2manyhobyz

iTrader: (4)

Here's an interesting article on intake manifold design. It would be cool to find out what a gutted VICS volume is.

http://amsperformance.com/pdfs/intakemani.pdf

JasonC SBB

Volumes of MSM and JDM mani here:
http://www.mazdaspeedy.com/2010/03/2...-vtcs-msm.html

Gutting the horizontal wall above butterflies in VICS mani has no effect on butterfly closed nor open positions, compared to stock.

usd2bfst

...yes but if RPMs are slowly rising, either power is not your concern at the moment or your tune sucks. :P

In calibrating lots of VICS N/A & FI engines, 5400 is a fat sweet spot for *most*.

arildh

Ahh... Finally someone did the dyno comparison. Great work.
I have a spare flattop lying around...

18psi

iTrader: (76)

Reviving this not so old thread:
pretty sure I've seen someone post on here that the 99-00 and 01-05 IM's are completely interchangeable, but can't find that thread/post.

Can anyone confirm this?

Looking to fit a 99 VICS mani onto an 01, and want to make sure its 100% do-able without throwing any CEL's or having fitment issues.

usd2bfst

They are interchangeable, however if you're running the stock ECU you'll probably get a CEL & will likely have poor cold start drivability. Plus, you'll have to set up a way to run the VICS or it's pointless.

FYI if you're running a turbo check this thread at M.net out.

18psi

iTrader: (76)

That basically confirms that vtcs mani sucks dongs and should be swapped out asap.
I'm planning on switching to a Honda mani in the future, but for now considering running the vics since I have a spare 99 mani laying around. So from what you're saying it wont simply "swap over" with a stock ecu?

triple88a

iTrader: (2)

Ian, turbo engine at 10-15psi flows a lot more than a NA engine, how doesn't that matter?

On a side note how about cutting and enlarging the top of the vics intake manifold some more? One more thing, the stock runners on the vics manifold are good for 3-5k rpm, I'd assume cutting the primary runners some more to make them shorter over all would raise that range a bit?

fooger03

iTrader: (2)

18 - already tried removing the VTCS butterflies in the 01+ mani?

18psi

iTrader: (76)

No. I can if that's the route I decide to take, but looking at these plots of one gutted vs the vics and flattop, it seems like its almost not worth even wasting time on the vtcs mani altogether.

usd2bfst

I suppose if you left the VTCS solenoid plugged in & tied out of the way it wouldn't throw a CEL. If you had a Hydra you'd be GTG.

Over the years I've learned that VICS works, use it.

usd2bfst

My theory is that it's not worth the effort, and here's why.
a) We know it makes zero difference N/A.
b) N/A is effected by VE changes where FI really isn't.
c) While gutting it may affect VE, it does not change the fact that your throttle body & your intake runner sizes are not changed a bit.
d) Therefore, I theorize that it won't make a bit of difference on a FI car except if you like adding mods to your mod sheet.

18psi

iTrader: (76)

/\ I am of the same mindset, though have don't have much proof of this theory (but neither do like 99% of us discussing this). A bottleneck in the intake is more significant than a bottleneck in the ehxaust IMO, and I'm not sure simply enlarging the plenum while keeping stock tb and runners will do much (on top of what the VICS already does). But again, intake mani resonance, waves, etc etc all that isht is over my head....I just know the basics

Faeflora

iTrader: (2)

Fwiw i measured plenum volume of my gutted 99 im and it was 2.3L not including runnaz.

y8s

iTrader: (8)

lazy dumb idea:

extrude hone the 01 intake manifold.

leave the VTCS in place. yeah sure so what if they dont "fit" anymore, they are already designed to not seal when closed. Use them just to raise port velocity when off-boost.

18psi

iTrader: (76)

Are you still on the completely stock 01 mani y8s?

And Fae: you threw the 99 vics mani onto your 03 right? did it change anything before you hogged it out, and did you do any modification to it before said gutting?

usd2bfst

Matt, D.C. must be clogging your brain. You're suggesting ideas that cost a lot of money, but don't actually improve anything! :P

y8s

iTrader: (8)

uhhh yah.



uhhh also yah. and also I wasn't volunteering to pay for it. I heard good rumors of some aftermarket honda manifolds being decent performers.

BUT if you want to look all OEM (with a turbo, yeah I don't know how that works), it's the way to rock.

Faeflora

iTrader: (2)

Plugged up vics hole. Hit with hammer. "Extrude honed" the ever living ---- out of it until we saw daylight. Covered holes with paper mache and beeswax.

triple88a

iTrader: (2)

How about completely cutting the top part and putting on a semicylindrical piece on there? The transition from the TB to the plenum is NASTY.