For those of you who run higher than stock compression in your KA, this question is for you. Do you run larger injectors? Im running flat top pistons ( for those of you that visit my build thread you know how I found this out the hard way) and know at a minimum I now need 93 octane. But what about a injectors? Should I upsize them too? Was thinking of an SR injector. What if I boost it? Still larger again I would imagine. Talk to me.

 

Your probably fine with stock injectors up to about 190hp at the crank...

but Id guess your tuner could tell you this? Or what are you using for engine management?

 

I guess the changes lead to that question as well. Does the high compression mandate a stand alone or rom tune? I "discovered" my engine had flat tops after doing aa teart down becausethe I popping my head gasket...im sure the fact I thought it was a stock KA that I bought for cheap and was running 87 octane contributed to that happening. As of now I simply run 93 octane gas, without any engine management mods.

 

I'd rock 370cc's just to be safe, get it ROM tuned and call it a day. If you want to turbo in the future you'll need atleast 550's anyway.

 

Could the need of a ROM tune explain why when i drop a timing light on the engine the ECU appears to be pulling some crazy crap on it presumably to avoid knock?

 

in timing set mode (tps disconnected before start) you should be able to set it regardless. Unplug the KS if you think its affecting it. See what happens. KAs, Ive noticed, are one of the easiest engines to actually hear knock. It sounds like dropping a BB into a coffee can.

 

Ill give that try. I have a separate fuel rail I can prep drop in...just to check if there would be a noticeably better in operationally.

 

Its not gonna get better than stock injectors man....lol

driveability usually only goes one way....down

As far as fuel mapping is concerned, the KA tune is prettty safe for hi comp. Stock ECU my car will go to 12.5:1 @ ~2500rpms then richen up to 11.5 by 3500ish. Hot days Id see 11.2:1 at redline... Its actually not even a bad fuel map for boost. lol

Timing is the issue ... KA timing curve sucks, especially when you add a header, intake, cams...etc. All you can do is run 93 and slowly turn the timing up till you hear knock at peak torque, then back it off.

Or get it tuned..chip burner, etc.



btw...you remember me? I called you awhile back about the title for the black coupe shell with red vert doors..

 

Dude! Yeah, I remember. I hope you got that worked out. What you described with the timing is exactly what I've had to do. Im sure that running zero emissions doesn't help matters. This engine has been a pain since I bought it. I refuse to let it win though...lol.

 

lol yeah thanks I got the title for it the next day.

About the emissions...I just took everything of my s13 ...it runs pretty good, only thing I would leave is the swirl control valve and solenoid. If you look at the factory vacuum schematic, the fuel pressure regulator takes its vacuum signal from the swirl control valve solenoid. Im pretty sure it uses it to adjust fuel pressure as well as open and close the SCVs...I had a noticeable drop in midrange TQ when I took that off..