fully built rb20 turbo upgrade? what kind?

Just bought an s13 off a fellow member. Just a quick clarification of the build:

mushimoto radiator
circuit sport catch can
slim line fans
rebuild gasket kit
piston rings
crank collar (to fix issue with possible oil pump failure)
ALC Race bearings (rods) installed by
ALC main bearings
ARP studs (rods)
ARP studs (head)
GTR Oil Pump
OEM Water Pump
Nismo Thermostat, Timing Belt, Tensioner and Idler Pulleys, Top Hat Front Facing Plenum
chipped ECU
255 walbro fuel pump
nismo fpr
fuel pressure gauge
FMIC
N60 maf
hks ssqv bov
rb25 turbo
Top Hat motor and Trans Mounts
kelford cams 10.2mm 260 (removed from car, but will be included in sale)
bronze valve guides
3 angle valve
port & polished
kelford valve springs

I wanted to get at least 300hp, so i was wondering if i should turn up the boost? (I heard 18 psi would be good)
Is a tune a MUST?(most likely is) Should i re-install the camshafts?
Since it's got a stock rb20 actuator (10lbs) which made 224whp on the cams, would i need to replace that?

I was wondering what the cheapest route would be. That would last at least a few months. Dumping money into other components, so i just wanted an extra 80ish hp for that kick!

So you got Dirty Dee's car right? RB20 with T28 can get CLOSE to 300 at 18psi. But that turbo will eat shit pretty fast at that psi, If you want a bona fide 300, you might wanna step to a 2871R or the like. Tune would MOST definitely need to be redone.

RB20s are goofball but at least they sound RADDDD.


If I were you id just throw the cams back in, turn the boost up to a comfortable 14-15psi and chillllllllll.

Tune is a must, no questions there. Get a full standalone unit, not a piggy back. Popular choices are Apex'i PowerFC and AEM Series 2. You can also look at ROM tunes as long as it is still dyno tuned to be tuned specifically for your vehicle. Enthalpy, Nistune, etc. IIRC, the computer has Nistune on it now. You can get that retuned. Talk to ILL Garage, I know they can tune it. (and have in the past)

What size injectors does it have? Make sure your fuel system is up to the task of the added air.

You will need to use a larger turbo and likely change the exhaust manifold to fit it. Something like a GT30 would get to you 300hp. A GT28RS may get you there as well and spool sooner. RB20's don't flow well and can be laggy down low with too large or a turbo.

Just run water through the system instead of coolant. You'll be straight.

Yeah, dstar- that's the one! How fast would the turbo get eatten up would ya say? And what's the maxmax, you'd boost. 16? 17? I'm on and off with cars, i'd only be keeping it for a few months, half a year i'd say. But it's always another 240 hah.

Funny thing is, it has a stock exhaust. What exhaust would you say sounds rad? My last rb20 was straight piped, and not going to lie, sounded fking dope.

Nachtmensch- It's actually currently chipped with a run-of-the-mill ebay chip. He removed the Nistune, i guess when he was beginning to part it out. I think i'm going to stick with the t28, all that work for the short period of time, meh.

I believe it has stock injectors. It's at the shop right now and he didn't mention anything about it and i didn't notice it to be something other than stock..

So just get it re-tuned, turn the boost up. Is the stock rb20 actuator adjustable? I'm going to give IllGarage a call and see what they can do.

Dave- Fuck it, yolo.

Thanks for the fast ass responses, that was unexpected!

It had some sort of injectors in there at some point. I was there when it was dyno'd. Injectors were put in while it was on the dyno. This could have all changed since then though.

Lol. Nah. But on some real shit. Throw a buddy club spec II on this mug. Or some Isis pipes. Also, throw in a screamer elbow on it.

Seriously, put some injectors on this shit, get it re-rom tuned or get a nistune, turn the boost up the 15psi, and just get that cheapass Isis straight pipe setup. Drive around making sickass inline turbo 6 noises.


I wouldnt boost that 25 T28 past 15psi if you want it to last. THat 18psi shit that was recommended to you would have that shit falling apart pretty fast.

Just shot Ill an email, know how much it'd cost to re-rom? Car's at cw werks right now, once i get it i'll know for sure if it's running stocks or not. If it is, what kind should i pickup? Im on that low low budget. Now that i got it some p45r's/lowered/welded diff/ that rear bumper replaced.

I'll grab isis pipes and crank it up to 15-16 psi/tuned. Cams re-installed. Damn, can't wait to tear it up.

I have a feeling she's a keeper, but only time can tell. Thanks!

She's gonna be a keeper if you make her a keeper..

Just read that this is Chris's old car.

And because of that, I would run the setup that he hand picked and assembled.

Definately would recommend for you to pursue other things to spend money on, the motor should be fine as is IMO.

Screamer pipe sounds like ass, straight exhaust leak at idle. Legit ewg dump or gtfo. Nistunes cool, it's what I'm running and ill tuned it. I'm actually going back next Friday with my new setup. Stock injectors are what like little 270's? At least they're top feed though and 550's can be had for nothing and would be straight if you're gonna run a 2871r

i say top mount mani with a gt30 and 700ish injectors since its all rebuilt with cams you have the supporting mods for it im a sucker for a gt30