Building N/A HP

[DMC]

Whats up everyone? I have been reading up on NA motors and how you can get decent numbers with them, and I decided I would like to try to build one. I honestly haven't done enough research yet, but I wanted to make a post so that make some people could answer a few questions to help guide me in the right direction. I have a spare ka24det and a disassembled sr20det in my garage. I read the post up here no about the NA sr and have read that srs na can make alot of hp and rev pretty high(obviously higher than the ka). People also said that the ka would be more torquey but not have as smooth a powerband. I think I would prefer the sr if it can rev smoother and higher than the ka, but how hard would it be to build a NA sr out of a turbo sr. The rods I know I can keep, I would get some high comp pistons. How high compression do people go for NA motors? I am trying to make a set of individual throttle bodies along with a custom intake tube(or whatever the word would be) which is very difficult if you cannot weld! I saw the very long argument about sizes of the throttle bodies, how does this effect the motors power band and power output? The ones I am trying to use are 45mm. I would put lots of work into the head, P&P, valve job, new valves, camshafts.
I also read that the KA ecu works on the NA sr, would this work for the sr I am trying to use? Also why do people need larger injectors for NA motors?


Ok sorry thats me rambling....

Cliffnotes
I want to build a NA motor.

How difficult would it be to do with an SR20DET?
How does Throttle body size of individual throttle bodies effect the engine?
What type of compression do people run on high output NA motors?
Does a KA ecu work for the na sr and will it work for a turbo motor turned NA?
Why are larger injectors used, do stock injectors max out that easily when the motor starts flowing better?

[theicecreamdan]

GTi-r throttle bodies are easily modified to fit on the rwd head.
hotshot headers can be modified to fit the SR head.
DET head flows good for NA power, cams are plentiful.
up the compression and you'll be a happy camper.

if you are serious about it, you can build a KA motor that will rev plenty high, Nissan race trucks that use KAs see around 11,000+ RPM when they are in the air. and put out close to 300whp and a little less torque than that.

[infinitexsound]

either or are great motors.. but id rather have the torque then the high rev sometimes...

whats the purpose of the motor?

[DMC]

purpose of the car is just to have a fun car to drive around town, maybe some autox, but For cheap. For me I honestly think i enjoy more building the engine and working on it and just seeing the car start then i do actually having a fast car.

[theicecreamdan]

NA horsepower is not cheap.

[sideview_180sx]

do a search for NA KA

[TurboB15sentra]

NA horsepower is not cheap.

Sure it is... drop a VQ35 in.. ;)

Travis

[!Zar!]

NA horsepower is not cheap.
I second that. But why do you want to use a 2.0 when you could go with a ka and 2.4? IMO Ka's are better for na power. Just look at the dime guys with their ITB setups and such. They are swapping IN ka's. I find it a bit ironic.

[ALTRNTV]

Sure it is... drop a VQ35 in.. ;)

Travis

The VQ alone already costs alot...

[that180guy]

I second that. But why do you want to use a 2.0 when you could go with a ka and 2.4? IMO Ka's are better for na power. Just look at the dime guys with their ITB setups and such. They are swapping IN ka's. I find it a bit ironic.

dime guys swap in ka's cuz theyre better then the puny L series they have. :ghey:
and carb'ed sohc frankenstien motors are..well a datsun specialty

na DOES NOT equal cheap
KA OR SR...if you do it the right way. VQs dont count cuz their cheating :P
and remember, proper tuning and timing is a must AND dont forget fuel octane.

[TurboB15sentra]

The VQ alone already costs alot...

Nah.. you can scoop up Maxima/Altima VQ's for under a grand all day long.. www.car-part.com

Headers, and plenum, and you're making almost the same power as the 350z VQ35.

Travis

[infinitexsound]

here we go again........with this dispute....

we should do a contest of who can make the reasonable amount of horsepower in NA with so so dollars... using the KA....

