RB20 s13 build with specific questions

[lovehateRBrelations]

Hi im from DFW Texas. I have a 1990 240sx coup and i have a rb20det swapped into it. Im dyslexic so please forgive bad grammer/spelling errors.
I know people have mixed feelings on the rb20det. I personally love it. its oversquare like a formula 1 car, revs nice, sounds good. Things I dont like are, poor head flow, no bottom end power. Engine for its stock performance and installed cost is a good value. To be honest, i just like a challenge but this swap is high maintenance and will nickle and dime the shizz out of you. Would not recommend the rb20det to people new to engines or arnt very hands on.
Stuff thats done on it
custom fab 3in exhaust (test pipe, dunk megaphone muffler, custom down pipe)
HKS shroom intake
everything else on engine is stock
car has wheels, complete suspension
other than that this is a blank slate. I will be ripping the whole engine out very soon and will be doing a rebuild, ill probably make a new wire harness while im at it since i was lazy the first time and halfassed it. It looks like crap. Question is should i do a basic rebuild and keep bore and stroke the same? Or will i see a big powerband improvment if i do like a 2.4 build. I have accesses to a machine shop so cost isnt an issue for me. I just wanna know if there really is a big bottom end power increase or if its not worth my while. Its getting new pistons, rods, crank, bearings, etc ne way, and Im doing head work on it. Basically im concerned about compromising the integrity of the block from the overbore. Any comments from people that have experimented with this. Ive build engines before, i have a lot of experience in doing performance headwork (mainly on motorcycles tho). I will be doing almost all the work myself. Its just reliability that is number one for me. BTW i only plan i extracting 400whp at the very tip top most from this engine. Its a street car, response and powerband width is key. Oh yea and dont be afraid to get really technical with your terminology. Specifics are good. Also ive heard all the fuss, i know i should just buy a rb25/26 blah blah. Well im not. cost isnt a factor i have access to all the equipment and im doing the work my self. I really dont wanna buy a whole new engine. I get the point, respect your opinion, but getting a whole new engine isnt an option for me. I simply dont have room in my garage for anything else.

[Yellow4g63]

RB24 is a good chunk of change. 26 crank and rods with custom 82mm or if you dare 83mm and bore out the cylinders to match. I think just going to 82mm or 83mm should do the trick that alone will increase flow and at that point some head work will be needed but @ 400whp the stock head should be fine just open up the bowl to match and you should be good. http://www.spoolimports.com/spool-conro ... 20-conrods sells Hbeam rods for the RB20det and pistons too.

My own RB20 is a fart away from 400whp (398 last time I dynoed) but I knew what I was getting into when I started down this road. It's laggy but I wasn't looking for a fast spooling motor from a 2.0 inline 6 lol.

[Yellow4g63]

you can also check out this guys RB24 build http://www.freshalloy.com/forums/showth ... p?t=196409

[lovehateRBrelations]

yea i they are definantly a chunk o change. But ive worked with RBs before and there are two truths about these engines. They are a pain in the a**, and will nickle and dime you to death. But when they are done its a beautiful thing. I been talking with some guys around here that said the precision 6262 w/bb center would be sweet. If i calculate that right based on what the set up would be, i should be about to get 400hp @17 psi with a nice quick mid-high 3k range. Either that or I can get an custom high flow rb25det for a nice price, and we have used these before and they will do 400+ on an rb25 no problemo. Spool is silly quick too. Choices Choices. I just really wanna emphasize response in this build. Its just to easy to build a lagged out high hp pig. Im going for a little more finesse in this build

[Yellow4g63]

the 6262 won't spool that fast on a 2.0 RB20. I have a SC61 on mine and I don't make over 200whp till like 5200rpm and full boost is around 5400rpm. I talked to a guy who had a the 6262 on his RB20 and he said it came in a little sooner on his but no where near 3k rpm. I think he said 5200 rpm full boost?

[lovehateRBrelations]

I considered that as well. But also remember that the final displacement of my engine will be 2.4L, so I would assume that the spool profile will be more similar to a rb25? I could just have my math all kinds of screwed up lol. Either way I have no experience with precision turbos or stroked rb's, so at this point looks like some more R&D in due. My other option is to take this rb25 turbo i got laying around wasting space in my garage, and have it rebuilt, high flowed (no more ceramic lol). We have used this turbo set up before on a couple of rb25's and they will flow 400rwhp+ easy, and the spool on it is unbelievable. Just about done with my turbo manifold design phase, and am about to do a mock up.