Adding a Turbo to a Stock KA24 (Noobs Read)

Your premier source for information on the Turbo KA: KA24E-T and KA24DE-T (KA with aftermarket turbo kit)!
User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

What Can My KAT Handle In Stock Form (Noobs Read)

Postby WDRacing » Tue Feb 06, 2007 4:56 pm

Hi, allow me to welcome you to Nico and KAT. If you've been a member for awhile now, well its about time you're interested in going turbo.

There has been a rash of threads and questions related to how much boost or how much horsepower a stock motor can handle before things start to break. I'm going to do my best to explain how and why things happen the way they do.

The KA24E and KA24DE are both very fun motors when boosted. They can be used for high horsepower drag cars or low boost dependable daily drivers. The selection of parts and where money is invested will determine exactly how and why things are going to happen to your motor.

First, lets start off with making sure the current motor and car are in fairly good condition. By that I mean the motor runs perfectly fine as it sits right now and the car isn't going to fall apart. Trust me, if you have any problems, adding boost is only going to compound them greatly.

Aside from running well and being mechanically sound there are a few things that should be looked at closely. One is the compression on all 4 cylinders. If you don't have a compression tester, I suggest buying one. They are about $30 from Sears where I bought mine. But they can be found at most auto parts stores. You're going to want compression numbers over 155 on all 4 cylinders and they should be within 10 psi of each other for the best results. If they are lower, I'd suggest a full rebuild before going with a turbo kit.

The next key part is the oil system. Its hard to tell the exact pressure without a standalone aftermarket gauge. But you'll want want 15psi or more at idle and over 30psi once the rpms have gone past 3000. Those are for an engine that's already warmed up. If its cold, they will be ALOT higher. Don't use those numbers. However, if you have low oil pressure when cold, and the car has been running for more then 2 minutes, shut the car off and inspect the oil system. Hopefully its just low oil level.

The coolant system should also be working well. Adding a turbo creates more heat inside the motor and more heat under the hood. So a good cooling system is a must have. The factory system will work fine for a low boost setup. Just make sure you keep an eye on things. Overheating a turbo motor will lead to detonation and can wreak havoc on every system in the car. You'll never hear people say, "Man, what a waste of money he put into that cooling system". If you do, chances are they don't know what they're talking about.

The last main system that needs to be inspected is the ignition system. Adding a turbo will require you to use a different spark plug. One that is one or two heat ranges colder. You'll also use a shorter plug Gap then stock. Start with BKR7E from NGK and gap them to .038 and close the gap as you run into spark issues. But that's a whole story by itself. If you want to change the wires while you're swapping plugs, might as well. There is no such thing as having something work "To Well".

With all that said, lets move on to the actual point of this thread. The stock internals in a mechanically sound motor will take a good bit of power. We have members pushing close to 500WHP on a factory parts. But we've also had motors fail in the 300's and 400's. A lot of this is do to poor tuning and or not taking care of the motor.

If the engine oil is changed frequently, then there should be no issues with the bearings seizing up. Clean oil is always a good thing. I relate some of the problems people have had to lubrication issues.

As far as tuning goes, money is the only thing that will limit your options. You have to really consider your end goal. Will a simple piggy back SAFCII or Greddy Emanage be good enough? Or should I look into Rom tuning or Standalone Ecu's? Well both work well for what they are. Cheap piggy back setups are good for making a small but fun amount of power. But if your needs are over 300, then I'd start exploring other options. The whole point of tuning is that without a good safe Air/Fuel mixture and the proper timing retard on boost. You could have the motor built with titanium parts and it will still break.

Finally, once you've got everything working correctly and you've decided on what method you're going to use for tuning. You come to the most important choice of all in my mind and that's what parts to buy or what kit to use. Every part in a system will have a max output. If that max output is lower then what your goals, then don't buy it. Trust me, settling on something will always haunt you. If you have to save for a few extra months to get what you want, then so be it. There are a lot of good deals to be found and a lot of choices that will work very well. But there are just as many bad choices along the way. Beware what you buy from EBay, some things just shouldn't be bought from a generic company. There is a lot of information in the KAT forum as a whole and a lot in the FAQ at the top of the page. If you can't find it there, then ask away. But please read through things at least a little before rattling off questions that are probably posted on the very first page already. A little research in the beginning will yield fantastic results later.

