KA24DET vs SR20DET

[URMachines]

many people dispute that the sr20det is supperior to the KA-t. but i think a built KA will equally rival, if not outpower, a built SR. heres what ive come up with:

-KA has .4 more liter of dispacement=more potential torque which is very important in drifting/
-KA has iron block oppsed to SR aluminum adding strength and resistance to warpage.
-KA will spool a larger turbo faster than an SR
-KA ends up only being 3-5 lbs heavier than the SR installed.

i really cant seem to think of anything the SR is better at.
once again this is in refernce to built motors,not stock.
ive always been a fan of the KA and never saw it as "the crappy USDM counterpart"
i dont know everything about either, so please feel free to oppose with solid info from either KA or SR.

[Tighty_wh1tey]

well the SR has shiny red valve covers! thats why its so GREAT

[raging panda]

you are right except for the KA actually weighs about 100lbs more than the all aluminum sr. Still not a big difference. I am very biased since I think its stupid to spend 2500 on a stock engine just to make 185whp instead of improving what you have for 2500 and make 250+whp. Only time I would consider SR is if I had a ton of money and ultimate horsepower is the goal, the SR has a much bigger aftermarket that the KA cant compare with.

[banged240_drift]

that is too too true.
and i belive also that 2500 for stock SR vs. 2500 worth of built KA
you will have a better motor with the KA, thats what im planning to do. but i have to get the motor in the car first...

[URMachines]

well im going to be building a KA this summer for my 240. so far here whats on the list:
CP/Wiseco forgd pistons 8.8-9:1 compression
OEM/Nismo race bearings
JWT cams and valvetrain
ARP head and ain studs
not too sure on the rods....maybe just shotpen them because aftermarket are so expensive.
greddy turbo kit

i wanna be in the range of 280-320whp daily driver. ill keep you guys posted cuz ill be getting parts in about a month.

[nissanguy_24]

The only thing to consider is the fact that the KA was never designed to be turbocharged or support anywhere near that much power. So make sure your fuel system and all the little things are up to the taske. Though it seems like you understand that.

As for the KA being vastly superior to SR, thats really not the case. both are good Motors. the only real advantage the KA has is the displacement, but thats all stroke. Look at any top race teams and see how long there strokes are.. there usualy pretty small. Its not really nessisary to have a long stroke with stump pulling torque on a race motor. You make power at the top and you use your gears to keep it in the power band. Now a drag racer is going to want some low end as well as good top end, because its one of the few forms of racing where they start from a stop.

Anyways im going off on a tangent. To me the SR does have some advantages over the good old KA, the biggest one is (ironicly) its difficult to find a low millage KA in america, at least around me. You can buy a rebuilt motor, but thats basicly going to run you the cost of a SR if not more. If yours is in good shape then its another story. But most guys i know are running pretty high milage on there KA how is. Often time someone like in my case, will look into a sr20 after they lose there KA. Stock turbo SRs are pushing 250 wheel horse power with various bolt ons. check out Nico for some guys with very impressive dynos from those engines. a sr pushing 250 with there stock turbo has quite a good power band. and im going to assume virtually no lag.

Speaking of lag that brings me to another issue. KA turbo kits.. they usualy run bigger turbos then im looking for. there designed to make like 400 hp and so.. if thats what you want that is great.. though i would be weary of pushing a nearly stock KA or SR to 400 hp. But especialy the KA considering it wasnt designed for boost in the first place.. Another issue the KA has higher compression ratio. and though its not awful by any means, Its just another thing to consider.

You could argue that it can cost you very very little to custom make a turbo setup with whatever turbo you want.. Well perhaps our friends who have welded and have access to a pipe bender can easily fabricate up a turbo system. Its not something a guy like me can easy do. Dont really have access to the equipment or the experience.

The thing is there really isnt any big cost difference between the two. And where im at i can get a lower millage SR.. Also the SR has a square bore and stroke, which is what i prefer in an engine. Theres nothing wrong with the KA. especialy if you need or really like that low RPM kick in the pants. I am a nissan guy, and i do like all nissan engines, and think they are all cool.

