VICS Sucks!!!!

[BlkZoomZoom]

isnt the one at the injectors the vtcs? the one that EVERYONE rips out? so actually i can rip out both... lose some low end torque.. but be okay at the high rpms?

i think i will just be the test bed and rip both the vics and the vtcs out... ill plug the holes at the end and see what happens... this also means that i wont need those two actuators on top of the manifold right? wonder how im going to run the vacuum lines after i take those out. steve... you got an extra intake mani just incase i **** this thing up? lol...

ill remove both vics and vtcs, fill the holes, port the end of the mani and see what happens. anyone have any good arguments as to why i shouldnt? my turbo is a gt3071 so i should be able to spool up fast anyways... less restriction should mean a little more flow at the upper rpms... we will see

I have a reason...You are going to lose lowend power and gain absolutley nothing on top end. The only gains possible is the lighter weight of losing .3lbs. Wow. You guys are brain surgeons here... lets spend 4hrs doing something that has already been proven to lose hp just because we can.

 

[BlkZoomZoom]

On top of that there will be NO gain in airflow through the manifold if you take the VICS butterflies out. It is NOT a dual runner set-up, it is an extra plenum. Period.

 

[BlkZoomZoom]

On top of all this, this thread should be deleted. Everyone is connfused and no one really understands what happened in the dyno's.

Summarization:

Turfburn f'd up when setting up his VICS. But in doing so He proved that they work exactly as designed, good low end torque production and a boost in higher rpm horsepower. So in closing, leave them alone because you will only lose horsepower or torque if you mess with them.

 

[TurfBurn]

But the point discussed earlier and why people want to disable them is TO lose low end... some people are intereseted in dropping some low end power in order to hopefully improve traction a bit...

The fact is the dynos themselves are worthwhile... if we want a mod to delete the thread then great and I'll repost the dynos showing the diff in power when vics is or isn't run.

We also explained there would be no gain in airflow... as it is a dead end chamber... but that seems to keep getting missed.

 

[BlkZoomZoom]

ill remove both vics and vtcs, fill the holes, port the end of the mani and see what happens. anyone have any good arguments as to why i shouldnt? my turbo is a gt3071 so i should be able to spool up fast anyways... less restriction should mean a little more flow at the upper rpms... we will see

I'm pretty sure he didn't get that. No offense.

 

[duMb KeoLa]

I'm pretty sure he didn't get that. No offense.

non taken... youre pretty funny

 

[Brian MP5T]

I got rid of mine and am just happy that there are fewer moving parts inside the mani.

 

[TurfBurn]

and since enough people now (3 I saw so far) have had the VICS screws fall into the engine... I'd say not having it in there for that reason alone is enough!

 

[igdrasil]

im going custom manifold so...i wont have them, i hope it helps.

I was also considering an EBC with gradual boost based on rpm

 

[TurfBurn]

I was also considering an EBC with gradual boost based on rpm

Isn't that known as a supercharger or a really big laggy ass turbo LOL.

 

[Lord_Zath]

lol sounds about right. or go the n/a way and drop a v6 in hehe

 

[Protege_Speed]

Sorry to bring this back but I am still a bit confused. Please clarify this again for me. I attached a chart that I made from my MPI datalog. You will notice that at WOT in 2nd gear, at 5200rpm, my AFR drops significantly to 11.6 and stays there until I let off. This happens because VICS physically closes or opens? Or is it because the VTCS opens or closes? And if I remove the VTCS, which I plan on doing anyway, will that fix it? Basically, what exactly is happening at 5200rpm and how do I prevent this from happening? Am I just not getting enough air volume into the engine? I also noticed that this only takes place in 2nd gear and up. One more thing I forgot to tell you, I am NA with the auto sportshift trans. See sig for mods. Thanks all.

 

[TurfBurn]

Sorry to bring this back but I am still a bit confused. Please clarify this again for me. I attached a chart that I made from my MPI datalog. You will notice that at WOT in 2nd gear, at 5200rpm, my AFR drops significantly to 11.6 and stays there until I let off. This happens because VICS physically closes or opens? Or is it because the VTCS opens or closes? And if I remove the VTCS, which I plan on doing anyway, will that fix it? Basically, what exactly is happening at 5200rpm and how do I prevent this from happening? Am I just not getting enough air volume into the engine? I also noticed that this only takes place in 2nd gear and up. One more thing I forgot to tell you, I am NA with the auto sportshift trans. See sig for mods. Thanks all.

The vics butterflies open at that point... but the reason for your AFR drops is the VE (volumetric efficiency) of our motor goes to crap after that point... that's why revving out to 8000 rpm's doesn't help a lot. Porting and polishing, and modification of the valves, and some cam changes are th eonly way to prevent it from happening.

You don't see it in first gear because the loads on the motor are likely not quite high enough, and it will happen quite a bit quicker.... you can adjust all fo this with the MPI and that will help you out... just add "negative" fuel to correct it out.

 

[Protege_Speed]

Let's say I disable the VICS from opening. Won't that keep my AFRs from dropping but would that hurt my power up top? What do you mean exactly by volumetric effiiciency? The engine is getting too much air volume that it can't handle or not enough air volume?