All of this comes to a close with me voicing my opinion and saying a safe bet for a sound motor when tuned properly is about 350WHP. Some will go farther, some will not. If my goals were more then 350WHP, I'd seriously consider saving for forged internals.

I hope this has helped some of you out. Never be afraid to ask questions. Worst case we'll just tell you where to look.

If you have questions after reading this please make a new thread. You won't be flamed for asking.

Happy BoostingWD


capwred
Posts: 598
Joined: Thu Jul 28, 2005 3:43 pm

Postby capwred » Tue Feb 06, 2007 5:10 pm

One of the best write ups i have seen.

Thanks

User avatar
Florida240sx
Posts: 11662
Joined: Thu Jul 01, 2004 7:17 am
Car: 93 Hatch 5spd
2012 altima coupe 2.5s
Location: DeLand FL
Contact:

Postby Florida240sx » Tue Feb 06, 2007 6:05 pm

Good write-up. Really needed since all the "new" people lately.... some of them were a bit cocky....

User avatar
eazye2000
Posts: 1881
Joined: Mon Jun 27, 2005 9:42 am
Car: S13 KA-DET
Location: Inverness, FL
Contact:

Re: (Florida240sx)

Postby eazye2000 » Tue Feb 06, 2007 6:22 pm

Florida240sx wrote:Really needed since all the "new" people.... some of them were a bit cocky....
Man, why you guys have to call me out like that?!

Just kidding. Glad to see someone posted something like this.

*edit* Sorry, had to fix it.. I couldn't make fun of WD like that.....'lord I apologize....' Don't wanna piss him off, he don't talk to me on AIM anymore.. LoL
Modified by eazye2000 at 8:40 PM 2/6/2007

User avatar
babowc
Posts: 3108
Joined: Mon Oct 25, 2004 3:26 pm
Car: 240sx
Contact:

Postby babowc » Tue Feb 06, 2007 7:29 pm

sounds good.the thing is however.. none of the noobs search...haha, i hope you guys sticky this in bright pink flashing letters, so newbs will actually NOTICE this.. instead of cluttering the ka-t sub-forum.

User avatar
XingYu
Posts: 355
Joined: Tue Feb 01, 2005 12:27 pm
Car: 1993 Nissan 240SX
Contact:

Postby XingYu » Tue Feb 06, 2007 7:35 pm

Great write up! +1 for the sticky~

NateDogg
Posts: 811
Joined: Sat Aug 24, 2002 2:20 pm
Contact:

Postby NateDogg » Tue Feb 06, 2007 7:39 pm

Yes just make the title "OMG 1000WHP KA-T STOCK BLOCK!"

Also, dont forget those poor SOHC engines dont have the same compression as DOHC engines. So when doing a compression test, maybe you should put a lower number for them. IMO compression should be above 165+-10psi for DOHC.

zanilth
Posts: 164
Joined: Tue Feb 07, 2006 4:30 am
Car: 1995 Nissan 240 SX
Contact:

Re: (XingYu)

Postby zanilth » Tue Feb 06, 2007 7:44 pm

I agree, searching is usually much easier...

I have been on the site for a while, in the KA forum. So, I do know that searching is usually easier (and faster) than asking something and waiting for answers. However, if you search for something, you usually get a crapload of different topics about what you searched for, and after looking at the first 10 or 15 and they all say "use the search!!!!" you get tired of looking.

Maybe someone should go through and clean stuff out?

I know its probably done anyway. I know I searched for something, and couldn't find anything on it. I searched three or four times before posting something, and sure enough...."try the search key."

User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

Postby WDRacing » Tue Feb 06, 2007 8:06 pm

This will be stickied after circulation for awhile. I'm not adding it to the FAQ but making it its own Sticky.

