bakerzxt Posted October 28, 2008 Share Posted October 28, 2008 Hi I have been researching about nissan rb motors for a couple of days now and I haven't had much luck on finding what are the capabilities on the stock internals for the nissan rb20 and rb25. I have seen some stuff some stuff on the rb26 but not that much about the others. I am lookin at a z that has an rb20det in it. My goal for a z when I get it is to make 400rwhp. What would i have to do to the rb20 to make that kind of power? thanks Quote Link to comment Share on other sites More sharing options...
stony Posted October 28, 2008 Share Posted October 28, 2008 An rb26 will make that HP by just turning up the boost. rb25 will take a turbo kits upgrade. rb20 will take alot. you will spend more on an rb20 to get 400 rwhp then just getting an rb26. every one of these swaps will require custom exhaust, engine management, custom intercooler ect ect non of which is cheap. Quote Link to comment Share on other sites More sharing options...
mtnickel Posted October 28, 2008 Share Posted October 28, 2008 Google is your friend here... http://www.skylinesaustralia.com/forums/Rb20-Limits-t238632.html The general consensus that i've seen is about 350whp for the RB20det. But a big question here is what is deemed "reliable". I asked myself the same question when deciding what HP to shoot for on my RB25. sure i've seen plenty dyno's with the engine making 400-460whp, but how long will they last. Daily driven, probably a long time if properly tuned and maintained. But with auto-x or lots of 1/4 mile runs, or any trackd days, the life could severely be compromised. I've settled on about 350whp for my comfortable goals on the rb25det. That's 65% more power than stock and over 410 crank HP. By comparison, a stock LS2 6.0L corvette engine makes 400hp. Perhaps i'm a pesimist, but from all my reading, i'd keep goals to 330whp Rb20, 375whp RB25, and 425 whp rb26 when not touching the bottom end. If you need more than 425 whp in a Z you should probably be building it up with the bare minimum of head studs, metal head gasket, better oil pump, and likely pistons/rods. Mark Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted October 28, 2008 Share Posted October 28, 2008 I am making low 400s at the wheels and have put 15k miles or so on this swap without indecent. I drive it hard, and do take it to the track. 100% stock internals. RB25DET. Evan Quote Link to comment Share on other sites More sharing options...
Careless Posted October 28, 2008 Share Posted October 28, 2008 haven't we been through like 800 of these threads? Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted October 28, 2008 Share Posted October 28, 2008 ^ Make that 801 Quote Link to comment Share on other sites More sharing options...
bakerzxt Posted October 28, 2008 Author Share Posted October 28, 2008 Sorry if I started a thread that has been covered before. I just have not been able to find a lot about rb20det motors. I was curious what type of mode have to be done to make 400rwhp and a reliable motor to be daily driven and an occaisional trip to the drag strip. Quote Link to comment Share on other sites More sharing options...
mtnickel Posted October 28, 2008 Share Posted October 28, 2008 Sorry if I started a thread that has been covered before. I just have not been able to find a lot about rb20det motors. I was curious what type of mode have to be done to make 400rwhp and a reliable motor to be daily driven and an occaisional trip to the drag strip. As stated... IMO, you're asking for trouble wanting 400whp on the rb20det without cracking the bottom end. But if you plan to build it a little, you'll need....pistons,rods,bearings,oil pump, arp rod/head/main bolts, and a bunch of seals. That's just on the inside...then as was previously stated.. "every one of these swaps will require custom exhaust, engine management, custom intercooler ect ect non of which is cheap" not to mention a BIG turbo. For the cost of building an rb20, you're probably 'better off with the Rb26. It'll handle 400whp reliably without touching the bottom and, and can get you pretty close to that HP on stock turbo's and injectors to boot! It's economically the best bet. Injectors and turbo for RB25 to get you to that HP level will be about 1200, or $600 if you can handle some fabrication and ingenuity (I'm using holset turbo and STI side-feed injectors on my rb25, $350 and $180 respectively). Quote Link to comment Share on other sites More sharing options...
Cal Poly Zmanaustin Posted October 30, 2008 Share Posted October 30, 2008 ^ Make that 801 You beat me to it. Quote Link to comment Share on other sites More sharing options...
pcs_russ Posted November 1, 2008 Share Posted November 1, 2008 Figured I would chime in here since I built my brothers 240sx with an RB20 and it makes a little over 400whp on pump gas. Here is what we spent to get there..... Motor was $1000 shipped. Once we got it we installed head studs and a steel head gasket. Maybe $300 for both. He drove the car for a while then we decided it needed more power. We changed the exhaust manifold to an ebay header for $175 and added a GT30R turbo at $900 and a Tial wastegate for $175. We also changed the intake manifold to one of the ebay RB26 style manifolds for $300 and added RB26 injectors that were laying around, a light weight flywheel and a centerforce clutch for $400. At 20lbs of boost the car makes a little over 400whp and is a blast to drive. It's a little laggy but you get used to it. We have made no internal modifications to the engine and we beat the crap out of this thing all the time. It has about 15000 miles on it in its current form. We have less that $3500 in the motor but its maxed out. This doesn't include things that you would need regardless of which engine you choose like ECU, Harness, fabrication, intercooler, driveshaft,etc. Figure with price like they are it would cost over $3500 now. If your on a budget and can't afford the RB26 then I guess the RB20 would better than the L series. You would be further ahead by saving and going with RB26 to start with since you can pickup a motor and a Z32 trans for less than $4000 and start with 400whp before doing the normal modification. Russ Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted November 1, 2008 Share Posted November 1, 2008 Hey Russ, good to see you drop in... thanks again for all your help and expertise you gave me. How's your RB26Z coming along? Quote Link to comment Share on other sites More sharing options...
pcs_russ Posted November 1, 2008 Share Posted November 1, 2008 Joel, My car is getting really close. I'm working on the interior stuff now. I will send you some pictures of some other cool things I've done with it. Russ Quote Link to comment Share on other sites More sharing options...
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