wondersparrow Posted November 11, 2008 Share Posted November 11, 2008 I have done a bunch of searching and I can't seem to find much info on the RB25DE. Yes thats right, the non-turbo (scca thinks turbos are evil). As I am going to be road racing my 240 starting next season, I want to have a spare engine ready to go. Right now I have a well prepared 2.4L L-series with triple Webers, racing cam, upgraded valvetrain, headers, flat pistons, etc. It will hit the dyno in the spring so I know what I am dealing with. I have had my eye on Rebello's "Big Bore" for a spare/upgrade. They claim 365 HP / 300 lbs-ft torque. I think that would make a nice GT-1 engine, but I want to keep my options open right now. I have done some asking around and there is no rule preventing me from running an RB series engine as long as its not a turbo (curses scca again). What kind of power can be made from an NA RB? Does anyone know of any good builders for RBs (pref. in north america)? Quote Link to comment Share on other sites More sharing options...
graham28 Posted November 11, 2008 Share Posted November 11, 2008 I have a RB 3.0 ( VL commodore block and RB 2.6 head ) NA makes 380 BHP at 8100 RPM in NZ , DYNO figs ---very `peaky ` Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted November 11, 2008 Author Share Posted November 11, 2008 I am pretty sure a carb'd L series won't exactly be smooth either. I was just wondering if the better head design and vvt (on some heads) is worth the trouble. If this was my street car, I would definitely be going with an RB25DET. Its just a pain trying to find a good engine that can be used in different racing regions. Quote Link to comment Share on other sites More sharing options...
zedman240 Posted November 11, 2008 Share Posted November 11, 2008 I just had my RB25DE setup dynoed and came up with approx 150 rwHp. But that is with a homemade ITB manifold and aftermarket ECU and stock engine. One thing you can tell when driving is the smoothness compared to an L series. Also the standard cams let it down at around 5-6000 rpm. It needs more air! I've been told to add some adjustable cam gears to gain around 20-30 hp.... In time when the funds allow Quote Link to comment Share on other sites More sharing options...
johnc Posted November 12, 2008 Share Posted November 12, 2008 I don't see how you're going to get your classed in GT-1. Even if you did, 365hp is about 60% of what you need to be competitive in GT-1. Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted November 12, 2008 Author Share Posted November 12, 2008 Ah, once again the difference between the regions comes out. That would be GT-1 up here, probably GT-2 in SCCA I am guessing. Anything over 2.6L is a GT-1 here tho they may bump you down if your p/w ratio is really low. We do allow turbos up here, so I am still toying with running a turbo, but then if I go and take a tour in the states I end up in some SPO catch-all class. Not that I am expecting to be really competative my first couple seasons anyway, I just want to race I just want to have a spare engine ready to be dropped in for when this one goes. Without pulling it all apart, I dont really know what is in there, it came with the car. I just figured running in schools and some rookie races with it won't do any harm. Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted November 12, 2008 Share Posted November 12, 2008 Your probably going to have to go with the RB30 block and RB25de head to be making that kind of power. If you have the money and resources to play with the RBDE then I say go for it. It's a stout engine and a really nice platform to build off of. However, there is very little aftermarket support for the engine as most tuners tend to go with the RB25DET instead. That's probably one of the main reasons why I was hesitant to mod my RBDE, and the money.. Also, if you plan on using the RB25DE tranny the gearing is horable for road racing. Quote Link to comment Share on other sites More sharing options...
NZeder Posted November 12, 2008 Share Posted November 12, 2008 I have a RB 3.0 ( VL commodore block and RB 2.6 head ) NA makes 380 BHP at 8100 RPM in NZ , DYNO figs ---very `peaky ` Hi Graham, I hear you are selling the RB30DE and putting in a V8 into the race car. Is that true? Also will your Targa car still be RB30DE powered? Sorry for the slight highjack - back to the topic at hand. I have a RB25/26DE hybrid that I am installing into my 260z here NZ (still waiting for the body to be complete) and I will be running triple TB like Graham and ZedMan240. However my power will be between the two I think as the engine is not standard but then not a RB30 bottom end with all the fruit like Graham's so I am hoping for around the 160-170KW at the wheels (or 220-250HP at the wheels) which is what a well build L28 can deliver - so I am hoping that the DOHC does count for something (hell it has to make up for the extra weight too) Quote Link to comment Share on other sites More sharing options...
graham28 Posted November 13, 2008 Share Posted November 13, 2008 Yes correct --sorta ---I have a supercharged all alloy ford V 8 just about completed in Aust -in a 260 Z --The targa car has a RB 3.0 which produces 320 BHP ( engine dyno ) so will be more` streetable ` than the 380 HP engined car---- If I wasn`t technoligicaly challenged i could post a photo of the V8 in the Z in OZ. You are well in formed !! Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted November 13, 2008 Author Share Posted November 13, 2008 How is the aftermarket support for the RB30 series? Any better? That could be an option too, just the cost of shipping an engine half way around the world seems like a waste. I hadn't really considered them maybe its worth looking into. Quote Link to comment Share on other sites More sharing options...
graham28 Posted November 13, 2008 Share Posted November 13, 2008 In the Antipodes there is plenty of Nissan 3.0 litre blocks ( from VL Holden Commodore ) and RB2.6 Heads --which by the way is FAR better than 2.5 version--in the sense that it flows more. Rob at R I P has intake plenum and other stuff readily available if you don`t want to use TWR ( CA) T/B `s The 2900 series 48mm fit the intake port spacing exactley . Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 14, 2008 Share Posted November 14, 2008 I'm putting an RB25DE NEO in a 240Z street car project. Stock it makes 200HP, so with an opened up intake and exhaust, it should be good for 170HP or so at the wheels. Stock ECU, internals, everything. It going to look like it came in there from the factory. Nice flat torque curve. I picked up the motor cheap. I'm thinking that I can do this swap for less than what it will cost me to build an L28 to make the same power, and and I won't have to screw around with a Megasquirt or carburetors. Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted November 14, 2008 Author Share Posted November 14, 2008 That looks pretty sweet. Did it come with a tranny? Which transmissions do the neos come with? That seems like a decent option. As much as I love the triple Webers, a nice standalone EFI system is pretty attractive. Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 14, 2008 Share Posted November 14, 2008 You can use an RB20DET or any RB25 transmission. I have a RB20DET transmission that I will probably use. The RB25 transmission is stronger, but for the RB25DE, the RB20DET transmission is plenty strong (and thin like a stock Z transmission). Pete Quote Link to comment Share on other sites More sharing options...
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