WD

dekansnowman
Posts: 141
Joined: Thu Apr 06, 2006 7:50 pm
Car: 1995 240SX w/RB25

Re: (WDRacing)

Postby dekansnowman » Tue Feb 06, 2007 10:01 pm

This is why I like Nico so much.....Thanks for the info. While I am not on a KAT project, its good to have tech and common sense info just laying around.

User avatar
babowc
Posts: 3108
Joined: Mon Oct 25, 2004 3:26 pm
Car: 240sx
Contact:

Postby babowc » Wed Feb 07, 2007 9:46 am

key terms, so ppl can find it with searching feature:

ka-t, kat, boost, pressure, stock psi, boosted, ka24de, ka24e, compression #, compression, numbers, cylinders, coolant, WHP, HP, power, Internals, stock internals, spark plug, sparkplug, turbo, ignition.

User avatar
Edub1
Posts: 1931
Joined: Thu Nov 10, 2005 2:20 pm
Car: 89 240sx KA-T

Re: What Can My KAT Handle In Stock Form (WDRacing)

Postby Edub1 » Sat Feb 10, 2007 6:27 am

Excellent article!

Another question they typically ask is how much boost the KA can handle. I think this is a valid question for the following reason.

We all know that there is a difference between boost and horse power. This is normally attributed to larger turbos flowing more air. If we consider this dynamic, we will find that it is in the upper RPM range that the larger turbo's increased flow comes into play. More to the point, when the motor exceeds 5250RPMs and HP exceeds torque the bigger turbo is able to provide quality boost while the smaller one makes heat. I believe this is where the HP discrepancy comes from. In the lower RPM rages, where both turbos are efficiant, there should be no difference between the two.

Because the larger turbo will ultimatly make more HP at a lower boost, many with smaller turbos plan to run more boost to compensate. What this does, if my thinking is correct, is produce more low end strain on the engine parts and loses efficiancy (make heat rather than O2 mass) in the high RPM range. Obviously this is bad.

Suppose one's goal is 300HP. While a T04E 50 trim will make this at a cool, easy ~11lbs. A super 60 will require around 17lbs - and a good amount will be heat rather than mass.

From this, we see that running a larger turbo with less boost is prefferable to a smaller one with more boost. The mistake we often hear is that a given boost level from a larger turbo makes more power and is therefore more dangerous. For the reasons cited above, I think this is somewhat of a mistake. While the larger turbo will obviously make more HP at a given boost level, I'd have to say that the larger one with the greater HP is by it's nature, the safer of the two at any level of boost.

So, the logic would break down like this:

For a given HP, bigger @ 10lbs = smaller @ 15lbs - and safer.

For a given boost level, bigger @ 325HP = smaller @ 270HP - as safe.

So, I propose that the bigger turbo can make a given HP more safely than a smaller one, and more HP with equal safety than a smaller turbo at the same level of boost.

So, the answer to how much HP can my motor handle might sound something like " 325 - 350 with a T4 or 250 - 275 with a T3."

User avatar
Hughretro
Posts: 73
Joined: Mon Apr 02, 2007 3:12 pm
Car: 91 240sx and a 92 240sx(project car)
Contact:

Postby Hughretro » Mon Apr 02, 2007 3:45 pm

Good write up. On my project car I'm going all forged and fat cams, but I'm not even close to finishing her yet.

Alsontime
Posts: 140
Joined: Fri Jan 19, 2007 6:29 pm
Car: 1993 Nissan 240SX Convertible
Location: North Carolina

Re: What Can My KAT Handle In Stock Form (Edub1)

Postby Alsontime » Sat Apr 14, 2007 6:09 pm

I agree, I was using a GT28 on my KA-T around 15 psi and switched to a T04E at 15 psi and what a difference. You have to consider that both are running at 15 psi but the T04E can move a larger volume of air at 15 psi, increasing hp.

nissanfanatic
Posts: 1314
Joined: Mon Nov 01, 2004 8:41 pm
Car: 1992 Nissan 240sx SE
Contact:

