pros/cons of going turbo KA or SR20?

[dmora]

Also the Ka has forged and shotpeened rods, forged crank, oil squirters to cool the pistons, and the only downfall is the ****ty pistons, but you will destroy any piston whether it be forged or not with detonation so IMO all the forged pistons are good for are as a safeguard from crappy tuning because they will take a few more "knocks" than a nonforged piston but it will eventually get the forged one to. So what is so big about having forged pistons if your running under 13-14 pounds of boost? Im running 14 on factory bottom end.

VERY interesting....It seems as if the KA is technologically the better engine, if what u say is true. Only reason people go for the SR is because of the better revving and cause its JDM tyte. And i understand what u mean about tuning vs building. Anyone can slap stuff together. if you cant tune it tho, it will pop, no matter what you have it "built" with.

What about electronics? What sorts of things are we looking at here, a Fuel Computer? a EBC? Will they just piggy back onto the KA ecu? Im considering going with an AEM as well.

[Def]

SR has the same stuff, but a better piston design with thicker ringlands. Plus an ECU that is much more "boost friendly" from the get-go.

Those two things go a long way if one is a bit careless with tuning or cranking up the boost...

[jmwenick]

Are there any turbo kits for the KA24E, or are we just talking about KA24DE?? If it is just DE, are there any kits for the 90-91 DE's??

[[s3]]

Ive got about 1400 in my ka24det with parts to reliably make around 300 hp if you have some common sense and a little know how its not expensive at all! It also helps to know a few people but thats besides the point anybody can build a turbo ka for cheap if they can do most of the work themselves. You dont really need to rebuild the ka in my opion if its in decent shape and has been taken care of, but pistons and rods for the ka are still cheaper than an sr20det hell you could even throw in a port and polish on the head and still come out cheaper. If you want more power out of the sr you still would have to upgrade injectors, turbo, fuel pump and then control the fuel so lets have some prices on that S3! Anyway a turboed KA would smoke your fatass heavyweight Z anyday (given the right boost) You say what if you ran the same amount of boost on the same size turbo or turbos, no the 240 wouldnt win. Why? There is no replacement for displacement. Period.

What are your mods on your KA24DET to get 300HP (Dyno HP?)

[karay240]

Although if they were both done right (and about the same hp), I think that the KA-t WOULD be faster due to the abudnace of torque. However, there are a couple reasons, besides JDM tyteness (lol), that I like about the SR: it's smoother and more boost friendly. By boost friendly, I mean that since it already came with all of the software, all you have to do is upgrade the hardware, and "tune" accordingly. You can do this w/ the KA, but it's a little more difficult to get it just right.

The reason for this is that there aren't as many off the shelf parts that are out for the KA motor. For example, Until recently, electromotive, I believe, was the only company making a standalone for the KA motor. Although this system can replace the distributor cap and modernize things a bit, it isn't the cheapest thing on the market. Of course, there are other non-vehicle specific standalone ECUs out there, but who has the money for Motec?

The neat thing about the SR is that is already has a distributorless ignition system, and all you really nead is a good standalone to take it from good to great. And for that much coveted standalone, you're not going to have to spend thousands of dollars like you would for the KA. The installation is simpler, too.

Having said that, if you're going seriously all out, it really doesn't matter which one you get. They are BOTH expensive, and the difference is nominal for the money that you'll be spending keeping fast and reliable.

[95hondakillr]

What are your mods on your KA24DET to get 300HP (Dyno HP?)

toyota ct-26 w/ modified compressor housing (to4e compressor wheel), custom mani, 550cc injectors, apexi super afc II, 300zx maf, custom intercooler, pfab top feed fuel rail, port and polish on head, b&m fpr, walboro 255lph fuel pump, fresh bottom end on stock internals. Havent had it to the dyno yet, but will post results when I do, hopefully it will be next week.

[AX75F92]

SR - 400+whp - stock block - nuff said.

[Nathan]

SR - 400+whp - stock block - nuff said.

There's SOOOO much more to the debate than just that though, its really NOT "nuff said".

