curious to know if any of you have my problem.....
i have a swapped jdm b18c1....with out the dual stage (secondary butterfly) hooked up becuase i was going to swap it out for a skunk mani ....but just havent gotten around to it
people are saying, that since the secondary is not hooked up, its makes the low end run rich. THe access fuel gets burnt through the exhaust therefore resulting in some sort of occasional smoke. also resulting in low end running like crap.
does this sound logical to anyone?

 

ttt

 

I would think it would make the top end run rich because the ECU expects that extra induction of air at like 58k rpm, therefore sending more fuel. But since its not hooked up, those plenums are opened the whole time. The ECU doesnt know that, and it's still gunna send that extra fuel. Idk if that made sense

 

at worst your car will run a lil lean because you are actually getting more air in because you don't have the smaller primaries. so as soon as you gun it it will spit out the same amount of fuel as it would while its running the smaller primaries until the secondaries opens up. when the time for the secondary to open up then you should be good to go. but you would run a little lean till then i think.

 

thanks for the info guys.,...anyone else want to put in their 2 cents?

 

anyother opinions?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LODOSS &raquo;</TD></TR><TR><TD CLASS="quote">at worst your car will run a lil lean because you are actually getting more air in because you don't have the smaller primaries. so as soon as you gun it it will spit out the same amount of fuel as it would while its running the smaller primaries until the secondaries opens up. when the time for the secondary to open up then you should be good to go. but you would run a little lean till then i think. </TD></TR></TABLE>
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I disagree with this. I have a p28 chipped ecu (which changes to just 1 of the runners) w/ a gsr manifold and i run rich and sometimes produce smoke because of it.

 

The reason why your producing smoke is cause your fuel maps arnt stock. As for the runner being open, You would run a tad bit lean as stated above. Reason is that your computer is programed to run with 4 runners at lower rpms and there is 8. Since you keep them open at lower rpm your gettin more air with all 8 runners open in lower rpms. Also to the person before, Even though your running a chipped p28 your secondaries could be closes wish causes your to blow smoke. I ran a few chipped p28's on gsr's and h22 and the secondaries would actually still be closed for some reason. But they wont open up since there not programed to. I solved this by disconnecting the vacumm to it. Have someone start your car as your look at the butterflies and see if theres any movement. If the linkage is shifted up this means its closed and if its down its open.

 

I converted mine from OBD II &gt; Obd I and i have a p72. I have an HP racing intake manifold and on the dyno it runs rich at 6 grand because of the butterflys not being there , so the computer is sending more fuel at 6 grand for the butterflys to open and get more air. But since the butterflys are not there to open it runs rich at 6 grand.

 

these replies are sure helping....but i guess for the most part alot of mixed thoughts..
thanks again.....
more opinions are welcome as they come...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by allMotor93Hatch &raquo;</TD></TR><TR><TD CLASS="quote"> I ran a few chipped p28's on gsr's and h22 and the secondaries would actually still be closed for some reason. But they wont open up since there not programed to. I solved this by disconnecting the vacumm to it. </TD></TR></TABLE>

If you are using any other ECU other than a P72/P13 then the secondary butterflies remain open ALL the time, the dont take a signal to open, they take a signal from the P72 ECU to remain closed till 5800rpm and since P30/P28 ECUs dont have this input sensor the butterflies will remain open at all times. I was temporarily using a chipped P30 with my B18C and the car bogged at low RPMs and didnt come alive till over 5500rpm as the secondary runners were open from start off....

 

i'm experiencing low end bogging as well.. its ever so slight, but i can feel it.
I understand what your saying about the ecu and secondaries. but would that still produce smoke at low rpms?

 

If the engine is 'labouring' at low revs (ie...having to work harder to get the car moving) then it is possible that you may get a little smoke, especially on an engine with high mileage, the rings may be slightly worn aloowing oil into the cylinders under load....

 

you know, an MSD rpm switch can be used to run your secondaries very easily.

A friend of mine has had good performance gains by adjusting when his secondaries open up.

 

I would not try to rig something like that. just wait until u get the manifold, and believe me its worth it.