Postby nissanfanatic » Sat Apr 14, 2007 6:54 pm

It all comes down to cylinder pressure. Just like a balloon or a soda bottle, the engine will break at a certain pressure level. Everything breaks under enough enough force. Pressure is force applied over area.

sniperbill3
Posts: 35
Joined: Fri May 11, 2007 9:44 am
Car: 1991 Nissan S13 240sx

Re: (Florida240sx)

Postby sniperbill3 » Fri May 11, 2007 9:47 am

You show great appreciation in the KA24DE and thanks for all your turbo info on the KA and what it can handle i would like to keep my Ka instead of a swap for the sr20. Since the ka can get more power out of it than the sr20

kheff46
Posts: 22
Joined: Wed Nov 17, 2004 3:03 pm
Car: 02 WRX wagon, 93 240sx, 06 DRZ supermoto blk
Location: wellington, ohio

Re: (sniperbill3)

Postby kheff46 » Sun Jul 08, 2007 6:00 am

sniperbill3 wrote:You show great appreciation in the KA24DE and thanks for all your turbo info on the KA and what it can handle i would like to keep my Ka instead of a swap for the sr20. Since the ka can get more power out of it than the sr20
both engines are completely different. besides the fact they both handle boost well. one revs to the moon. one will torque your house off the foundation(it WOULD be cool) almost... they are just different not better than one another. they were made for different purposes from the factory by engineers.

the KA's got a hella strong bottom end(the crank journals are bigger than the RB's are). and that means only good things for us!

please don't read into things/assume things like that. it can/will make you feel silly.

--keith

User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

Re: (kheff46)

Postby WDRacing » Sun Jul 08, 2007 7:52 am

kheff46 wrote:
both engines are completely different. besides the fact they both handle boost well. one revs to the moon. one will torque your house off the foundation(it WOULD be cool) almost... they are just different not better than one another. they were made for different purposes from the factory by engineers.

the KA's got a hella strong bottom end(the crank journals are bigger than the RB's are). and that means only good things for us!

please don't read into things/assume things like that. it can/will make you feel silly.

--keith
Actually, his statement is pretty on par. In fact it's much more correct then your's. The SR doesn't "rev to the moon" especially in factory trim. The KA has been taken to 8500 rpm...so I fail to see the difference there. The torque curve isn't THAT big of a difference. The main thing is the KA already resides inside of the 240, so why swap in a smaller motor? Everything comes down personal preference.

The article is simply talking about the KA, so there's no real reason at all to compare it to the SR20, which in itself is a very well built motor.

WD

kheff46
Posts: 22
Joined: Wed Nov 17, 2004 3:03 pm
Car: 02 WRX wagon, 93 240sx, 06 DRZ supermoto blk
Location: wellington, ohio

Re: (WDRacing)

Postby kheff46 » Thu Jul 12, 2007 4:01 am

i was quoting his statement of "KA being somehow better than SR". and thats false in a generic sense. both are good engines. just different for different reasons. i personally don't think a smaller mill is good either. revs can be helped by fixing the valvetrain and certain other limitations from stock. SR's rev more out of the factory. KA's have torque from factory. these are different applications from factory. this is all i stated.

--keith

User avatar
bam 240sx
Posts: 36
Joined: Sat Oct 07, 2006 11:44 am
Car: 95 240se, 525i
Contact:

Postby bam 240sx » Mon Jul 23, 2007 12:31 pm

great info now i know what to ask

thanks

rbfastback
Posts: 28
Joined: Mon Aug 20, 2007 10:16 am
Car: 91 rb20 240sx fastback

Re: What Can My KAT Handle In Stock Form (WDRacing)

Postby rbfastback » Mon Aug 20, 2007 10:58 am

could a ka with a t-25 keep with a stock rb20???

