Forged Rb20

[N1 RB26]

ok so i've spun a big end bearing on my RB20DET so it's time for rebuild i'm wanting to get a bulletproof 280rwkw that i can go bash on the limiter all day at the track and i want some opinions on what sort of setup would be best so far i'm thinking bore and hone the block, port the head, run hks 264/9 cams and gears, run wallbro intake pump, gtr injectors, t04 or eqiualent, nistune, forged rods and pistons, acl race bearings, and metal gasket with a hell of a lot of boost

am i heading on the right track?? or can someone help point me in the right direction got a pretty good understanding of engines and i will be assembling it myself

opinions on turbo? cams? someone help me out

and i know some think i'm wasting my time cause it's just a 20 but i want to do something different

[BlueRB240]

Don't run a precession SC61 turbo lol.

[N1GTR]

i'm wanting to get a bulletproof 280rwkw that i can go bash on the limiter all day at the track

External oil pump is needed.

This will not be a cheap build.

[N1 RB26]

or maybe rb25neo high flow turbo cause have been told they can flow them up to 450hp by hypergear don't know if it's true or not but that would be better as i already have a standard 25 neo trubo

[N1 RB26]

yeah i realise it won't be cheap but could this setup make that sort of power

[Simon-S14]

drop a stock 25 in there with mods... tuned correctly it will return years of service at 280 rwkw with no problems PROVIDED your bolt ons are up to the task

[R31Nismoid]

and i know some think i'm wasting my time cause it's just a 20 but i want to do something different

Everyone wants to do something different until the realise the cost vs the gain just simply isn't there with an RB20

For the cost of a $500, you could put another wrecker motor in - and then just get a TD06 kit (there are 2 for sale ATM in the FS Area). You then make 260rwkw like everyone else and then drive it hard as you want. If the motor breaks, you just buy another one and repeat. Simple, cheap, effective.

I mean for starers you are talking about building a motor thats going to cost upwards of 5-7k... But you want to put a 1970's $800 T04 turbo onto it? This makes no sense and is backwards thinking.

No motor will survive on the limiter forever unless you spend 5 figures. Even then, who knows. A $200 part like your Walbro pump could fail and then take it out entirely

[N1 RB26]

i realise it gonna cost a bit but i do get the benefit of having a father that has built a few motors 600hp+ in the drag scene and can get some machining done cheaper at mates rates yeah i just put to4 cause that's what popped into my head first i'm just planning and just want some ideas

[R31Nismoid]

RB20 & big builds are not really useful. RB25's cost vs gain simply demolish the RB20 in every way.

More torque, more power, with less boost = less stress/better reliability.

Have a bit of a search, maybe using "built RB20" or similar. You'll find barely any users end up going through with it as most come to their senses

Dyno results thread will also back that up when you hardly see any big builds compared to 25/26/30 threads where there are plenty of builds and barely any "build" is under 300rwkw. Most are 350rwkw+

Going over tried and proven 250-260rwkw/stocker RB20... Whether you save a few bucks on machining or not, is just far too expensive and you get the returns you would with a 25/26/30.

[Dose Pipe Sutututu]

You could reach your requirements with an unopened RB25, put on a decent harmonic balancer, a decent oil pump, a baffled sump and a nice turbo + all the supporting mods.

With a good tune, and lowish timing up high, you could rev bash and drift the schizzle all day on the track and save all that coin of building up a RB20DET

[zoidbergmerc]

My built RB25 only cost like $7k and loves what ever I throw at it. Limiter bashing is never good for a RB, something about the harmonics of it breaks the oil pump? (happy to be corrected) I try and keep it to a minimum but it's hard sometimes.

Edit: I get 310kw with a GT3076R

Edited June 28, 2011 by zoidbergmerc

[eightsixboy]

Good luck getting 280 rwkw out of a rb20. Roy has done it but i'm pretty sure that was on E85 and he has spent alot of time and money trying different things.

As Nismoid said get a wrecker rb20 and get a td06 and you should see an easy 260.

I have been thinking along the same path as you in regards a built 20 but there really is no point as the gains are minimal compared to just getting a wrecker motor. A built motor might give you an extra 20 kw but for the extra 5-8k its hardly worth it.

