Rb26 Engine Conversion

[DaGr81]

hey guys just wondering what's more cost effective

Rebuilding the current rb25 or dropping an rb26 motor and box in there

Why? Because I can LOL , I know there's heaps of advantages with the rb26 + I'll get to have twins the only thing stopping me at the moment is what sort of labour hours it will take + my motor currently has the following mods

52mm radiator

Intercooler

PFC

Turbo back exhaust

The obvious pod and enclosure

+ I just got some gauges put in

I'm just not sure what will have to be sold off and what can stay to work perfect

The cooler will have to be changed the dump and front pipe as well

How about the radiator ?? Will the radiator hoses fit??

The PFC can make way for a gtr PFC or stock ecu for a while

The reasoning behind this is it'll cost 4k for a mild build to handle roughly 325rwkw while a gtr engine shouldn't need a build for that much should it? Plus I get solid lifters and the 6throttles and twins not to mention extra capacity

Anyhow calling everyone that's done this before to advise me on what has to be changed

[GTRsean]

26 ain't cheap, to fix, parts etc.

Rebuild the 25= fresh engine, tough etc.

If you got the money though, go for it lol.

[R31Nismoid]

Depending on the age/condition, the RB26 will need more than 4k thrown at it just like the 25.

Either way, the RB26 wont take 330rwkw forever. Few years probably but thats it

The extra capacity, is next to nothing, its not even a 100cc, about half that

A 26 conversion isnt cheap, and IMO you'd be crazy not to at least through new pistons/bearings etc through it before installing it

[im late]

26 ain't cheap, to fix, parts etc.

Rebuild the 25= fresh engine, tough etc.

If you got the money though, go for it lol.

I agree with GTRsean. If you got the funds, go for the RB26.

But to be honest what is your target RWHP figure????

That will determine whether you even need to go RB26.

I have seen some strong RB25's doing 500RWHP all day every day...................

I have two GTR's. But that does not mean that I will push and promote RB26's........

RB25 is a very solid motor.................

Again, what is your target figure?????

[GTScotT]

rb20s are cheap and strong

[im late]

rb20s are cheap and strong

That is true. RB20's are a fantastic motor.

However he already has a RB25. So why would he put an RB20 into his ride?????

It's a case (as he stated in his initial thread post) whether he should rebuild his Rb25 or outlay for a RB26 (Money Pit..............)

[DaGr81]

yeah target is 300rwkw to around 350rwkw umm it's just for a bit of fun really something to use at the odd track day, motorkhanas etc

Well combining my tax return and savings I've got 7k and I really would like to keep everything as hidden as possible from the eyes of the po po's so low mounts, I've forgot to mention it used to be a non turbo (turbo conversion) so I'm not even sure how much more it can take I've got 202rwkw at the moment oh I'm not doubting the rb25's they are awesome but I am doubting my de bottem end haha, I've had a chat with a few places and really they said just for 300rwkw there is a low mount that can support it + I can get a mild build with gtr rods + upgraded rod bolts and pistons that they have said should be enough for that power figure (and ofcourse a compression ratio of 9:1)

+ I'm not sure how much machining it will need

Anyway at the moment i'm just in the thinking stages

Cheers

[DaGr81]

also like to have a fairly wide power band something that can rev cleanly to 8000rpm (area under the curve) etc

[GTScotT]

i know my rb20 comment made me look stupid yet it wasnt seious, on a serious note however have you considered an rb30, still looks stock so popo dont notice, depending on the turbo can keep you current exhuast and intercooler, retune the power fc you have and keep your radiator, would take more money to get it to 8000 revs though, yet a 500cc increase you will notice more than just 100cc

[im late]

I think with your budget ($7K) you don't have a choice but to go with the RB25 route.

By the time to buy a decent RB26/gearbox +Turbos and associated supporting hardware you will blow the $7K budget.

If you can save more you will not regret getting the RB26.

But as Nismoid said before, the Rb26 is really only 100cc's more. What the point of going RB26???????????

[DaGr81]

yeah I have considered it, I've also seen people just chuck the stock rb30 with upgraded bolts on make a reliable 270rwkw what do you guys think it's cheap will last 250rwkw and will leave me cash for other areas of the car

[GTRsean]

Price up some pistons and some rb26 rods for your rb25 plus bearings etc(rebuild).

300 plus kw with a t04Z yeeeeeha

[R31Nismoid]

t04z on a RB25? nonono, 450rwkw = t04z, not the turbo for him at all

[R31Nismoid]

id have to say with that budget, stick with the RB25, GTR rods and just pistons and be happy with 280rwkw with a 2835, or a 3071/3076... run the legs off it and it'll last anyhow if the build is good.

[DaGr81]

so we are looking at pistons, gtr rods upgraded rod bolts, acl bearings and new gaskets all round that only looks to be setting me back around 2k will I need to do any machining etc? After all it's not an all out build this way I can spend on other areas , maybe If I can keep it to 4k then I can spend 2k on the turbo and 1k tune up, but like I said before if I did the rb30 just with rod bolts and gaskets it'll only be like 1k then 1k bolting it up then 2-3k on new turbo and I'd have 2k to spend on other areas of the car, who's the guy that's done this before he just bolted a stock rb30 bottom end up to his rb25 bigger turbo and started drag racing?

[STATUS]

RB25 all the way, slap on a T67 GT2835 or GT-rs.

[johnbarry88]

I did the same thing I wanted to upgrade to a rb26 instead of the rb25 and it has cost me in the excess of $20k, this is what you should do if you go for the rb26..

Cost of engine $3000-$5500 (please make sure they supply comp test and op test & a warranty if possible)

Cost of head gasket from Nissan $80.00 this is so you can pull it down and inspect, there is nothing wrong with genuine head gaskets. This is where it cost me so much, engine was sold to me as a good runner but we pulled it down and found damage to the block and pistons so complete rebuild.

Rewire of wiring harness to run rb26 computer $200-$600 (depending on where you go)

Computer $300-$5500 (depending on where you go & what you use)

Modify intercooler plumbing $150-$500 again (depending on where you go)

Modification to sump $300-800 (depending on where you go)

If you want to make power at high rpm a good oil pump and coller is recomended, can go into the whole debate here but an N1 is a good start its supperior to a standard item to start with.

A good harmonic ballancer ATI or ROSS most profer ATI as do I.

Oil control, while modifing the sump ensure extra compacity and baffles maybe even a return from the back of the head to sump.

If you are staying with the twins make sure you change the dump pipes while the engine is out of the car likewise if changing the turbos. (its hard enough doing it when the engine is out let alone in the car)

Replace all heater/vacume/oil lines under intake plenum while engine is out too this is for peice of mind.

I think staying the the rb25 and upgrading the rob bolts to start with is a much wiser choice and will be cheaper in the end. I could keep going but hopefully this will be some help to you.

[DaGr81]

great info there cheers for that yeah I'm still pondering I know the de block will go bang it's just a matter of when so I either need to get something ready or do something before it happens

[TiTAN]

Spool currently have their RB25 rods with arp bolts for $645. depends how much the GTR rods + upgraded bolts are that may be a better option.

http://www.spoolimports.com/content/SPOOLRB25CONRODS.asp

[R31Nismoid]

GTR rods are $150 or less