# BEST ENGINE FOR A '91 240SX?



## zoomiguel (May 17, 2007)

WHATS THE BEST, MOST HP ENGINE YOU CAN GET FOR A 1991 240SX S13 LE..... NOW I HAVE A KA24DE BUT IM LOOKING FOR THE BEST ENGINE POSSIBLE

IS A RB25DET BETTER THAN A SR20DET?

LET ME KNOW

IDK IF A RB25DET FITS A '91 240SX... DOES IT?


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## Dustin (Dec 14, 2003)

yes, it fits, but what is your determining factor of "better"? fuel mileage, stock horsepower? stock torque? weight? throttle response? the "best" motor is stock, why? because it's inexpensive, parts are still readily available, and they're reliable.


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## zoomiguel (May 17, 2007)

Dustin said:


> yes, it fits, but what is your determining factor of "better"? fuel mileage, stock horsepower? stock torque? weight? throttle response? the "best" motor is stock, why? because it's inexpensive, parts are still readily available, and they're reliable.


so should i keep my KA and add a turbo to it? or should i just buy a new engine with a turbo?

does a RB26DET fit on my 1991 240sx?


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## 180hero (Apr 23, 2007)

well... an RB25DET is pretty expensive... if ur gonna go RB then go RB26... but I think that SR is the way to go cuz of the aftermarket backup that it offers... parts are more readily availible...


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## Nismo240 (Jul 24, 2004)

180hero said:


> well... an RB25DET is pretty expensive... if ur gonna go RB then go RB26... but I think that SR is the way to go cuz of the aftermarket backup that it offers... parts are more readily availible...


RB25 is no where near as expensive as a RB26 swap. and if you look hard enough, you can find an RB25 cheaper than a SR.


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## Dustin (Dec 14, 2003)

honestly, it's all about what you want. do you want to go fast, not spend a lot of money, and still be able to get parts at autozone, or do you want to spend a good bit of money, deal with wiring, mounts, and all sorts of fun headaches, and then have to dump money into it to fix it, with a good bit of downtime, or do you want to build a car that costs way too much, has way too much time into it, but it'll hold it's own with anything, after you get traction?

honestly, i'd rather be able to get parts, and still hang with ls1's.. but, that's just me.


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## zoomiguel (May 17, 2007)

guesss ill do the sr20det

is there an sr20dett


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## Nismo240 (Jul 24, 2004)

zoomiguel said:


> guesss ill do the sr20det
> 
> is there an sr20dett


no. a tt setup on a 4 cylinder is pointless.


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## zoomiguel (May 17, 2007)

ohh.........


i guess ill get an sr20det


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## DriftX (Mar 29, 2007)

RB20 for life. Some of the sexiest sounds you've ever heard and a ridiculous redline.


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## XxJerem619 (May 27, 2007)

zoomiguel said:


> WHATS THE BEST, MOST HP ENGINE YOU CAN GET FOR A 1991 240SX S13 LE..... NOW I HAVE A KA24DE BUT IM LOOKING FOR THE BEST ENGINE POSSIBLE
> 
> IS A RB25DET BETTER THAN A SR20DET?
> 
> ...




what is the difference between all the engines?
and which is the cheapest?
i need a new one also:]


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## madmax240 (Apr 1, 2007)

Any engine that is "RB" is going to be an inline 6 cylinder, it's the displacement that differentiates them. RB26 (2.6 liter), RB25 (2.5 liter), RB20 (2.0 liter). The RB26 being the mack daddy engine but hugely expensive in comparison. RB swaps into 240sx's are possible, they're just a little tight, urrrr and heavy!(I'd say an additional 125-250 lbs) 
SR20det is an inline 4 cylinder 2.0 liter turbo, KA24e is a sohc inline four cylinder 2.4 liter N/A, and the KA24de is a dohc inline four cylinder N/A. They all will fit, oh but don't forget that the RB26 is originally equipped with an AWD tranny.


