more reliable SR20DET or KA-T

Your premier source for information on the Turbo KA: KA24E-T and KA24DE-T (KA with aftermarket turbo kit)!
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hannibal
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I am new to the world of modifying 240s and this is my first post. I'll skip the usual comments about how great these cars are; I'm sure the admiration is mutual.I'm still shopping for an S14 at the moment, but I'm trying to plan ahead. I'm trying to decide between swapping in a stock SR20DET or turbo'ing a KA24DE running at low boost (6-9 psi)?I'm pretty handy around an engine bay and I'm confident I can install either properly. But I know I'll have problems with tuning and troubleshooting. With no experience with either the SR or KA, I'm kinda scared I'll end up finishing the build, then have to spend the next few months and even more money on having someone else work the bugs out. Obviously, the whole reason I want to install it myself is to save on labor costs.So my question is, between swapping in a SR20DET from a quality importer (like After-Dark Tuning) and bolting on a low boost turbo kit (like NSport or F-Max) on a KA, which would be easier to tune and troubleshoot for a decent mechanic with no NISMO experience?Thanks for any advice you can give me...


ninjak84
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Go with a new motor from AfterDark tuning. If something goes wrong with your KA turbo, you're kind of screwed. But AfterDark tuning is run by a very reliable guy, who will backup his products if they fcuk up. He''l troubleshoot it with you, help out as much as he can, and make sure you're happy.

Go with a new motor. Costs just as much after you buy supporting turbo parts, and you get more out of it. Period.

trpower7
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I have a couple big reasons for my fondness for KA24DET so I'll give them to you.

A) Parts. KA parts are ALL OVER THE PLACE, you will have no trouble finding anything you mess up if you do.

B) Rocker arms belong on Fords

C) Iron = Good

D) 7PSI of boost on a KA makes gobs more torque and power than 7 PSI on an SR

E) If you decide to build a KA up from scratch it isn't that unreasonable, motors and parts are so easily attained.

F) Tuning isn't THAT bad if you have some smarts about you, an FSM, and some online support.

G) EVERYONE and their sister has the SR. Wait till they hear your rip-roarin 2.4L turbo tearing their *** up at a lower boost.

H) NEVER will there be a more cost effective replacement for displacement. You'd be amazed how much .4L makes a difference.I think that's it for the moment........

TruboostPerformance
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I totally agree with building the KA, I do say though to the above comment you are not screwed if you mess up your turbo KA, if you are going to turbo anything you need to do your research and have a good working knowledge of the KA motor and turbo's, with this the KA @ 7psi will out do the SR with much less money, 2.4 will out do the 2.0 anyday as many people have said before me know this...

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aleph1
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Agreed. KA-T makes more power for similar or less money than and SR swap...of course half the high cost on an SR is the labor, so if you do that yourself youll save a bundle. SR can borrow some parts from the SR20DE and such. But parts for the SR arent that hard to get anymore, albit the KA is still easier, but most shops that NICO members are familiar with carry SR parts now.

Personally, my plan is KA-T, for 4000-5000 g's I can make my KA put down 300-350rwhp at 10psi max. Theres a guy on this board that is at 14psi with his KA-T and makes 400+hp (although he has lots of other mods like port/polish)!! SR at 14psi? Maybe around 280rwhp with equivilent mods. Not to mention the KA is a torquier engine.

As far as reliability...it really depends on tuning the KA just right. The main cause for detonation is too little fuel, make sure you have a GOOD amount of fuel for your goal of boost. The KA has forged rods and piston oil squirters, so its really not all that not meant for FI. Anything above 10psi get new pistons, and maybe rods if you like to run the redline. Also depends on miles on the KA before hand.

trpower7
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Agreed, I'd say bang for the buck if you know what you are doing and have the time a KAT is by far the best thing. And while SR parts are available, they are inevitably more expensive and take longer to get. AutoZone has just about everything you could ever need for your KA

george
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the KA is a better motor, in my mind, than the sr20

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aleph1
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See in the US the SR is illogcial, unless your goal is for pure JDM. The SR is a good engine, but since it came STOCK (in K's) in Japan, they can put more money into tuning it, rather than wasting a good chunk of it just to put the SR in like here. SR is a waste of money in the US if your main goal is performance. Period.

george
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well said alephi you should check out my KA sometime and see that power it produces you will be amazed and how much cheaper than the sr20

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aleph1
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I might just have to do that...=)

Youre in SD right? Im in SD aswell.

Good240
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20% more displacment definetly makes a difference...

and very fresh used KAs are everywhere online.As for buying new, I think it'd be nice to buy a engine with all the turbo equiptment attached like the SR because turbo kits aren't much cheaper than a professionally done SR swap. Actually many are more.