[Warped]

um you can get 400+ on a stock ka if you dont detonate what are you saying

[95hondakillr]

Bottom line AX7594263t54823- Horsepower is a byproduct of TORQUE! Yeah you can make up for your lack of torque by revving the hell out of your engine, but wouldnt you just be better off buying a honda? BIG HP numbers dont mean jack shiznit. Thats just a mechanical fact but whatever.

[95hondakillr]

And I wonder why they make that 2.2L stroker kit for the SR20DET:thinker

[karay240]

or what about the 2.4 kit from JimWolf. . . and the same SR vs KA debate goes on again. . . lol

[Nismo_Freak]

Bottom line AX7594263t54823- Horsepower is a byproduct of TORQUE! Yeah you can make up for your lack of torque by revving the hell out of your engine, but wouldnt you just be better off buying a honda? BIG HP numbers dont mean jack shiznit. Thats just a mechanical fact but whatever.

You fail to understand physics...

[AX75F92]

The SR is one of the most over built production motors out there. Where are you getting this 400+hp stock KA info from? Are there a lot of those roaming around over there in Arizona? What kind of race gas were they using? Did they end up swapping in an SR after it blew? The KA can be a great motor. I have friends who were able to get some pretty impressive numbers out of a built KA-T. However, the KA24 was never meant to see boost and it was built accordingly, therefore precautions must be taken. The KA was an after thought used to get the "bigger is better" Americans to accept the 240 as a sporty car.

If TORQUE is your main concern...I say you go with the new 5.9L Cummins turbo diesel. 600ft./lbs of torque and 325hp. Not to mention your incredibly increased towing capacity!!

8,000 RPM is hardly "Revving the hell" out of a 2L class 4 cyl. The KA should actually have a higher rev potential than the SR due to its better rod:stroke ratio (1.72:1 vs. 1.58:1). Given the proper valve train and head work, the KA should out rev an SR.

They make 2.8L kits for RB26.... what's your point? :fruit

In the end it comes down to $$$ and personal preference. The maximum power potential of a built KA should be higher than that of an SR (no replacement for displacement). If you are building a drag car... go KA. If you dont want to dive into the internals... SR.

[masticatingcow]

If you dont want to dive into the internals... SR.

Even on the SR, if you want to pump 400 whp, you have to dive into the internals.

[C-Kwik]

Bottom line AX7594263t54823- Horsepower is a byproduct of TORQUE! Yeah you can make up for your lack of torque by revving the hell out of your engine, but wouldnt you just be better off buying a honda? BIG HP numbers dont mean jack shiznit. Thats just a mechanical fact but whatever.

Big HP is a product of torque and high RPM. And HP represents the actual potential of a motor to move a certain amount of weight a certain distance within a certain time or to a certain speed. So HP is actually a lot more representative of the actual work a motor can do.

[C-Kwik]

The SR is one of the most over built production motors out there. Where are you getting this 400+hp stock KA info from? Are there a lot of those roaming around over there in Arizona? What kind of race gas were they using? Did they end up swapping in an SR after it blew? The KA can be a great motor. I have friends who were able to get some pretty impressive numbers out of a built KA-T. However, the KA24 was never meant to see boost and it was built accordingly, therefore precautions must be taken. The KA was an after thought used to get the "bigger is better" Americans to accept the 240 as a sporty car.

If TORQUE is your main concern...I say you go with the new 5.9L Cummins turbo diesel. 600ft./lbs of torque and 325hp. Not to mention your incredibly increased towing capacity!!

8,000 RPM is hardly "Revving the hell" out of a 2L class 4 cyl. The KA should actually have a higher rev potential than the SR due to its better rod:stroke ratio (1.72:1 vs. 1.58:1). Given the proper valve train and head work, the KA should out rev an SR.

They make 2.8L kits for RB26.... what's your point? :fruit

In the end it comes down to $$$ and personal preference. The maximum power potential of a built KA should be higher than that of an SR (no replacement for displacement). If you are building a drag car... go KA. If you dont want to dive into the internals... SR.

The differences between a OEM turbo motor and an OEM NA motor tend to be minor. Typically, only precautoins to reduce the potential from detonation and those that reduce the potential for damage due to detonation are made. About the only significant factor about the KA that perhaps can cripple high boost on a KA is the high compression. But 15 psi has been seen reliably on a KA.

