what engines have dual butterfly? single?

from what i thought, its h22 that has dual only
doesnt a b18c have single? isnt that why you can use a chippedp28 with a b18??

just curious if i use my p28 from my d16
ANY info would be appreciated
thanks

 

Courtesy of Katman

 

I guess the purpose of these is to keep low engine speed(RPM) torque up them when the engine gets to a higher RPM they open to increase flow? I thought that was what the Vtec was for?

 

it adds to the effect

 

"I bet Erick's Racing is still running theirs in their 10 second coupe" J/K hehe

 

Among hondas (that i'm familiar with) the B18C1 and the H23A prelude type S motors have it. I don't know about the newer K series. Similar systems are used by Porsche, BMW, and Toyota among others. Tried and true air flow mojo.

Mike

 

The 1984-85 model Mazda RX-7 GSL-SE has butterflies that work in the same principial. THe engine has 6 ports, 4 that mork most of the time and the other 2 open up later in the power band. The new Mazda RX-8 has a system that is similar that opens up perephial(sp?) ports at higher rpm and keeps them closed at lower RPM And idle. That is how the rotary met US low emissions standards...FYI

 

the ecu determines when the 2ndarys open? or is it a vacuum soleniod?
cuz if its a soleniod then i understand......
if not how is it that you can use a p28 for a gsr engine?

 

bontke its actualy to keep the air flow at a high speed to keep a good mixture of A/F once it gets into the combustion chambers

if it was just one giant opening, low rpm airflow would be slow -weak mixture of air/fuel

 

also, what ecu does a 95 b18c use? p72? what about 96-00?

 

vacuum opens the secondaries on gsr mani. With the secondaries removed (and their shaft also), it becomes a high rpm mani. We ran 9.40 @ 156mph with gsr mani (no butterflies). Going to JG Edelbrock to see if it will work better.

 

FYI other year rx7's have it too (not sure which ones, i thought it was all NA 13B's)
my buddy's 91 has it.its not a gsl-se

 

First gen RX-7's (79-85) differ from sendond gens. The only first gen model that had the extra butterflies was the GSL-SE. I don't believe that the second gens (86-91) turbo or NA had any extra butterflies, allthough I could be wrong because I have only dealt with the turbo 2nd gens. Third gens were only turbo and the only extra set of butterflies were there to keep the engine air flow down until the engine was warm. After the engine was warm the were alwys open.

 

I have mine on my GSR still, I have an ITR block and the TQ is great.
Have yet to completely break in and dyno. I am estimating over 120
at 5250 SAE corrected, all else stock

 

I had my butterfly's out for my 12.81 (read signature, NHRA Altutdue correction = 11.87) w/ stock GS-R intake. I've since replaced it w/ a Victor X, and as far as drag racing is concerned, it will be a better IMANF. A lot of top-end power is added, but it would be beneficial to increase the red line to gain full benefit. I noticed when I ran the GS-R IMANF w/ the butterflies in it, there was a HUGE power jump when the vac. solenoid opened 'em up at 5800rpm. And so I took them out, and lost power when VTEC was off.

Also, on a side note, Honda's Velocity magazine refers to the GS-R manifold system as "VVIS" or Variable Volume Induction System.

 

84-85 GSL-SE Rx7's and 86-91 NA rx7's had F.I. 13b motors with a 6port config. This was for smoother power delivery and could be tuned for better fuel efficiency. As stated, the 2nd two ports opened under harder throttle conditions. The turbo 86-91 13b's (13bt), due to the nature of their configuration, were 4 port.


[Modified by RotaryBzzz, 2:21 PM 8/23/2002]

 

thanks!!!!! i feel smarter now

 

Honda JDM/US H22A series (not sure about H23 though) & US/JDM B18C (SiR/SiR-G/GSR) engines both use the dual-butterfly intake manifolds. Almost every non H22 and B18C/C1 uses a single-butterfly intake manifold.

All 94+ Integra GSR's use a P72 ecu, which controls the 2ndary butterflies. You can actually use a reprogrammed P28 on a dual butterfly engine as long as the vtec is set an optimal point (around 5200-5400rpm somewhere); although you still risk losing torque since the P28 renders the 2ndary butterflies useless (leaves them wide open all the time).

You can upgrade to a Skunk2 manifold for P72/GSR head and eliminate any worrys about the 2ndary butterflies...

 

I Love rotarys, I didn't know that the NA 2nd gens still had port acturtors. But I was a turbo rotary man. Now if i could just get it to go in my civic....The newer BMW's are supposed to use variable valves to control the air entering the engine. No throttle body. That will be a big jump in the auto industry. Imagine increasing your cam lift and duration to what ever you want with the control of a computer. You can have the low end torque and have the cam really open up at top end for power.