RB 20 BUILD UP Options

[DRFT32]

hey guys.. i have done searches on this but still can't answer the postion i am in so

i am in need of some help..

i have decided to do a complete rebuild of my RB20 at a mates place who has all the tools...

so far we have it all out and in pieces. cylinder #2 is stuffed so we decided it needs reboring..

sorry i have alot of questions

ok the engine was completely stock, stock cooler and exhaust

Now i have a rebuilt VG30 BB turbo for it..

a big cooler and a 3" exhaust comming soon

Now

what options for pistons do i have..i herd 4AGZE pistons work..

if i bore it out and use the 4AGZE pistons and VG30 turbo will i need to upgrade fuel system..if so what part or all of it. ??? or any other part ..ECU ???

if i bore it out and use RB25 crank and rods with 4AGZE pistons with VG30 turbo will need anything upgraded if so what

if i bore it out and use RB26 crank and rods with 4AGZE pistons with VG30 turbo will need anything upgraded if so what

what other options do i have...but it has to run with a VG30 and be bored out

i am not out to get any sort of power figure i just want it to run sweet with no troubles.

so if someone could send me in the right direction for a setup i would be very thankful

thanks guys

[silver gts-t]

bump im intrested too

[cameron]

What sort of power gain's you after ?

Anything over 300rwkw's I'd buy a bare block RB25 and build that up with standard RB25 crank, RB26 Rods and Forged pistons.

IF you just want to get you'r car working, Use your standard RB20 crank, RB20rods and some forged pistons

Avalible piston types: Arias, Wiseco, Venoli, HKS, Jun, Trust

Avalible connection rods: Eagle, Crower, HKS, Jun, Trust

If your after power you will need all the surporting upgrading system's

eg: Apexi Power FC ECU - Others are avalible (Wolf 3D, Motech, Mictotech, Autronic)

AirFlow meter Z32

Fuel pump

Boost controler

Intercooler

Exhaust 3"

Dump/front pipe

You get the idea.

If your after parts for your build look at my signature below.

Jun

[Roy]

IF you just want to get you'r car working, Use your standard RB20 crank, RB20rods and some forged pistons

 

Avalible piston types: Arias, Wiseco, Venoli, HKS, Jun, Trust

 

Avalible connection rods: Eagle, Crower, HKS, Jun, Trust

Are you sure that all of the above readily make RB20 rods and pistons?

[cameron]

No, I didnt say that came as RB20. They come as RB26. But i meant to add that if you are after big power and going to use forged pistons, rods you'll have to upgrade your crank shaft to RB25 or RB26.

No company i've seen makes forged rods specified for RB20 or RB25 they are all RB26 items.

Jun

[DRFT32]

so wil 4AGZE pistons fit onto the standard rods and standard crank ???

has anyone done the 4AGZE pistons in an RB20 ???

what are other pistons worth ???

and can i get anyway with using the standard injectors ???

Thanks

[DRFT32]

i am not after a specific power amount....i just want the engine to run well and have no problems....whatever power i get out is fine...money comes before power

[cameron]

Yes you can use the standard injectors, as long as you dont boost it too much. Changing the bottom end doesnt require you to change them inless you have got a bigger turbocharger etc:

I havent tryed your idea so i dont know if it will work.

Give stick a ring (number in my signature) - tell him your from sau and ask him for a price on some forged pistons.

[DRFT32]

ok so dont boost it too much...whats too much ??? 1 bar 1.5 .....

yeah thanks i will call him tomoz.....

in terms of turbo charger i got a rebuilt VG30 BB so that is bigger than standard ???

the block went today to get bored and balanced etc but he can't do anything tilll i get pistons.. ok so i am quickly loosing the idea of 4AGZE pistons...

so if i get a set of pistons from stick that are say 80 mm 2 mm oversize than standard and use the VG 30 wanting to run between 1 and 1.5 bar of boost what do i need to get...fuel pump , injectors or can i get any with just a fuel reg ??? any body know ??

help is greatly appreciated

[Roy]

No, I didnt say that came as RB20. They come as RB26. But i meant to add that if you are after big power and going to use forged pistons, rods you'll have to upgrade your crank shaft to RB25 or RB26.

So whats wrong with the RB20 crank? Do you think it should be upgraded for displacement or strength.

If strength (you refer to forged internals which imp;lies you are referring to strength) ... I dont think there is anything wrong with the RB20 crank, dont forget that they used to race RB20s in Grp A and they used std crank and rods for 9,000rpm , boost levels something like 1.5bar and around 420-450hp...

So i dont think its fair to say their is anything inherently weak about the RB20 crank. Sure it limits your displacement but my thoughts are the biggest problem with the RB20 is the head and valve sizes, nothing strength related.

[cameron]

I didnt say they were weak.

I'm not a 100% sure but forged RB26 rods & Pistons dont fit on a RB20 crank due to stroke length and clearence. They proberly can fit but it will need modifying to the engine block for valve clearace.

The smallest RB20 pistons i can find are 82mm - expensive, But the rest that are for RB26 are 86 & 87mm bore size. If you get your block bored out too much it will weaken it.

Have a chat to stick and he'll let you know prices and that.

Jun

[DRFT32]

ok but what about accesories i will need

anyone know ??? mainly fuel and ecu i am worried about

[cameron]

the VG 30 wanting to run between 1 and 1.5 bar of boost what do i need to get...fuel pump , injectors or can i get any with just a fuel reg ??? any body know ??

help is greatly appreciated

Yes you will need to upgrade Fuel pump and Injectors if your going to run over 14 psi. (dont want to lean out your new bottom end) VG30's can handel upto 18psi - Apparently.

And if your running bigger injcetors you'll most likley need it tuned so a power FC ecu would be good to keep things running sweet, Also a airflow meter will also need to be upgraded for better tuning resolution.

Jun

[DRFT32]

ok can i get away with a APEXi SAFC or do i need the whole kit and kaboodle ???

damn rebuilds minimide your bank accound figure

i didn't really want to go aftermarket ecu purely because of cost..

thanks.

[cameron]

Yep that is also an option to keep the fuel under control. Just your ignition timing will be standard intil you can afford an aftermarket ecu.

So yes a safc will do fine. - Just you need to get it tuned correctly on a dyno to get the a/f ratios in the safe zone.

As you said you only want to get the car running, but if your after power later on a aftermarket ecu will be the way to go.

Jun

[DRFT32]

ok so to recap

i will be ok with a set of say 80mm pistons with standard crank and rods

with a VG 30, GTR injectors, GTR Fuel pump, an APEXi SAFC

yes it will be tuned on a dyno. so the maximun boost will be worked out on that.

also i know i can get a re chip for the ecu.. so i can get that as a last resort

[cameron]

Yep all should be fine, Im not to sure that you can get 80mm bore size forged pistons, Check with stick.

Hope it goes well,

Jun

[DRFT32]

ok thanks cameron

i'll give him a call tomoz

if i have to go out to 82mm will i need to adjust the head ???

i think i will

any idea ??

[Roy]

My advice is reconsider the turbo you are going to run. With a VG30 turbo i can promise you wont need bigger injectors...and if you overbore the engine too much then yes you will need to play around with combusiton chambers and gaskets.

Sell the VG30, save the money from injectors, and buy a more modern turbo that will flow the same cfm at less boost.

[DRFT32]

what sort of turbo do you recommend Roy.....