TeamTooQuick

I have a 94 GSR and I heard there is a way to rig a vacuum hose up so that your secondary butterfly's will stay open all the time. The reason why im thinking about doing this is my car is running abnormally rich and im trying to find ways to lean it out some. A lot of people told me about doing this and they say since they will be open none stop ill get more air flow meaning that it will lean me out some. Is this true? If so is there any negative sides to doing this? TIA.....

Edit: Forgot to put "I" between if and get in the topic.....Long day...

mr_mbuna

They are delayed in opening for a reason. Why don't you just fix the richness the right way, whatever that may be, instead of jury-riggin some hooptie ****.

Ben

216.226.142.95:27016

you will loose a lot of midrange if you do this

TeamTooQuick

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mr_mbuna &raquo;</TD></TR><TR><TD CLASS="quote">They are delayed in opening for a reason. Why don't you just fix the richness the right way, whatever that may be,instead of jury-riggin some hooptie ****.

Ben</TD></TR></TABLE>

I was just asking if this would help me since im hearing so much about it from other people. Just seeing whats the ups and downs of doing this, im not trying to"jury-rigg some hooptie ****" but its cool, just a simple question im trying to learn about....

mr_mbuna

for not being a dick like I was. Maybe it was a test... maybe not. Good luck.

Ben

One Bad GeeSeeR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 216.226.142.95:27016 &raquo;</TD></TR><TR><TD CLASS="quote">you will loose a lot of midrange if you do this</TD></TR></TABLE>

is that because the vtec is set at 4400k stock? now would it be bettter if you raised the vtec point up if you want to keep the secondaires on and gain the midrange back?

Carlo

.xcalibur.

Well, if you really wanna keep the secondaries open, just remove the vacuum hose that connects to the bronze thing (IAB) on top of your manifold. then stick a screw or something in the hose so it doesnt mess up the vacuum for the rest of the car. This way, the secondaries will be open ALL the time. Its true, you will lose about 10 ft*lbs of torque in the low and midrange. Why not get a vafc or safc to lean out your system. You might wanna check to see if your spark plugs and wires are still good and make sure they are burning all the fuel. A new o2 sensor wont hurt either.

Stewie

If you keep the secondaries open you'll only make your problem worse. You loose low end to mid range because there's less air. Long runners and low rpm don't go well.
Less air + same amount of fuel = even richer

Stewie

If you keep the secondaries open you'll only make your problem worse. You loose low end to mid range because there's less air. Long runners and low rpm don't go well. Less air = same amount of fuel = even richer

IN VTEC

iTrader: (3)

Power drops from 3200rpm to 5700rpm for the most part with losses up to about -11lb*ft and -11whp. It also seems to negate the 4000rpm "hump" produced by the AEM CAI. Up and above that point, the curves are nearly identical.

SAE corrected, curve smoothing = 1

u2civic1

u can just unplug the iab plug to keep it open

roadrunner

ummm, low-rpms is where longer runners are better. The secondary plates affect the shorter, high-rpms runners. Opening them shifts the resonance frequency higher, for better high-rpm cylinder filling. If you have the shorter runners open for low-rpm running, you will not be in resonance frequency range that will efficiently fill the cylinder, so you will run even richer there than before.

I agree with mr_mbuna that you should find the actual cause of your rich running rather than try a band-aid fix.

Br1t1shguy

If you were to keep you're secondaries to stay open you would loose power, and if anything, run richer. The primaries are longer and thinner for a reason. At low RPM, the primaries act like you sucking air through a straw, the air is sped up, filling the cylinders better. The secondaries open up at high RPM, when the motor is drawing enough CFM that it would start to choke if it used the primaries, so it switches to the fatter shorter secondaries. There is also intake resonance tuning at work, but I'll leave that out. Just because the car switches to them at high rpm doesnt make them better, it just means they are good then. So no, keeping you're secondaries open wont make more power, wont "let more air in" (that statement alone shows you dont know what you're talking about, since when is air being "let in" to the motor!!?"), and wont make you run leaner. If anything you'll run richer because you'll be killing all the N/A plenum tuning honda put into the motor.

