Barbagallo to be finished so I can get back out there and try to get the 400 to the ground :D

Edited by Hanaldo
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Martin you big girl lol.

Lol it's not easy man. Slightly worn semi's, standard calipers and EBC Green Stuff pads certainly don't help, but you really do realize how fast a 400rwhp car is when you're trying to brake late into corners and then trying to get out of them fast without spinning the wheels. I found I was getting better track times when I turned the boost down. Not to say the lack of traction isn't fun in itself :P

Edited by Hanaldo
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25/30 still seem so unreliable

no less reliable than any other modified RB. the standard 30 blocks are very tough, most problems arise from the build not being done right the first time, stuff like oil feeds and vct mods etc.

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  • 2 weeks later...

I think you'll find it's a colloquial term for an engine which has been rebuilt with forged internals (or at least pistons). It's a bit easier than having to type "building an engine with forged pistons and possibly conrods" every time you want to refer to a "forged motor".

I tend to agree with some of what's been said by others. Unless you are aiming for significantly more power, why bother doing a "budget" rebuild? Keep what you've got and either rebuild it once it's cactus or just get another second hand long motor and switch it.

I too tend to find the comment of "forged engine" very funny. Many of my mates say "oh yeh, my cuz has forgies, etc, it means he's engine has heaps of power, bla bla bla." I just humour them and agree. But what they fail to understand is that "forging" is just the process of making the metal part, i.e. a piston. It is the process of compacting (pressing down) aka dropped forged, a piece of metal to shape it into a piece/part. It does not in any way "make power".

What people don't realise is that forged internals exist from factory.lol The factory made components in engines have all gone through a process known as liquid forging or cast forging. The difference is that, dropped forging ensures 99.9% of the metal molecules are "stressed" in the same way through the manufacturing process and liquid forged tend to have molecules heavily separated, etc. this is why most liquid forged or cast items cannot withstand the pressures that most dropped forged components do. This, however, does not necessarily means the factory items are bad in any way. I.e my r33 has been completely rebuilt (will post thread in next few weeks) and when searching for parts, I tended to seek manufacturing processes. I chose to replace the parts since I saved my pennies and start a project with my father who has been a mechanical engineer for 35 years, however, the stock bottom end of the rb25det is strong to 500hp reliably everyday.

My pistons are JE custom made to my specification of compression ratio of 8.6:1 and they are definitely not liquid forged items. They are billeted aluminium dropped forged blanks that have been CNC machined to near perfect thresholds.

Just my two cents anyway.

Edited by Jimz
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I wondered about this too, I know a r33 which was modded to 270rwkw at 120,000ks and then 300rwkw at about 175,000ks, now has done about 235,000ks and still going strong, it's taken a ruthless beating! road car(he's an idiot on the road!) with track days, and poor maintenance! Another drift track only with 300 for about 5 years and now 340 still going strong, both have good tunes as we keep hearing for good reason, mine's at 300rwkw now and will probably stay under 320 and will be going for track days, will leave the std motor and see how goes!haha

Cheers

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