A Few Oddball Questions

[nisskid]

Alright guys, get ready for some very likely noob questions, but i promise i have searched, just trying to wrap my head around the situation atm, right now i have 2 R32 GTS-t's, a 2dr with an RB26, with engine mods, and a 4dr with an RB20, no engine mods.

Now ideally i'd like to put a big setup in the 4dr, but i'm trying to figure out which direction to go. i have been looking into RB30's for quite some time (always the R32 RB25DE head on RB30e block), but this new car with RB26 has thrown some possibilities in the mix. my main issue is keeping the car able to go through regency (inspection) with ease. changing turbos is fine, but changing engines each time for regency is too much. so what the engine i run must past regency, i dont mind bolting on/off a few bits though, just not whole engine blocks or heads.

I guess my first idea was just keep the RB26 and put it into the 4dr without fiddling about. problem is having to engineer it, and from what i understand, just arent cutting it compared to the RB30's (as sad as i am to say it). RB30/25's however can look identical to RB20's, and with a restamping, will get through regency.

but RB26 heads are better, and i have one now, with all the mods ready, including full turbo setup (T78). so if i could go a RB30/26, not only would it be easier having everything already, but better.

i guess my first question is, is the extra performance really worth it from the RB26 head? i dont plan on pushing much more than 350rwkw to start with, but i love my revs, so the revability of the 26 head interests me, im just not sure if there's any point in a revvier head if the bottom end will have dramas with the revs first.

My 2nd question is in regard to the visual side of things, ive read up on swapping valve and cam covers, but couldnt find any definitive answer. i want to put RB20 covers on a RB26 head. i know it sounds ridiculous, and with the plenum and other obvious differences, it will probably be useless for regency, but still useful for police.

3rd question is, can the RB26 exhaust manifolds be modified to suit a RB25DE head (if i chose that route)? i dont feel like parting out the turbo kit, would rather use it all. from what ive read it's just the bolt pattern.

4thly, i have an RB26 powerFC, from what i understand these can be used on RB20's, therefore i assume on a R32 RB25DE head. i believe the issue is with the RB20 running one AFM as opposed to 2 on the RB26, but as ill be running the T78 kit which runs 2x Z32 AFM's, this shouldnt be an issue right?

[DVS JEZ]

you noob, this is all illegal and devious... i like it

i reckon you should go 30 with 26head, then the T78 would be even awesomer.

if your gonna do a restamp then you can do whatever you want anyway.

the 30 sits abit too high in the engine bay so you have to work that out

[jrm]

How are you going to get the PowerFC and T78 past regency either?

[R31Nismoid]

i guess my first question is, is the extra performance really worth it from the RB26 head? i dont plan on pushing much more than 350rwkw to start with, but i love my revs, so the revability of the 26 head interests me, im just not sure if there's any point in a revvier head if the bottom end will have dramas with the revs first.

My 2nd question is in regard to the visual side of things, ive read up on swapping valve and cam covers, but couldnt find any definitive answer. i want to put RB20 covers on a RB26 head. i know it sounds ridiculous, and with the plenum and other obvious differences, it will probably be useless for regency, but still useful for police.

3rd question is, can the RB26 exhaust manifolds be modified to suit a RB25DE head (if i chose that route)? i dont feel like parting out the turbo kit, would rather use it all. from what ive read it's just the bolt pattern.

4thly, i have an RB26 powerFC, from what i understand these can be used on RB20's, therefore i assume on a R32 RB25DE head. i believe the issue is with the RB20 running one AFM as opposed to 2 on the RB26, but as ill be running the T78 kit which runs 2x Z32 AFM's, this shouldnt be an issue right?

Similar issues I went through here in Vic, and hence I chose the RB26DETT (twin T config).

So

1. The head, more so the ITB’s are where the business happens. Mating ITB’s to a RB25 head is a bit of work, if you can go the 26 factory route, works out basically the same cost. (#3 is related, see later)

2. Not sure, might as well engineer it with a RB26 in there. Realistically it’s not a lot different to engineering with a RB25 I wouldn’t have thought. Give a NEO is 206kw, as is a RB26

3. They can, but same as #1, you need adaptors made up which again is more cost and effort – might as well start with a 26 rather than go adaptors for intake and exhaust, it’ll cost you more to do that than the RB26 route would have.

4. Not gonna touch that one

Overall if you can get a RB25 NEO engineered in SA, there is no reason you cannot get the RB26 done.

So if you did go the RB26 route…

- Lowmount turbos are invisible. 330-340rwkw with GT-SS’s is nice and super responsive. Don't need to swap a thing = bonus!

- The PFC is a 30 sec swap over to a factory ECU = bonus!

- All that leaves really is injectors and Nismo AFM’s to swap out for any inspection really... 45mins work if you slow.

The other options you have are for you to weigh up really against the above. I say go RB26 if you are worried about legalities.

The effort to get it engineered, once done, will be worth it. Nice, legal, easy power without much stress/worry should you be defected.

These were my main reasons for going RB26 for mine.

[nisskid]

How are you going to get the PowerFC and T78 past regency either?

i can pull them out.

