vics + turbo
 

Hey 1st post wooo been a lurker for far to long :P

ok i have heard this vics manifold is there to give more top end power by opening a resonance chamber at around 5200rpm, i have heard it also shortened the air passege into the engine but this is not true from what i can see on the manifold .

this vics system works on vacuum to remain closed at idle and low rpm then as the throttle is 'WOT' the lack of vacuum and higher rpm will cause the vics to open.

i am installing a turbo to the car which is going to eliminate the vics from working due to no vacuum in the manifold i have 4 options but don't really know which one to go for ....

1. install an actuator electronicly controlled so the vics opens at 5200?
2. do 1. + gut the top of the manifold so the vics is used as a shorter distance for the air to flow?
3. close the vics and never use again ?
4. totally gut the manifold so there is no vics at all? (never seen this done so a bit weary of it )

vics standard
https://www.miataturbo.net/attachmen...ine=1390513901

vics top of manifold gutted (number 2 on what to do)
https://www.miataturbo.net/attachmen...ine=1390513901





and for those who thought i was on about viks here is a tip ,, rub it on places you dont want your cat to scratch or your cat and dog peeing.... also if you put it on yourself it stops horses trying to shag you ... never know could be useful one day

5. leave it alone and use VICS as intended you still have a vacuum manifold, you retard.

Don't gut the VICS unless you're never planning on running the engine slower than ~6k RPMs.

The butterfly valves open up an additional resonance chamber, increasing the engines ability to stuff more air into the cylinders at lower RPMs. At higher RPMs, those butterfly valves close, effectively (though not linearly) shortening the runners of the intake manifold.

braineack thanks for the welcome i guess ill be not listening to you then .

fooger i thought it was the other way round i thought there closed at slower rpm dependant upon the activation of the actuator and then they open at higher rpm

Don't hurt his feelings like that.

Way to go noob. Tell the admin that you don't plan on listening to advice, when it is the correct advice.

Why even bother asking if you won't hear the right answer?

Read up on intake tuning. Short runners are more beneficial at high rpms and long runners are more beneficial at low rpms.

although i could program this in i will be using a standalone ecu so was wondering if i could use the manifold like a short/long runner a bit like they do with the honda engines ?

there have been a few dyno reslults showing the torque is higher at low rpm while open but lower at high rpm and vice versa and the crossover point been close to 5200 ish rpm so i was going to run it manualy as a short /long runner application

acedeuce your right and i just explained it the wrong way round oops :s

Ok so throw it on the dyno and control the switch with your ECU and just set it on whichever gives you the most area under the curve.

thats what i was thinking tbh i guess its the only way to get an accurate understanding

You know there's a check valve for the vacuum reservoir built into the manifold right? My vics works perfectly.

with the standalone ecu i wont have anything to run it also would it be even worth having on a turbo ??

i give up

VICS is worth having on a turbo motor.

And buh-bye.

I tried.

Me too, I had to keep the quality control levels in check.

Sometimes you just got to call a spade a spade, and an eggplant an eggplant.


*Wow that phrase sounds super fucking racist out of context.

and sometimes aunt flow comes into town and you gotta ban a noob.

Bring the dead thread up, I know the benefits of the VICS on a stock car, but has anyone tested the power/torque with VICS on and with VICS off in boost? I use the VVT map feature on my ecu to control the VICS solenoid.

So that's a PWM output, which I've tried on the dyno. Unfortunately you're controlling a electrical solenoid, which responds to the PWM, but it's controlling a vacuum actuator, unlike the VVT oil control valve. So you'd want a large vacuum canister to hold vacuum in order for it to work. According to my dyno testing on a naturally aspirated, VVT equipped car, there would be a benefit, but it would be incredibly minor. After two dyno pulls back to back, we found two cross over points, the stock ~5250 point, and one at ~3500 IIRC, it's been a while. We tried "PWMing" the output, which started to show minimal benefits, but as I said ran out of vacuum. In the end, we set it back to a switched output, active above 3500 and below 5250, or whatever those two RPMs were.

On boost, I've found the VICs feature to still make small power differences, but 5hp on a 130hp engine is a much bigger deal than 5hp on a 300hp engine. I would do two dyno pulls, one with it set to 1000rpm, one at 10000rpm. Find where those two dyno's cross over, set your programmable switched output to that RPM, and forget it.

i was going to gun VICS but then thought about the low rpm benefits.
i'm going to follow the advice but electronically open and close, not using vacuum. we'll see how it works

even if 2 hp difference, it seems it is still worth it...

What do you even mean by controlling it electronically? The opening and closing times are already controlled electronically via solenoid and fully tunable with any standalone ECU.

Are you planning to run an electronic actuator?

If he is, that's kinda cool. crazy amount of effort for almost nothing, but cool

Possibly less than nothing. Isn't vics just providing additional plenum volume with the butterflies open? I don't think half open butterflies are going to effectively allow for half the volume increase. It may create some other strangeness in flow that could be beneficial though. I guess curlys findings are encouraging.

Do the thing and post the data please.

Once again reviving this thread. I’m about to swap a BP4W into my ‘90 Miata. I started to wonder if the VICS would be beneficial when running boost. From what I’ve read, very minimal.

When you tune the car on the dyno, do a before/after comparison. It's definitely useful and all it costs is a few ounces of weight to use the Mazda solenoid and a spare digital output on your megasquirt.

--Ian

I’m running a Beer Money Motorsports ECU and definitely plan to use it. The engine came from a running and driving car that a tree fell on. So I have everything I need down to the harness.