I tried pulling a ton of fuel with the MPI at that range but it just does the same thing.

 

[TurfBurn]

Let's say I disable the VICS from opening. Won't that keep my AFRs from dropping but would that hurt my power up top? What do you mean exactly by volumetric effiiciency? The engine is getting too much air volume that it can't handle or not enough air volume?

I tried pulling a ton of fuel with the MPI at that range but it just does the same thing.

Keep VICS from opening (by lockign actuator in the pulled spot) and the AFR's will get even richer and you'll lose a ton of power (noticeably so).

Volumetric efficiency means how good the motor is at pulling air in at a given rpm... how much actual volume of the cylinder is used... You don't actualy get "100%" filling on every stroke... if you kept the pressure the same at the bottom dead center stroke, and used that as your 100% if you left that open to the air... the motor probably peaks out around 80% filling during normal operation... (i don't know the real number, but I could calculate it roughly based on fuel consumption)... as you get toward redline on our motor, it drops off considerably.... maybe to 50 or 60% ... so suddenly as you pass 5200 rpm's you are getting about 20-30% LESS air that makes it into the motor... now if you inject the same amount of fuel as at 5200 rpm's you suddenly are a whole lot richer...

You should be able to pull fuel out... or the MPI may not be capable of doing so... it sounds like it is not doing it for some reason. Either something is the matter, or the MPI can't lean out fuel.

 

[igdrasil]

VE is the clue for optimal power. Some honda engines have stock ratings of 105% VE, thats how a 1.8L n/a b18 can push 200+ whp, playing with VE.

VE changes thru the powerband. Torque peak is where most engines reach 100% VE, but depending on the manifold and head design, some engines, like ours, cant keep 100% thus dropping a lot of power on high rpms.

Think about it, why the FSZE has ~160/170 hp, the head and intake manifold were optimized, then you add HC pistons and fine tune, you get power out of the same block.

hey Turf:
Remember de 600whp FSDE powered 323?? guess what....well...i should not tell but lets say they are tunning for 800whp. He accomplish that...Im going to leave my car to him eyes closed.

 

[TurfBurn]

Ha.. nice... you slipped into spanglish for a half second there (de 600 whp FSDE) funny thing was it took me reading it several time to get it right...

That explains the Honda's... I didn't realize they were getting over 100% VE... (it takes inertial charging etc to achieve that... which they obviously did pretty well)... so that explains their ridiculous numbers

That is impressive on the 323 though... I'll be curious to see if they can hold it and how it goes! I think if i make it to my goal of 450 horse that it will be plenty!

 

[igdrasil]

JAJAJAJAJ yeah!!!! "de" my english is getting poorer every day, Im working at at Santander Bank, no one here speaks english damn, so, no practice at all!

About the FSDE, man you are happy with 450, im happy with 350. Im looking for reliable HP on pump gas...

But to be realistic, gas prices will go higher and higher...I dont know what Im going to do.

Venezuela has it for $0.12 a gallon of 87 octane gas, here in PR is around 2.80 a gallon aprox. I guess you people pay $3+

I leaned out the fuel mixture but the car pings/knock like hell with 87, and some ping with 93! But one full tank is giving me around 300miles.

HALT!!! *Im getting off topic...

Ha.. nice... you slipped into spanglish for a half second there (de 600 whp FSDE) funny thing was it took me reading it several time to get it right...

That explains the Honda's... I didn't realize they were getting over 100% VE... (it takes inertial charging etc to achieve that... which they obviously did pretty well)... so that explains their ridiculous numbers

That is impressive on the 323 though... I'll be curious to see if they can hold it and how it goes! I think if i make it to my goal of 450 horse that it will be plenty!

 

[Spooled]

Yep, which is why variable valve timing and variable cam phasing are great; they optimize VE across the powerband.

I know we've discussed this a lot, but I don't feel like reading through all the old threads. What I want to do is alter when the VICS closes off the extra runner area (5200 rpm stock). I want it to close that off as soon as I have positive boost since it's pretty much useless after the turbo kicks in. How is the valve triggered? If it's just a solenoid driven by a signal from the ECU, I could disonnect that and hook up a boost switch to trip the solenoid.

Anyone try something like this?

 

[TurfBurn]

Yep, which is why variable valve timing and variable cam phasing are great; they optimize VE across the powerband.

I know we've discussed this a lot, but I don't feel like reading through all the old threads. What I want to do is alter when the VICS closes off the extra runner area (5200 rpm stock). I want it to close that off as soon as I have positive boost since it's pretty much useless after the turbo kicks in. How is the valve triggered? If it's just a solenoid driven by a signal from the ECU, I could disonnect that and hook up a boost switch to trip the solenoid.

Anyone try something like this?

Yeah, I did it before... the thing is that VICS OPENS at 5200 and lets that extra area come into play...

It is just a solenoid that pulls vaccumm.. it is "normally closed" for the solenoid action (aka activated, powered, energized) all the way up until 5200 rpm's... so the extra plenum stays closed until then. In all honest you can just disconnect the wires and leave VICS open all the time and your power band is prety much just as fat as best as I saw from my dyno (my VICS was closing at 4500 rpm's... I ran it backwards because I thought it worked the way you are thinking... and found out later it didn't work that way).