Well, like the title says...I've got a minor problem. My B20B feels increasingly good from 0k to 5k but right at 5k...the power output seems to drop off. It almost feels like it leans out. From 0 to 5k...i hear a loud groul from the exhaust and then after that...all i can mostly hear is my intake as if it's not getting enough fuel and too much air? I know it's definitely not running rich and it's burning all the fuel it's receiving. I've had my exhaust system done a week ago and normally by now, the muffler would be noticeably black on the inside of it....like all my friends' cars. Even a stock car will do that...but me...nope. My muffler is still almost chrome on the inside...which scares me. I don't think i'm getting the fuel i need to in my top end.
I mean, has anyone else ever experienced this problem? I can take B16 crx's off the line (and im shifting at 5k rpm) until they hit the beginning of third gear. I wish i had a better top end so it would be a good race but it's pissing me off....cuz i have this great power and then a great falloff in power.
Is that just what i should expect from a B20?
If so, what can i do for more top end power? I currently have an AEM intake and 2.5 catback. I got the dcsports 4-2-1 on its way. I was thinking maybe some cams? or even just drop the ls cams in there (is there a difference?)
If i'm running lean, what can i do to get more fuel? I was thinking of an S-AFC w/ tuning...any other opinions?

Here's the setup:
88 crx
B20b
y1 sir tranny
OBD0
running all 91 teg stuff including OBD0 PR4 ecu
No check engine lights

 

Put a vtec head on it or turbo it.

 

b20's are built for CRVs. They have torque to move the heavier vehicle. On top end they kinda run outta steam.

The b16a has little torque, but is a terror on the topend.

They aren't great to compare, but work well combined....

 

if your not looking to swap a whole head a P&P job never hurts i can swear i saw cams for the B20b/z out they would help some too. but a b16 head works very well

 

are you even sure you are running lean???
you should get a wideband air/ruel gauge to find out
and if you are there is most likely a problem with the timing, maybe to far advanced???

since i dont have a honda i wouldnt know much about them but those are a few things you should check

also is you o2 sensor in good condition?

its usually just simple things like that, that will effect your top end performence

 

if u think ur running lean at the end then get yourself a fuel rail and pressure regulator

 

so what should i get?
S-AFC w/tuning
fuel rail w/FPR

I am buying the B&M fuel pressure gauge today to see what i'm running for pressure...i have a feeling it is going to be extremely low.

 

turbo edit that sucker so u can CUSTOM tune like a hondata.

also.. slap a vtec head on there and you'll get that top end pull for sure

 

well like they said b20 are for more heavier cars so itll run out of steam at top end if u want a good engine get a b18 the integra motor itll easiley drop u from stock high 16's to mid 13's or high 13's

 

damn wheres my thread about building ls - b20 all motors....

well with a pr4 you probably are leaning out on the top end.
b20 will need more fuel.

heres what i'd do for a decent b16 *** woop'n b20 no vtec
fpr !
Good header
2.5 exhaust
crower 62403 at least!!! or 62404!
upgrade valvetrain
60mm or larger tb
skunk2 IM (b20 one sucks ballz)
chipped pr4 to raise redline to 8,000rpms
cam gears
ACF or better
stock compression pistons (9.??)
on a healty motor you should be able to make about 150-165whp...
hehe b16 (most i-h-e) only dyno at freaken 138-145ish...

let me know if you need any help

 

you have a b20, its all torque...top end power wasnt thought of for this motor, cause its purpose didnt call for it. Your best bet is to either build the stock head and get some descent cams and ecu program and or rework the whole motor with a vtec head. When I say rework the whole motor I mean from top to bottom...no need in going ls/vtec and not having a bottom end that can go the distance with the head....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNDER PRESSURE &raquo;</TD></TR><TR><TD CLASS="quote">Put a vtec head on it </TD></TR></TABLE>

 

your running a 1.8 liter motor ecu on 2 liters

 

i just bought the command flo fpr.
I also did some research and found out that the obd0 90-91 teg Intake manifold is highly restrictive...which is what im using. I'm going to swap to the 94+ one cuz i got two of them laying in my garage...i'll swap that out when i wake up tomorrow. I am also running the 90-91 teg exhaust manifold which is the worst b-series E.M. ever made so my next investment will be a nice 4-2-1. i also ordered the b&m command flo fpr and pressure gauge.

my plans for next are the 4-2-1 header, skunk2 intake mani., s-afc, crower cams and aem gears

 

While there's good advice in the thread, particularly Charlie Moua, you don't know what your particular problem is.
You can throw money/parts at it and maybe get lucky but you're better off going for some dyno time with wideband o2 sensor. 1/2 an hour or three pulls should be sufficient to start.
This will tell you if air-to-fuel is an issue and give you a baseline for future tuning.