But it distrubs me when i hear this new trend of.. and forgive me if this isnt you, but its what im hearing... "Why would people even want the SR?? it sucks, the KA is by far superior, they just heard the KA sucks in a magazine, so there ricers, im not a ricer, i dont read, thats why i like the vastly superior KA"

Honestly the only advantage the KA has is its already in your engine bay and it has more displacement. Personally i think the rb25 is cooler then hell. it has more displacement AND a shorter stroke... but there expensive and not light. not the cheapest thing to slip in and make work great.. but if you had the money and experience it would rock.

In my case the KA is in my engine bay, but doesnt work. The Extra displacement though apealing for all reasons that we like extra displacement (i usualy side on the side of extra displacement) is all gained threw stroke. Which kind of puts it off for me.. Im a high RPM kind of guy i supose!


Anywas just remember there are alot of guys out there with different ideas and philosiphies on engines and power bands. Its all cool. None of these engines are Vasty superior to each other (RB, CA, SR, KA) They all have advantages and disadvantages. Its great though because one person can pick the engine thats there preference, making it more personalized. Remember drifting is personal.. Do as you wish, luckily nissan has given us anumber of engine choices to do it with.

Oh the other advantage of the KA is its smog legal for the CA guys.. However few turbo kits will pass smog. So your pretty much screwed either way there.

When its all said and done i want a pretty stock internally SR, with a S15 gt28 turbo running about a bar, maybe 15 psi on a high boost setting (im assuming its near the top of the turbos efficientcy.. i havent seen a compressor map though). Perhaps a small front mount.. nothing big, im really going to shoot for response you know sence i am going to run a 2 liter i want it spooled as soon as possible. down the road i want lightened parts fly wheel, driveshaft, underdrive pullies.. blah im just rambling off my wishlist now.. The point is, im shooting for a mild 250 whp.. any more then that is just a bonus.

(this was a second post but i combined them to one)

Originally posted by URMachines
well im going to be building a KA this summer for my 240. so far here whats on the list:
CP/Wiseco forgd pistons 8.8-9:1 compression
OEM/Nismo race bearings
JWT cams and valvetrain
ARP head and ain studs
not too sure on the rods....maybe just shotpen them because aftermarket are so expensive.
greddy turbo kit

i wanna be in the range of 280-320whp daily driver. ill keep you guys posted cuz ill be getting parts in about a month.

That sounds like a cool set up. What kind of turbo do you plan on running? and sence i guess this is a SR vs KA type thread, how much do you think it will all cost to have about 300 whp like you want?

[BENJO]

that was a good post

[Ripper]

well, you see, SR20's are just more JDM. in my opinion

[nissanguy_24]

Originally posted by Ripper
well, you see, SR20's are just more JDM. in my opinion

I fail to see why that would mater.

[Chas]

I know a guy who made 375whp on a KA with these mods, it was reliable.

T3/T4 Turbo (Similar to the greddy TD06)
Ross Pistons
Pauter Rods
SDS Stand Alone Computer
HKS Hiper Exhaust


The greddy kit should be good enough to get the numbers you want, and still allow more room for upgrades(the turbo will be enough to get you around 400hp). It comes with a fuel rail and 370cc injectors. It also comes with E-Manage, a piggy-back fuel contorller.

[URMachines]

good post nissanguy-24. you said alot of stuff im just too dam lazy to type. i dont consider the KA to be superior but i wanted it just to be recognized for its potential. the sr20 is also an awesome platform which i still may consider. i also agree
100% with yur preference of a "response" (hense my name Ultimate Response Machines). response is my goal in building a machine/engine. if i were to build my KA, i actually probably would rather use a gt28, as you prefer, which could make killer response and high end for the KA.

As far as stroke goes, im not crazy about it myself. 96mm is very big and cuts down on rev potential. this would be my only reason for getting an SR. im a rev-happy person myself coming from a honda engine backround. id love to rev out a KA to 8000 rpm but thats not gonna happen.

now an SR is a different story. 86x86 is the same Bore and stroke as the k-series RSX motor wich can spin to 8000 stock. all the sr needs is some 264 or 270 cams and valvetrain and it ill be a rev happy monter

sorry if ive mislead anyone to thinking this is a "KA dominates" thread. i like learning the differences of each and prefences

[nissanguy_24]

Nah its cool. Its just a trend i noticed. Its cool though, your not one of them.

