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Hi all,
I install a dual carb on my civic a view years ago.
got more power and better fuel mileage.
thanks Dog and this thread for inspiring me to make simple a dual carb.
here is the pict
hey bro..
i see you didn't use the "black box"
did you use auto/ manual choke?

if it was auto choke, did it had rough idle when cold start?
 

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same
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hey bro..
i see you didn't use the "black box"
did you use auto/ manual choke?

if it was auto choke, did it had rough idle when cold start?
Look at his profile. 6 posts in 3 years and he posted this back in April. Don't think your going to get an answer.
 

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Look at his profile. 6 posts in 3 years and he posted this back in April. Don't think your going to get an answer.
woot...
LOL.. I didn't ralize dat :uh:..
trololololol:3dbiggrin:

ok..
back to carb thing..
I had a D13b2 carb engine with the spaghetti vacum hoses
then I convert it it to use the twin carb, and still use the black box

now, I heard that ditching black box will gain about 7 hp or at least a better throttle response.. Is it true?

I had the auto choke one, if the black box missing, will the auto choke will malfunction?

last, read a few pages back, there is a carb with pgm-ecu.
how I know mine is the pgm one?


thx,sorry for the baaaaaaddd english..:D:D
:sign4:
 

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The Wife and the Car
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I read most of this post. And most of the links on the first post.
Somewhere on there. A guy says with carbs you can tune for more power or more Fuell Economy but not both.

I beg to dis-agree.

THe best mileage and power I have achived was with carbs.
The trick is you want to get a carb with a duall buterfly setup.

On my Suzuki Turbo 8 valve head. I could get insane power and insane mileage off 25 Km/LTr on the highway.

This is how you do it. By default. The accell cable only activates the first tiny butterfly.
After that its the engines manifold vacum which opens the larger 2nd buterfly.

Since this is a Turbo. The Vacum actuated 2nd Buterflly is not going to work. So what you do is install a link plate which links the first buterfly to the 2nd. Based on the shape of the link plate you can set it up so
0-50% only the smaller 1st buterfly opens. After that from 50-100% on the first buterfly the second larger Buterfly goes from 0 to 100% open.
My setup was 0-75% only first tiny buterfly opens. Then From 75-100% of the first the 2nd larger Buterfly opens.
Each Buterfly is feed by its own main jet.
So on the Small Buterfly I ran really really lean.
But on the 2nd Buterfly I ran rich.
The Cam plate has a stiff spring. So you know eactlly when your transition from the first to the second happens. When you want mileage just make sure you dont open your throtell more than 75%. When you want power take it past that.

There are huge huge advantages to using linked Buterflys. The advantage is very high velocity of the intake charge. (Same funda as the V-Bost system as used on Yamaha V-Max Bikes).
That little Suzuki carb of mine even handled 28 PSI of boost in a Blow through configuration with no issues. The car ran over 100,000 Kms with me. And now its new owner is still enjoying it.
The only other carb I would recommend over this would be 4 x 32mm Lectron Carbs.
Im pretty sure you cant beat 4x Lectrons on a Honda Build.
 

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I also have a dual carb motor. Been looking for a service manual for it. Mainly for the vacuum routing. Anyone know where I can find one?


Sent from my Autoguide iPhone app
 

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It's a shame this thread (and it's links) went dead...
There isn't as much information floating around about the old dual carbs anymore...
Maybe we need to create a new carb thread?
 

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formerly allnaturalrex
1989 honda crx si
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i too wish the info and links weren't broken. i tend to look for answer on 4GUK • Index page since carbs are really popular over there.
 

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i have a 1990 civic lx 1.5 mfi system.
i swapped my stock engine with a jdm d15b.
my problem is with the distributor. the us models are basic where as the jdm has a vacuum advance diaphragm on it. it has 2 vacuum lines on it and im not sure where to hook them up at.
so my questions are
1)can i hook them up and if so where
2)do i need to swap on my old usdm distributor
3)can i just remove the diaphragm and cover it up with something

im not a big car person so im lost on this. and would rather not swap it out and just make it work.
 

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Hi guys. I know this is an old thread, but m after some info/ideas/help if possible. Im a UK Banger Racing driver, and Im running a 5th gen Civic converted to twin carbs/2 wire dizzy. The vtec is pemanently wired to the ign as the ecu has been binned. The carbs have run fine in the past, but yesterday I was racing at a meet, and the car only had power from 3/4 throttle onwards. It was REALLY struggling at low revs, I had to keep dipping the clutch to get the revs back up... as a result I had a short days racing and a trip to the barrier courtesy of another driver stopped play! I did notice that the fuel filter was dirty, so I guess that could be the prob... or could the carbs just need a good clean? Any ideas as to the prob would be much appreciated!
 

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In regards to ignition timing if I recall we had to modify the distributor to get enough advancement as well as an adjustable cam gear.... Unfortunately the link is dead :( Has anyone had any experience using an ignition timing controller in conjunction with msd? Also if anyone has a good link to the distributor modification i would appreciate it. I know one the ears had to be opened up for more advancement but I forget ugh!
 

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hi guys,

I'm placing some bike carbs on my d14a1.
I just have 1 problem.
The vacuum lines on the dizzy.Is it ok to just fit them to a
vacuum block?Can the car run without?

Grtz from belgium
 

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D-series Janitor
Front Engine Dragste
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hi guys,

I'm placing some bike carbs on my d14a1.
I just have 1 problem.
The vacuum lines on the dizzy.Is it ok to just fit them to a
vacuum block?Can the car run without?

Grtz from belgium
Vacuum is to operate the vacuum advance . . . without vacuum advance your timing will either be locked out or operate solely on springs/RPM.

Not sure what is in the inside of your distributor.
 

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Vacuum is to operate the vacuum advance . . . without vacuum advance your timing will either be locked out or operate solely on springs/RPM.

Not sure what is in the inside of your distributor.
So if i connect the 2 hoses to a vacuum box it would be ok?
Or better to the intake?

Thx for the help
 

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Mrs

Hello to you all

I am writing in this forum to help shed some light on my misbehaving Honda CRX. It is a 1991 with the dual carbs.:wacko:

I have been rebuilding her slowly funds permitting when a few weeks ago had the distributor pinched off my current ride. So suddenly I have no option but to get my Honda purring again as I have no wheels to get the kids to school with.

I have cleaned out the carbs and replaced all the iffy vacuum hoses but she has a problem of rough running on start up and post warm up.

there are quite a few canisters etc between the intake manifold and am not sure what their purposes are.
i would like to check what is going on but do not have the knowledge.

i have noticed that as a new member I cannot access any of the photos so I am lost. What shall I do?

Regards flamelily
 
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