High RPM ka

[RogueGamer]

does anyone have a high rpm redline KA? i would like to do a 9k redline ka but have some trouble getting good info on higher rpm motors.

thanks for the help

[Fla240sx]

bad idea

if ur hell bent on it.. find a cheap SR20DE JDM motor

solid lifter conversion/RockerArmStoppers/BIG CAMS/4-1 header/Intake manifold

thats about the best we got IMHO

KA will still make power though, they have race KA24E's in the 270chp range, they have a lot of crank work done to them I believe... mainly lightening it

we just have too much stroke to rev that high

our KA24E will still make more power then a built civic d16 that revs that high with just bolt ons and maybe a cam........ so take that into consideration.....

I've seen higher CR, Cam'd, D16's put out about 140 to the wheels... thats with every bolt on too

another idea for a Nissan engine with a short stroke is the RB20DE

[RogueGamer]

i know our crank is the thing holding us back on the rpm range. what is the highest we can get the KA to rev to?

i want to add rpm's bc i am turboing mine and dont want to spool till 3k to 3500 for DD reasons but i want more rpms to play with while racing

[Fla240sx]

thats a question no man can answer....

i'd say it balances between longevity.......

but let me tell you one thing

you say daily driver.. then you say high rpm's... that just doesn't go together... the higher the rpm's and the more you take it there, the more stress is put on a lot of things

crank, rods, pistons, accessories, pressure plate, transmission, rear end.....

if you want your turbo to start spooling at 3500, which is kind of low actually... you will have plenty of power in your boost producing RPM rang to have fun with, more so then many other setups... 3500-7000rpm will be a good ride and will pull strong, your rpm's will not drop below 3500 on a good fast shift........ basically u have the ability to be as fast as any other turbo nissan engine or any other KA-t setup

I wouldn't worry about it

on the flip side you could always change gears, I forget the exact number.. maybe its 300zx r200 gears, they are lower like 3.80 I believe compared to the 240sx 4.03?

[RogueGamer]

thanks for the input man it has helped

i also wanted more RPMs b/c i track the car too and i find that if i have just 500 or 1000 RPMs i wouldnt be shifting as much and could pull better times

anyone else have some input to help?

[Fla240sx]

regear it then

especially if u turbo it and have more power

[-RJ-]

Quote »on the flip side you could always change gears, I forget the exact number.. maybe its 300zx r200 gears, they are lower like 3.80 I believe compared to the 240sx 4.03?[/quote]does 3.80 give you more top speed or more acceleration? i forgot

[neverlift]

you guys need to hit the flashy search button. b/c is/was gonna mak some fully balanced ka cranks. IDK whats what with it but a big thread is on here.

that will get you your higher "honda" like revs have you driven a tuned ka~t? you wont need higher revs, with the right turbo.

[RogueGamer]

i know about the crank thread and i keep reading it, thats y i was asking about a high rpm ka, bc i want to know wat else is required.

and no i have not been able to ride in on yet, i am having a hard time finding someone in my area that has one, i know of 3 guys working on it right now and i will be the forth soon but i am the only one who drives auto-X and road course so our setups will be different but the engine setup should not be far off.

my friend has a modifies FD and i must say i love 10k redline...lol

[Fla240sx]

the lower the number the higher the top speed

[neverlift]

i know about the crank thread and i keep reading it, thats y i was asking about a high rpm ka, bc i want to know wat else is required.

and no i have not been able to ride in on yet, i am having a hard time finding someone in my area that has one, i know of 3 guys working on it right now and i will be the forth soon but i am the only one who drives auto-X and road course so our setups will be different but the engine setup should not be far off.

my friend has a modifies FD and i must say i love 10k redline...lol

I dont think with the crank you would make "useable power" that high, I mean you could, but in D/D condition it would be a pita if your peak hp is at 9k or so. The ka makes good trq so you dont need to rev it out that high, just something to allow power to be made after 5500 rpm is why the crank is being designed. every n/a dyno sheet is the same for ka 5k or so and extreme falling off starts. Its from the crank wanting to destroy itself from the crazy harmonics. I'm still waiting for yellow car to come back with results of the b/c stroker kit, makes your ka into an "fj" ish motor, more square piston diam. : stroke ratio with the balanced crank.... should make an easy 200 whp.

