NA KA24DE Horsepower

[GRiDRaceTech]

That is probably the highest horsepower KA24DE I've personally seen. Dyno-tested 178rwhp and 184lb-ft of torque. (That's equal to roughly 209bhp and 216lb-ft at a 17.3% assumed drivetrain parasitic loss) Here is the mod list:

11.0:1 JE pistons
Crower rods
Block bored .040 over
Polished and lightened crankshaft
All internals balanced
Fresh rebuild last year
Ported and polished cylinder head
Port-matched and extrude honed intake
Custom cams 228 duration 390 lift @ .050 lash
All new valves
Bored and polished throttle body
Injen intake with cai
Greddy header
Greddy exhaust with electric cutout installed after first convertor
Greddy radiator
Underdrive pulleys
Fidanza flywheel
New ACT clutch
New starter
New alternator
New water pump
370cc injectors
300zx fuel pump and filter upgrade
Two 10" Electric fans

The owner, ni*2*ss*4*an*0* at NICO, claims he has about $5,000 in the engine alone. Therefore, we must determine that naturally aspirated horsepower is expensive. However, it is dynoing more than a bone-stock early SR20DET... without any lag at all. This should tell you kids who want massive horsepower with a NA KA that it's simply not going to happen unless you pony up the dough. Expect similar results from your setups and I hope this cleared some things up for some people.

My take on this is that if one were to swap in a smaller, more square engine and make it rev higher, it could make more horsepower than the KA. Of course, who's going to swap a SR20DE in? If I had the dough and the mechanical wherewithal to do such a rare swap, I'd make sure to do stuff such as ITBs, a stand-alone EMS and extreme head work.

What was the point of this post? To show newbies that their NA 240SX won't make tons of power, but then again, that's not the point. We're not drag racers, we're drifters... sideways is all that matters. Learn what you can... I'll update this post with dyno runs with different mods so you all can see their effects.

[mranlet]

KA's in both NA and Turbo can make plenty of power where it's important - through the entire powerband. A lot of people swear by the KA because of it's large displacement and high torque, which is important when you drop rev's mid corner and need to pull yourself out of bog-down.

ITB's and NA will give you ultimate response, but even ITB's and turbo or a well-shaped plennium and turbo will be pretty quick at lower boost levels.

I hope that this doesn't precipitate the age-old "Turbo vs. NA" battle, because they're both good and both have their advantages and should both be taken seriously.

-MR

[GRiDRaceTech]

Well, this thread was simply to show people that the NA KA isn't a horspower monster. However, like MR said, that isn't the point... the point is tractability. More likely than not the 178whp engine is tractable from around 3000rpm all the way up to redline. That healthy dose of torque is more than enough to be quick through the gears and can pull quite hard.

Here's two baseline dyno runs:
This one's from the SCC project car a while back

This one's from the Import Tuner project car

[GRiDRaceTech]

More:
Purple lines are stock, white are stock cams and Jim Wolf ECU, green are Jim Wolf cams and ECU (PS- Thanks to whoever put these up on the net. They are NOT mine nor do I lay claim... if they are yours please tell me so I can acknowledge their ownership)

Next is a cat versus no cat run:

Now with Hotshot headers:

Now with Injen intake:

[nissanguy_24]

Yes... Unfortionately that long stroke on the KA lowers its revolutions. Although it gives you a nice wide powerband you simply can not make alot of power naturally aspirated with out revving high in a small displacement motor. Maybe you can hit 200 or so if you especially design every part to work together and design it to make power at about 7000 rpms its peak, and bump the rev limited to 7500 or so. I still feel theres alot more to learn about these engines, but its going to take more then throwing parts at it. And its not going to be cheap eitherway.

Ultimately what you want for a NA motor is a bored out SR20, or a NA Rb25.. that will give you even more displacement and has a shorter stroke then the KA, but the extra weight from the motor could be a problem. On the plus side NA SRs can be had cheap if you find an importer who will bring them in.

The old saying there is no replacement for displacement is correct however it doesnt consider making power with a long stroke small displacement motor. A NA Sr designed to rev to 9k would be cool, but it wouldnt have all the low end power a KA has. But if you were a good enough driver, and you had Nismo's 4.6 rear end (stock is 4.06 i think) you could keep it in the power band. It would be similar in power to the NA rotarys. So it would be alot like that, having to keep it high in the powerband. And as long as you stay there your okay. Gearing would be important though.

However i think turbo technology is pretty good these days, and i think a small well sized turbo can be superior to Naturally aspirated on these engines. Superior in overall performance. However this is just a theory, ill have to prove it by building an engine that way. Which i plan to do.

[GRiDRaceTech]

With revs, you lose tractability.

I have a few KA-T dyno graphs, but they're for another time and another thread.