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## DriftX (Mar 29, 2007)

forget about rb26. your asking alot of noob questions about it. rb20 is a little more friendly because all you need is an r32 crossmember or custom mounts. It also uses a smaller ka like tranny, not the ones similar to the 300z which youll find under the rb25. sr 20 is a direct bolt in using the same mounts and factory exhasut locations. If you want to attempt the rb swap, it's going to be a hair more difficult on the wiring side, but not alot harder than an sr swap. It's been done so many times by now that you can google rb swap and read and read for hours.


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## 91240SXGuy (Jul 1, 2007)

I have a rebuilt KA24DE with head work (10mm), forged pistons/rods, cams, cai, 4-1 ceramic header, full catback exhaust plus some suspension work. I love it to death...it's all ready for a turbo kit. But if I could, SR20 with turbo would be daddy. My opinion, but I'm happy with my KA.


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## Ratrice (Jul 1, 2007)

Keep your KA... and read about the other motors in your spare time. Why would you look into spending over 4g's on something you know nothing about?


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## DKLandonC (Jul 26, 2007)

In My Opinion, The turboed KA24DET is the Best setup. even if you have no technical experience, you can Turbo a KA, even rebuild and THEN turbo, for cheaper than buying a stock SR and Putting it in. On top of that, the Turbo KA will get about 50+ more Torque than the SR on the SAME turbo that the SR has, and equal horsepower. And the Rule of thumb when it comes to racing is "HORSEPOWER SELLS CARS, TORQUE WINS RACES" you can do it yourself for less than 1200- 1700 dollars and get around 300 to 400 horsepower on the KA ( depending on whether you use stock pistons or not) , or spend just as much if not MORE just for 205 hp and 180 ft/lb tq. all yu need is a couple of instructional DVD's as to how to rebuild a KA, a good buddy with some tools, and a lil intellectuall fortitude, and you can drive a VERY fast 240sx.


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## 2high2aim (Jul 8, 2007)

Hey man you are like me and it is good asking your own questions and all easy to get information too but you have to do your own research this way you know more about the engine and well it depends how much money you have and what is your goal. KA24DE are better then SR because they are first already in your 240, second it is a caste iron block, it has a longer stroke and gives you more of a push, means you go faster at a lower RPM then an SR, third KA with the same turbo as an SR, KA would be faster, KA is also stronger, Fourth KA is Smog legal but the SR has more bolt on stuff but the KA has a bolt on from Greddy and some other companies also you can make you own turbo. First thing I would suggest is rebuild the engine with forged internals because it will reduce the chances of engine detonation and it is a good idea for forced induction engines for example turbo-ing it. If I were you i would rebuild the engine and piece together my own turbo that is if you have knowledge on turboing a car. It is cheaper to piece together your own turbo then buy one from Greddy also you would have you own design to. If you are planing on going over 350RWHP you should upgrade the following:

Things for turbo:Turbo Manifold
Blow Off Valve (BOV)
External Wastegaste 
Front Mount Intercooler (FMIC)
Turbo (AMS GT35) (AMS GT32) (T3/T4 hybrid Turbonetics turbo) LOL my choice
Downpipe 2.5"
Pipe to connect turbo to throttle body 
Replace the Exhaust
Boost gauge
Boost Controller

Fuel Control:Walbro 255 Fuel PumpSR 370cc Injectors or 550ccApexi SAFC2 Greddy Emanage MSD BTM At this stage I would be running the BTM to control timing retardWideband O2 Sensor should be installed for tuning

Mounts (THis is good but you dont need it, it stops engine and stickfrom shaking ):Nismo 3 Piece Engine and Transmission Mounts S13 S14 S15

Block Internals:Forged Rods
Forged Pistons 
Stock Crank Bearings
Headgasket
Valves
Retainers
Cams
Injector
Resistors
Plus your typical rebuild items that i forgot to list
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HOPE THAT HELPED HEY I HAD THE SAME QUESTION AND IF YOU HAVE ANY IMPROVEMENT OR SOMETHING I FORGOT PLEASE POST YOUR THOUGHTS ON MY THREAD THANKS
http://www.nissanforums.com/s13-240sx-1989-1994/135550-racing-drifting-sr20det-noobs-pro-q-3.html


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