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Well, after 345,000kms my old girl has shown signs of needing a new heart. So, do I go for the 25/30 and deal with the legalities of a larger engine including possibly getting an emissions and engineering check or go with a 25 and usual forged goodies.

The dirty 30 is going to need mods to get under the bonnet and slight mods to the exhaust at the new height. It will easily go 350kws on standard rods so money saved there. It's just that all the hassle of getting it legal is just too much trouble with my time frames.

The forged 25 with oil control will get me to 300kws but will have to work hard to do it but it really is just a straight swap plus the engine I will build is the original engine that broke a timing belt at 165,000k so that would make it just a blue slip for rego. What do I do ?

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Why not just put a stock rb25 in there? There's quite a few making over 300rwkw on here that aren't rebuilt with forged internals. Then if one breaks, you just put another one in.

If anything happens to your built rb25 or your 25/30, you're kinda "all in".

Well, after 345,000kms my old girl has shown signs of needing a new heart. So, do I go for the 25/30 and deal with the legalities of a larger engine including possibly getting an emissions and engineering check or go with a 25 and usual forged goodies.

The dirty 30 is going to need mods to get under the bonnet and slight mods to the exhaust at the new height. It will easily go 350kws on standard rods so money saved there. It's just that all the hassle of getting it legal is just too much trouble with my time frames.

The forged 25 with oil control will get me to 300kws but will have to work hard to do it but it really is just a straight swap plus the engine I will build is the original engine that broke a timing belt at 165,000k so that would make it just a blue slip for rego. What do I do ?

Im an avid believer in the RB30 and by all means go for it!

However, if you dont have the time (or the patience) to do the full job (getting it legally rego'd), then just go the RB25 Neo. Speaking from personal experience, I have a RB30DET in my 32 and I do nothing but worry bout getting pulled up by the boys in blue. So much so I have toyed with the thought of selling the car/engine as a package or separate. That said, in SA we dont have yearly RWC to meet so its alot easier to get by with an illegally modified car.

go the 25/30 and keep vct. the best of all worlds right there.

Response out the wahzoo and torque to burn.

If its a gtst simply use 32 engine mounts and it will drop the engine to not much higher in the bay than the 25.

I kind of knew some would go with the 30 but I work seven days a week and just dont have the time like I used to. When I had 2 full days off a week I did most of the previous work myself but slowly that time has been taken away from me. If I could get an engineers promise that it is a straight forward swap then I'd definately go for it. When I was younger I would have just gone for it, now of course, I am older and wiser. I definately dont want to go stock 25, I want 300kws all day every day. I have tried to create a sort of sleeper so far with the 4 door as it looks fairly standard.

I also have the 30 block sitting there doing nothing. What to do. I guess the 25 with cams and forged with attention to assembly and 3076 in standard position is a far better bet, though I want 256 inlet and 264 exhaust cams to try to milk it as best I can. There, I've answered my own question. Water methanol injection would also be on the cards.

go the 25/30 and keep vct. the best of all worlds right there.

Response out the wahzoo and torque to burn.

Noel is right. This is the setup to use for streetable torque. Getting approval in NSW might be the stumbling block if time and effort is factored in.

Yes I do Dave, I have been meaning to wave to you every time I see your car but I'm usually on the car phone or late for a meeting. ( I build houses). You have the very clean 33 though have only seen you several times. My other car is a 34 2door. Completely stock, very quiet and auto for getting from A to B.

Every pore in my body says ring Lewis Engines and send them all my good stuff for a 2530 build but just lately I've had second thoughts. I have made contact with a local engineer but he hasn't done one yet and will get back to me in regards to legalities. If I get the all clear then I'll go for it.

As an aside question, can anybody tell me the biggest turbo for a 25/30 in a low mount position, not hitting the frame rails, wiring, brake lines or any other problems. Just the biggest bastard turbo I can fit. I was thinking 3076 and 1.06 exhaust with internal waste gate.

For 300kw all day everyday i still think i NEO and 3076 turbo is pretty hard to beat! You can put Type B cams in which are 260's etc..... Its not original but instead of big $ on an engine build you can spend the $ where it counts to make the NEO reliable and fun :D And yes i am 200% biased towards this setup :laugh:

Yes I do Dave, I have been meaning to wave to you every time I see your car but I'm usually on the car phone or late for a meeting. ( I build houses). You have the very clean 33 though have only seen you several times. My other car is a 34 2door. Completely stock, very quiet and auto for getting from A to B.

Every pore in my body says ring Lewis Engines and send them all my good stuff for a 2530 build but just lately I've had second thoughts. I have made contact with a local engineer but he hasn't done one yet and will get back to me in regards to legalities. If I get the all clear then I'll go for it.

As an aside question, can anybody tell me the biggest turbo for a 25/30 in a low mount position, not hitting the frame rails, wiring, brake lines or any other problems. Just the biggest bastard turbo I can fit. I was thinking 3076 and 1.06 exhaust with internal waste gate.

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GT3540 will fit the same as a GT30xx.

Get a quote for a RIPS bottom end as an alternative to Lewis.

For 300kw all day everyday i still think i NEO and 3076 turbo is pretty hard to beat! You can put Type B cams in which are 260's etc..... Its not original but instead of big $ on an engine build you can spend the $ where it counts to make the NEO reliable and fun :D And yes i am 200% biased towards this setup :laugh:

Agreed. Copy this dude's build.

Supercar power to weight ratio without (really) cracking the engine or budget open.

Not really any point putting a massive flowing low mount turbo on that manifold, the manifold will probably be the choking point. As a scary aside, I have a feeling I have heard of people putting FP3794HTA turbos with internal wastegate housings on XR6 Turbos. They are pretty much the same frame as a GT30/35R but are good for a kosher 1000hp+ at the engine on E85. Mental.

Agreed. Copy this dude's build.

Supercar power to weight ratio without (really) cracking the engine or budget open.

Oh dont get me wrong, the budget was cracked well open :P

Not really any point putting a massive flowing low mount turbo on that manifold, the manifold will probably be the choking point. As a scary aside, I have a feeling I have heard of people putting FP3794HTA turbos with internal wastegate housings on XR6 Turbos. They are pretty much the same frame as a GT30/35R but are good for a kosher 1000hp+ at the engine on E85. Mental.

Are you at it again? :P

Will you guys stop it ? Your confusing me. Stuff it, I'm going V8................Just kidding. But seriously, if I thought for one second it would be an easy job I wouldn't hesitate for a second.

Find a low km RB25, nistune, injectors, pump, GT30##, clutch, tune and away you go. Dont be hung up on a number as I'm sure you will have more than enough for the street to make you happy. <br />Seeing as you use the car everyday you still want to keep it relatively driver friendly. <br />So you are looking at about 10k to get you there. <br />

Not really any point putting a massive flowing low mount turbo on that manifold, the manifold will probably be the choking point. As a scary aside, I have a feeling I have heard of people putting FP3794HTA turbos with internal wastegate housings on XR6 Turbos. They are pretty much the same frame as a GT30/35R but are good for a kosher 1000hp+ at the engine on E85. Mental.

the stock manifold wont be a choking point at 300 rwkw.. it will do just fine..

its pretty proven. i wouldnt wast time and money building an enging. just buy a mint condition neo engine and do a 3076 ex gated with a adaptor between turbo and manifold for the gate. run the gate low and plumb it back for street.

the money spent building a motor could be spent on ID1000's, vipec, ethanol sensor and setting it all up to run duel fuels with maps that adjustaccording to the ethanol content any time.

a neo is a strong as engine. i made 360 rwkw on a stock motor and it was thrashed hard at the track.

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