rb20 + $5000 (what to do??)

[backdog]

Ive got a 32 gtst, and about 4-5 grand to spend on it. just wondering if the guys puttin big turbos on the rb20s are replacing piston rings (or pistons) when they do this? Beacause im thinking if i have to do rings/pistons, turbo, cooler, ecu, and fuel system would i be better off selling the engine and putting in the 2.5lt. or should i go rb30 bottom end with my rb20 head for the extra torque, does anyone know how much machining is involved in fitting the head and who does it (sydney area) just want to get as much feedback as i can before spending the dosh. anyone who has done mods on a similar budget let me know what you did and how it worked out. thanks

[predator]

you won't be able to use the RB20DET head on a larger block.. it ends up being too restrictive.

[R32Big_boy]

The head does fit, but major mods are needed. A 25de head fits on a 30 block rather sweetly with only drilling for a pulley tensioner needed. I would use the money and get a 25, i myself have a rb20 and would kill to put a 25 in. But a rb30DET would be rather nice, and for 5 grand you might be able to do it, depends on the internals coz the block should only cost $50 to $100 and a rb25 no more that $1000. My friend is doing this and putting it into his EH holden.

[bbenny]

well it would cost you $5000 to put in a 2.5 but then you would still have a standard engine not puting out alot of power.

I guess the question comes down to whether you plan to make further modifications. If you only want to spend $5000 and leave it at that, you may find you will get more power by modifying the RB20. rather than having to buy and install an RB25, as you wont have alot of change after the conversion.

However if you plan to perform further mods, having the 2.5 will be a great advantage...

what are your plans with the car?

[Bl4cK32]

The head does fit, but major mods are needed. A 25de head fits on a 30 block rather sweetly with only drilling for a pulley tensioner needed. I would use the money and get a 25, i myself have a rb20 and would kill to put a 25 in. But a rb30DET would be rather nice, and for 5 grand you might be able to do it, depends on the internals coz the block should only cost $50 to $100 and a rb25 no more that $1000. My friend is doing this and putting it into his EH holden.

An RB20 has 78mm bores (from memory), and a Rb30 has 86mm bores. That must be major mods to make it fit considering it wont go on....

:Oops:

[Roy]

Assuming your RB20 is completely std, the $5,000 will get it singing, may need a few extra $$$ for things like clutch etc though, but for engine mods, 220-230rwkws and 12sec qtr times is achievable with 5k,

I wouldnt bother with an RB25 or RB30, unless you were chasing +300rwkws

[summoner]

best thing to do is remove the RB20 and put in RB25DET+gearbox

[GTR-Ben]

Sell RB20det buy RB25,RB26 or RB30.

The first one is a mutant, the other 3 or related.

[Roy]

So does anyone think at 170,000kms std RB20 with aftermarket turbo can make 240rwkws with boost in by 4,500rpm???

All that money to have a std Rb25, doesnt make sense?

Especially when my std Rb20 with std turbo with an IC/ filter wasnt getting left behind by R33s with the same modes on the straights at Eastern Creek, actually none of them pulled away from me, a few i use to even catch up a little. (yes i know about weight etc etc)

Im about the only one who seems to think the Rb20 can get the job done. My Rb20 hasnt melted a piston, with plenty of sustained hard driving under its belt. Not saying its the greatest setup around, but ppl spend so much money on starting with another blank canvas, when that money coudl go to making the RB20 haul the mail

[summoner]

r33 heavier than r32.

RB25 is a canvas with alot more potential, more off boost reponce etc.

For his $5k budget he's better off with a reliable streetable package like an Rb25(even stock) over a tickled RB20.