[DMC]

well i realize that na isnt going to be cheap cheap but i mean im not planning on building a race motor, just something thats fun to drive and experiment with. if anyone is going to say go turbo, i am turboing the engine that is in the car right now. so i will probably rebuild the ka for turbo and build the sr for NA. I jsut gotta do alot more research.

I can see where headwork would cost alot, but other than the falling what else can be done to improve horsepower output?

Port and polish
valve job
new camshafts
new valves
new valvesprings
Intake and exhaust
Lightened everything
High compression pistons
ITBS

tuning ofcourse

[infinitexsound]

knife edging and crank scrapers helps alot .......

[sideview_180sx]

if you want to build an NA SR, just order an s14 sr20de. those sell for very cheap.

[wootwoot]

or you can build the motor that comes in the car stock =)

[TurboB15sentra]

here we go again........with this dispute....

we should do a contest of who can make the reasonable amount of horsepower in NA with so so dollars... using the KA....

Not really a "dispute", but more like personal preference.. and debate.

Travis

[that180guy]

dont forget balancing and strenghten everything.

s14 sr's with the vtc are useless because youd want big cams which would disable it. extra 3-400 bucks...worthless imho.
best bet with na sr is to use a det motorset and rebuild, because the de has no piston oil squirters. NA sr's with high compression have problems with heat and pinging. sr blocks arent as efficent as lets say a honda block with the heat disappation, the det block would help becuase the squirters help keep cool.
fyi, using sr16ve pistons would yeild around 12:1 or 11:5:1 i think...some one correct me.

[DMC]

well as for which sr to buy, i already have a redtop SR20DET disassembled in my garage. Knife edging and balancing will help it rev higher, but how high do na motors make power to? actually could someone describe what an na power curve is like. I know turbo is week that just goes up as the turbo spools, but then dont turbo motors start losing power up top?

[Jonnie Fraz]

Toda has a 43mm set up, and those are good for at least 400hp. I want to see somebody hook one of these systems up.
http://img.photobucket.com/albums/v635/Fraz-Man-One/Redline-ITB.jpgId give it a shot, but I have not got a spare $2600 (to start) Laying around.
"Speed costs money... How fast can you afford to go?

[wootwoot]

Just scrap this entire Nissan high hp inline4 thing. Put an f20c in the 240 and then modify the f outta it. First person to say it has no torque looses a testicle because it makes more than a stock ka.

[that180guy]

well as for which sr to buy, i already have a redtop SR20DET disassembled in my garage. Knife edging and balancing will help it rev higher, but how high do na motors make power to? actually could someone describe what an na power curve is like. I know turbo is week that just goes up as the turbo spools, but then dont turbo motors start losing power up top?

depending on the route you go, your curve should be vary. but generally, if you shoot for ultimate na power, your band...would be...i guess.....exponentially linear. maximum power would be found at the top end. kinda lika turbo setup, but no lag..just a gradual increase in power. lets say if u had 12:1 compression and 280 deg cams, lets say yould net 200hp, ur 200 hp would be at 6500rpm. throttle response.

turbos loose power at high rpms because they loose efficency ie; too much heat, not designed to spin that fast. NA motors, it all depends on how high the motor itself can rev, and how much air and fuel it can effiecently burn.
hence forth, the gigantor cams that they use to gulp as much air as possibe. higher revs to gulp maximum air faster, and higher compresion to produce a greater explosion with more kinetic energy = more hp.

high much horsepower?
i got a friend who works with a scca prorace team that runs a fully built na kade that makes 310whp.
european guys that do the primeria( ser or g20 in us) cup run na sr20s that make 300sum odd hp also.
(understand these are all out race motors)

[DMC]

How can you meter airflow if your are just running velocity stacks? If the answer is a MAP sensor could someone explain how that works?

[infinitexsound]

http://www.twminduction.com/faq/faq-FR.htmlhttp://www.twminduction.com/faq/images/fuel_inj_system.jpg

[DMC]

I appreciate it, but maybe im looking at it wrong because I still don't understand how airflow is measured.

