Difference between RB20 & RB25?

[RedDrifter]

I'm all for the RB20.

I dont have much below 4500rpm but when it comes on :Bang: Hold onto your hats boys.

[predator]

yeah its a bit fun with the sucking noise and then shrroom.. and the push..

rb20 still better than a heck of a lot of other engines out there for the next 10 years, so its not too bad.

I think in next few years, rb25 R32 will be very common.. so many cheap rb25's out there to buy.. and the price is so much cheaper than it was than a few years ago. And rb20's are getting a bit old now and starting to get to that level of destructing.

[RedDrifter]

yeah its a bit fun with the sucking noise and then shrroom.. and the push..  

rb20 still better than a heck of a lot of other engines out there for the next 10 years, so its not too bad.

I think in next few years, rb25 R32 will be very common.. so many cheap rb25's out there to buy.. and the price is so much cheaper than it was than a few years ago. And rb20's are getting a bit old now and starting to get to that level of destructing.

Yeah RB25 powered R32's will definately be alot more common.

Mind you I would love o build an RB22DET using the tomei pistons.

That with a decent stage two or 3 cam would be nuts.

Mmmmmmmmmnnnnnnnn Maybe an RB25 Neo motor (R34) Now that would be something.

Oh well back to reality.

[KIL.08S]

i have an RB23DET with some mods and even with a 2535 turbo the think was a weapon, still had no torque but who cares once your on power you cant compare.

[RedDrifter]

i have an RB23DET with some mods and even with a 2535 turbo the think was a weapon, still had no torque but who cares once your on power you cant compare.

RB23 thats with 25 crank and rods in a RB20 block?

Surely that would have a decent amount of torque especially with a 2535?

Still u dont see that set up often.

[Sydneykid]

I had the choice in the R32GTST;

Rebuild the RB20DET

Build an RB23DET (I had most of the bits, RB26 crank and rods and 4AGZE pistons)

Stick an RB25DET in there (there was one on the floor)

or an RB26DETT (needed 6 forged pistons, had all of the rest)

Build an RB31DET (using the RB26 top end and an RB30 bottom end with forged rods and pistons)

I went for building an RB31DET, the 55% increase in capacity and the average power potential that brings was too hard to resist.

[RedDrifter]

I had the choice in ther R32GTST;

Rebuild the RB20DET

Build an RB23DET (I had most of the bits, RB26 crank and rods and 4AGZE pistons)

Stick an RB25DET in there (there was one on the floor)

or an RB26DETT (needed 6 forged pistons, had all of the rest)

Build an RB31DET (using the RB26 top end and an RB30 bottom end with forged rods and pistons)

I went for building an RB31DET, the 55% increase in capacity and the average power potential that brings was too hard to resist.

Damn 3.1 Litres.

In an R32 the torque would be insane.

[raz0r$harP.UK]

my bro has a 33 which puts out just under 200 on 12psi and my r32 with td06 puts out 185 on 10... he had his on 8psi which is about similar power levels and we were pretty much neck and neck... although everytime i drive his car it feels damn fast in reality they are similarly paced... on 12psi or even 10 im sure he would blitz me but eventually once mines properly tuned and on 18psi his rb25 r33 isnt going to stand a chance

but then again im a fan of the r33... id rather have a nice 97model r33 then an r32

so with the money it would cost to convert an r32 id say buy a 33

[elboro]

yo,

just put my 33 in for a new computer and bigger air flow meter. how much boost can those stock injectors handle? would 15psi be reasonable?

thanks, ElBoRo

[nemz]

just make sure u get it tuned elboro, fuel starvation isnt cool

[TimmyC]

I had the choice in ther R32GTST;

Rebuild the RB20DET

Build an RB23DET (I had most of the bits, RB26 crank and rods and 4AGZE pistons)

Stick an RB25DET in there (there was one on the floor)

or an RB26DETT (needed 6 forged pistons, had all of the rest)

Build an RB31DET (using the RB26 top end and an RB30 bottom end with forged rods and pistons)

I went for building an RB31DET, the 55% increase in capacity and the average power potential that brings was too hard to resist.