Torque should be a concern for anyone trying to make power. The more torque you have, the more power you make. Not necessarily peak torque, but torque where you need it the most.

8000 RPM is pretty high for any motor. Pistons speeds get way high around there. Motors designed to rev this high need beefy rods and are usually designed with keeping piston speeds down as much as possible(large bore, short stroke).

The KA does not have potential to rev higher. The stroke is long. Piston speeds would be very high at 8000 RPM. Probably higher than an F1 motor. The tensile loads on the rod and piston would be incredible. The factory rods would likely never hold at those speeds.

The replacement for displacement is RPM. It increases airflow over a given amount of time. More air and fuel burned = more power.

[MikeMurphy]

Thanks C-Kwik. You saved me the lengthy reply.

bump for an awesome thread =)

I had forgotten about all these points since last week when we discussed it twice

(Just giving you a hard time )

[karay240]

8000rpm+ is too high for BOTH motors. . . Yea, the SR seems like it likes to be revved, but ask anyone who's blown the SR motor, and you'll either get detonation or overrevving. It's been discussed many times, but here I go. . .

The SR has a crappy valvetrain, and the KA has too long of a stroke for anyone to rev it SAFELY past its factory redline. It sux, I know. There are ways to make is safer, like lightning the valvetrain in the SR or using the rockerarm stoppers etc, or use a beefier connecting rods, HOWEVER, these are safety measures JUST IN CASE you overrev your motors.

Even with Skyline motors that can potentially rev really really high, there are many precautionary measures people need to take in order to do it safely (changing waterpump to a lower volume, upgrading oilpump, lightning valvetrain etc). How much more difficult do you think it is with the SR to make it a RELIABLE high revving machine.

Now that I've said all this, I know there are going to be some people out there that know people who rev their SRs to the moon, or bring up the D1 cars into this argument. . . good for them. It's your motor, do whatever you like, but I'm keeping the factory redline as safety measures.

If you really want a high revving motor, get the CA18. If you want a torquey motor, keep the KA. If you want the happy medium, get the SR. That's the best advice I can give anybody. . . good luck

KennyUnderground Motorsports

[Import_Tuner]

Ive got a ka24de dohc 16v in my car and I had a few questions I wanted to ask someone who has experience in them.

1) If I wanted to get around 400 ponies out of it what parts would I need to buy. (Is there a website that has every one of them.)

2) Around how much will it cost me?

Thanks for any information you can give me.

[masticatingcow]

Ive got a ka24de dohc 16v in my car and I had a few questions I wanted to ask someone who has experience in them.

1) If I wanted to get around 400 ponies out of it what parts would I need to buy. (Is there a website that has every one of them.)

2) Around how much will it cost me?

Thanks for any information you can give me.

ANSWERS

1) An high end turbo kit (big turbo, FMIC, etc etc...), forged internals, probably 1991 DOHC cams, upgraded fuel delivery, catback exhaust, hopes and dreams.... yeah, it's a long list. But it's a list that's already been posted probably 100 times. Search... and there is one site you can find it all, NICO. Go to http://www.nissaninfiniticlub.com. Then search.

2) A lot.

[AX75F92]

Internal construction between the two are obviously different, they are completely different motors. One was built for turbo, one wasnt.

And no....you do not have to upgrade the stock SR bottom end to make 400whp...this is proven. So is the fact that there is NO replacement for displacement.

The psysical length of the stroke on a KA is quite long (hense its 2.4L displacement). This will no doubt hinder its ability to rev high. Point well taken. But the rod is fairly long as well, keeping the rod:stroke ratio very close to ideal, which is a good thing when it comes to keeping side loads and piston speeds in check.

I agree with Karay completely.

[masticatingcow]

And no....you do not have to upgrade the stock SR bottom end to make 400whp...this is proven. So is the fact that there is NO replacement for displacement.

:bsface Show me. I do not believe you. I'm tired of people making statements like this and expecting it to somehow be common knowledge. In most of the time, it ends up being hearsay.

Everywhere I've read, 300 whp is pushing it on both engines. Maybe that's a little low, maybe... but not 100 whp low. No way. I don't believe that.

Also, explain to be why F1 engines pump 700 horses out of 2.6 liter engines. Why isn't the 6 liter Vette able to push that kind of power? Isn't the mere existence of the F1 engine PROOF against what you say has been PROVEN?