[RogueGamer]

i thought it was our cams that stopped us from producing power over 5500 rpm's and i though the crank harmonics were all yacking after 7k rpm

[WWJD]

it's a number of thing... mainly (to me that is) the longer stroke with the half balanced crank make it hard to rev high. there are reasons why the factory put's rev. limiters on car to start with.

[DeXteR]

a good way to start would be with a butchered and balanced crank...



i told darren at fast forward that he should contact the niconauts. i haven't seen him on here, but these guys have been in the dsm world for a while and have a good reputation. http://www.ffwdconnection.com/butchercrank.shtml

the key to high-revs is a balanced rotating assembly and a built valvetrain. removing rotating mass (butchering the crank, lightweight clutch/flywheel, lightweight crank pulley) and reducing drag (lightweight rods/pistons, lightweight pullies) is also a great way to add to your redline; however, it's not going to do much good if your rotating assembly is out of balance. as far as building the valvetrain goes, you need to build your valvetrain (springs, retainers, lifters) that can withstand the higher rpms and stresses.

something else to keep in mind, of course, is that with higher rpms you get higher temperatures. so you'll need to keep things cool. i'd suggest getting a bigger radiator with dual fans and running an external oil cooler setup.

just my $.02

[neverlift]

the head in general dont have the flow for high rpm. So yah its a combo kinda. But the real issues are the crank doesnt physically have the abilty to continue turning without damage. hence rev limiter at 7k. I think power could be made up top but the money involved isnt worth it, I just boosted for under 300 dollars and thats including a q maf and 370 injectors I have yet to install as well as a cheap *** eghey bov. Point is even with a crank at 1300 dollars that will bring your revs up to a " more usable rpm"(pointless with the torq a ka has IMHO), a simple non IC'd turbo job will smoke it. May not be by much but boost is making the stock cranked ka build torq till the normally 5250 and then power is still made thanks to boost.

[DeXteR]

i absolutely agree that a high rpm ka is a waste of time/money. the torque output on the 2.4L is great. the trade-off is that you can't rev the piss out of it like a 1.8L and get high-end power.

torque ftw.

[RogueGamer]

thanks for all the input guys, you all have really helped. I love high rpm but through all the research and your guys input i will just drop some smaller rear end gears in instead.

i do have a question though, what head setup will help me produce power above the 5500 mark?

the whole reason for all of this is i road course all the time and i need to build a block that has hi end power but is built well for DD
Modified by RogueGamer at 12:01 PM 9/12/2007

[WWJD]

that's a tought trade off your asken for. If your tryen' to get your DD to perform on the weekend's, it's gonna suck at DD. you got 2 options pick a middle ground of power to where it's FUN. Or go ball's out and make it track worthy, then sit in traffic or even cruse felling uncomfy as hell.

To get the car runnen' good up top go boost, or reasearch cam options.

builden' a KA for "high" power with a pricie Crank is worth it out this way (to me anyway) cause our state law is really harsh. so, if a cop were to pull me over and make's me pop my hood and see's everything "stock" I really dont got nothen to worry about. Where as with a turbo I might get the car taken' then crushed . If you look at it that way, how would you feel about it. I wish I could do boost and not worry about getten' poped

[DeXteR]

...I might get the car taken' then crushed...

**** california law makers. that's the stupidest thing ever. car enthusiasts should all move.

[WWJD]

LOL I know they are. I would move but everywhere I've been to has the worst weather, wich is why I like the Bay Area. sorry not an opption. I've though of moven' thogh

[RogueGamer]

i am not worried about being comfy, when i refer to DD i am just worried about the motor taking the punishment and getting me home