RB25det

Discuss the RB20, RB25 and RB26 series engines.
240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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I am thinking about swapping a rb25 into a 90 240sx. I have a budget of about $6000. Is that enough? Iv done an sr swap before but never an rb, and i know you have to have the r33 crossmember or something, not exactly sure on everything needed but was just wondering if 6k would be enough to have a running rb in a 240.


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BoostFab
Posts: 3529
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that should be enough for a turn key basic swap. if you carefully and plan out your purchase, you should do fine.

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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Cool deal I have been debating on a stock rb or slightly modded sr, but I think the rb is worth the extra money. Iv done some searching and I cant seem to find a r33 crossmemeber, where can I find one or would it be cheaper to buy mounts for the ka crossmembe?

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BoostFab
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you need to start reading the stickie posts; it has all the info you need.

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lilskyline240
Posts: 1887
Joined: Fri Oct 14, 2005 9:55 am
Car: 90 240sx w/ rb30det

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all the info you seek is in the stickies at the top of the RB forum

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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Iv already read that stuff I dont remember seeing anything ab where to buy a crossmember, but I think fabin my own or buyin some that will allow me to use the ka is better, my main question was to weather or not 6k was enough money to swap a rb25 or not, and I posted bc lots of you have already done the swap and already know how much it cost. I found an RB25det for $2550 shipped with everything including maf and ignitor, so was tryin to calculate how much it would cost

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BoostFab
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240dk wrote:Iv already read that stuff I dont remember seeing anything ab where to buy a crossmember, but I think fabin my own or buyin some that will allow me to use the ka is better, my main question was to weather or not 6k was enough money to swap a rb25 or not, and I posted bc lots of you have already done the swap and already know how much it cost. I found an RB25det for $2550 shipped with everything including maf and ignitor, so was tryin to calculate how much it would cost
if you are using custom mounts, you don't need the rb cross member

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lilskyline240
Posts: 1887
Joined: Fri Oct 14, 2005 9:55 am
Car: 90 240sx w/ rb30det

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use mckinney mounts and driveshaft. it will have the motor sit a ton better in the engine bay in my opinion

Darius
Posts: 4820
Joined: Sun Mar 02, 2003 9:48 am
Car: RB25DET S14 - 665 WHP (SOLD)
Location: Chicagoland

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In hindsight, that is the one area I wish I hadn't gone for el-cheapo (TopHat). The engine hits so much harder with the McKinney mounts that they are well worth the price. Unless you make your own of course.

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RB_Seth
Posts: 152
Joined: Sun Jan 07, 2007 10:39 am
Car: 92 240sx RB25
91 240sx LT1
95 240sx 280k mile DD

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If your having problems finding parts look here: used parts:http://shop.rawbrokerage.com/c...Id=35

R33 crossmember:http://shop.rawbrokerage.com/p...d=128

mount kits:http://shop.rawbrokerage.com/c...d=108

^ great service and lots of help

(he also sells mckinny mount kits btw)
Modified by RB_Seth at 8:52 AM 7/16/2008

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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So I have been doing some extensive research on swapping a rb engine, and I think I may acually go with the rb20det, and use the extra money to put a top mount t3/t4 turbo, full exhuast, clutch, ecu, injectors, ect. The rb25det will pretty much only be turn key, fmic and exhuast. I know the rb25 is an awesome engine but for the money it seems I can have more horsepower for my money. Seems like common sense to go with the rb20 with mods vs stock rb25. Unless there are things about the 25 that make it $2000 better, I havnt seen it yet. Im pretty sure a rb20 with a t3/t4 turbo and tune will kill a stock rb25.

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BoostFab
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240dk wrote:So I have been doing some extensive research on swapping a rb engine, and I think I may acually go with the rb20det, and use the extra money to put a top mount t3/t4 turbo, full exhuast, clutch, ecu, injectors, ect. The rb25det will pretty much only be turn key, fmic and exhuast. I know the rb25 is an awesome engine but for the money it seems I can have more horsepower for my money. Seems like common sense to go with the rb20 with mods vs stock rb25. Unless there are things about the 25 that make it $2000 better, I havnt seen it yet. Im pretty sure a rb20 with a t3/t4 turbo and tune will kill a stock rb25.
the rb25 handle more power stock and the rb25det transmission alone worth $800 and can hold more power than the rb20det's transmission, so i think you get more for that difference . venus-auto sells the rb20det for $1200+shp, and the rb25det for $2200+shp; so it's $1k difference for the motorset, where did you get the $2k price difference ?

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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Well I priced a rb20det for 1250 shipped, and the rb25det 2250 shipped, plus you have to get a custom driveshaft for the 25, like 300 lets say, so it would be a difference of 1300. I looked at my numbers wrong. I priced a turn key rb25det with fmic and exhuast for $4225, not including random parts, and a rb20det with t3/t4 turbo, injectors, top mount, maf, clutch, and ecu for $3990. I would guess the rb20 with those mods would have +/- 350hp and the stock rb25 would be at 250hp, and I come out cheaper. I also looked into if something breaks like the transmission or bottom end the rb20 is wayyyyyy cheaper to replace. I was really lookin into the rb25 at first but day by day I keep thinkin about a rb20 and moddin it, idk yet

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Carl H
Posts: 5985
Joined: Mon Aug 04, 2003 4:09 am
Car: 1995 Nissan 240SX SE RB30DET

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i can wring 400whp out of a 20 with 4k or less...food for thought.

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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Carl, what turbo and mods would make 400whp for 4k? just curious

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Carl H
Posts: 5985
Joined: Mon Aug 04, 2003 4:09 am
Car: 1995 Nissan 240SX SE RB30DET

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standard good stuff off the shelf...garrett t3/t4 57 trim .63ar turbine, 550cc injectors, z32 maf, fmic, and a good rom tune.if you wanna ball out some then a gt3071r and the afformentioned mods would be around there as well...

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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thats exactly what my plans where, but wasnt sure if it would make that much hp! that would be a HUGE difference from my bolt on sr @ 10psi.

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Carl H
Posts: 5985
Joined: Mon Aug 04, 2003 4:09 am
Car: 1995 Nissan 240SX SE RB30DET

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werd.best bet is to email or aim me, info is in my profile.also not too far from you...so if you ever feel like driving down to clt to chat about any setup just lmk.

240dk
Posts: 160
Joined: Fri Apr 20, 2007 3:17 am
Car: 92 Nissan 240sx SR

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acually iv moved to danville, va which still isnt far, I am in the charlotte area every now and then. I have aim ill add. May need some advice on where to get parts and such when I start the swap, which should be pretty soon. How much harder is it than a sr swap? I can do an sr swap with my eyes closed but have never touched an rb


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