bpt323

Heres a cheap mod for anybody willing to take the time.....Its a noticeable difference too.

http://www.angelfire.com/extreme3/32...emanifold.html

you can email me if you want it done or try and do it yourself...

bpt323@yahoo.com

spooki

i took apart my spare intake a while back and was wondering about that.
what did you use to cut/grind out arrow 1 ?
hows your low-end power?

im glad some one had the ***** do do this

Bruce95fmla

Id like to see a dyno ,, to show that the trouble and downtime is worth it

bpt323

do not have any dyno sheets to post....its just a cheap modification.... you have to it all in about 30 minutes.... is that really alot of downtime now? plus you can get a chance to clean your intake manifold out from all the oil and dirt residue build up.

Low end power was not effected...at least that was notice able
its a modification for your top end only...and works excellent in conjunction with the RX7 maf sensor. when the VICS system is engaged this modification also for 2 times the amount of air to flow through than before at least. and it doesn't really slow the speed of the incoming air either just moves alot more.

if you want to have another opinion on it ask

AOLim: ltparis25
or ltparis47

I installed this on his car and has used it as a daily driver since installing it.... he should be able clarify any gains far better than me...at least at this point in time.

bpt323

try using a very small angle grinder, or a dremel but with the dremel you'll be changing and cleaning the bits off quite often seeing as the aluminum sticks to the bits.

spooki

i was just thinking (hear we go)

the intake has two air paths. one by-passes the secondaries (low-end power) and the second goes to the secondaries (top-end power)
i cant remember witch path arrow 1 is in (i think the top-end path)
if thats the case you increased the top-end and leaft the low-end the same.

im going to do mine today.

bpt323

Maybe true......however it does still make a noticeable difference...regardless of how it is acheived

bpt323

How do you figure it to be slower???
What leads you to think this?

bpt323

well in truth im not sure how you can imply that still....the cutting only rmoves small sections from the manifold that the air must travel around or should i say under it would be more likely to speed up the velocity instead of slow it down. your only removing blockage from the airs path of flow which shouldn't reduce velocity but instead increase it.
if the velocity is slowed it would not be anything that could be effected
and to each his own
it also depends on how much material is removed from the manifold...

question for yoiu tho
based on what your saying though you would be against port and polish of the manifold wouldn't you??
it has been shown to make a noticeable difference in other cars why should it effect these and have a reverse effect....it just doesn't make logical sense

spooki

cutting that piece out is just making the air path shorter. true, you are making that space bigger, but as far as better air flow im not sure.
if you think about it, it would be like taking a tube and making one section of it bloated. which would make turbulance in your air flow.
wish i had a dyno at the shop.

SgtRauksauff

I think this would perhaps smooth out your airflow, since it doesn'thave those blockages in the passage, and actually reduces turbulence. BUT it also increases the volume of air passing through the manifold, without necessarily increasing velocity. So I'm thinking this mod would be more evident at moderate to high speeds, in high rpm's. I don't think it would help the torque at the low end, and it could possibly hurt it a little.


but that's just my take on the matter.


--sarge

protejay

very interesting in that i had been thinking of doing the same thing to the 2nd gen (Sephia) VICS manifold i have.

the ridge you grinded away in the *lower half* of the 1st gen LX manifold is NOT there in the 2nd gen's manifold.....it looks just like your picture.

however, the 2nd gen's *upper manifold* DOES have the same ridge as the 1st gen's. Why? Was it intended as something functional? Or was it easier/cheaper to cast it that way?? (that would seem HIGHLY unlikely...)

anyways my uneducated observation/opinion on this is that it would shorten the path and possibly?... reduce the turbulence. the openings in and out of the 2 chambers are still the same.....its just that the ridge that the air has to travel around is no longer there....

so i don't think the volume would increase, but perhaps the engine would breathe 'easier' at the higher rpms - or at least @ the switchover point: 5000rpm.

i'm not going to say anything about *enlarging* the ports , other than to say i WOULD like to smooth/polish the inside surfaces....

bpt323

hmmmm
well I knew it all along that gude is a complete ripp-off
but thats besides the point.
It appears from the pictures posted that they just decked the surface where the manifold seals and possibly smoothed out the runners.......tell me how much it cost too do that.....and what kind of gains are they claiming for that.
I don't trust gude and never did.... their work is not that of much quality...in my opinion. Its not worth the costs

bpt323

What kind of ECU work are you impling should be done as a reference to anybody planning on having gude do work on their BP....

protejay

thanx for the pics Jesse!

so in regards to THIS modification, either Gude DOES know what they're doing or they DON'T...

to clarify my ideas about this mod: with the 1st gen manifold; seems like it WOULD increase the airflow - as the path is very small due to the ridges in BOTH the upper AND lower manifold....

with the 2nd gen manifold; i wonder if there would be an *increase* in airflow as the path is larger....due to the fact there is NO ridge in the lower manifold.

and as was brought up, is an increase in airflow even desirable?? seems that it *could be* at the higher rpms

the mod without a doubt does *shorten* the path; which i definitely take as a good thing at high rpm. the factory manual basically describes that as the purpose of VICS: ability to vary the *length* of the intake tract for a "resonance induced charging effect".

i take it then when VICS switches @ 5000rpm, NO (or very minimal) air would flow through the long runners....the air would *seek* the shorter path and so would only flow from chamber to chamber and then dump straight into the lower manifold's runners.....?? anybody follow?

in other words, i remembering someone on the miataforum saying that when VICS switches at 5000rpm, it lets in ADDITIONAL air - the air flows through the long runners AS WELL AS through the 'butterfly' ports??? that doesn't sound right, though....

so why'd they cast those ridges there? maybe 'cause they knew if they didn't, our overbuilt econocar BP would MAKE 160 HP @ 7000rpm!!!!! haha

hopefully i'll be able to experiment some this weekend and at least finally see if i can get the 2nd gen manifold to 'bolt-up' to our 1st gen. i've talked about it enuff - its time to see if it workable......