[karay240]

OK, I'll show you. Enjuku racing's 240sx, Mckinney Motorsports' 510, and the list goes on. . . Actually I think their cars are both around the 500hp range, if I'm not wrong. Here's the oversimplified version of the list, but the bottom-end is untouched--They slap a pair of cams, a metal head gasket, set of injectors, ECU, and a BIG Turbo and your'e ready top go.

Kudos for them tempting their fate.

For a daily driver, however, I'd stay around 300 with the stock motor (except the metal head gasket that you SHOULD have put in before you installed your SR). If you wanted to go further, you can use the stock NA SR cams, and retune you're ECU and go around 350. That's personally where I'd stay. I don't know about you, but I like driving more than tearing motors down, nor am I made of money. lol.

BTW, about your "PROOF". . .

Try putting that F1 motor in a vette and lets see what happens on the road. . . and BTW, you CAN modify the vette engine to 700hp, and it'll probably be faster than the vette w/ the "700hp" F1 ). I'm even going to go as far as to say that I believe you can make more power w/ a vette motor than you can with the aw-inspiring SR motor. lol.

The thing is, in order to make those kinds of numbers, the F1 motors need to rev well over 10,000 rpm, uses pneumatic (sp?) valves, and a VERY expensive assortment of internals. Heck, it's a racing engine. What's the vette? Yea, you guessed right. A PRODUCTION engine. This means that the engineers are more worried about emmissions, gas mileage, longevity (to an extent), productrion cost, and lowend torque (something that's not necessary on a very light weight race car). This lack of torque is the reason many people shy away from the CA, and opt for the SR.

[masticatingcow]

You touched on what I think most people would agree is a very important aspect of building a performance engine... dependability. You want to depend on your engine, not have it the other way around.

If the formula for a solid high-output car was so simple as "slapping on a pair of cams, metal head gasket, injectors, ECU and a BIG turbo" don't you think more people would be doing it?

The answer is no, and the reason is because of another point you so correctly made: there's a big difference between race engines and production engines. The SR is a production engine, and its owners are generally concerned with reliability. As you said, Enjuku and McKinney are "tempting their fate." But to what degree? These are tuner tech houses, not private owners. They can treat the SR like a race engine and blow it without worrying, right? They have ready access to replacements. We can't look at the handful of uber-high-HP SRs and make the assumption that all SRs are so capable, especially in the hands of a private owner who has unfortunately less resources to draw on.

Right on about the CA, BTW. Some would never consider it for a swap. And you know what? Some wouldn't bother with a SR... surprised? Probably, but, personally, I would turbo the KA before playing with either other option. Why? Torque. I agree completely with what you said about torque (or implied anyway) but was I working under the assumption that we were talking about high-revving, high-HP engines. Oops.

[Onizuka]

:bsface Show me. I do not believe you. I'm tired of people making statements like this and expecting it to somehow be common knowledge. In most of the time, it ends up being hearsay.

Everywhere I've read, 300 whp is pushing it on both engines. Maybe that's a little low, maybe... but not 100 whp low. No way. I don't believe that.

539hp on the stock blockhttp://www.secretservicesinc.com/trogdor.html

544hp on the stock blockhttp://www.enjukuracing.com/racecar.html

526hp on the stock blockhttp://www.store.yahoo.com/pha....html

hearsay it aint

movingviolation240 has a SR daily driven with 400ish hp on the stock bottom end with a GT25R.

[masticatingcow]

Touche, monsieures J-Spec Tuner and karay240. I stand corrected. :dunce

[Onizuka]

Not entirely , those are cars that have some real tuning (AKA on a dyno in the hands of the very, VERY experienced). Plenty of people mistake those figures as what anybody can reach and just strap on a huge turbo and blow up their motors.

I love KAT's and SR's, I dont understand why it always has to be a compitition between the two. And between any nissan motor for that matter.

[[s3]]

Now lets see some links to KA motors pushing over 400HP and 500HP.

[masticatingcow]

Wasn't there a privately owned S13 FB with a KA-T for sale on eBay a couple months ago pushing 411 rwhp? I can't remember for sure... but that wasn't on stock internals. I'm sure about that.