I made 306rwhp on an RB20 on a budget was fun etc but off boost like most RB20's its a pain. I'd of rather saved money

[Clint32]

rb20s are a very tough engine i tried and couldnt brake mine, so for up to 230-240rwkw with a 2530 or trust t51xx setup they are very goo and while lacking a little down low will rev to 8k all day. and cheap so if it breaks drop another in.

for 5k you should if spent carefull fit a cooler, turbo, exh, fuel pump, injectors and get it remapped to suit, for 5k you will be lucky to fit a std rb25 engine, so if 10 was the budget then its a diff story

[BHDave]

First i'd get your current engine checked out, ie compression test and leak down test at the least to see if it's still healthy. If so then keep it.

For about 5 to 5.5k you can get turbo, intercooler, full exhaust, Injectors, pod filter and Remap of the stock ecu, should make over 200rwkw easily. Then you'd need a clutch and afm upgrade and another tune and you could make closer to 230rwkw

5k for an engine swap that will make you maybe 150rwkw without mods and it doesn't really compare. Though if you plan on going further then it may be worth while, particularly if your existing engine is a bit shagged.

[Roy]

r33 heavier than r32.

RB25 is a canvas with alot more potential, more off boost reponce etc.

For his $5k budget he's better off with a reliable streetable package like an Rb25(even stock) over a tickled RB20.

I made 306rwhp on an RB20 on a budget was fun etc but off boost like most RB20's its a pain. I'd of rather saved money

I have been in a couple of std turbo R33s, and whilst they do have good response down low, they dont exactly have much top end. Not saying the engine are no good, but given a 5k budget i wouldnt even look at any other motor then whats in the car.

My thinking is :

- 2nd hand Jap 3" exhaust : $1,000 fitted

- Hybrid I/c : $900 fitted

- Air filter : $200 fitted

- 2nd hand Boost controller : $500 fitted

- clutch and flywheel : $1300 fitted

- Fuel pump : $300 fitted

So for a little over 4 grand you would have an engine working better, not harder.

I wouldnt bother with re-writing the ECU, even though there are power gains to be had. The car will go a lot better then std...if you want to make more power, well from here on in its a matter of selecting a turbo and re-writing the ECU.

If you can install stuff yourself, then there is more money to spend and could strectch the budget to an unloved HKS 2510/2530 T3/4 with rising rate regulator and a re-written ECU.

[backdog]

thanks for all the help guys. thinking about my budget i might as well stick with the rb20, i just didnt want to do the mods and have the bottom end shit itself. my motor has 115000kms on it and when i got the car it was boosting to 15psi so i thought the rings may/should be replaced. What i want from the car is a daily driver that can still manage consistent low 13s (and i do rack up the kms) Are these engines as bulletproof as everyone makes them out to be. I guess its all in the tuning. should i go for an aftermarket ecu straight up and save the hassel later? i dont want anything overly powerfull cause then the rest of the drive-line suffers (trans,diff,driveshafts,ect) just want to blow a v8 every now and then.

[Roy]

My car has 170,000kms, with over 3,000kms on the track. The last 20,000kms have been with a hillbilly tune with aftermarket turbo, an the engine lives, even though some say it shouldnt have. The engine has even had about 6-8excursions past 9,000rpm with an ecu that was on it for about 2 months.

By improving the effeciancy of the engine, you arent rally making it work that much harder, its not like if you have a 40% increase in power, the engine is working 40% harder.

If your budget was 15k, id agree with everyone and boat anchor the RB20, but at 5k Rb20s are good toys.

[Drifterdan]

Bl4ck32: Not meaning to start shit, but the rb20 head will fit with modification of the water galleries, however the ports are smal(as you said) and power is limited. Mind you, you can't belive everything you read in magazines.

[DCIEVE]

why drop in an rb25 when the two have similar potential on the std bottom end (the 20 a safe 300rwhp, the 25 a safe 350rwhp) doing similar mods. Just end up spending all that cash for a motor that has limited advantages over that which you started with. If it dies, rather than rebuilding the 20 grab a stuffed 25 to rebuild instead, which would be a much better proposition with forgies. If you know from the start your going to want over 400hp dont bother with either and start saving for the 26 straight away