Gutting upper vics manifold
 

So i've been searching a lot on gutting the upper part of my vics manifold.

The plan is to remove the vics chamber on the upper manifold and leave the bottom one alone... leave the butterflys in tact and control them with my standalone.

So far i've seen people gut the bottom and completely remove the butterflys but no results in cutting the upper shelf. I see that pat is running with the top gutted but i havent seen any results. Any one else running with the top gutted and the butterflys still in tact?


If so at what rpm do you guys have them set to open?
Whats to be expected after gutting the top?
What method/tools did you guys use to cut the shelf?

So, today i went at it, got it done.
I feared the injectors wont do so i installed my 800cc injectors. Went in boost and afr went in the mid 10s... I removed some fuel but didnt test it, after restart the bloody wideband is fouled and is all over the place so i couldnt test anything. I guess i'll have to get a new one.

Do you have photos of your work? I am very I interested in more details.

i have a rough photo right after i pulled the center piece, I don't have the required tools to clean it up all the way too the wall so i had to round it off and leave it sticking out a little bit. I'll upload it in a sec.

Damn pic is dark but you can see i used a drill bit to get rid of the center piece and then used grinding wheels for my hand drill to make whats left of the shelf smaller. Dont have a good pic of the finished manifold.

https://www.miataturbo.net/attachmen...ine=1329788976

Holy Crap. Go to Harbor Freight and spend the $20 for a rotary tool. :)

So what your basically saying is, if I had a machinist actually remove that stuff and polish the inside of the intake; it would work pretty awesome.

that must have taken forever... i used a hammer and chisel to bust a hole and used a sawz all to make the long cuts. i did end up using a carbide cutter on a power drill for the smoothing though. youre lucky... the miata vics looks much smaller than the protege vics i cut up...

were you planning on removing the 4 rings left on the top and hollowing out the lower section?

before
https://www.miataturbo.net/attachmen...ine=1329790661
after
https://www.miataturbo.net/attachmen...ine=1329790506

before
https://www.miataturbo.net/attachmen...ine=1329790506
after
https://www.miataturbo.net/attachmen...ine=1329790506

I used a dremmel but it didn't work too well and my rotary saw was too big. Long story short, i should have had an endmill or something similar.

Festiva, i do not plan on cutting anything on the lower manifold. My vics butterflys are still in tact and are set to open at 5k rpm. Sadly cant try it out since that damn sensor...

Im doing one of these right now for my buddies car who has an S4 Begi kit. We shall see numbers before and after.

In for numbers. Must be Matt's car eh?

Correct, Then im taking his off and doing the same thing for my car, Plus Polydyn!

will the butterflies effect anything with that upper chamber hollowed out? i ask cause the runners look like they would be so close to the same size it doesnt look like there would be much gain in actuating the flappers. at least thats what im seeing by this pic. id love to see some numbers.

https://www.miataturbo.net/attachmen...ine=1329807272

When the butterflies are closed, its just like it was before however now that space contributes to a bigger plenum, with the butterflies open, it gives you a shorter runner for the higher rpms.

Alrighty my new wideband is in, i shall do few pulls later. Old sensor looks...black so i'm guessing its salvageable.

Alrighty my new wideband is in, i shall do few pulls later. Old sensor looks...black so i'm guessing its salvageable if i can find a propane tank to burn off the carbon build up. Anyone ever cut one of these sensors apart?

Alright well somethings fucked up.

blues open
reds closed
3rd gear pull

https://www.miataturbo.net/attachmen...ine=1329964345

??

What happened? It looks like you made a significant amount of more torque at lower RPM's, unless I'm not seeing this correctly.
I ask because I have my spare intake apart in my garage and I am looking to gut this thing, only if there is a proven benefit.
What RPM does your actuator open? Please explain how you did your pulls...was it completed closed for one pull and completely open for another?

Too much RPM data.