I have a stock bottomend jdm b20b. I have stock jdm 1st gen b16a head w/ stock cams & cam gears +2 I & -1 E. I have an ITR IM & GSR t-body. JDM ITR Header. Custom exhaust = 2.5" cat & 2.33 ID cat back. Iceman intake for sohc. That pretty much does it for the setup. Also, running 93 octane.

I have noticed w/ the 240 cc injectors that above 7000 rpms... the engine needs a lot more fuel than the 240's can give. The injectors are @ 85% @ 7000. The engine starts to lean out @ 7100 rpms & then by 7700 rpms, the injectors are @ 98-100%!!! My fuel cut is 8200. My timing is set to 14 degrees.

There is a noticeable feel @ 7100 rpms. You can feel the engine just slowly gaining instead of the OMG that you were getting before. It feels like you hit a brick wall @ 7500-7600 rpms. Its cuz the injector is wide open & cant give you any more fuel, therefore, you aint gaining much more power.

I am switching to a bigger injector... but due to time constraints & the other car Im working on, I wont be able to get the rest of the info to you until later.

The info I need is what injectors are people using that have about my basic setup. Im thinking if I go w/ some 5th gen Ludes (290 cc) that they may be too small, also. If I go w/ the JDM obd1 lude injectors (345 cc) that they may be too big & then I have to cope w/ the hassle of also installing a resistor pack. I hope someone can give me some ballpark figures so I dont have to waste too much more valuable time & $$$ on some injectors.

Thank you for the info about the injectors if someone knows & I hope someone learned that 240 cc injectors are too small if you want to rev over 7k rpms on a stock b20/vtec. We were reading duty cycle on a Hondata & also an AEM EMS FYI.

Pete


[Modified by pest, 4:35 AM 12/28/2002]

 

Well thats good info to know. I am using 240's on my built crvtec and according to my NASA engineered Autometer A/F guage there are not any lean spots. I also have a Walbro 255 h/o pump and the fuel pressure is set to 60psi. I rev to 8k (pulling hard the whole way) and the guage is usually on the last bar of the stoich and the first bar of the rich. I have thought about getting a wide band setup for the car and runnin a afc hack, but it seems to be fine for now.

 

Have you ever dyno'ed your car??? I would like to see what is going on w/ your injector duty cycle, also.

Pete

 

I have the same set-up you have. I dynoed my car a few months ago the engine put out 174whp. My air fuel ratio graph did show I did have lean spots on certain rpm range. I later change the stock fuel pump to 255 lph fuel pump & set my fuel pressure to 43psi.

 

310/255

 

No, I havent dynoed it yet. I am waiting to put on my digital 6 and DC header then I'll get it dynoed. As long as my foot is on the floor the a/f seems to be ok all the way to at least 8k and some times beyond.

 

rc 310cc injectors are very nice for almost every street setup depending on comp ratio of course. they are no to expensive and are readilly available. if you are running an obd0 ecu on your crx then you will need 320cc injectors because of the difference between peak and hold injectors and saturated injetors.

 

my set up is 'stocker' than yours, only have air filter, cam gears and lightened flywheel

i dynoed and teh A/Fs were fine, i cant host it but if you cut and paste this link - it is there - http://www.geocities.com/b20bvtecpre...ynamicssml.jpg

if you arnt going to make too many more modifications and have a saturated set-up, use the 290cc's.

that would make sense.

hth,

t..


[Modified by tinkerbell, 9:40 AM 12/30/2002]

 

hey pest - what sort of fule pressure regulator are you using?!?!

my FP is set to 51psi with the B&M one...

t..

 

i ran rc 310cc's and had no problems

 

310cc
255lph fuel pump

and psi @ 40-50

 

Hey tinkerbell, are you runnin 240's or 290's? I might need to upgrade...it'll give me an excuse to do somethin else on my car.

 

nah, 240's

teh dyno shop guys said the 240's will be OK till 60psi, i am at 51psi right now, i am making 98kw (135HP) = about 160 USA WHP

probly will go up a few psi after type R cams go in... (cant wait!!!)

plus im getting an V-AFC for cheap, so i am not concerned about injectors...

it is the damn PCV system i am still messing with, just made my own morosso style catch can from an old aluminium Honda air-conditioning canister... (write up on here soon as is finish it...)

HTH,

t..