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I don't care if it supposedly adds torque...

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AFSil80

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Discussion starter · #1 ·
But these USELESS butterfly valves are coming out.

I recently blew my headgasket, and tonight I lifted the head and removed the intake manifold.

All I gotta say is that there is NO CONVINCING ME that these things 'help' the motor. There is nothing good that comes from gummed up cylinder ports. PERIOD.

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Stupidest thing Nissan did to this motor.[/rant]
 
Discussion starter · #3 ·
I would imagine they are gummed up because the butterflys block off those ports when not in use.

And honestly, how can you say this is the best thing Nissan did? Unless you're being sarcastic.

Food for thought:

If they're SOOOOOOO great, why don't any RB motors have them?

Hell, even my UK-CA18 head doesn't have this stupid shit.
 
Discussion starter · #5 ·
nissanfreak8 said:
It is all a game of emmisions.
Click to expand...
^ EXACTLY! Emissions and fuel economy. Low end torque is a minor bi-product/propaghanda because you're trying to force the same amount of air through an oriface that's twice as small!

You don't shrink ports when you're trying to gain performance. You expand for more airflow!
 
#6 ·
wrong.

low end torque relys on speedy airflow which wouldn't happen thorugh the 2 ports, so the butterflies close half and increase the airflow through the one port at lower rpm's, and then open when the vacuum increases. And your ports are gummed because your seals are shitty somewhere.

SO, mr. engineer, don't go knocking something you obviosuly don't understand. and put some seafoam in that shit. wow
 
#7 ·
mikethebiker said:
wrong.

low end torque relys on speedy airflow which wouldn't happen thorugh the 2 ports, so the butterflies close half and increase the airflow through the one port at lower rpm's, and then open when the vacuum increases. And your ports are gummed because your seals are shitty somewhere.

SO, mr. engineer, don't go knocking something you obviosuly don't understand. and put some seafoam in that shit. wow
Click to expand...
True. Large volume ports chock up the air at low engine speeds. Smaller ports increase low end torque, which is why they have the secondaries. You will defiently lose some spool time without them. You don't know much about flow dynamics or engine building do you?
 
Discussion starter · #8 ·
mikethebiker said:
wrong.

low end torque relys on speedy airflow which wouldn't happen thorugh the 2 ports, so the butterflies close half and increase the airflow through the one port at lower rpm's, and then open when the vacuum increases. And your ports are gummed because your seals are shitty somewhere.

SO, mr. engineer, don't go knocking something you obviosuly don't understand. and put some seafoam in that shit. wow
Click to expand...
nofuckingshit Mr. Smartypants.

Thanks for re-stating what I just said, but trying to make it look like it's a good thing.

Please explain to me how this:
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Is inferior to this:
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My head in the first pic is going to flow more air. Period. More airflow = more power.

Same airflow with a valve and rod disrupting it....you see where I'm going with this?

Lets see...

S13 KA24's have them.
B18C1's have them.
STi's have them.
J-Spec CA's have them.

RB26 does not.
SR20 does not.
UK-Spec CA does not.

Now, if you don't mind answering a few questions...

I see you're 19 years old, and you're building a KA24E. Do you have ANY experience around a CA18? Or are you just trying to relate since the KA has the retarded butterfly valves too?

I've done enough with CA's and other motors to BELIEVE what I am typing. Like I originally stated, there may be *some* low end torque, but there is NO other improvement.

As I've said before. If they're sooooooo good, how come they aren't used in the racing community?

This design does nothing for performance. Period.

And for the guy quoting 'flow dynamics' and whatnot, we're gonna re-cap with the UK-head. If it was deemed to be necessary for the performance of the motor, then howcome the UK head DID NOT GET THEM? You can't argue this point because there is no basis.

And if you're trying to say I don't know shit about engines, then please share with me how you know so much. Maybe it will choke with a peashooter T25 running stock boost, but seeing as how I've witnessed 4 port CA's with a T28 on 16 psi WALK on a T28 SR at 16, you're still not going to convince me.
 
Discussion starter · #9 ·
Ya know....I smell a challenege...

When I redo this headgasket and bottom end rebuild, my mod sheet will be:

Stock boost, stock SR20 turbo.
Stock displacement, ACL rod bearings being the only internal mod, re-ringed pistons.
Cometic MLS headgasket, ARP studs
Gutted intake manifold
FMIC
3" exhaust
HKS 200mm intake
CA18 MAF
Stock fuel

Does anyone care to do a dyno competition? This is something that has crossed my mind SO MANY TIMES. I've wanted to see dyno PROOF on exactly what the butterflies do. I might end up posting this on NICO and 240atlanta as well.