[atom]

Physics 101............for a given intake air temperature and pressure you can derive the volume of air.

[allmotorKA]

Physics 101............for a given intake air temperature and pressure you can derive the volume of air.

Don't forget engine RPM...you can have the same intake manifold pressure but at different RPMs. The MAP based fuel system doesn't measure air flow...it measures manifold pressure and RPM and looks at the fuel table to figure how much fuel to deliver. If you change the efficiency of the engine by going with a different cam or larger intake valves then you have to input new values in the fuel table to compensate. Tuning is done with a wideband O2 sensor to determine fuel vs MAP values at various RPMs.

[that180guy]

^^ wheres devious ka at? lol

[DMC]

OK guys I feel real dumb so if you can just bare with me! The one thing in school im actually good at is physics. but this i do not comprehend! The air is moving through the velocity stack, how does this create pressure? Could someone explain it to me in stupid person terms? or if someone wants a challenge my AIM name is DMCS14 thanks alot.

So does the engine not measure how much air is going in, instead it takes the rpm into account and the throttle position and "guesses" how much is being taken in?

[jspecusa]

we have research and spoke to Tomei about building a N/A SR.
it's about $6,000 just to build one to 250hp at the crank at our cost.
anything is possible just matter of the question "is it worth it?"
320hp n/a sr in japan are 1. not streetable 2. don't last long(just like in real racing they rebuild or swap out motor after each race). 3. only for people who's back with unlimited budget.
just talk to those honda heads in other forums, they would rather drop in a K20/24A motor and mod it for N/A hp then spend the money buidling a B16/18/20 motor.
cheers,

sam

[Mirage]

I think someone needs to find a definitive way to put a sr20ve head on a rwd de block. FWD guys with sr20ve's with sr16ve n1 cams and bolt ons are getting well over 180 whp

[DMC]

Is the v for the vtc, like the s15 sr?

[wootwoot]

I believe the neo's have more then just VariableTimingCam but havent found much information about all the tricky stuff they have

[SoSideways]

The NEO VVT heads are basically the Nissan version of the VTEC.

The head consists of 2 oiling channels, which looks like a long metal rod, but is hollow for the oil to flow through once the solenoids activate. The rocker arms are slipped over these rods (1 rod per bank of valves).

When the solenoid activates, oil flows through those channels and goes into the rocker arms via little oiling holes on the bottom of the rocker arms, and pushes the middle "big cam follower" into the cams, thus making contact and voila, you're running on the big cam profile now, which is longer duration and higher lift.

This happens on both sides.

There are a few people already doing the VE head swap on RWD SR20DE blocks and such into the S-chasis. It isn't as hard as everyone thinks.

You basically have to drill and tap the block between the 3rd and 4th cylinder on the intake side into the oil galley, and put a fitting on there for the oil for the solenoids. Then you weld up the hole on the back of the block for the oil return on the DE block, and the hole on the bottom of the head for the oil feed.

If you have a later style DE block that HAS the extra aluminum between cyl 3 and 4 on the intake side then you don't have to drill and tap the block, and everything will work like stock/OEM.

You'll have to use a low profile CAS like that from a 20V motor or someone said an MR-2 CAS. That way it'll clear the firewall.

The solenoids were rumored to be able to be taken apart and the only part you'll actually need to put on the back of the head should clear the firewall as well, but it is not substantiated yet as I don't think anyone has gotten that far yet. If you don't go that route, you can always make some sort of plate to block off the back of the head, put a couple of fittings on there, and run those solenoids from a remote location.

There are a ton of info on the www.sr20forum.com forums. They have 5 pictures showing exactly how the VE heads work. I did not link those pictures here because I am not even a member there, I wouldn't want to steal their bandwidth and not give credits and what not, so I might as well just refer you guys to go over there and read up on it.

[Mirage]

looks like more people have done it since the last time I looked into it. I dont check the 've forum that much anymore since I dont have a se-r anymore.