View Full Version : NA power mods list

07-21-2001, 05:04 PM
I've conjoured up a list of mods to enhance the performance of the KA24DE without adding a turbo. My target is 200-250rwhp. I want to know what following mods/parts should or can be done and how much power it would produce.

Throttle body
Intake manifold
Port and Polish
Valve springs and any other engine mods

Pulley set and other drivetrain mods

AFC, Fuel pump/FMU, injectors, MAF/MAP sensor and other Air/Fuel mods

ECU, ignition and other electrical mods

And please tell me who (manufacturer/shop) is able to do what and for what prive, if applicable.

So, will 200-250hp NA be acheivable? And please feel free to add any other mods (no nitrous/turbo). I'm basically going for a street sleeper.


07-21-2001, 05:28 PM
In fact even a 300hp N/A KA is possible. But donít even look at driving this on the street with over 200-flywheel hp. The cam will rattle your teeth out when you idle; and you will have to run gas with triple digit octane. BTW Fuel system modifications are useless unless you really have the need for all that fuel, the stock system isn't even used to full potential. Just go turbo, learn all you can and it won't be so intimidating, and a turbo engine will make less noise that an N/A engine with a lumpy cam, if you are going for that street sleeper look. You can even get a Skyline intercooler, which come in black, and you can route the BOV back into the intake stream to reduce noise further. IMO a subtle turbo car is a better sleeper than a race prepped N/A motor.

[This message has been edited by White240sx (edited 07-21-2001).]

07-21-2001, 06:55 PM
true that, thanks, I will go turbo, but for now, I'm focusing on trying to releive the engine of the restrictions it has.

Does the throttle body need boring/modding? Does the intake manifold? Can I change the crankshaft of the engine to a better one?

Is there a pulley set (ps, wt, alt) available for the 240 and who makes one? I only know of underdrive pulleys.

What about Ignition controllers? Are they useless once I get an ECU? And is it the same for AFC's/FMU's?

is a MAP sensor an upgrade from a MAF sensor?

07-21-2001, 07:04 PM
The crankshaft doesn't need to be replaced, but if your going all out, do a knife-edge blade crankshaft

07-21-2001, 07:27 PM
The throttle and intake manifold should be just fine, they aren't the restrictions. Get some '91 cams for more power, they are streetable and will be more comfortable than race cams. There is no aftermarket crank available for the KA, but I think (Crower?) offers a stroker kit, but it requires 10 orders for them to start producing it. Unfortunately the long stroke is probably what is limiting this engine. If you ever look at a power curve for it, you will see it drop off dramatically after ~6000rpm, it is a torque motor, you cant really treat it like a high revving, peaky torque engine. As long as you have all the bolt-ons, intake system, complete exhaust system, and some mild cams, you have eliminated about all the restriction you can. As far as computer systems go, just get the JWT reprogram, it is plug and play and you can have it tuned for anything. I am not sure on the MAP/MAF thing but I believe Nissans donít even have a MAP sensor. I think a MAP sensor is what Hondas have, since their engines monitor airflow in the intake manifold and MAP stands for Manifold Absolute Pressure sensor. I don't think it is an upgrade; it is just a different way of measuring air volume. I believe also that it is easier to get around the MAF when you go turbo, but don't quote me on this.

07-21-2001, 09:23 PM
Get a header for now, it will produce some nice power gains and free up the exhaust.

07-23-2001, 12:28 AM


07-23-2001, 09:57 AM
what exhaust did you use for that run Alex? It doesn't look like a good performer.

07-23-2001, 10:18 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by anthony240:
what exhaust did you use for that run Alex? It doesn't look like a good performer.<HR></BLOCKQUOTE>

5Zigen, but my catalytic converter might be badly clogged, and if that's the case then the exhaust wouldn't do anything to help the situation.


07-24-2001, 03:19 PM
My 5Zigen exhaust actaully showed better numbers compared to Mav's. I was running an HKS exhaust with the hot shot header prior to the 5Zigen FireBall. Per the dyno you can see the difference between the HKS R-2 and the Fireball (8.9 difference to the wheels more than the HKS!)

Email me at shawn@autoimaging.com for copy of the dyno.