For 5k you could easily go a 25 and a 3076r which will easily make 280 and wont be laggy at all compared to a 20 with the same power.

Dont get me wrong I love 20's and plan on keeping mine a 20 for awhile but once you start wanting more then around 230-240 it starts getting very expensive on a 20.

Edited June 28, 2011 by eightsixboy

[BlueRB240]

I don't see why it would be hard? 280kw with the right turbo and it's golden. Then again I don't know if he cares about having power lower than 4k rpm. My laggy SC61 pulled 297rwkw @ 7000rpm and 18psi. Would have been more but my intercooler pipe is too small for my maf so it cut out @ 7k rpm vs the 8krpm rev limiter I have.

[N1 RB26]

nope not worried i realise it's gonna be laggy, if i could get full boost by 4-4500 i'd be cheering, anyone else got any ideas on what turbo?

[GTScotT]

I think 300kw of RB20 is about 5000+RPM of full boost.

For turbo selection on the power, look at an RB25 and make a deduction. I think for up to 280ish KW the deduction would be 20kw, with with over I think more like 30-40.

A kando T67 would do 5500-9000RPM of 300kw RB20, but that is an expensive RB20. You could probably bring it on before 5 with a good setup. Be aware we are talking some serious head work.

Well GL anyway. If it were me I would either size up or aim lower. I know I enjoyed the RB20 long ago, but that was at a far lower (read realistic) output.

[Roy]

i'm wanting to get a bulletproof 280rwkw that i can go bash on the limiter all day at the track

Such an engine does not exist. You abuse an engine it will die...[end of story] No amount of oil pressure, forged internals, quality fuel, tuning and balancing will mean an engine is bullet proof. A clogged injector, lazy fuel pump, fuel pr oil surge or fouled plug or failed plug, or loose boost line, jammed wastegate will kill any engine and if you are abusing it on the track then these things happen quicker.

Good luck getting 280 rwkw out of a rb20. Roy has done it but i'm pretty sure that was on E85 and he has spent alot of time and money trying different things.

My engine has never run E85, it is tuned for 98RON at 275rwkws, though it has run reliably at the track at 260rwkws on 100RON as the fuel gives me a little more confidence when things get hot. And the fact is all the money I have spent trying things has meant I have gone backwards, not made power. Stick with a botl on Greddy kit and tune it well. Cams are a waste of money, inlet plenums an even bigger waste of money. So spending money didnt make my setup better, it made it worse...Nissan got it pretty right

As for all the other advice re RB25, RB30 etc well, you will do whats right for you...but drop your power requirement to 260-280rwkws and a std motor will last a long time at minimal cost.

Whatever you decide, ask yourself why did your old engine spin a bottome end. A std RB20 can be pretty reliable. An RB20 with a an oil pump more reliable again... an RB20 with a sump, oil pump and rebuilt bottom end would still be a great thing. Not too many RB20s melt pistons or bend rods

[eightsixboy]

My bad not sure why I thought E85.

Either way I think Roy's setup is a great example of what can be achieved with a 20, I'm actually surprised it made that much on 98, guess the 20's arnt that bad after all .

20's never really seem to throw a leg out of bad, prob due to there bore/stroke ratio making them have less strain on the rods.

[STATUS]

std everything but fit some nice je's or cp's and cam gears.... add td06l2 and bingo 280.

[N1 RB26]

thanks guys for the feedback but i'm still going a head with what i planned maybe not as far anymore maybe still just keep it a 20 rather than 2.2 cause it seems there a plenty of guys making close to 280 with standard internals but i'll still put a set of forged rod's and pistons for that added piece of mind and go from there...looks like tdo6l2 is the way from what i've heard from you guys and what i've found from other forums...can any one tell me when full boost will hit on the 20? and is l2 version actually more responsive or is it just really a gimick?

[sav man]

A circuit car down here has run 300rwkw on a stock RB20 for a year now (Fuel is E30), only mod is a front intake plenum, and a GT3071. His previos stock RB20 ran the same power for 2 years, but spun a bearing cause of the shitty standard sump.