I will strap my car down just to see how much stock power she makes, but for the sake of argument, I want to see what someone will put down with a very similar mod sheet (which shouldn't be hard) while having butterfly valves installed.

Anyone game?
 
#10 ·
Lets take a step back here. My knowledge is based on real life experiences and schooling was in high performance engines. I might just know something here. You mentioned you don't see secondaries in racing. Well this true for the most, its becase race cars don't any time in the bottom end where the secondaries would be closed. The fact is that removing them, without other supporting head mods and getting retuned, your only going to hurt the car performs as a whole.

You also said, "More airflow = more power."

This is true only in upper RPM's. Its a proven fact. Some people do care about low end torque because they daily drive their cars. When I get my car dynoed, stock turbo, I'll use one of my runs to leave the butterflys open so everyone can see a comparision. The only problem is I won't be getting dynoed for a couple of months at best.

I'd love to see flow numbers for the 4 port CA vs 8 port CA.
 
#12 ·
AFSil80 said:
...these USELESS butterfly valves are coming out....

....there is NO CONVINCING ME that these things 'help' the motor. There is nothing good that comes from gummed up cylinder ports. PERIOD....

You don't shrink ports when you're trying to gain performance. You expand for more airflow!
Click to expand...
hence why i said wrong. you sure talk a lot for not knowing what you're talking about. like he said, bottom end comes from airspeed, if you are so smart you would know that. i never said increasing airflow doesn't makes more horsepower in HIGH rpm's. It does, but the fact is, and i took the time to quote..
YOU ARE WRONG
about everything that is in that quote, except that gummed up ports hurt your motor. unfortunately for you, that is your problem, not nissans. looks to me if it wasnt for nissan you would havce twice the gummed up ports.. butterflies on one side isn't just gonna make all that shit dissapear. the whole point to the butterflies was to make more torque at low rpm's to make DDing easier for grandma. everyone isn't flying around spooling their turbo at 4k all day, and that is why this technology came about. If you think this is useless why do different makes use this on multiple motors? hmm food for thought
Saying i wouldn't know what im talking about because im 19 is pretty ignorant, considering the above said. just because some people swap motors all day, doesn't mean they actually know shit about what they are using. obviously.
as for your dyno competition, that will always be a biased competition, unless both were dynoed at the same elevation, same temperature, on the same gas, on the same dyno. i have seen enough differences on dynos at one shop, let alone 2 randoms from across the u.s.
 
#14 ·
Meh, I just jb welded the secondaries open on my KAE and didn't notice a difference. I would prefer to take them out but I can't have my 240 down to take them out right now. And I had a friend that has a spec-v sentra that had the little screws that hold the secondaries in place on the rod come out and eff up the cylinders. And before you say he messed with them, no he didn't, he never touched the motor in the 2 years he had owned it, bought it in 03, and nissan put a new motor in for him in 05. May be a moot point but watev.
 
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#16 ·
CA18DETswap said:
I'm just willing to bet that your car won't idle for shit or run well at all in the lower RPM range if you take that system out since I've read on these forums about people taking them out and having nothing but problems.
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It requires a lot of retuning to get them to run properly. Its not worth your time at all. Leave them in and reek the benefits.
 
Discussion starter · #17 ·
mikethebiker said:
hence why i said wrong. you sure talk a lot for not knowing what you're talking about. like he said, bottom end comes from airspeed, if you are so smart you would know that. i never said increasing airflow doesn't makes more horsepower in HIGH rpm's. It does, but the fact is, and i took the time to quote..
YOU ARE WRONG
about everything that is in that quote, except that gummed up ports hurt your motor. unfortunately for you, that is your problem, not nissans. looks to me if it wasnt for nissan you would havce twice the gummed up ports.. butterflies on one side isn't just gonna make all that shit dissapear. the whole point to the butterflies was to make more torque at low rpm's to make DDing easier for grandma. everyone isn't flying around spooling their turbo at 4k all day, and that is why this technology came about.
Click to expand...
First off, I find the bold print contradicting. Why would you boost performance for the middle aged secretary in her 180SX? Fact: Made for fuel economy. Lower end torque is a bi-product of this. This is how people justify it.

But it doesn't answer how the 4 port CA's were affected by this.

Look at my pictures. The gummed up ports are the ones with the valves. Look at david86's thread. Same thing. The cleaner ports are the unrestricted ones. How on earth would I have TWICE the gummed up ports without them?

You've dodged my statement when I said it is useless for performance. If I want to save gas, I'll keep off the throttle, simple as that.

