How hard would it be to fabricate an intake manifold?

Go to junk yard get a 1.8L corolla TB and a xa, echo, or xb intake mani incase you want to go back to stock.

Couldnt we just get 3 1/2 or 4inch tube for the "stack" before the intake holes. Get a welder that has a mandrel to bend a few tubes and connect the tubes to the new TB?

You would think that 200 bucks is much cheaper than 700....

Alot of people seem to be doing DYI turbo, exhaust etc, why not the mani?

Since I am short of cash ATM I am thinking of maybe doing this once I go back to school because I know a local exhaust guy that welds, machines, and assembles for a case and 40 bucks...all I have to do is get the metal.

Just a thought, suprised no one has "tried" this yet..

in good regards,

Regis

 

Building it isn't what costs the $$, doing the initial design is where the promoney goes. That development cost then needs to be recouped in the volume production sales cost, and I don't know many people buying manifolds, so added cost / unit for development payback is pretty high. You could exactly copy the Weapon-R runner lengths, bend angles and plenum volume and may be alright, but you don't just slap some tubes and a can together and expect an increase.

Manifold design is a balance, built around maximizing air velocity and volume. it's easier to get a faster airflow with a smaller tube but you get less overall volume. This is also engine RPM dependant. Too slow of flow and you'll starve the upper RPM's, too big and you get no low end power. Laminar flow is key to airspeed, and fast moving gas fluids tend to do funny things as you move across the frequency band.

There's a series of calculations based on Helmholtz resonance that can be done to get somewhat close but in the end it boils down to trial and error on a dyno. How many times do you want to build that $200 manifold (and good luck finding a welder + stainless steel stock for $200) before you get a good design? Go with the wrong dimensions and you'll be at a worse performance level than stock.

Probably the best way to do things for production is to design in CAD using a flow modeling simulation plug-in, rapid prototype and test on a dyno, then to final design and production.

Solidworks flow simulation should work pretty well for design and simulation, but it ain't cheap.
http://www.solidworks.com/sw/product...s-software.htm

 

I agree, some aftermarket intake manifolds actually make less power than stock. I am not sure I would trust Weapon R...

 

Hmm I knew there was a considerable amount of math needed for these things but i just want lower end. If I had better lower end I would never have to rev it past 5k.

Has anyone done ITB's?

Would be great to hear and/or see a dyno if anyone has done ITB's.

 

Everyone who's bought one has reported significant increases throughout the powerband...

To the OP, if you're interested in one, the Weapon-R route might be the best.

 

Siphon did an article on a Yaris with ITB. Different car but same 1NZ-FE motor. Gains were impressive, but still not what you'd see with a turbo.

 

vetterddie thanks for the info about the 1nz-fe ITB's. Were they short like 30mm or 60, 90mm?

Did he have filters on them (foam, panty hose, w/e)?
I heard the filters can reduce the hp significantly but it keeps the engine clean

You get what you pay for...turbo 5k, ITB's 1.5k depending on parts etc..

ITB's, header, highflow cat, EMS for AFR's, cat-back, and a good tune would be sweet in this car. Loud, nimble, and reliable.

Thanks for the info.

 

Another question...would porting the stock intake mani be beneficial in any way? I looked in there once when cleaning my TB and it seems "crowded"...

 

the stock intake mani is as efficient as it will get.... "porting it" will only change the air circulation withing the manifold and will most likely decrease performance

 

Looks like I am going to be saving up for the Weapon R.

Thanks guys, If I had not asked I would of been building it already LOL.

Do you recomend the 1.8 corolla TB as well?