[nisskid]

you noob, this is all illegal and devious... i like it

i reckon you should go 30 with 26head, then the T78 would be even awesomer.

if your gonna do a restamp then you can do whatever you want anyway.

the 30 sits abit too high in the engine bay so you have to work that out

lol, my car has always been about being only legal enough to get through regency. and by that, i mean if they cant tell it's illegal from an inspection, then it's legal. lol

[nisskid]

Similar issues I went through here in Vic, and hence I chose the RB26DETT (twin T config).

So

1. The head, more so the ITB’s are where the business happens. Mating ITB’s to a RB25 head is a bit of work, if you can go the 26 factory route, works out basically the same cost. (#3 is related, see later)

2. Not sure, might as well engineer it with a RB26 in there. Realistically it’s not a lot different to engineering with a RB25 I wouldn’t have thought. Give a NEO is 206kw, as is a RB26

3. They can, but same as #1, you need adaptors made up which again is more cost and effort – might as well start with a 26 rather than go adaptors for intake and exhaust, it’ll cost you more to do that than the RB26 route would have.

4. Not gonna touch that one

Overall if you can get a RB25 NEO engineered in SA, there is no reason you cannot get the RB26 done.

So if you did go the RB26 route…

- Lowmount turbos are invisible. 330-340rwkw with GT-SS’s is nice and super responsive. Don't need to swap a thing = bonus!

- The PFC is a 30 sec swap over to a factory ECU = bonus!

- All that leaves really is injectors and Nismo AFM’s to swap out for any inspection really... 45mins work if you slow.

The other options you have are for you to weigh up really against the above. I say go RB26 if you are worried about legalities.

The effort to get it engineered, once done, will be worth it. Nice, legal, easy power without much stress/worry should you be defected.

These were my main reasons for going RB26 for mine.

thanks mate, you've touched on a few points i was thinking too.

i guess my worry is with engineering is that it's f**king expensive when u plan on doing the swap urself.

i love the RB26 (although tbh the RB20 is my first love) and it interests me more than the RB30, my main worry is once the RB26 goes, it's big $$ time. and tbh, i have to ask myself would i be better getting the high $$ asking for RB26's and spend it elsewhere?

the low mounts are a good idea, i was thinking about it the other day, but my worry is any signs of aftermarket turbos (they will check) and it's all over, that includes any new looking parts, braided lines etc etc. am i better off just having some stock turbos to swap over when its regency time.

[Lazy-Bastard]

putting the stock exh manifolds, turbos and dumps back on is definitely not a 45 min job....

[nisskid]

who said it was?

[DVS JEZ]

its normally and engine out job too, or just as easy to pull the engine out. just get matt black paint and paint all the turbos braided lines etc black

[R31Nismoid]

No idea lol

But i tell you now, factally, there is NO way anyone can tell you have upgraded turbo's.

GT-SS's (Garrett -9's) are the same exterior as factory. It is the wheels inside, which would mean pulling the turbo off and measuring... which simply wont happen so there is no factual way to really tell.

I reckon you need to find someone that's engineered a RB26 into a RB25/RB20 body over there and see what it was.

In terms of actual cost here in Vic, it was like $750 for engineers & RWC, that's all. Effort of installing was my own, but honestly it's a bolt in job expect for the wiring. Totally direct fit even into my HR31 chassis

[Simon-S14]

engineering here is more so a joke. Costs upwards of $1500 to get it done... and more if they require additional testing.

stew have you thought about just going track only? if you have two 32's u could make one a nice street car and the other a dedicated track car with no comprimise.

[DVS JEZ]

or just swap the plates over and paint them the same colour

[nisskid]

No idea lol

But i tell you now, factally, there is NO way anyone can tell you have upgraded turbo's.

GT-SS's (Garrett -9's) are the same exterior as factory. It is the wheels inside, which would mean pulling the turbo off and measuring... which simply wont happen so there is no factual way to really tell.

I reckon you need to find someone that's engineered a RB26 into a RB25/RB20 body over there and see what it was.

In terms of actual cost here in Vic, it was like $750 for engineers & RWC, that's all. Effort of installing was my own, but honestly it's a bolt in job expect for the wiring. Totally direct fit even into my HR31 chassis

alright cheers man, reckon ill look into it, anyone want a T78? lol

[DVS JEZ]

i'll have it...

[STATUS]

alright cheers man, reckon ill look into it, anyone want a T78? lol

shit a week ago i could have swapped it for a brand new set of -9's.... i love the T78 especially on a rb2630.

go to the wreckers buy a na rb30 ($150-200), re-ring and shell it, bolt up the head (12mm head stud mod) and then dial in 18-19psi with the t78 and hang on.

Or forge it and h-beam it and dial in 25psi .

[nisskid]

shit a week ago i could have swapped it for a brand new set of -9's.... i love the T78 especially on a rb2630.

go to the wreckers buy a na rb30 ($150-200), re-ring and shell it, bolt up the head (12mm head stud mod) and then dial in 18-19psi with the t78 and hang on.

Or forge it and h-beam it and dial in 25psi .

if im honest, this is what i was thinking. ill have to put a rb20 side by side with a rb26 to suss what differences besides the big things (covers, plenum etc etc) i would need to change (and what wont be able to be changed), but if so it would be nice to have a rb20 lookalike sitting in the engine bay which is actually a 26/30. even if it has a big t78 i need to cover up on the roads with some "heat shielding"

as simon mentioned, engineering is pretty f**ked here, and $1500 was roughly the figure i had in my head.