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Why do you want to make it smaller? Big is good in most respects. Big = easier to tune AE. Big = less pressure drop on each intake stroke. Big is fine :-)

Admin wrote:Why do you want to make it smaller? Big is good in most respects. Big = easier to tune AE. Big = less pressure drop on each intake stroke. Big is fine

Okay.

Well it's gonna get a bit smaller so it's good that I made it over twice the recommended size

The open end is massive. I could probably fit a 120mm throttle on the end if i wanted to. That would make it impossible to tune/drive methinks.

the rate the pressure changes is key, so if you have a 1000 litre plenum and a 120mm throttle, it will change very slowly (on an ecu time scale) mine with 3+ litres and 70mm was sweet with stuff all tuning. big throttle on small plenum = hell though. engine size of course matters too, as that controls the other half of the equation, ie, how quickly it empties it out when you close it etc.

Wowzers. I love it. 10k RPM ready

What are your plans for bonding the aluminum and fiberglass?

And why didn't you use CF

I'm going to build some intakes for my EJ22, going to do mild steel first for proof of concept but I love the 'Glass or Carbon Fibre for v2.0.

GartnerProspect wrote:Wowzers. I love it. 10k RPM ready

What are your plans for bonding the aluminum and fiberglass?

And why didn't you use CF

I'm going to build some intakes for my EJ22, going to do mild steel first for proof of concept but I love the 'Glass or Carbon Fibre for v2.0.

(1) I think my engine will float valves/asphyxiate at around 8000 rpm

(2) The aluminum and fiberglass is currently edge-bonded with Norton 1 Minute Urethane Panel Adhesive. When the final geometry is determined, more layer of fiberglass will be added that extend right over the aluminum runners. West System sticks to rough aluminum very very well.

(3) My dad does fiberglass repair on heavy trucks. This project has cost me $15 so far...the cost of a spare ABA lower intake manifold to hack up. Plus I don't care about the looks so much, I plan on smoothing and painting it black cherry just like the stock manifold.

The hardest part of the project was developing a good system for forming the mold core. I even had an equal-length runner intake made up that looked like an exhaust header but we couldn't get part of the core out. I might make another one now that I "know what I am doing". It looked way more hardcore than this manifold. People might even think I had a Honda engine in it

oooh, you're cheating!

I wish I had free supplies. lol

The core mold issue has pretty much stopped me from dealing with fiberglass much. I also wanted to try my hand at custom silicone hoses as the materials and technique is easy, but anything but a straight hose seemed like too much work to figure out the core...

I'll stick with non-enclosed fiberglass for now:


<- Thats me taking a picture of my LCD panel/custom dash panel for my car while it takes a picture of me.

I did figure out a good core method in the end, I was just too impatient to do a really good job on the intake manifold. Pink polystyrene insulation from Home Depot glued together with urethane epoxy, then cut and sanded to shape. Finally, coated with latex paint or seam sealer (doesn't eat away styrofoam) and a release layer of PVA.

To get rid of the core, you pour paint thinners/acetone in and it all melts and turns into napalm. Pour it out, flush it good, pull the remnants of epoxy, latex, and pva out and you are done.

Thanks. Filed away in my what-if-I-do-it-someday list. I have tons of that pink foam at home thanks to renovations!

If you had it two piece with a chamber and velocity stack section and intermediate flange (like mine) you could spend more time sanding and perfecting the entrance to the airflow where it really matters, and save yourself the trouble of sticky goey melted styrene. Petrol/gas also dissolves it pretty quickly ;-) That method is no go if you want to make more than one. In that case you need another stage of two piece external mould to create the throwaway ones for the the final product. In my eyes, two piece = better flow with less work, but opinions and mileage may differ :-)