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Bbill528
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KA isn't meant to be a turbo engine, SR20DET is a turbo engine. So pretty much a lot of work will be needed w/ the KA, a lot more than w/ the sr20. Bigger turbo on an SR20DET is a must after you raise the boost to like 14 psi. So for cost i'd say get an Sr20 which is in my eventual plans. Also i have heard KA-T's don't last very long, so reliability is an issue.

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aleph1
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Ive heard they dont last when people cant tune them correctly. Not the engines fault. As with any big change to an engine, you need to tune the engine for it. The KA-Ts that blow (like Chris Mays, 3 times actually) have all been because of lack of attention paid to fuel delivery. Everyone who has tuned the fuel delivery right, its lasted since they put the turbo in.

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Bbill528 wrote:KA isn't meant to be a turbo engine, SR20DET is a turbo engine. So pretty much a lot of work will be needed w/ the KA, a lot more than w/ the sr20. Bigger turbo on an SR20DET is a must after you raise the boost to like 14 psi. So for cost i'd say get an Sr20 which is in my eventual plans. Also i have heard KA-T's don't last very long, so reliability is an issue.


He said up at the begining of the post that he only wanted 6 to 9psi. The turbo kits "complete" out there for the ka's run on all stock internals at 7psi. I know people who have put these on and have had no problems. He won't need to mess with fuel dilivery or injector upgrades if he stays below or at 7 psi I think. Not to mention the I like the torque curve in the power band of the ka alot better, not to mention the displacement.

trpower7
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Here is the deal. KA at 7PSI needs a good kit put on well and fuel management adn an engine with usually less than 125K miles. Do those and you will be fine. More than 7PSI you need to either have a fresh motor, or a built one, and some serious fuel delivery, again. ANY car can go turbo, the KA actually seems to me to be a more capable turbo motor than the SR, iron block, no rocker arms, it still has piston oil squirters and forged rods from the factory. Bang for the buck, if you are smart and have the time and don't just bolt a T4 on and expect to run all day long. Be smart, read the boards, KA is the way to go.

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WDRacing
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Since I don't own a 240 as of yet, I figure I'll have an unbiased opinion. I've built the entire line of RB's from GTR's to GTS-t's. I've also built a few SR20's and CA18's in the 180's over here.

The big difference I can see from reading about the KA is the intake and head on the SR20. The SR is designed for forced induction. But the KA series is a very efficient NA motor. If you lower your compression with a thicker head gasket you'll be able to run as much boost as any SR. Your RPM's might not be able to compete because of the longer stroke...but thenagain the KA is a 2.4 also.

The main reason I stuck with the RB20 over here is strictly becasue there everywhere, just like the KA. As far as forced induction goes, I cut my teeth on the Skyline. I've been learning and am still learning about bigger and better ways of tuning. You'll be able to do the same thing.'

If you do it yourself you'll have a better knowledge of whats going on with your motor. Having a shop do it is for people with no skills and a big budget in my eye's. I like the pride of building my own engines.

Granted I may ask questions, but thats the only way to learn. I've been through 5 motors and a ton of head and cam combo's. I'm still having fun. Race it, boost it, blow it up.

You have to becareful once you cross into the world of forced induction, boost is like Heroin, very addictive with the groing need for more. But life is to short to settle for average.

WD

george
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boost is the most addictive thing in the world..i started with 8 and i told myself it would be enough...yeah right i am up to 30psi

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ST240
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WDRacing wrote: Race it, boost it, blow it up.


I like this idea! :yesnod

-Andre

Digital 9INE
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Sup guys. Everything I've read here has helped me in my journey just a tad. I'm still stuck in that elusive state of "SWAP HEADACHE". When I got back to California about a year ago, I knew i wanted a 240sx(always have...should of never purchased the Trans Am). Fresh out of college..time for fun. The only problem I have isnt maintenance, Money, misc probs..etc. etc.Its choosing what engine to go with. My brother and I have been at a battle for sometime. Deciding between the VG30ET Swap, or going with a Turbo KA. And personally, and this isnt to knock the SR20, but -everyone- is doing this swap now. This isnt me, Im not the bandwagon person...even though it is a BAD *** swap. But so many things come into play..emissions, registering yadda yadda. You name it. So when I roll my vehicle out of the garage, i want to have some satisfaction of greatness. Not be worried where im going to take my car to be smogged within the 2-3 year mark for another 300 bucks. Anyways... seeing how the KA may be applicable to my situation. The biggest question of all is,,,

How much power could i be looking at realistically on a KA24DE(Built up with Nismo / Nissan Motorsports Internals) Also being Cryo treated, Ported and Polished, New ECU, Turbo and all the other trimmings. And pretty much what should i expect out of it? What suggestions do you have for pistons? Because Ive seen some pretty sick stuff in the Nismo Catalog for KA24's.