The problem i've noticed with nissan fans, especialy S chassis fans is the "my engine is choice is superior to all" thing.. Poke around nico, or basicly any forum with nissan guys on it and you will see what i mean. It doesnt mater what the engine, CA, SR, RB20/25/26 KA or KA+T you get alot of guys like that.

Guys like you and me though we like all the nissan engines, and have different preferences and goals. We pick an engine accordingly. One thing i was going to say in defence of the KA but forgot (long post) was it does weigh about the same as the SR. it may have a heavier iron block, but no turbo, stock for stock there suposed to be with in a few pounds.

And one final thought. i do hear the iron block mentioned as a reason why the CA or KA is superior to the SR. However few of us will ever be at the point where our block is holding us back.

[URMachines]

yea, as far as the strength of the iron KA vs aluminum SR, both have been pushed beyond what any drifter road racer really needs or can handle. Signal proved the SR with a 600 hp s15 and KA's have been big in drag racing from what ive heard making upwards of 500 easily. So the block of both isnt holding back anything.
Im building a car with drifting and track events in mind and response as target tuning. it will also be my street car so that is a big key when it comes to turbo, suspension,brakes.

when do you plan to get the Sr nissanguy?

[Chas]

600 on stock block, jun has surpassed the 900 mark with there hyperlemon s14.

[nissanguy_24]

Originally posted by URMachines

when do you plan to get the Sr nissanguy?

With in a few months i hope to have the car back up and running. I am just finishing up a technical school right now and havent been working lately. Hopefully all will go well and i can land a decent job soon and start putting money away.

[SHIFT_DET]

in all respects its all based on the person and how they wanna approuch there PROJECT car weither or not to put in a KA or SR to me its all the same"not literally" but as long u have fun and put ur time into it all the power to u goin side ways

['97 S14 SE Turb]

For FYI purposes:

I have the longest running, most reliable KA+T in the US. 4+ years, 60k+ miles.

Stock internal, daily driven at 14.5psi (1.0 bar), 91 octane. Car gets used for road course, drift etc.

Bounces off redline often while drifting (7,200rpm).

At the boost level, the engine makes over 318rwhp and 330lb-ft of torque. A very, very driveable package that works for topspeed, grip, drift, and all around daily driving.

The peak power is @ 6k to 6.5k rpm. Yes, there's a flat curve there.

When Benson Hsu drove my car, his comment was interesting. "Drives like a SR!"...

My point here is:

With a properly setup package, reliability is not an issue, and driveability is also great. The KA doesn't have a top rpm issue when boosted. Most SR folks that talk down on KA, haven't been in a KA+T or KAT. (+ for bolt on). Even if the peak power is the same, the KA will have a broader powerband.

An often used example was back in 2001, during the first Nissan 240SX convention in Kansas City, Mo, where 2 different cars, KA vs SR, with same peak power did an impromptu test. The heavier S14 with the KA+T was able to walk away everytime... More power in the powerband...

As for block strength, stock block, well, it's still holding up on my friend's T66 534rwhp KAT. No issue.


But as I've concluded time and time again in this seemingly ageless question of KA vs. SR/SR vs KA. Vanilla vs Rocky Road? Which is your favorite flavor? Just pick one and enjoy... Both are good.

[ToplessFC3Sman]

I havent had much experience with either the KA or the SR, but if you like revs, go for the 13B! JK, i had a CA20 N/A before, and altho it was redlined at only 6500 (in my old S12), it absolutely loved to rev, almost as much as the 13B N/A. Lighter valvetrain, etc, helps with that, and Im sure the lighter flywheel and drivetrain would make a huge difference.

[new12drift]

I agree with the train of thought of "it really depends on what you want". Both engines are great and have their strong and weak points. I have a 97 S14 and the county that I live in is possibly going to start doing emmisions (obdII scans) starting next year. So that limits me to the KA if I want to keep my car streetable. To boot, my car is an automatic so I need as much help in the torque department as I can get :-) I have to admit though if I live somewhere that emmisions didn't apply, then I'd chose the SR. Strictly from a cost perspective, it makes more sense. I get a 5 speed swap in the package and the engine will support 250 whp or so easily assuming that you do a decent job setting up the fuel system.