P.S. In the future, lets assume that honda designed these things to make more power, not less. Therefore ******* with the IM switchover, VTEC engagement etc, on a bolt-on car, is going to net you less power. I swear to god the next time someone asks "should I just turn vtec on at 1000rpm so I get power all the time?", I'll just reccomend they sell their car and buy a metro.

ltho1998

It's sorta like overporting. Total cross sectional flow area and fluid velocity for a given fluid is inversely proportional. What happens is that when you increase the total cross sectional flow area, (i.e.- Opening the secondaries) your flow velocity goes down. However, at high rpms when fluid head loss becomes a problem then the secondaries open maintaining a relatively high fluid velocity with less head loss. This is why secondaries open in the high ranges. If you just stick them open, you'll lose flow in the low/midrange.

So if you want to diagnose your richness problem, start with your O2 sensor, clean your throttle body, check all your vacuum lines for leaks. If worst comes to worst-- get a VAFC.

i2un

You know I've heard some good things about doing that trick before.

When my car was mostly stock, I used to race a local guy alot (Carlsbad Raceway & Pomona). We both had 98' GSR's with comparable mods. He used to beat me all the time at Carlsbad (usually 14.8 to my 15.2)....pissed me off.

Then one time at a event in Pomona he told me to pull the vacuum line and stick a screw in it, to keep my secondaries open....he said that's what worked for him.

I never tried it, but I was always curious....I now have a different set-up/ manifold without a secondary, so I never was able to verify any gains/ losses.

Might be worth a try.

TeamTooQuick

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Br1t1shguy &raquo;</TD></TR><TR><TD CLASS="quote">
P.S. In the future, lets assume that honda designed these things to make more power, not less. Therefore ******* with the IM switchover, VTEC engagement etc, on a bolt-on car, is going to net you less power. I swear to god the next time someone asks "should I just turn vtec on at 1000rpm so I get power all the time?", I'll just reccomend they sell their car and buy a metro.</TD></TR></TABLE>

Hey guy, I don't remember when I asked "Im gonna hook my VTEC up to my high beams so when i turn my high beams on ill be in VTEC YO" And if the designers made Honda's so much then why do people put after market parts in their car? So please before you try and be a smart *** on me, think about what you say. All I did in this post was ask a question since everybody is recommending me do what I asked in the topic. I was just trying to learn more and see if they were wrong...

Angry Joe

The longer your intake runners are, the lower your power and torque peaks are. Long runners mean a low peak followed by a loss in power in the high end. Short runners give a lot of peak power at high engine speeds at the expense of midrange power. Dual stage runners get you both, you'll be sabatoging this if you permanently keep the high-rpm runners open.

Plus, there has to be a good reason your car is running rich, and you would do well to isolate that problem rather than trying to bypass it.

96dc2

Here is what happens when you leave the secondaries open all the time. It's the dark blue line.





NOTE: Not my car.

Let me know if the pics don't load.

TeamTooQuick

It seems like whoevers car that was gained more around 6500 then any other line. With me I have a SI tranny and I launch around 6500-7000 and stay above 6500 through pretty much every gear.... So if this is true i would benefit this in a race, and it will hurt my low mid range. I was planning on doing this just on occasion and not a everyday thing....

IN VTEC

iTrader: (3)

Don't try to fool yourself. The run-by-run variations in whp above 6000rpm that you're seeing are less than 2whp and 2lb*ft of torque.

The graph I posted and the graph he posted show virtually identical data. You're just looking at it differently.

ingrate

Why would there be a significant difference in peak power? After 5750 RPM the flow for both setups are exactly the same. 2 of my dyno runs back to back with nothing changed showed greater variation than that chart past 6500 RPM

bew

Dosent the Skunk2 IM eliminate the secondaries? If so, why would they do this if there a large noticable whp loss from it? I have a Skunk2, and if I'm actually losing whp from it, I'll ditch it.

IN VTEC

iTrader: (3)

The Skunk2 IM is more like eliminating the primary runners, not the secondary runners. You can tune out the midrange dip.