I have been doing a little (very little) research into putting a 25 in my 32gtst before i choose a turbo. I figure a 2530 is the right choice for a 20 but not the right choice for a 25. Anyway the thing i cant seem to get a straight answer on is price !! i have heard from 4 to 10 grand to put a 25 in, does this sound right ??

how much was it to put the 31 in ?

what NEEDS to be changed to put a 25 in cos i think that is where the big price variations are comming in. AFAIK (which isn't much) a 25 pretty much just drops in ??. All my mates are bagging the idea cos they think if you are going to put a 25 in why not a 26 in... but that needs a whole lot more stuff to be changed right ?

anyway sorry for all the questions but i want to start some serious modding but i feel i have to make my mind up to do the engine swap or stick with the 20 before i buy a turbo or put any more money into the car.

[Cubes]

Each have their downfalls.

RB25 - requires wiring mods for the vct.

RB26 - requires wiring mods for the extra afm.

It depends on your final power goals.

[predator]

I have been doing a little (very little) research into putting a 25 in my 32gtst before i choose a turbo. I figure a 2530 is the right choice for a 20 but not the right choice for a 25. Anyway the thing i cant seem to get a straight answer on is price !! i have heard from 4 to 10 grand to put a 25 in, does this sound right ??

2530 should be a good mix across both RB20 and rb25.. From what I have seen, plenty of low and mid-range for both, although your main problem is that it might run out a bit up top on rb25 compared to what it does on rb20. Still, most seem to be getting around 220-230rwkw on an rb25 which is still a very streetable setup. From all I can see its a pretty compromise on both engines.. but not for outright power.

I have a "2530 equivelent" in a high-flowed RB25 turbo.. Plan is to put it on the rb20, then after that, after I'm bored of that, put the rb25 in with the same turbo. It will be an interesting experiment.

Anyway the thing i cant seem to get a straight answer on is price !! i have heard from 4 to 10 grand to put a 25 in, does this sound right ??

It really depends on where you take it, what you spend, and who you know. My rb25det cost $1600 with full loom, ecu and engine (- turbo). I'm hoping for at least $1000 for sale of working RB20DET, so its not expensive there for the engine changeover. But some can pay like $3500 just for the engine, and then it can depend what you get for that price.

The cost will be dropping it in (I am planning on doing that myself) and getting it wired up. Realistically that shouldn't take more than a couple of days labour (x $120/hr workshop rate = $2k install if you got them to do it). Again, I just hope to pay somebody to do the wiring, so there is maybe a $1500 saving there.

[FATAZZ]

is there a rb26 single turbo engine??? or just twin turbo???

and are they the some appart from the obvious.

[jazza08]

Only rb26s that have singles are largely modified!!

There was a rare rb26de that came out, but dun see that engine too often..

[FATAZZ]

cheers 4 clearing that up 4 me jazza,,

[Starionturbo]

Damn, I cant beleive how much of Crap is being spun on this thread. The RB25 conversion into a R32 is one of the most worthwile conversions going. I swear if one of you jumped into one, you wud shit ur pants and want to do the conversion. My old cars low end and midrange was so much stronger than my R33 due to its lighter weight and different chassis behavior.

The only downfall to this conversion that I see is like any conversion, If the cops pick it out, ur ****ed. I was at protek in Preston yesterday and there was a nice burgandy 32, RB25DET, microtech etc 250 kw at the rears - it got a EPA PROHIBITED VEHICLE sticker on it. The poor guys gotta get it passed over pits and engineered now.

So think about that - And as far as im concerned - stick to ur RB20s, wudnt want the exclusivity to become common! I was happy in the fact my car was the only one of two RB25 converted R32 Skylines in Perth.

[Cubes]

R32 RB25DE motor looks exactly the same as the rb20det motor.

Drop a set of forged slugs in that.

[RedDrifter]

Why wouldn't you get it engineered to start with?

[slow13dude]

but then again im a fan of the r33... id rather have a nice 97model r33 then an r32  

so with the money it would cost to convert an r32 id say buy a 33

I'm sure the people contemplating the conversion for an R32 have considered and dismissed such an idea.