[kclo4]

So why exactly isn't the SR20DET able to pass emissions? And what is a obd2 scan compared to the one where they meter what is coming from the pipes? I thought that as long as you had a cat. converter that it really didn't much matter, especially with a stock engine.

['97 S14 SE Turb]

SR20DET has never been certified/legalized for us in North America. It's illegal flat out... Simple as that.

And OBDII is a North American market requirement. Doubt you find a Japanese market engine having the same system. So, immediately you will fail emission testing.

[marshun]

Originally posted by raging panda
you are right except for the KA actually weighs about 100lbs more than the all aluminum sr. Still not a big difference. I am very biased since I think its stupid to spend 2500 on a stock engine just to make 185whp instead of improving what you have for 2500 and make 250+whp. Only time I would consider SR is if I had a ton of money and ultimate horsepower is the goal, the SR has a much bigger aftermarket that the KA cant compare with.

i'd love to see where you got your information about the weight of the engine. cause when i did the swap for a friend we actually weighed the motors. and it was not 100lbs difference. more like 35-40lbs.

and aftermarket as in what? connecting rods, piston heads, valves and valve springs? the aftermarket support is bigger than you think.

the KA is supported well. but if you compare how the KA is supported here in the US and how the SR is. theyre pretty much on the same level. with that being said it would just be easier and and a tad cheaper to keep with the KA. of course when you run it hard something is going to give. and it would be allot easier to replace a KA block or water pump than to have to wait for an SR piece.

[raging panda]

Thats awsome, then the KA is lighter than I thought. Someone posted "official" engine weights on the NICO forums once, I took them for fact, but first hand knowledge beats out. I was comparing the KA total aftermarket to the SR total aftermarket, worldwide. The SR is much more supported, but yes in the US each are pretty close aftermarket-wise. I know all about the KA aftermarket, I was in it until I sold my S13. I know you can get all that stuff plus some. It is big, but still nothing to the SR aftermarket where you have complete head packages with rocker arms, cams, valves and springs, coming from 2 different companies. The KA cant compete with that.

That is a big draw I think for the KA, the fact that you can replace your engine, possibly that week, where the SR you are going to shell out some money for another engine, and you might have to wait.

[nissanguy_24]

The thing about the SR legaity is... It doesnt mater what it produces. Or what equipment it has. it was never sold in america so the smog station will simply not pass it legally.

Now there is grounds to question that. So anyone with a law degree or a good layer might be able to pass emissions with one, The grounds is there is at least 1 company that is importing and selling legalized S15 silvias. which run the sr20 motor. That means the Sr is now sold in america. Which means test and BS had go to threw to sell. So would be no different then swapping in a different legal engine. like some of the S10 guys do when they swap in late model V8s legally.

Now good luck convencing the smog guy.. like i said bring a lawyer.. its not something the average enthusiest will be able to do. And dont take my comments here as proof the SR is legal or anything.. far from it.

On the same note the RB25 and RB26 are sold by motorex in the skyline.. may be a legal path to persue for those guys too. No doubtable they had to add alittle equipment to these motors.. but i imagine its nothing big.. really its the paper work and bureacuracy..

That said.. few KA turbo setups are california legal either so... welcome to the world of the S13..

[new12drift]

Another point to note is that for all practical purposes, both engines will achieve the same power levels that a "high powered" drift car would have. Figure in the neighborhood of 350whp. That number is well within the limits of both engines. While the SR would handle that power with a better head gasket and stud kit (just to be prudent) the KA might require a better set of pistons to make power at that level reliably. The KA will make more torque lower in the RPM band which to me would be a desireable quality when it comes to drifting. It also has a flatter torque curve. The SR on the other hand can turn significantly higher than the KA. It's turbocharged from the factory so the initial cost of operating it is probably a bit less than a turbo KA. Figure it'll cost 2 grand for the motor, ecu and trans and right there you're at or near 200whp. You're going to have to spend close to 3k with the KA on a turbo kit but you'll probably make more power and definately more torque. The biggest winning factor for the KA is that for the traditional drifter (the guy/gal that drives the same car to work the next day) a KA+T will still be able to pass emmisions. That's a biggie folks...