370cc in a KA N/A.....

[STEEZxIT]

Well ive been reading and reading alot. And from my understanding 370cc will act funny, let alone the engine if slapped on a DOHC KA w/o proper tuning, especially if no turbo's are involved.

From my experience, ive owned a S13 SR N/A, and those come in with 270cc, but when i slapped on the 370cc and reset the ECU, it started just fine and from what i noticed, ran better with bigger injectors.

Why might i want to put bigger injectors in a stock KA you might ask? Im planning to build an all motor, not so much for internals just yet, but cams, header, valve job. P&P head.etc..Not in the process just yet but im still trying to gather up more info on this build.

[Sileighty_85]

You need proper tuning to run SR 370cc injectors in a KA

All S13 SR20DET's come with 370cc Injectors

[nismoman]

Um no. S13 sr's come with 370's. Maybe you mis typed and unless you end up putting down more than 200 hp you really aren't gonna need 370's. I assure you you can't just slap in bigger injectors and have the ka run great without some kind of tune. That's 37% more fuel!!

Oops you beat me to it

[jacobs13]

Yeah ive had 370s on an n/a ka and it ran like shit bogged alot and backfired because it was way too much fuel

[Nick_04K]

Umm yeah...exactly what those intelligent zilvians said .
However, im sure it would be much appreciated and praised if you posted a VERY detailed build thread on your NA build. If your really going to drop the coin, you might as well do all the usual bolt on's, SOHC pistons, ported and polished head, cams with valves and retainers to run to 7200....And get a hell of a tuner to work some magic. I cant imagine you would make under 200whp with all that on 93 or up/or e85 or some other bull shit.

DO IT!!

[STEEZxIT]

Originally Posted by Sileighty_85

You need proper tuning to run SR 370cc injectors in a KA

All S13 SR20DET's come with 370cc Injectors

i mightve miss a detail on here..

My S13 SR was the N/A version. And that motor came with the 270cc injectors...but when i put the 370cc, it ran better.

thats why this question surfaced is that, what differs from both motors when both had 270cc to begin with. And me putting 370cc.. So i read it boggs and start up all funky.

anyways. heres my plan before jumping the gun

Intake
TB and Intake mani spacer
port match manifold
P&P head
cam, valve angle job
BC piston, eagle rods
hotshot header

etc...pretty much anything a regular joe can do to a motor.

[4-20sx]

Well when I ran 370cc on my ka n/a I used a SAFCII to turn down the fuel. I think I did -27% or was it 37%? I don't remeber.

Having the 370cc in, It did run like shit!!!
I do think with the n/a build your trying to do with the 370cc and proper tune. You should put down some decent power.

[psychos13]

I wanna do the same but idk bout injector size as well

[theboy]

if your going to put cams and head work in a ka, you mite as well do internals as well, its not that much more since you your stripping it down to a short block anyways. DO it rite the first time, and you might as well turbo it too. My last n/a motor was nice, but was a boat anchor compared to my ka-t

[project-D180]

sohc pistons my fooot, your bound to ben your valves with bigger cams.u need forged with valve reliefs.the 370 injectors shouldnt flood your motor if u reset the ecu and it relearns itself.. your ecu should adjust your fuel maps for those injectors so it doesnt flood itself just like your maf sensor,you can use a (maxima maf)n60 maf on a stock or mildly modified motor if reset your ecu wire it up correctly

[turbonola]

Originally Posted by STEEZxIT

i mightve miss a detail on here..

My S13 SR was the N/A version. And that motor came with the 270cc injectors...but when i put the 370cc, it ran better.

thats why this question surfaced is that, what differs from both motors when both had 270cc to begin with. And me putting 370cc.. So i read it boggs and start up all funky.

anyways. heres my plan before jumping the gun

Intake
TB and Intake mani spacer
port match manifold
P&P head
cam, valve angle job
BC piston, eagle rods
hotshot header

etc...pretty much anything a regular joe can do to a motor.

nice list, you should do itb's and megasquirt instead of a bigger tb or p&p tb. megasquirt cost just as much as a tuned ecu. plus you'll be able to control all parameters yourself.

[nismoman]

Originally Posted by project-D180

sohc pistons my fooot, your bound to ben your valves with bigger cams.u need forged with valve reliefs.the 370 injectors shouldnt flood your motor if u reset the ecu and it relearns itself.. your ecu should adjust your fuel maps for those injectors so it doesnt flood itself just like your maf sensor,you can use a (maxima maf)n60 maf on a stock or mildly modified motor if reset your ecu wire it up correctly

there is no way in hell the ecu can relearn the maps for bigger injectors. All the maps a programmed in assuming that the injectors are a certain size. It doesnt know when you change them to bigger! If this was the case you would never need tuning.

[modulation]

If you put 370cc injectors in a stock ka24de you'll run way too rich.
You'll have problems starting the car (flooding it during starts.)

It'll also run slower.. The stock ka24de runs rich as hell already for safety at high-rpms, I'm talking 11:1 AFR's. Running larger injectors would only cause you to run even richer.

[Nick_04K]

Why do you want to build it NA anyways? Class rules? Smog? What is it..?
If your honestly staying NA with no intent to ever go turbo, I think that aftermarket pistons and rods are a huge waste of money. Whats the purpose unless your going to bore it as much as you can?..Which still leaves NO need for expensive rods. 370cc is only a good idea if your doing a good amount of mods and having it tuned properly...Otherwise it is POINTLESS!

[4-20sx]

Originally Posted by nismoman

there is no way in hell the ecu can relearn the maps for bigger injectors. All the maps a programmed in assuming that the injectors are a certain size. It doesnt know when you change them to bigger! If this was the case you would never need tuning.

exactly... Haha