GTLegend
Posts: 108
Joined: Mon Aug 27, 2007 12:25 pm
Car: 1993 240sx-S13
Location: nj

Postby GTLegend » Mon Aug 27, 2007 12:46 pm

i just had my KA24de rebuilt i was wondering what kind HP i would be looking at if i was running a t-25 at 8 psi, high flow cat, and a cat-back?? is there any kinds ballpark figure?

User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

Re: (GTLegend)

Postby WDRacing » Mon Aug 27, 2007 12:59 pm

The average is 10 WHP for every one PSI of boost.

User avatar
Driftnoob
Posts: 29
Joined: Fri Mar 02, 2007 3:43 pm
Car: S13 240sx

Postby Driftnoob » Sat Sep 22, 2007 12:54 pm

WOW........the frist post.......outstanding!!!!!!im sure theres goin to be more ka-t now!!!ima be 1 of themThanks WD !!!!!!!!!!!!

User avatar
Driftnoob
Posts: 29
Joined: Fri Mar 02, 2007 3:43 pm
Car: S13 240sx

Postby Driftnoob » Sat Sep 22, 2007 1:04 pm

i think the t25 is too small for the ka, it may spool too fast, then the powerband is goin to be too low......just thinkin in my head.......correct me if wrong.and is the ka able to handle a 14b turbo with stock injector's, i know u said ppl are pushin 300 to the wheels with stock everything but with a fresh like motor... sorry im really lazy "_"

User avatar
neverlift
Posts: 3700
Joined: Mon Apr 24, 2006 6:26 am

Re: (Driftnoob)

Postby neverlift » Sat Sep 22, 2007 2:36 pm

Driftnoob wrote:i think the t25 is too small for the ka, it may spool too fast, then the powerband is goin to be too low......just thinkin in my head.......correct me if wrong.and is the ka able to handle a 14b turbo with stock injector's, i know u said ppl are pushin 300 to the wheels with stock everything but with a fresh like motor... sorry im really lazy "_"
lol better get you hard hat on then... noone is pushing 300 on stock everything.

how many psi with a 14b isnt that comparable to the t25? anyways no more than 5psi and thats with a good *** romtune or an afc and btm cause you gonna have det on stock map....

nissanfanatic
Posts: 1314
Joined: Mon Nov 01, 2004 8:41 pm
Car: 1992 Nissan 240sx SE
Contact:

Postby nissanfanatic » Wed Oct 10, 2007 12:18 pm

Apparently the stock rods and pistons can hold 496whp/436wtq.

User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

Re: (nissanfanatic)

Postby WDRacing » Wed Oct 10, 2007 4:35 pm

There are far more engine failures at that level then success stories though. At that level Ivan was bending connecting rods. So that's really not a good statement to make, some of the noobs don't realize the extent of trial and error involved. It is however correct. People have been busting the 300 mark for the last 6 years on stock internals. But this thread is about what the KA can be made to produce reliably. And by reliably I mean by quite a few people for a long duration of time.

How Long have you been daily driving at your power level now?

WD

nissanfanatic
Posts: 1314
Joined: Mon Nov 01, 2004 8:41 pm
Car: 1992 Nissan 240sx SE
Contact:

Postby nissanfanatic » Wed Oct 10, 2007 5:57 pm

Whenever I can afford to run race fuel. I try to fill up the tank at least bi-weekly and have some fun on race gas. I might go this weekend and have some fun.

I only post information, nothing further. I think, based on conclusive stories, that far too many failure stories are related to operator error. Should that data be deemed inaccurate?

I've been over 400whp since April of 2006.

User avatar
WDRacing
Moderator
Posts: 23881
Joined: Mon Nov 25, 2002 2:00 am
Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
Location: MFFO
Contact:

Postby WDRacing » Thu Oct 11, 2007 4:46 pm

Operator error definitly contributes to most of the problems for sure. I just like to err on the side of caution when telling others what "safe" limits will be.

I of course simply stop when I've maxed out my fuel system. But in my case I tossed a rod shortly there after. I was at 165,000 though and was still using the stock oil pump. I definitly think a spun a bearing and tossed the rod.

WD


Return to “KA24ET / KA24DET Forum”