If you think this is useless why do different makes use this on multiple motors? hmm food for thought
Click to expand...
Useless for performance. If you're gonna quote me, don't cut out what you don't want included. And you still haven't answered my question.

If you think it's such a great thing, then how come it wasn't incorporated into the RB or the UK-spec CA? Everything else on those motors is damn near identical, right?

as for your dyno competition, that will always be a biased competition, unless both were dynoed at the same elevation, same temperature, on the same gas, on the same dyno. i have seen enough differences on dynos at one shop, let alone 2 randoms from across the u.s.
Click to expand...
Which is why I'm trying to find someone local to me.

CA18DETswap said:
I'm just willing to bet that your car won't idle for shit or run well at all in the lower RPM range if you take that system out since I've read on these forums about people taking them out and having nothing but problems.
Click to expand...
Well, I can see both sides of this. Again, UK spec head has no problem without butterflies, BUT. The fuel injector port is DEAD center. Without buttefflies, this will be offset to the side, but thing is, with them open, it still is.

You can count on me posting up how it idles when I get the car back up. :thumbsup

End statement for this post, and this was in my thread title:
They may help provide some torque, but why do people consider this a performance accessory when they were clearly made for fuel economy.
 
#18 ·
AFSil80 said:
End statement for this post, and this was in my thread title:
They may help provide some torque, but why do people consider this a performance accessory when they were clearly made for fuel economy.
Click to expand...
Is horsepower not a direct darivitve(sp?) of torque? Kill low end torque, you will in turn kill of horsepower too. To what extent it will offset your horsepower/how much longer it will take to come on as hard, who knows.
 
#19 ·
The butterflies were not "clearly made for fuel economy". They were put there to increase low-end TQ by increasing the velocity of airflow into the cumbustion chamber at low-RPMs and when underboosting. There are already dyno charts on NICO depicting power outputs with and without butterflies. The ones with the butterflies had 20% more torque in the low end. The high end isn't affected with or without the butterflies installed so any thought of a gain in the higher RPMs is worthless. As far as the 4 port heads go, people in the UK and Sweden actually SHRINK the size of the runners by welding material in them because they say the 4 port runners are too big. I'm not saying everyone does it, just food for thought. Yes, the butterflies cause the gumming as shown in your pics. If you remove them you will lose torque down low (if you had them correctly hooked up to begin with), but top end will not be affected. The butterflies only affect output in lower (pre-4k) rpms. Some people swear by them, others say they are not neccessary. Come up with your own conclusions as to which category you fall in, but there is no real right or wrong here. If you want to keep some low end torque then keep them. If you dont care about the low end torque then ditch them.
 
Discussion starter · #20 ·
lostmenoggin said:
The butterflies were not "clearly made for fuel economy". They were put there to increase low-end TQ by increasing the velocity of airflow into the cumbustion chamber at low-RPMs and when underboosting. There are already dyno charts on NICO depicting power outputs with and without butterflies. The ones with the butterflies had 20% more torque in the low end. The high end isn't affected with or without the butterflies installed so any thought of a gain in the higher RPMs is worthless. As far as the 4 port heads go, people in the UK and Sweden actually SHRINK the size of the runners by welding material in them because they say the 4 port runners are too big. I'm not saying everyone does it, just food for thought. Yes, the butterflies cause the gumming as shown in your pics. If you remove them you will lose torque down low (if you had them correctly hooked up to begin with), but top end will not be affected. The butterflies only affect output in lower (pre-4k) rpms. Some people swear by them, others say they are not neccessary. Come up with your own conclusions as to which category you fall in, but there is no real right or wrong here. If you want to keep some low end torque then keep them. If you dont care about the low end torque then ditch them.
Click to expand...
Well, not to seem like a cockbag, but do you have links to support those claims?

If they actually shrink the size of the runners, then why does Norris Designs (the people that ported my UK head) continue to gasket-match the head ports and intake runners? Their CA18DET made over 600hp to the crank.

Granted I know this is no 600hp monster, hell, it ain't even half of that, but it still makes ME think that these things weren't put here for performance.

I know how they work. I know they make some low-end torque. But I've heard LORD KNOWS how many times that 'someone has seen the dyno charts of CA's with them and ones without them' but I have yet to see them myself. Call me a Doubting Thomas, I suppose.

Like I said, I'm not trying to be a dick to you, I just want to see proof. I know what CA18's without butterflys can do and I can provide that proof at the drop of a hat. I don't believe anything in the automotive community unless I see proof via dynocharts.
 
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