and also..because i know im cramping everybody's eyesite with this long *** post. How realistic is the VG30ET in a 240sx? Its been done. My brother has faith that him, 2 friends of ours and myself can do it. For one of the ultimate sleepers, next to a RB of course, and definitely not leaving out the KA. Once again..either way i look at the situation the engine will be sitting on an engine stand for the next 3 months being fitted with proven parts capable to the power i want to make. Cryo treating is also a MUST on either swap i do. ..and thanx ahead of time for the feedback

:smoker

midnight brother
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Quote »How much power could i be looking at realistically on a KA24DE(Built up with Nismo / Nissan Motorsports Internals) Also being Cryo treated, Ported and Polished, New ECU, Turbo and all the other trimmings. And pretty much what should i expect out of it? What suggestions do you have for pistons? Because Ive seen some pretty sick stuff in the Nismo Catalog for KA24's.[/quote]

i'm sorry but if you don't know the answer to that then maybe you shouldnt do it. "turbo" is pretty vague. saying "how much power coule i be looking at realistically" doesn't help. you can make power from +50hp to 500hp it depends on what turbo. we cant give you an answer because we don't know what youll choose, if you push it to the psi limits, etc.

there is a reason because alot of people are choosing the sr. maybe because of bandwagon but also because we know it works and it works good. why bother choosing an vg? i'm sorry thats the dumbest thing i've ever heard. putting an lt-1 engine in makes more sense then that. you will spend so much money trying to get it work and even if you have sucess you will have a problem with space. the engine is already cramped in the 300zx its going to be worse in the 240. as for an ultimate sleeper? ha i think not. the only sucessful 300z's ive seen has been the escort one. thats with a great tuner and great companies backing him and his car. it is no where near a great sleeper. and then anything can be a sleeper. an engine doesn't make it a sleeper its the appearance of the car.

if you want to be even more different go get a ca. whatever you do obviously do more research.

Digital 9INE
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I've done quite a bit of research for the Z31 VG i was talking about. Maybe not crysal. The only one that a number of tuners have told in some instances would be harder than a RB swap is the VG30DET, or TT. which just isnt possible without a really steep wallet, and ALOT of time. Ive asked Dauntless about this very thing. As far as the VG30ET most shops have all pretty much said the same thing, minor mod work, a bunch of tuning, and trial and error. When being able to see stock 200hp and 227 ft/lb on the torque side..is actually pretty damn decent. Especially for close to $1000 less.

And the question about the possible power value of the KA24 engine was how much could i look at realistically before going turbo. Some have said possibly 200-215, depending on the parts, and depending on the current state of the engine. In the end being totally rebuilt would give the best results. Taken into case..i wasnt trying to be flamed.. :) simply asking for some feedback from owners that have done the KA rebuild. Not a noob by anymeans but its always a good thing to hear out horror stories and lessons before making a final decision. Sleeper or not.. Noone in Northern Cali i -know- of has a VG30ET.:eek: Especially when in this case it is pretty cost effective when compared to a SR Clip + install (if i didnt decide to do it at our garage) and still be capable of Much more power and boosting levels in the end.

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WDRacing
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Digital 9INE wrote:I've done quite a bit of research for the Z31 VG i was talking about. Maybe not crysal. The only one that a number of tuners have told in some instances would be harder than a RB swap is the VG30DET, or TT. which just isnt possible without a really steep wallet, and ALOT of time. Ive asked Dauntless about this very thing. As far as the VG30ET most shops have all pretty much said the same thing, minor mod work, a bunch of tuning, and trial and error. When being able to see stock 200hp and 227 ft/lb on the torque side..is actually pretty damn decent. Especially for close to $1000 less.

And the question about the possible power value of the KA24 engine was how much could i look at realistically before going turbo. Some have said possibly 200-215, depending on the parts, and depending on the current state of the engine. In the end being totally rebuilt would give the best results. Taken into case..i wasnt trying to be flamed.. :) simply asking for some feedback from owners that have done the KA rebuild. Not a noob by anymeans but its always a good thing to hear out horror stories and lessons before making a final decision. Sleeper or not.. Noone in Northern Cali i -know- of has a VG30ET.:eek: Especially when in this case it is pretty cost effective when compared to a SR Clip + install (if i didnt decide to do it at our garage) and still be capable of Much more power and boosting levels in the end.


The VG is a big bastard, I hate(absolutely hate) working on 300Z's. If you want mad power and total originality, stuff in a 3.8 from a grand national.

Personally I'd go with the turbo KA24DE. With a full build and GT30 or bigger your looking at 450+.

WD

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WDRacing wrote:
If you lower your compression with a thicker head gasket you'll be able to run as much boost as any SR.


