Denisst99

i ported a couple of those manifolds...



most of them are casting line from "mismatched" mold, some mnaifold are worst then others,i've seen up to about 1/8" of casting offset

the one he started with wouldn't be the baddest one i've seen

the 2 indents on the middle cylinder are there for tools clearance when torquing down the middle bolts



How are you going to finish up the inside of the box (runner wise)?

slow 2K2GT

I thought that as well before removing any casting. The indents they are only on the runners for cyl 2 and 3 which are pretty much straight shots right into the head. I would be more inclined to think they would be on cyl 1 and 4 if that were their purpose. Cyl 2 and 3 kind of slope toward each other but the indents are on the same side of the runners as well which is another sign that med me to believe they werent there for any special reason.



The little nipple that I am pointing to was more of a plateau right in the center of the runner and didnt extend any further forward towards the manifold flange...perhaps just a casting flash in the mold.

slow 2K2GT

The holes are going to be cut just slightly larger than the OD of the runners and a nice smooth "stack of dimes" seam will be put around each one so the weld gives a transition into the runner.



Thank you for explaining what the two indents were for!

iheartmyrd

i absolutely love the idea of this. keep us updated please.

Tibbi

Inside the box what are you going to feed the air? I have seen a lot that simply used short air horns. Just don't leave it bare, the flow will be hindered

slow 2K2GT

This is what my friend has on his 2001 Neon, he is making 520whp and I think we may go that same route for making the transition into the runners. Get the exact cutout we want and then toss it on a router to round off some edges.



I have looked at pics of other custom manifold with stacks and this is a nice close alternative to having them.

tanc

Not to knock on your ambition but have you done any sort of research on tuning intake manifolds for forced induction? Have you done any engineering calculations? You seem to be basing this on other designs and thats it. Runner length is important in forced induction as well, same goes with cross section, runner volume, plenum volume...list goes on.



What's the plenum volume your going for? Your goal of feeding as much air as possible in as little time as possible is all fine and dandy if you live among the clouds and ride on unicorns. Have you even considered head design? valve sizes, cam spec? Our head's are not the most efficient oem, not like Hondas. Do you know what happens to the air when the valves close? You want MORE are as FAST as possible. Build a $2000 head and worry about the intake manifold after.



Goodluck non the less, but I doubt you'll see any major gains in your hp/tq # compared to stock. What you even might see is a powerband that your engine/head wont support and it'll have you sluggin around anywhere under 5k rpm.

slow 2K2GT

Well thanks for your thoughts and considerations thats why I opened this thread. I wont fault you on not knowing anything about my car since im pretty new here, yes I had a built head...it smashed and now I have another one...oversize valves, professional port and polish, throats and seats opened up to accommodate the larger valves, dual springs, high lift cams with low overlap. Pauter rods, CP pistons, Valeo XTRM clutch...yada yada the list goes on, believe me I have more time and consideration put into my car than I care to think about, taking a manifold and chopping it up to try something new is just to occupy my time.



This motor is going in track destined car I putt around in a BWM 528i the rest of the time.



Rest assured if I dont like how it drives than I will put a stock manifold back on the car, funny thing about trial and error huh. Please other than the picture I posted above please show me where and how I am basing this manifold off of other peoples ideas or that I havent done any reading up until I decided to try something new...Again thanks for the input and feel free to check back any time.

faithofadragon

i just took the simple route



"easiest way to have a larger plenum and a 65mm throttle body"



paid 300 to have this done, rockin a mustang tb

slow 2K2GT

Looks great! Im still at $0 cost, maybe $50 after a Mustang TB like you.