Not necessarily. Modern heads are designed with quenchpads on the outer edge of the combustion area. The space in this area at top dead center is quite small. Small enough that most of the mixture can be pushed towards the middle of the combustion chamber. This aids in preventing detonation, and helps to lessen the chance of damage when there is detonation. The mixture that is still trapped in this area tends not to burn at TDC since the mixture sits right up against the cooler(relative) metal of the heads and piston. A thicker headgasket will increase this space and may take away some of the quenching effects of the cylinder head.

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C-Kwik
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midnight brother wrote:there is a reason because alot of people are choosing the sr. maybe because of bandwagon but also because we know it works and it works good. why bother choosing an vg? i'm sorry thats the dumbest thing i've ever heard. putting an lt-1 engine in makes more sense then that. you will spend so much money trying to get it work and even if you have sucess you will have a problem with space. the engine is already cramped in the 300zx its going to be worse in the 240. as for an ultimate sleeper? ha i think not. the only sucessful 300z's ive seen has been the escort one. thats with a great tuner and great companies backing him and his car. it is no where near a great sleeper. and then anything can be a sleeper. an engine doesn't make it a sleeper its the appearance of the car.


If space is such a concern, why choose an LT-1? It's a rather large V-8.

300ZX's have a similar engine compartment size as the 240. 300ZX's are wider overall, but cram a double wishbone front suspension, which does take more space. Just a estimation from looking at underhood specs of a collision estimating guide, it appears the 300ZX engine compartment may be narrower than the 240SX's.

The VG's limitations really stem from a lack of space. The motor is plenty strong, especially when built. But inside the 300ZX chassis, turbo size and manifold design is quite limited. Some of the Parallel Twin Turbo set-ups for the Supra use equal length manifolds and large T4 based turbos and acheive astronomical amounts of power. If you could get these types of parts into the 300ZX, I'm sure you could be making similar power.

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ST240
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aleph1 wrote: The KA has forged rods and piston oil squirters, so its really not all that not meant for FI. Anything above 10psi get new pistons, and maybe rods if you like to run the redline. Also depends on miles on the KA before hand.


umm are you sure it has forged rods? i thought only the crank was forged?

-Andre

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WDRacing
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C-Kwik wrote:Not necessarily. Modern heads are designed with quenchpads on the outer edge of the combustion area. The space in this area at top dead center is quite small. Small enough that most of the mixture can be pushed towards the middle of the combustion chamber. This aids in preventing detonation, and helps to lessen the chance of damage when there is detonation. The mixture that is still trapped in this area tends not to burn at TDC since the mixture sits right up against the cooler(relative) metal of the heads and piston. A thicker headgasket will increase this space and may take away some of the quenching effects of the cylinder head.


Most of the SR's people are getting that are actually JDM are 1991 to 1995. So the head casting should be of the same, shall we say, technology. I've done some reading on quench. It's important for a completely tuned and balanced engine. Not somthing most people on these forums should ne concerned about. If you want big boost you have to lower compression. If you don't have the money for pistons and rods then a head gasket will allow you to raise the boost a bit without the fear of destroying your engine at anything greater the 10 psi.

I personally would design my engine with quench in mind. But I'm building an engine to except over 30 psi at high rpms. So the little things would help me out more then the average Joe.

WD

flip240
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Quote »So pretty much a lot of work will be needed w/ the KA, a lot more than w/ the sr20.[/quote]Sure, if you don't EVER plan on upgrading your SR20.

The only thing I have to add to this discussion is that IMO, its a matter of preference between the SR20DET and the KA24[D]ET. They both make monster power but at different parts of the power band.

The KA24 descended from a long line of Nissan engines (L -> NAPS-Z -> KA), and it has some very serious potential from its design. Like trpower7 said, any engine can be turbo'd with as much the same reliability as any other turbo engine. A well tuned and well maintained KA24[D]ET will last about 90% the same life as a N/A KA24 (Corky Bell). Anyone who has said otherwise that the KA24 will blow up if you FI it doesn't know what they are talking about.

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ST240
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flip240 wrote: A well tuned and well maintained KA24[D]ET will last about 90% the same life as a N/A KA24 (Corky Bell). Anyone who has said otherwise that the KA24 will blow up if you FI it doesn't know what they are talking about.


well stated :)

george
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turbo KA all the way...sr20 are not motors without weaknesses. price to power the ka is unbeatable. and parts are easy to find too

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Tony Starks
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After thinking things through I've come to the conclusion that for me it comes down to what's more readily available,bang for the buck,and also performance purposes.From what I understand the SR20DET has a nice amount of hp from the factory,BUT the KA24DE has torque.

Besides I can get what I need at any parts store if anything goes wrong.


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